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IntroductionHPTN 083 demonstrated the superiority of long-acting cabotegravir (CAB-LA) versus daily oral emtricitabine/tenofovir disoproxil fumarate (TDF/FTC) as pre-exposure prophylaxis (PrEP) among cisgender men and transgender women who have sex with men (MSM/TGW). HPTN 083 provided the first opportunity to understand experiences with injectable PrEP in a clinical trial.MethodsParticipants from two US sites (Chicago, IL and Atlanta, GA) and one international site (Rio de Janeiro, Brazil) were purposively sampled for individual qualitative interviews (N = 40), between November 2019 and March 2020, to explore trial experiences, barriers to adherence and other factors that may have impacted study implementation or outcomes. The blinded phase ended early due to efficacy; this analysis includes interviews conducted prior to unblinding with three groups defined by adherence (i.e. injection visit attendance): adherent (n = 27), non-adherent (n = 12) and early discontinuers (n = 1). Data were organized using NVivo software and analysed using content analysis.ResultsParticipants (mean age: 27) were primarily cisgender MSM (90%) and Black/African American (60%). Reasons for trial enrolment and PrEP use included a preference for using HIV prevention medication versus treatment in the event of HIV acquisition; the ability to enhance health via study-related education and services; access to a novel, convenient HIV prevention product at no cost; and contributing to MSM/TGW communities through research. Participants contrasted positive experiences with study staff with their routine clinical care, and emphasized increased scheduling flexibility, thorough communication, non-judgemental counselling and open, affirming environments (e.g. compassion, less stigma) as adherence facilitators. Injection experiences were positive overall; some described early injection-related anxiety, which abated with time and when given some measure of control (e.g. pre-injection countdown), and minimal injection site discomfort. Some concerns and misperceptions about injectable PrEP were reported. Barriers to adherence, across all adherence categories, included structural factors (e.g. financial constraints, travel) and competing demands (e.g. work schedules).ConclusionsRespondents viewed injectable PrEP trial participation as a positive experience and a means of enhancing wellbeing. Study site flexibility and affirming clinic environments, inclusive of non-judgemental counselling, were key facilitators of adherence. To support injection persistence, interventions that address structural barriers and promote flexible means of injection delivery may be most effective.

BACKGROUND: Pregnant and breastfeeding women (PBW) in sub-Saharan Africa have high HIV incidence rates and associated risk of vertical transmission to their infants. Oral preexposure prophylaxis (PrEP) and injectable PrEP (long-acting cabotegravir, or CAB-LA) can potentially reduce this HIV transmission, but population-level impacts are uncertain. METHODS: We extended a previously developed model of HIV and PrEP in South Africa to allow for variable PrEP duration and preference in PBW. We considered three potential scenarios for PrEP provision to PBW: oral PrEP only, CAB-LA only, and allowing oral/CAB-LA choice, with uptake and retention assumptions informed by South African data, each compared with a base scenario without PrEP for PBW. RESULTS: Without PrEP for PBW, the model estimates 1.31 million new infections will occur between 2025 and 2035 in South African adults and children, including 100 000 in PBW, 16 800 in infants at/before birth, and 35 200 in children through breastmilk. In the oral PrEP-only scenario, these numbers would reduce by 1.2% (95% CI: 0.7-1.7%), 8.6% (4.8-12.9%), 4.0% (2.1-5.8%), and 5.3% (3.0-8.2%) respectively. In the CAB-LA-only scenario, the corresponding reductions would be 6.1% (2.9-9.6%), 41.2% (19.8-65.0%), 12.6% (6.0-19.4%), and 29.5% (13.9-46.8%), respectively, and in the oral/CAB-LA choice scenario, similar reductions would be achieved [5.6% (3.4-8.0%), 39% (23.4-55.9%), 12.4% (7.4-16.8%) and 27.6% (16.5-39.9%) respectively]. CONCLUSION: CAB-LA has the potential to be substantially more effective than oral PrEP in preventing HIV acquisition in PBW and vertical transmission, and can also modestly reduce HIV incidence at a population level.

Dimeric indole‐containing diketopiperazines (di‐DKPs) are a diverse group of natural products produced through cytochrome P450‐catalyzed C–C or C–N coupling reactions. The regio‐ and stereoselectivity of these reactions plays a significant role in the structural diversity of di‐DKPs. Despite their pivotal role, the mechanisms governing the selectivity in fungi are not fully understood. Employing bioinformatics analysis and heterologous expression experiments, five undescribed P450 enzymes (AmiP450, AcrP450, AtP450, AcP450, and AtuP450) responsible for the regio‐ and stereoselective dimerization of diketopiperazines (DKPs) in fungi are identified. The function of these P450s is consistent with phylogenetic analysis, highlighting their dominant role in controlling the dimerization modes. Combinatorial biosynthesis‐based pathway reconstitution of non‐native gene clusters expands the chemical space of fungal di‐DKPs and reveals that the regioselectivity is influenced by the substrate. Furthermore, multiple sequence alignment and molecular docking of these enzymes demonstrate a C‐terminal variable region near the substrate tunnel entrance in AtuP450 that is crucial for its regioselectivity. These findings not only reveal the secret of fungal di‐DKPs diversity but also deepen understanding of the mechanisms and catalytic specificity involved in P450‐catalyzed dimerization reactions. [ABSTRACT FROM AUTHOR]

In the biosynthesis of the tryptophan-linked dimeric diketopiperazines (DKPs), cytochromes P450 selectively couple DKP monomers to generate a variety of intricate and isomeric frameworks. To determine the molecular basis for selectivity of these biocatalysts we obtained a high-resolution crystal structure of selective Csp2 -N bond forming dimerase, AspB. Overlay of the AspB structure onto C-C and C-N bond forming homolog NzeB revealed no significant structural variance to explain their divergent chemoselectivities. Molecular dynamics (MD) simulations identified a region of NzeB with increased conformational flexibility relative to AspB, and interchange of this region along with a single active site mutation led to a variant that catalyzes exclusive C-N bond formation. MD simulations also suggest that intermolecular C-C or C-N bond formation results from a change in mechanism, supported experimentally through use of a substrate mimic.

The fungal genus Trichoderma is a rich source of structurally diverse secondary metabolites with remarkable pharmaceutical properties. The chemical constituents and anticancer activities of the marine-derived fungus Trichoderma lixii have never been investigated. In this study, a bioactivity-guided investigation led to the isolation of eleven compounds, including trichodermamide A (1), trichodermamide B (2), aspergillazine A (3), DC1149B (4), ergosterol peroxide (5), cerebrosides D/C (6/7), 5-hydroxy-2,3-dimethyl-7-methoxychromone (8), nafuredin A (9), and harzianumols E/F (10/11). Their structures were identified by using various spectroscopic techniques and compared to those in the literature. Notably, compounds 2 and 5–11 were reported for the first time from this species. Evaluation of the anticancer activities of all isolated compounds was carried out. Compounds 2, 4, and 9 were the most active antiproliferative compounds against three cancer cell lines (human myeloma KMS-11, colorectal HT-29, and pancreas PANC-1). Intriguingly, compound 4 exhibited anti-austerity activity with an IC50 of 22.43 μM against PANC-1 cancer cells under glucose starvation conditions, while compound 2 did not. [ABSTRACT FROM AUTHOR]

A new butoxy substituted indolediketopiperazine (1), together with five known indolediketopiperazines (2-6), which are derivatives of brevianamides, were isolated from the marine derived fungus Aspergillus sp. 66may. Careful analysis and comparison of the HRESIMS, as well as 1D and 2D NMR datasets, identified the structures of the isolated compounds. The subsequent antibacterial and anti-inflammatory activities showed that compound 4 possessed antimicrobial bioactivities against Bacillus subtilis ATCC 39620 with minimum inhibitory concentration (MIC) value of 64 µg/mL. Compounds 1, 2, 4 exhibited potential inhibitory activities against NO production with IC50 value of 28.2, 21.3, 23.6 µM, respectively. It seems that butoxy substitution at C-9 in brevianamides have little effects on their antimicrobial and anti-inflammatory bioactivities. [ABSTRACT FROM AUTHOR]

During an experiment where we were cultivating aflatoxigenic Aspergillus flavus on peanuts, we accidentally discovered that a bacterium adhering to the peanut strongly inhibited aflatoxin (AF) production by A. flavus. The bacterium, isolated and identified as Klebsiella aerogenes, was found to produce an AF production inhibitor. Cyclo(l-Ala-Gly), isolated from the bacterial culture supernatant, was the main active component. The aflatoxin production-inhibitory activity of cyclo(l-Ala-Gly) has not been reported. Cyclo(l-Ala-Gly) inhibited AF production in A. flavus without affecting its fungal growth in a liquid medium with stronger potency than cyclo(l-Ala-l-Pro). Cyclo(l-Ala-Gly) has the strongest AF production-inhibitory activity among known AF production-inhibitory diketopiperazines. Related compounds in which the methyl moiety in cyclo(l-Ala-Gly) is replaced by ethyl, propyl, or isopropyl have shown much stronger activity than cyclo(l-Ala-Gly). Cyclo(l-Ala-Gly) did not inhibit recombinant glutathione-S-transferase (GST) in A. flavus, unlike (l-Ala-l-Pro), which showed that the inhibition of GST was not responsible for the AF production-inhibition of cyclo(l-Ala-Gly). When A. flavus was cultured on peanuts dipped for a short period of time in a dilution series bacterial culture broth, AF production in the peanuts was strongly inhibited, even at a 1 × 104-fold dilution. This strong inhibitory activity suggests that the bacterium is a candidate for an effective biocontrol agent for AF control. [ABSTRACT FROM AUTHOR]

Prenyltransfer is an early-stage carbon-hydrogen bond (C-H) functionalization prevalent in the biosynthesis of a diverse array of biologically active bacterial, fungal, plant, and metazoan diketopiperazine (DKP) alkaloids. Toward the development of a unified strategy for biocatalytic construction of prenylated DKP indole alkaloids, we sought to identify and characterize a substrate-permissive C2 reverse prenyltransferase (PT). As the first tailoring event within the biosynthesis of cytotoxic notoamide metabolites, PT NotF catalyzes C2 reverse prenyltransfer of brevianamide F. Solving a crystal structure of NotF (in complex with native substrate and prenyl donor mimic dimethylallyl S-thiolodiphosphate (DMSPP)) revealed a large, solvent-exposed active site, intimating NotF may possess a significantly broad substrate scope. To assess the substrate selectivity of NotF, we synthesized a panel of 30 sterically and electronically differentiated tryptophanyl DKPs, the majority of which were selectively prenylated by NotF in synthetically useful conversions (2 to >99%). Quantitative representation of this substrate library and development of a descriptive statistical model provided insight into the molecular origins of NotF's substrate promiscuity. This approach enabled the identification of key substrate descriptors (electrophilicity, size, and flexibility) that govern the rate of NotF-catalyzed prenyltransfer, and the development of an "induced fit docking (IFD)-guided" engineering strategy for improved turnover of our largest substrates. We further demonstrated the utility of NotF in tandem with oxidative cyclization using flavin monooxygenase, BvnB. This one-pot, in vitro biocatalytic cascade enabled the first chemoenzymatic synthesis of the marine fungal natural product, (-)-eurotiumin A, in three steps and 60% overall yield.

AimsCabotegravir delivered as a long-acting intramuscular injection has shown superior efficacy to oral tenofovir-emtricitabine as pre-exposure prophylaxis (PrEP) for HIV. Cabotegravir pharmacokinetics (PK), like those of other long-acting depot preparations, exhibit variability between individuals and between injection occasions. The aim of this study is to describe the population pharmacokinetics of long-acting cabotegravir (CAB-LA).MethodsUsing available PK measurements from 133 participants in the HIV Prevention Trials Network (HPTN) 077 trial, we analysed CAB-LA PK data using nonlinear mixed-effects modelling to develop a population PK model.ResultsA two-compartment model with first order absorption best described the CAB-LA PK. The analysis identified between-occasion variability (BOV, i.e., differences in PK within one individual from one injection to the next) as a significant covariate affecting the absorption rate, with an estimated contribution of BOV to PK variability on the absorption rate (ka ) of 38.5%. Sex and body weight were identified as significant covariates influencing the absorption rate and apparent clearance of CAB-LA after intramuscular injection at various doses and frequencies. Male participants had 67% higher ka than female participants. Serially adding to the model body weight on clearance, sex on ka , and BOV on ka led to a decrease in the objective function value (OFV) of 24.4, 36 and 321.4, respectively.ConclusionThe public availability of this model will facilitate and enable a wide variety of future clinically relevant simulations to inform the optimal use of CAB-LA.

AimTo characterize cabotegravir population pharmacokinetics using data from phase 1, 2 and 3 studies and evaluate the association of intrinsic and extrinsic factors with pharmacokinetic variability.MethodsAnalyses were implemented in NONMEM and R. Concentrations below the quantitation limit were modelled with likelihood-based approaches. Covariate relationships were evaluated using forward addition (P

Purpose of reviewTenofovir-based oral PrEP has been effective in reducing population-level HIV incidence in multiple settings, although disparities remain. Injectable cabotegravir-based PrEP is an alternative that may be attractive to individuals with adherence challenges or who do not desire to take a daily medication. We review promises and challenges of cabotegravir-based PrEP.Recent findingsCabotegravir has demonstrated higher effectiveness than oral PrEP in two randomized trials, with a hazard ratio of 0.31 for HIV incidence among MSM and transgender women across multiple settings [95% confidence interval (CI) 0.18-0.62] and 0.11 for cisgender women in sub-Saharan Africa (95% CI 0.040.32). Cabotegravir was also highly effective among populations with disproportionate HIV incidence. Although cabotegravir breakthrough was rare, diagnosis was delayed with use of antigen/antibody-based HIV tests, and resistance occurred with breakthrough infections. Implementation will need to overcome several challenges, including HIV RNA laboratory monitoring not being widely available, requirement for additional staff time and clinic space, and need to provide oral medication during interruptions in dosing.SummaryCabotegravir-based PrEP is a highly effective additional PrEP option that will expand HIV prevention options. For successful roll-out, strategies for streamlined and accessible delivery of cabotegravir in real-world settings will need to be developed.

Malaria, Chagas disease, and leishmaniasis are tropical diseases caused by protozoan parasites of the genera Plasmodium, Trypanosoma and Leishmania, respectively. These diseases constitute a major burden on public health in several regions worldwide, mainly affecting low-income populations in economically poor countries. Severe side effects of currently available drug treatments and the emergence of resistant parasites need to be addressed by the development of novel drug candidates. Natural 2,5-Diketopiperazines (2,5-DKPs) constitute N-heterocyclic secondary metabolites with a wide range of biological activities of medicinal interest. Its structural and physicochemical properties make the 2,5-DKP ring a versatile, peptide-like, and stable pharmacophore attractive for synthetic drug design. In the present work, twenty-three novel synthetic 2,5-DKPs, previously synthesized through the versatile Ugi multicomponent reaction, were assayed for their anti-protozoal activities against P. falciparum, T. cruzi, and L. infantum. Some of the 2,5-DKPs have shown promising activities against the target protozoans, with inhibitory concentrations (IC50) ranging from 5.4 to 9.5 µg/mL. The most active compounds also show low cytotoxicity (CC50), affording selectivity indices ≥ 15. Results allowed for observing a clear relationship between the substitution pattern at the aromatic rings of the 2,5-DKPs and their corresponding anti-Plasmodium activity. Finally, calculated drug-like properties of the compounds revealed points for further structure optimization of promising drug candidates. [ABSTRACT FROM AUTHOR]

The fungal strain BC17 was isolated from sediments collected in the intertidal zone of the inner Bay of Cadiz and characterized as Emericellopsis maritima. On the basis of the one strain–many compounds (OSMAC) approach, four new eremophilane-type sesquiterpenes (1–4), together with thirteen known derivatives (5–17) and two reported diketopiperazines (18, 19), were isolated from this strain. The chemical structures and absolute configurations of the new compounds were determined through extensive NMR and HRESIMS spectroscopic studies and ECD calculation. Thirteen of the isolated eremophilanes were examined for cytotoxic and antimicrobial activities. PR toxin (16) exhibited cytotoxic activity against HepG2, MCF-7, A549, A2058, and Mia PaCa-2 human cancer cell lines with IC50 values ranging from 3.75 to 33.44 µM. (+)-Aristolochene (10) exhibited selective activity against the fungal strains Aspergillus fumigatus ATCC46645 and Candida albicans ATCC64124 at 471 µM. [ABSTRACT FROM AUTHOR]

BackgroundThe HIV Prevention Trials Network (HPTN) 083 trial demonstrated that long-acting cabotegravir (CAB-LA) was more effective than tenofovir disoproxil fumarate-emtricitabine (TDF/FTC) in preventing human immunodeficiency virus (HIV) in cisgender men and transgender women who have sex with men. We characterized HIV infections that occurred in the blinded phase of HPTN 083.MethodsRetrospective testing included HIV testing, viral load testing, quantification of study drugs, and HIV drug resistance testing.ResultsFifty-eight infections were evaluated, including 51 incident infections (12 in CAB arm and 39 in TDF/FTC arm). In many cases (5 in CAB arm and 37 in TDF/FTC arm), infection was associated with low or unquantifiable study drug concentrations. In 4 cases, infection occurred with on-time CAB-LA injections and expected plasma CAB concentrations. CAB exposure was associated with prolonged viral suppression and delayed antibody expression. In some cases, delayed HIV diagnosis resulted in CAB provision to participants with undetected infection, delayed antiretroviral therapy, and emergence of drug resistance; most of these infections would have been detected earlier with viral load testing.ConclusionsEarly detection of HIV infection and prompt antiretroviral therapy initiation could improve clinical outcomes in persons who become infected despite CAB-LA prophylaxis. Further studies are needed to elucidate the correlates of HIV protection in persons receiving CAB-LA.

Background: Marine sponges and other marine invertebrates are considered hidden treasures for a variety of secondary metabolites with pharmacognostic and pharmacological activities which have the potential to create future "super drugs." Dysidea species is one of the most widely distributed sponge species in the world which is found mainly near the shores of the Red Sea, Australia, Yap State, and the Philippines. Dysidea species are considered a source of bioactive natural metabolites that exhibit outstanding chemical diversity. They revealed polybrominated diphenyl ethers, sesquiterpene hydroquinones, furano-sesquiterpenes, diterpenes, chlorinated diketopiperazines, and Amino acids. They showed a broad spectrum of potent biological activities, such as antimicrobial, antimalarial, anti-inflammatory, antitumor, potent cytostatic, antifungal, and antioxidant activities. Conclusion: This review presents an overview of the isolated secondary metabolites from Dysidea species, and their recorded biological activities covering the published reports in the last 30 years. [ABSTRACT FROM AUTHOR]

This work examined the role of selected non-volatile compounds in cooked cheese flavour, both as tastants and as precursors of aroma generation in the Maillard reaction. The effect of cooking on the concentration of selected non-volatile compounds (organic acids, sugars, amino acids, γ-glutamyl dipeptides, and diketopiperazines) in six cheeses (mature Cheddar, mozzarella, Parmesan, and mild Cheddar (low, medium, and high fat)) was determined. Sugars, amino acids, and γ-glutamyl dipeptides were extracted and analysed by LC, whereas diketopiperazines were extracted by solid-phase extraction and analysed by GC-MS. Sugars, amino acids, and γ-glutamyl dipeptides decreased in concentration during cooking, whereas diketopiperazines and some organic acids increased in concentration. Diketopiperazines were above the taste threshold in some cooked cheeses and below the threshold in uncooked cheeses. The role of fat content in cooked cheese flavour is discussed. Furthermore, γ-glutamyl dipeptide concentration increased during 24 months of ageing in low, medium, and high-fat Cheddars, with similar levels of γ-glutamyl dipeptide detected in aged low and high-fat Cheddars. This work will give valuable insight for the dairy industry to inform the development of cheeses, especially low-fat variants, for use in cooked foods. [ABSTRACT FROM AUTHOR]

The lifelong relationship between the Hawaiian bobtail squid Euprymna scolopes and its microbial symbiont Vibrio fischeri represents a simplified model system for studying microbiome establishment and maintenance. The bacteria colonize a dedicated symbiotic light organ in the squid, from which bacterial luminescence camouflages the host in a process termed counterillumination. The squid host hatches without its symbionts, which must be acquired from the ocean amidst a diversity of nonbeneficial bacteria, such that precise molecular communication is required for initiation of the specific relationship. Therefore it is likely there are specialized metabolites used in the light organ microenvironment to modulate these processes. To identify small molecules that may influence the establishment of this symbiosis, we used imaging mass spectrometry to analyze metabolite production in V. fischeri with altered biofilm production, which correlates directly to colonization capability in its host. "Biofilm-up" and "biofilm-down" mutants were compared to a wild-type strain, and ions that were more abundantly produced by the biofilm-up mutant were detected. Using a combination of structural elucidation and synthetic chemistry, one such signal was determined to be a diketopiperazine, cyclo(d-histidyl-l-proline). This diketopiperazine modulated luminescence in V. fischeri and, using imaging mass spectrometry, was directly detected in the light organ of the colonized host. This work highlights the continued need for untargeted discovery efforts in host-microbe interactions and showcases the benefits of the squid-Vibrio system for identification and characterization of small molecules that modulate microbiome behaviors.IMPORTANCE The complexity of animal microbiomes presents challenges to defining signaling molecules within the microbial consortium and between the microbes and the host. By focusing on the binary symbiosis between Vibrio fischeri and Euprymna scolopes, we have combined genetic analysis with direct imaging to define and study small molecules in the intact symbiosis. We have detected and characterized a diketopiperazine produced by strong biofilm-forming V. fischeri strains that was detectable in the host symbiotic organ, and which influences bacterial luminescence. Biofilm formation and luminescence are critical for initiation and maintenance of the association, respectively, suggesting that the compound may link early and later development stages, providing further evidence that multiple small molecules are important in establishing these beneficial relationships.

The fungal genus Trichoderma is a rich source of structurally diverse secondary metabolites with remarkable pharmaceutical properties. The chemical constituents and anticancer activities of the marine-derived fungus Trichoderma lixii have never been investigated. In this study, a bioactivity-guided investigation led to the isolation of eleven compounds, including trichodermamide A (1), trichodermamide B (2), aspergillazine A (3), DC1149B (4), ergosterol peroxide (5), cerebrosides D/C (6/7), 5-hydroxy-2,3-dimethyl-7-methoxychromone (8), nafuredin A (9), and harzianumols E/F (10/11). Their structures were identified by using various spectroscopic techniques and compared to those in the literature. Notably, compounds 2 and 5–11 were reported for the first time from this species. Evaluation of the anticancer activities of all isolated compounds was carried out. Compounds 2, 4, and 9 were the most active antiproliferative compounds against three cancer cell lines (human myeloma KMS-11, colorectal HT-29, and pancreas PANC-1). Intriguingly, compound 4 exhibited anti-austerity activity with an IC50 of 22.43 μM against PANC-1 cancer cells under glucose starvation conditions, while compound 2 did not.

Streptomyces sp. N11-50 was isolated from deep-sea water and found to produce diketopiperazine (DKP) compounds such as albonoursin and cyclo(Phe-Leu). This study aimed to reveal the potential to synthesize diverse nonribosomal peptide and polyketide compounds as the other secondary metabolites different from DKP after clarifying the taxonomic position. Strain N11-50 was identified as Streptomyces albus, as it showed 100% 16S rRNA gene sequence similarities and 95.5% DNA–DNA relatedness to S. albus NBRC 13014T. We annotated the nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) gene clusters in the genome. Consequently, five NRPS, one hybrid PKS/NRPS, five type-I PKS and one type-II PKS gene clusters were observed, of which we predicted the products through bioinformatic analysis. These gene clusters were well conserved in already whole-genome sequence (WGS)-published strains belonging to S. albus. On the other hand, our taxonogenomic analysis revealed that three WGS-published S. albus strains were not S. albus. Two of the three should be classified as Streptomyces albidoflavus, and the remaining one was likely a new genomospecies. After reclassifying these appropriately, we demonstrated species-specific profiles of the NRPS and PKS gene clusters with little strain-level diversities. [ABSTRACT FROM AUTHOR]

The dimeric diketopiperazine (DKPs) alkaloids are a diverse family of natural products (NPs) whose unique structural architectures and biological activities have inspired the development of new synthetic methodologies to access these molecules. However, catalyst-controlled methods that enable the selective formation of constitutional and stereoisomeric dimers from a single monomer are lacking. To resolve this long-standing synthetic challenge, we sought to characterize the biosynthetic enzymes that assemble these NPs for application in biocatalytic syntheses. Genome mining enabled identification of the cytochrome P450, NzeB (Streptomyces sp. NRRL F-5053), which catalyzes both intermolecular carbon-carbon (C-C) and carbon-nitrogen (C-N) bond formation. To identify the molecular basis for the flexible site-selectivity, stereoselectivity, and chemoselectivity of NzeB, we obtained high-resolution crystal structures (1.5 Å) of the protein in complex with native and non-native substrates. This, to our knowledge, represents the first crystal structure of an oxidase catalyzing direct, intermolecular C-H amination. Site-directed mutagenesis was utilized to assess the role individual active-site residues play in guiding selective DKP dimerization. Finally, computational approaches were employed to evaluate plausible mechanisms regarding NzeB function and its ability to catalyze both C-C and C-N bond formation. These results provide a structural and computational rationale for the catalytic versatility of NzeB, as well as new insights into variables that control selectivity of CYP450 diketopiperazine dimerases.

Natural bioresources, predominantly plants, have always been regarded as the richest source of drugs for diseases threatening humanity. Additionally, microorganism-originating metabolites have been extensively explored as weapons against bacterial, fungal, and viral infections. However, the biological potential of metabolites produced by plant endophytes still remains understudied, despite significant efforts reflected in recently published papers. Thus, our goal was to evaluate the metabolites produced by endophytes isolated from Marchantia polymorpha and to study their biological properties, namely anticancer and antiviral potential. The cytotoxicity and anticancer potential were assessed using the microculture tetrazolium technique (MTT) against non-cancerous VERO cells and cancer cells—namely the HeLa, RKO, and FaDu cell lines. The antiviral potential was tested against the human herpesvirus type-1 replicating in VERO cells by observing the influence of the extract on the virus-infected cells and measuring the viral infectious titer and viral load. The most characteristic metabolites identified in the ethyl acetate extract and fractions obtained by use of centrifugal partition chromatography (CPC) were volatile cyclic dipeptides, cyclo(l-phenylalanyl-l-prolyl), cyclo(l-leucyl-l-prolyl), and their stereoisomers. In addition to the diketopiperazine derivatives, this liverwort endophyte also produced arylethylamides and fatty acids amides. The presence of N-phenethylacetamide and oleic acid amide was confirmed. The endophyte extract and isolated fractions showed a potential selective anticancer influence on all tested cancer cell lines. Moreover, the extract and the first separated fraction noticeably diminished the formation of the HHV-1-induced cytopathic effect and reduced the virus infectious titer by 0.61–1.16 log and the viral load by 0.93–1.03 log. Endophytic organisms produced metabolites with potential anticancer and antiviral activity; thus, future studies should aim to isolate pure compounds and evaluate their biological activities. [ABSTRACT FROM AUTHOR]

Malaria, Chagas disease, and leishmaniasis are tropical diseases caused by protozoan parasites of the genera Plasmodium, Trypanosoma and Leishmania, respectively. These diseases constitute a major burden on public health in several regions worldwide, mainly affecting low-income populations in economically poor countries. Severe side effects of currently available drug treatments and the emergence of resistant parasites need to be addressed by the development of novel drug candidates. Natural 2,5-Diketopiperazines (2,5-DKPs) constitute N-heterocyclic secondary metabolites with a wide range of biological activities of medicinal interest. Its structural and physicochemical properties make the 2,5-DKP ring a versatile, peptide-like, and stable pharmacophore attractive for synthetic drug design. In the present work, twenty-three novel synthetic 2,5-DKPs, previously synthesized through the versatile Ugi multicomponent reaction, were assayed for their anti-protozoal activities against P. falciparum, T. cruzi, and L. infantum. Some of the 2,5-DKPs have shown promising activities against the target protozoans, with inhibitory concentrations (IC50) ranging from 5.4 to 9.5 µg/mL. The most active compounds also show low cytotoxicity (CC50), affording selectivity indices ≥ 15. Results allowed for observing a clear relationship between the substitution pattern at the aromatic rings of the 2,5-DKPs and their corresponding anti-Plasmodium activity. Finally, calculated drug-like properties of the compounds revealed points for further structure optimization of promising drug candidates.

The fungal strain BC17 was isolated from sediments collected in the intertidal zone of the inner Bay of Cadiz and characterized as Emericellopsis maritima. On the basis of the one strain–many compounds (OSMAC) approach, four new eremophilane-type sesquiterpenes (1–4), together with thirteen known derivatives (5–17) and two reported diketopiperazines (18, 19), were isolated from this strain. The chemical structures and absolute configurations of the new compounds were determined through extensive NMR and HRESIMS spectroscopic studies and ECD calculation. Thirteen of the isolated eremophilanes were examined for cytotoxic and antimicrobial activities. PR toxin (16) exhibited cytotoxic activity against HepG2, MCF-7, A549, A2058, and Mia PaCa-2 human cancer cell lines with IC50 values ranging from 3.75 to 33.44 µM. (+)-Aristolochene (10) exhibited selective activity against the fungal strains Aspergillus fumigatus ATCC46645 and Candida albicans ATCC64124 at 471 µM.

The mechanism of permanganate-mediated dual C-H oxidation of complex diketopiperazines has been examined with density functional theory computations. The products of these oxidations are enabling intermediates in the synthesis of structurally diverse ETP natural products. We evaluated, for the first time, the impact of ion-pairing and aggregation states of the permanganate ion and counter-cations, such as bis(pyridine)-silver(I) (Ag+) and tetra- n-butylammonium (TBA+), on the C-H oxidation mechanism. The C-H abstraction occurs through an open shell singlet species, as noted previously, followed by O-rebound and a competing OH-rebound pathway. The second C-H oxidation proceeds with a second equivalent of oxidant with lower free energy barriers than the first C-H oxidation due to directing effects and the generation of a more reactive oxidant species after the first C-H oxidation. The success and efficiency of the second C-H oxidation are found to be critically dependent on the presence of an ion-paired oxidant. We used the developed mechanistic knowledge to rationalize an experimentally observed oxidation pattern for C3-indole-substituted diketopiperazine (+)-5 under optimal oxidation conditions: namely, the formation of diol (-)-6 as a single diastereomer and lack of the ketone products. We proposed two factors that may impede the ketone formation: (i) the conformational flexibility of the diketopiperazine ring, and (ii) hindrance of this site, making it less accessible to the ion-paired oxidant species.

There is an increasing interest towards the development of new antimicrobial coatings, especially in light of the emergence of antimicrobial resistance (AMR) towards common antibiotics. Cyclodipeptides (CDPs) or diketopiperazines (DKPs) are attractive candidates for their ability to self-assemble into supramolecular polymers and yield gel coatings that do not persist in the environment. In this work, we compare the antimicrobial cyclo(Leu-Phe) with its heterochiral analogs cyclo(D-Leu-L-Phe) and cyclo(L-Leu-D-Phe), as well as cyclo(L-Phe-D-Phe), for their ability to gel. The compounds were synthesized, purified by HPLC, and characterized by 1H-NMR, 13C-NMR, and ESI-MS. Single-crystal X-ray diffraction (XRD) revealed details of the intermolecular interactions within the supramolecular polymers. The DKPs were then tested for their cytocompatibility on fibroblast cells and for their antimicrobial activity on S. aureus. Overall, DKPs displayed good cytocompatibility and very mild antimicrobial activity, which requires improvement towards applications. [ABSTRACT FROM AUTHOR]

Cyclodipeptides (CDPs) or diketopiperazines (DKPs) are often found in nature and in foodstuff and beverages and have attracted great interest for their bioactivities, biocompatibility, and biodegradability. In the laboratory, they can be prepared by green procedures, such as microwave-assisted cyclization of linear dipeptides in water, as performed in this study. In particular, five CDPs were prepared and characterized by a variety of methods, including NMR and ESI-MS spectroscopies and single-crystal X-ray diffraction (XRD), and their cytocompatibility and anti-aging activity was tested in vitro, as well as their ability to penetrate the different layers of the skin. Although their mechanism of action remains to be elucidated, this proof-of-concept study lays the basis for their future use in anti-age cosmetic applications. [ABSTRACT FROM AUTHOR]

Background: Although long-acting, injectable cabotegravir (CAB-LA) pre-exposure prophylaxis (PrEP) has proven efficacious for HIV prevention in clinical trials, research is needed to guide effective implementation in real-world settings. Formative work with community members and health care providers (HCPs) is important to provide insight into the needs and contexts of specific populations and reveal potential barriers and facilitators for implementation projects., Objective: We aimed to describe the results from formative work to develop an implementation package for CAB-LA PrEP within the ImPrEP CAB Brasil study., Methods: ImPrEP CAB Brasil is an implementation study of same-day delivery of CAB-LA PrEP for young sexual and gender minority (SGM) groups (aged 18-30 years) in 6 existing oral PrEP public health clinics. We conducted formative research to prepare for the implementation of ImPrEP CAB Brasil through community mobilization, process mapping with HCPs with experience in CAB-LA, and focus group discussions (FGDs) with young SGM groups (n=92) and HCPs (n=20) to identify initial perceptions of facilitators and barriers for CAB-LA PrEP implementation, refine the mobile health (mHealth) educational tool, and evaluate the acceptability of using a text message appointment reminder intervention through WhatsApp. FGDs were recorded, transcribed, systematically coded, and analyzed with thematic categorization by trained researchers using a qualitative data analysis program ATLAS.ti (version 7)., Results: A community mobilization team comprising 34 SGM community leaders collaborated in creating a prototype for an mHealth educational tool and contributed to the planning of peer education activities. We created 3 process maps for each site to describe the initial visit, follow-up visits, and laboratory flow. The main challenge identified for same-day CAB-LA PrEP delivery was the extended duration of clinic visits due to the numerous laboratory tests and HIV counseling steps required. Proposed solutions included having point-of-care HIV rapid tests instead of laboratory tests and additional counseling staff. Barriers for CAB-LA PrEP implementation identified through FGDs were the training of HCPs, support for adherence to injection appointments, and stigma or discrimination against SGM groups and persons using PrEP. The mHealth educational tool and WhatsApp reminders were highly acceptable by SGM groups and HCPs, indicating their potential to support PrEP choice and adherence. Content analysis on the cultural appropriateness of the language and overall clarity of the material contributed to the refinement of the mHealth tool., Conclusions: Structured formative work with SGM persons and HCPs generated important refinements to context-specific materials and plans to launch ImPrEP CAB Brasil in public health clinics. Ongoing implementation monitoring will use the process maps to identify additional barriers and potential solutions to same-day delivery of CAB-LA PrEP. Summative evaluations are needed to measure the effectiveness of the mHealth educational tool to support PrEP choice and the use of WhatsApp appointment reminders., (©M Cristina Pimenta, Thiago Silva Torres, Brenda Hoagland, Mirian Cohen, Claudio Gruber Mann, Cristina M Jalil, Eduardo Carvalheira, Lucilene Freitas, Nilo Fernandes, Debora Castanheira, Marcos Benedetti, Julio Moreira, Keila Simpson, Roberta Trefiglio, Gabrielle O’Malley, Valdilea G Veloso, Beatriz Grinsztejn. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 24.10.2024.)

Background: HPTN 084 compared the safety and efficacy of long-acting injectable cabotegravir (CAB) to daily oral TDF/FTC for prevention of HIV-1 in uninfected African women. Like a similar trial in MSM/TGW (HPTN 083), the trial was stopped early for efficacy, expediting the need to consider introduction strategies for different populations. We examine survey and qualitative data from a four-country sub-study to examine oral and injectable PrEP acceptability and considerations for CAB access among African women., Methods: Participants completed baseline and follow-up surveys on HIV risk perception, sexual behavior. product acceptability and adherence during the blinded trial. Additionally, up to two in-depth interviews each with 73 sub-study participants explored product use and trial-related experiences, during the blinded and unblinded study periods. Using survey data, we classified participants as: engaged in female sex work (FSW), having multiple non-transactional partners, or monogamous. A study statistician identified participants' assigned study arm. We followed a thematic analysis process to read transcripts, develop a codebook and apply codes in NVivo to transcripts with intermittent intercoder reliability checks; using Excel matrices to explore differences across risk categories and study arms., Findings: Participants overwhelmingly preferred injections to pills, appreciating the ease, convenience, and privacy of a long-acting formulation. Many participants described challenges with contraceptive and/or study pill adherence, impeded by late night work, unexpected travel, or heavy drinking. Women in the TDF/FTC arm were more likely to describe side effects, compared to those in the CAB arm. Pain also varied widely by study arm. When considering post-trial access to CAB, limited PrEP knowledge, cost and concerns around stigma and poor service quality were potential access barriers., Conclusion: Women's desire for privacy and ease of use outweighed injectable concerns, resulting in a strong preference for CAB. Cost and accessibility will need to be addressed by implementation programs., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Tolley et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Antiretroviral therapy (ART) for HIV infection has evolved substantially. The development of long-acting drugs, such as cabotegravir (CAB) and rilpivirine (RPV) might improve treatment satisfaction among people living with HIV (PLWH). The real-world effectiveness of long-acting ART and its effect on patient satisfaction needs to be assessed. This study investigated antiviral effectiveness and treatment satisfaction in PLWH who switched from conventional to long-acting ART (CAB + RPV)., Methods: This prospective cohort study included PLWH aged 18 years and older who switched to CAB + RPV and received the injections every 8 weeks between June 2022 and May 2023, after a 4-week oral lead-in phase. The eligibility criteria included viral suppression, absence of hepatitis B virus (HBV) DNA, and no prior RPV resistance mutations. Clinical data, including renal, lipid, and glucose biomarker levels, were monitored from the baseline to 44 weeks after switching. Treatment satisfaction was assessed using the HIV Treatment Satisfaction Questionnaire. A linear mixed-effects model was used to estimate changes in clinical data from baseline., Results: Thirty-eight male participants were enrolled. Some participants had detectable levels of viral replication; however, all participants maintained viral suppression (HIV-RNA < 50 copies/mL) at 44 weeks and no cases of virological failure were detected. The creatinine level decreased by - 0.04 mg/dL (95% confidence interval [CI]: - 0.07 to - 0.01), lipid and glucose profiles remained stable, and treatment satisfaction increased by 6.6 points (95% CI: 2.4 to 10.8) after switching to CAB + RPV., Conclusions: Long-acting ART provides effective viral suppression and enhances treatment satisfaction in PLWH switching from conventional ART. Long-acting ART can improve patient well-being; however, patient selection and monitoring to prevent HBV-related complications are important., (© 2024. The Author(s).)

The ABCG2 membrane transporter affects bioavailability and milk secretion of xenobiotics and natural compounds, including vitamins such as riboflavin. We aimed to characterize the in vitro and in vivo interaction of ABCG2 with lumichrome, the main photodegradation product of riboflavin, which has proven in vitro anti-cancer activity and a therapeutical role in antibacterial photodynamic therapy as an efficient photosensitizer. Using MDCK-II polarized cells overexpressing murine Abcg2 and human ABCG2 we found that lumichrome was efficiently transported by both variants. After lumichrome administration to wild-type and Abcg2 -/- mice, plasma AUC 20-120 min was 1.8-fold higher in Abcg2 -/- mice compared with wild-type mice. The liver and testis from Abcg2 -/- mice showed significantly higher lumichrome levels compared with wild-type, whereas lumichrome accumulation in small intestine content of wild-type mice was 2.7-fold higher than in Abcg2 -/- counterparts. Finally, a 4.1-fold-higher lumichrome accumulation in milk of wild-type versus Abcg2 -/- mice was found. Globally, our results show that ABCG2 plays a crucial role in plasma levels, tissue distribution and milk secretion of lumichrome potentially conditioning its biological activity.

It is imperative to optimize chemotherapy for heightened anti-tumor therapeutic efficacy. Unrestrained tumor cell proliferation and sustained angiogenesis are pivotal for cancer progression. Plinabulin, a vascular disrupting agent, selectively destroys tumor blood vessels. Tirapazamine (TPZ), a hypoxia-activated prodrug, intensifies cytotoxicity in diminishing oxygen levels within tumor cells. Despite completing Phase III clinical trials, both agents exhibited modest treatment efficiency due to dose-limiting toxicity. In this study, we employed methoxy poly(ethylene glycol)-b-poly( D, L -lactide) (mPEG-b-PDLLA) to co-deliver Plinabulin and TPZ to the tumor site, concurrently disrupting blood vessels and eliminating tumor cells, addressing both symptoms and the root cause of tumor progression. Plinabulin was converted into a prodrug with esterase response (PSM), and TPZ was synthesized into a hexyl chain-containing derivative (TPZHex) for effective co-delivery. PSM and TPZHex were co-encapsulated with mPEG-b-PDLLA, forming nanodrugs (PT-NPs). At the tumor site, PT-NPs responded to esterase overexpression, releasing Plinabulin, disrupting blood vessels, and causing nutritional and oxygen deficiency. TPZHex was activated in response to increased hypoxia, killing tumor cells. In treating 4T1 tumors, PT-NPs demonstrated enhanced therapeutic efficacy, achieving a 92.9 % tumor suppression rate and a 20 % cure rate. This research presented an innovative strategy to enhance synergistic efficacy and reduce toxicity in combination chemotherapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Long-acting injectable (LAI) cabotegravir and rilpivirine for HIV treatment and LAI cabotegravir for pre-exposure HIV prophylaxis are being rolled out in a multitude of countries worldwide. Due to the prolonged exposure, it can be challenging to undertake 'traditional' pharmacokinetic studies and current guidance is derived from their oral equivalents or physiologically based pharmacokinetic studies. This review aims to consider pharmacokinetic characteristics of cabotegravir and rilpivirine and describe anticipated drug-drug interactions (DDIs) with frequent concomitant medications in African settings. Relevant co-medications were identified from the WHO 2021 List of Essential Medicines. All original human and physiologically based pharmacokinetic studies published in English on PubMed, discussing DDIs with LAI cabotegravir and rilpivirine prior to April 2023, were reviewed. The Liverpool HIV interaction database was also reviewed (https://www.hiv-druginteractions.org/checker). LAI cabotegravir and rilpivirine have half-lives of 6-12 and 13-28 weeks, respectively. Cabotegravir is primarily metabolized by UDP-glucuronyltransferase (UGT)-1A1 and rilpivirine by cytochrome P450 (CYP)-3A4. LAI cabotegravir and rilpivirine themselves exhibit low risk of perpetrating interactions with co-medications as they do not induce or inhibit the major drug metabolizing enzymes. However, they are victims of DDIs relating to the induction of their metabolizing enzymes by concomitantly administered medication. Noteworthy contraindicated co-medications include rifamycins, carbamazepine, phenytoin, flucloxacillin and griseofulvin, which induce CYP3A4 and/or UGT1A1, causing clinically significant reduced concentrations of rilpivirine and/or cabotegravir. In addition to virologic failure, subtherapeutic concentrations resulting from DDIs can lead to emergent drug resistance. Clinicians should be aware of potential DDIs and counsel people receiving LAI cabotegravir/rilpivirine appropriately to minimize risk., (© 2024 The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

An efficient method for the synthesis of functionalized peptidomimetics via multicomponent Ugi reaction has been developed. The application of trifluoroethanol (TFE) as a reaction medium provided desired products with good yields. Further, using the developed cyclisation reaction, the obtained peptidomimetics were transformed into the cyclic analogues (diketopiperazines, DKPs). The goal of the performed studies was to revised and compare whether the structure of the obtained structurally flexible acyclic peptidomimetics and their rigid cycling analogue DKPs affect antimicrobial activity. We studied the potential of synthesized peptidomimetics, both cyclic and acyclic, as antimicrobial drugs on model E. coli bacteria strains (k12, R2–R4). The biological assays reveal that DKPs hold more potential as antimicrobial drugs compared to open chain Ugi peptidomimetics. We believe that it can be due to the rigid cyclic structure of DKPs which promotes the membrane penetration in the cell of studied pathogens. The obtained data clearly indicate the high antibiotic potential of synthesized diketopiperazine derivatives over tested antibiotics. [ABSTRACT FROM AUTHOR]

Three new 2,5-diketopiperazines, speramide C (1), 3,21- epi -taichunamide F (2), and 2- epi -amoenamide C (3), along with four known analogs (4 – 7), were obtained from the sponge-derived fungus Aspergillus sclerotiorum GDST-2013-0501 collected from the South China Sea. The chemical structures of new compounds were elucidated by analyzing NMR and MS spectroscopy data, and their absolute configurations were determined by electronic circular dichroism (ECD) calculations. Compound 1 represents the first prenylated indole alkaloid with an ethylene oxide ring at the isopentenyl side chain. Compound 4 displayed DNA topoisomerase I inhibitory activity and antibacterial activity against Staphylococcus epidermidis. The low cytotoxic or non-cytotoxic compound 4 displayed DNA topoisomerase I inhibitory activity, which could provide a starting point for the development of antitumor agents. [ABSTRACT FROM AUTHOR]

Eight naphtho-gamma-pyrones (NγPs) (1–8), together with four known biosynthetically related coumarin derivatives (9–12), were isolated from the potato dextrose agar media of a marine-derived fungus Aspergillus niger S-48. Among them, natural compounds 1 and 2 were tentatively subjected to benzohydrazide reaction to evaluate the importance of pyran rings in NγPs. Their structures were elucidated by extensive 1D and 2D NMR spectroscopic data and MS spectra. Compounds 1–4 showed obvious activity for reducing cholesterol absorption verging on ezetimibe. This work highlighted the potential of natural NγPs as NPC1L1 inhibitors. [ABSTRACT FROM AUTHOR]

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The unmet need for specific anti-leukemic agents for the treatment of acute lymphoblastic leukemia led us to screen a variety of marine-derived bacteria. The fermentation broth extract of Streptomyces sp. LY1209 exhibited the most potent anti-proliferative effect against Molt 4 leukemia cells. A chromatographic anti-proliferative profiling approach was applied to characterize the metabolites with bioactive potential. Among all the metabolites, the major anti-leukemic constituents were staurosporine and a series of diketopiperazines (DKPs), including one novel and two known DKPs identified from nature for the first time. The structures of these compounds were identified using extensive spectroscopic analysis. The anti-proliferative potential of these metabolites against the Molt 4 cancer cell line was also determined. According to the in silico analysis utilizing a chemical global positioning system for natural products (ChemGPS-NP), it was suggested that these DKPs are potential anti-microtubule and alkylating agents, while staurosporine was proposed to be a tyrosine kinase inhibitor. Our findings not only identified a series of anti-proliferative metabolites, but also suggested a strategic workflow for the future discovery of natural product drug leads. [ABSTRACT FROM AUTHOR]

Two undescribed cytochalasins, emeriglobosins A (1) and B (2), together with nine previously reported analogues (3–11) and two known tetramic acid derivatives (12, 13) were isolated from the solid culture of Emericellopsis sp. SCSIO41202. Their structures, including the absolute configurations of their stereogenic carbons, were fully elucidated based on spectroscopic analysis and the calculated ECD. Some of the isolated compounds were evaluated for their cytotoxicity and enzyme inhibitory activity against acetylcholinesterase (AChE) in vitro. Among them, 8 showed potent AChE inhibitory activity, with an IC50 value of 1.31 μM, and 5 showed significant cytotoxicity against PC-3 cells, with an IC50 value of 2.32 μM. [ABSTRACT FROM AUTHOR]

The biological screening of 44 marine sponge extracts for the research of bioactive molecules, with potential application in the treatment of age-related diseases (cancer and Alzheimer's disease) and skin aging, resulted in the selection of Scopalina hapalia extract for chemical study. As no reports of secondary metabolites of S. hapalia were found in the literature, we undertook this research to further extend current knowledge of Scopalina chemistry. The investigation of this species led to the discovery of four new compounds: two butenolides sinularone J (1) and sinularone K (2), one phospholipid 1-O-octadecyl-2-pentanoyl-sn-glycero-3-phosphocholine (3) and one lysophospholipid 1-O-(3-methoxy-tetradecanoyl)-sn-glycero-3-phosphocholine (4) alongside with known lysophospholipids (5 and 6), alkylglycerols (7–10), epidioxysterols (11 and 12) and diketopiperazines (13 and 14). The structure elucidation of the new metabolites (1–4) was determined by detailed spectroscopic analysis, including 1D and 2D NMR as well as mass spectrometry. Molecular networking was also explored to complement classical investigation and unravel the chemical classes within this species. GNPS analysis provided further information on potential metabolites with additional bioactive natural compounds predicted. [ABSTRACT FROM AUTHOR]

Background: Recently, injectable cabotegravir/rilpivirine (ICAB/RPV) became available for HIV treatment. However, there are no real-life data on the impact of switching to ICAB/RPV on sleep disturbances (SD). Therefore, we aimed at assessing and investigating this aspect in our cohort., Methods: A SD multidimensional assessment (Epworth Sleepiness scale, Insomnia severity Index, Berlin Questionnaire, and Pittsburg Sleep Quality Index, PSQI) was performed to all people who consented before starting ICAB/RPV and 12 wk after the switch. Demographics, life-style habits, laboratory, and clinical data were collected from medical health records., Results: To June 2023, 46 people were included, 76.1% males, with a median age of 48.5 (IQR: 41-57), 50% had multimorbidity, 13% was on polypharmacy. Median age with HIV and CD4 + T cell count nadir were 10 (5-19.5) years and 360 (205-500) cell/mm 3 , respectively. The reason to start a long-acting strategy was person's choice in all cases. Baseline antiretroviral regimens were mostly: tenofovir alafenamide/emtricitabine/rilpivirine (39.1%) and dolutegravir/lamivudine (32.6%). No significant changes were observed in any of the scores for each questionnaire, but for a worsening PSQI. 37% people reported a subjectively improved sleep quality, even if statistically significant changes were not observed in almost all the sleep parameters., Conclusions: To the best of our knowledge, this is the first study exploring impact of switching to ICAB/RPV on SD. Despite integrase inhibitor have been associated with SD, we did not observed a negative impact on sleep quality after the switch to ICAB/RPV. More studies and with larger number of people are necessary to confirm our results.

Farnesol, a self-secreted quorum-sensing molecule (QSM) of Candida albicans , has been known to limit yeast-to-hyphal transition by blocking the RAS1–cAMP–PKA pathway. In a similar fashion, certain bacterial QSMs have also been reported to be successful in attenuating C. albicans biofilm and hyphal formation at relatively high cell density. This prompted us to investigate the antihyphal efficacy of certain bacterial QSMs through virtual docking against seminal drug targets, viz., CYCc and RAS1, that have been reported to be the hallmark players in C. albicans dimorphic virulence cascade. Against this backdrop, 64 QSMs belonging to five different bacterial QS signaling systems were subjected to initial virtual screening with farnesol as reference. Data of the virtual screening unveiled QSMs belonging to diketopiperazines (DKPs), i.e., 3-benzyl-6-isobutylidene-2,5-piperazinedione (QSSM 1157) and cyclo(l-Pro-l-Leu) (QSSM 1112), as potential inhibitors of CYCc and RAS1 with binding energies of −8.2 and −7.3 kcal mol−1, respectively. Further, the molecular dynamics simulations (for 50 ns) of CYCc-QSSM 1157 and RAS1-QSSM 1112 complexes revealed the mean ligand root mean square deviation (RMSD) values of 0.35 and 0.27 Å, respectively, which endorsed the rigid nature, less fluctuation in binding stiffness, and conformation of binding complexes. Furthermore, the identified two QSMs were found to be good in solubility, absorption, and permeation and less toxic in nature, as revealed by pharmacokinetics and toxicity analyses. In addition, the in vitro antihyphal assays using liquid and solid media, germ-tube experiment, and microscopic analysis strongly validated DKP-QSSM 1112 as a promising inhibitor of hyphal transition. Taken together, the present study unequivocally proves that DKPs can be used as potent inhibitors of C. albicans virulence dimorphism. [ABSTRACT FROM AUTHOR]

Natural bioresources, predominantly plants, have always been regarded as the richest source of drugs for diseases threatening humanity. Additionally, microorganism-originating metabolites have been extensively explored as weapons against bacterial, fungal, and viral infections. However, the biological potential of metabolites produced by plant endophytes still remains understudied, despite significant efforts reflected in recently published papers. Thus, our goal was to evaluate the metabolites produced by endophytes isolated from Marchantia polymorpha and to study their biological properties, namely anticancer and antiviral potential. The cytotoxicity and anticancer potential were assessed using the microculture tetrazolium technique (MTT) against non-cancerous VERO cells and cancer cells—namely the HeLa, RKO, and FaDu cell lines. The antiviral potential was tested against the human herpesvirus type-1 replicating in VERO cells by observing the influence of the extract on the virus-infected cells and measuring the viral infectious titer and viral load. The most characteristic metabolites identified in the ethyl acetate extract and fractions obtained by use of centrifugal partition chromatography (CPC) were volatile cyclic dipeptides, cyclo(l-phenylalanyl-l-prolyl), cyclo(l-leucyl-l-prolyl), and their stereoisomers. In addition to the diketopiperazine derivatives, this liverwort endophyte also produced arylethylamides and fatty acids amides. The presence of N-phenethylacetamide and oleic acid amide was confirmed. The endophyte extract and isolated fractions showed a potential selective anticancer influence on all tested cancer cell lines. Moreover, the extract and the first separated fraction noticeably diminished the formation of the HHV-1-induced cytopathic effect and reduced the virus infectious titer by 0.61–1.16 log and the viral load by 0.93–1.03 log. Endophytic organisms produced metabolites with potential anticancer and antiviral activity; thus, future studies should aim to isolate pure compounds and evaluate their biological activities.

Farnesol, a self-secreted quorum-sensing molecule (QSM) of Candida albicans, has been known to limit yeast-to-hyphal transition by blocking the RAS1–cAMP–PKA pathway. In a similar fashion, certain bacterial QSMs have also been reported to be successful in attenuating C. albicans biofilm and hyphal formation at relatively high cell density. This prompted us to investigate the antihyphal efficacy of certain bacterial QSMs through virtual docking against seminal drug targets, viz., CYCc and RAS1, that have been reported to be the hallmark players in C. albicans dimorphic virulence cascade. Against this backdrop, 64 QSMs belonging to five different bacterial QS signaling systems were subjected to initial virtual screening with farnesol as reference. Data of the virtual screening unveiled QSMs belonging to diketopiperazines (DKPs), i.e., 3-benzyl-6-isobutylidene-2,5-piperazinedione (QSSM 1157) and cyclo(l-Pro-l-Leu) (QSSM 1112), as potential inhibitors of CYCc and RAS1 with binding energies of −8.2 and −7.3 kcal mol−1, respectively. Further, the molecular dynamics simulations (for 50 ns) of CYCc-QSSM 1157 and RAS1-QSSM 1112 complexes revealed the mean ligand root mean square deviation (RMSD) values of 0.35 and 0.27 Å, respectively, which endorsed the rigid nature, less fluctuation in binding stiffness, and conformation of binding complexes. Furthermore, the identified two QSMs were found to be good in solubility, absorption, and permeation and less toxic in nature, as revealed by pharmacokinetics and toxicity analyses. In addition, the in vitro antihyphal assays using liquid and solid media, germ-tube experiment, and microscopic analysis strongly validated DKP-QSSM 1112 as a promising inhibitor of hyphal transition. Taken together, the present study unequivocally proves that DKPs can be used as potent inhibitors of C. albicans virulence dimorphism.

Introduction: Long-acting injectable antiretroviral treatment (LAI-ART) has emerged as a novel alternative to the burden of daily oral pills. The bi-monthly intramuscular injectable containing cabotegravir and rilpivirine holds the promise of improving adherence to ART. The perspectives of potential users of LAI-ART, the majority of whom reside in Eastern and Southern Africa, are still largely unexplored. We set out to understand the experiences of people with HIV (PWH) who received LAI-ART at Fort Portal Regional Referral Hospital in mid-Western Uganda for at least 12 months., Methods: This qualitative study, conducted between July and August 2023, was nested within a larger study. We conducted four focus groups with 32 (out of 69) PWH who received intramuscular injections of cabotegravir and rilpivirine. In-depth interviews were held with six health workers who delivered LAI-ART to PWH. Data were analyzed by thematic approach broadly modeled on the five domains of the Consolidated Framework for Implementation Research (CFIR)., Results: There was high acceptability of LAI-ART (30 /32 or 94%) participants requested to remain on LAI-ART even after the end of the 12-month trial. Adherence to ART was reportedly improved when compared to daily oral treatment. Participants credited LAI-ART with; superior viral load suppression, redemption from the daily psychological reminder of living with HIV, enhanced privacy in HIV care and treatment, reduced HIV-related stigma associated with taking oral pills and that it absolved them from carrying bulky medication packages. Conversely, nine participants reported pain around the injection site and a transient fever soon after administering the injection as side effects of LAI-ART. Missed appointments for receiving the bi-monthly injection were common. Providers identified health system barriers to the prospective scale-up of LAI-ART which include the perceived high cost of LAI-ART, stringent cold chain requirements, physical space limitations, and workforce skills gaps in LAI-ART delivery as potential drawbacks., Conclusion: Overall, PWH strongly preferred LAI-ART and expressed a comparatively higher satisfaction with this treatment alternative. Health system barriers to potential scale-up are essential to consider if a broader population of PWH will benefit from this novel HIV treatment option in Uganda and other resource-limited settings., Trial Registration: Trial Registry Number PACTR ID PACTR202104874490818 (registered on 16/04/2021)., (© 2024. The Author(s).)

Introduction: HIV treatment currently consists of daily oral antiretroviral therapy (ART). Cabotegravir + rilpivirine long-acting (CAB + RPV LA) is the first ART available in Spain administered every 2 months through intramuscular injection by a healthcare professional (HCP). The objective of this analysis was to assess potential healthcare resource use (HRU) and cost impact of implementing CAB + RPV LA vs. daily oral ART at National Health System (NHS) hospitals., Methods: Online quantitative interviews and cost analysis were performed. Infectious disease specialists (IDS), hospital pharmacists (HP) and nurses were asked about their perception of potential differences in HRU between CAB + RPV LA vs. daily oral ART, among other concepts of interest. Spanish official tariffs were applied as unit costs to the HRU estimates (€2022)., Results: 120 responders (n = 40 IDS, n = 40 HP, n = 40 nurses) estimated an average number of annual visits per patient by speciality (IDS, HP, and nurse, respectively) of 3.3 vs. 3.7; 4.4 vs. 6.2; 6.1 vs. 3.9, for CAB + RPV LA vs. daily oral ART, and 3.0 vs. 3.2; 4.8 vs. 5.8; 6.9 vs. 4.9, respectively when adjusting by corresponding specialist responses. Estimation by the total sample led to an annual total cost per patient of €2,076 vs. €2,473, being €2,032 vs. €2,237 after adjusting by corresponding HCP, for CAB + RPV LA vs. daily oral ART., Conclusions: These results suggest that the implementation of CAB + RPV LA in NHS hospitals would not incur in increased HRU-related costs compared to current daily oral ARTs, being potentially neutral or even cost-saving., (© 2024. The Author(s).)

A patient in Japan with HIV began antiretroviral therapy because of acute hepatitis B virus (HBV) 15 years ago, with low hepatitis B surface antibody, and experienced breakthrough HBV reactivation 4 months after switching from bictegravir/emtricitabine/tenofovir alafenamide to cabotegravir/rilpivirine. An immune escape mutation, E164V, was identified in the isolated HBV DNA.

Introduction: Cabotegravir plus rilpivirine (CAB + RPV) is the first complete long-acting (LA) regimen recommended for maintaining HIV-1 virological suppression. Cabotegravir And Rilpivirine Implementation Study in European Locations (CARISEL) is an implementation-effectiveness study examining the implementation of CAB+RPV LA administered every 2 months (Q2M) in European HIV centres. We present staff study participant (SSP) perspectives on the administration of CAB+RPV LA over 12 months., Methods: Eighteen clinics were randomized to one of two implementation support packages: standard arm (Arm-S) or enhanced arm (Arm-E). Arm-S included video injection training and provider/patient toolkits. Additionally, Arm-E included skilled wrap-around team meetings, face-to-face injection training and continuous quality improvement (CQI) calls. SSPs completed surveys on the acceptability, appropriateness and feasibility of CAB+RPV LA as an intervention and its implementation into their clinics, as well as barriers and facilitators to implementation. All surveys were completed at Month (M)1 (baseline), M5 and M12; data collection was completed by February 2022. Qualitative data were obtained from semi-structured interviews at M1, M5 and M12. The primary objective was assessed via formal statistical comparisons between study arms of the Acceptability of Implementation Measure, Implementation Appropriateness Measure and Feasibility of Implementation Measure surveys (1-5 Likert scale ranging from 1 = "completely disagree" to 5 = "completely agree"). Equivalent measures anchored to CAB+RPV LA as a therapy were also assessed., Results: Seventy SSPs completed surveys and interviews at M1, 68 at M5 and 62 at M12. Mean acceptability/appropriateness/feasibility scores were ≥3.8 (out of 5) at M12 for implementation- and intervention-based measures. An analysis of covariance showed no significant differences between study arms for these outcomes. Although barriers were noted, most SSPs were not overly concerned that these would impact implementation; concern about these anticipated barriers also decreased over time. At M12, 90.3% (n = 56/62) of SSPs held a positive opinion about CAB+RPV LA implementation. Qualitative interviews and CQI calls highlighted three top practices that supported implementation: implementation planning; education about CAB+RPV LA clinical efficacy; and education around administering injections and managing pain/discomfort after injections., Conclusions: CARISEL demonstrated that CAB+RPV LA dosed Q2M was successfully implemented across a range of European locations, with SSPs finding implementation highly acceptable, appropriate and feasible., Gov Number: NCT04399551., (© 2024 ViiV Healthcare and The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of International AIDS Society.)

Structural modification based on existing drugs, which ensures the safety of marketed drugs, is an essential approach in developing new drugs. In this study, we modified the structure of cabotegravir by introducing the front alkyne on the core structure through chemical reaction, resulting in the synthesis of 9 compounds resembling 1,2,3-triazoles. The potential of these new cabotegravir derivatives as tumor suppressors in gastrointestinal tumors was investigated. Based on the MTT experiment, most compounds showed a reduction in the viability of KYSE30 and HCT116 cells. Notably, derivatives 5b and 5h exhibited the most significant inhibitory effects. To further explore the effects of derivatives 5b and 5h on gastrointestinal tumors, KYSE30 cells were chosen as a representative cell line. Both derivatives can effectively curtail the migration and invasion capabilities of KYSE30 cells and induce apoptosis in a dose-dependent manner. We further demonstrated these derivatives induce cell apoptosis in KYSE30 cells by inhibiting the expression of Stat3 protein and Smad2/3 protein. Based on the above results, we suggest they show promise in developing drugs for esophageal squamous cell carcinoma., (© 2024 The Authors. ChemistryOpen published by Wiley-VCH GmbH.)