Search

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder characterized by the predisposition to develop tumors such as malignant peripheral nerve sheath tumors (MPNSTs) which represents the primary cause of death for NF1-affected patients. Regardless of the high incidence and mortality, the molecular mechanisms underneath MPNST growth and metastatic progression remain poorly understood. In this proof-of-concept study, we performed somatic whole-exome sequencing (WES) to profile the genomic alterations in four samples from a patient with NF1-associated MPNST, consisting of a benign plexiform neurofibroma, a primary MPNST, and metastases from lung and skin tissues. By comparing genomic patterns, we identified a high level of variability across samples with distinctive genetic changes which allow for the definition of profiles of the early phase with respect to the late metastatic stages. Pathogenic and likely pathogenic variants were abundant in the primary tumor, whereas the metastatic samples exhibited a high level of copy-number variations (CNVs), highlighting a possible genomic instability in the late phases. The most known MPNST-related genes, such as TP53 and SUZ12 , were identified in CNVs observed within the primary tumor. Pathway analysis of altered early genes in MPNST pointed to a potential role in cell motility, division and metabolism. Moreover, we employed survival analysis with the TCGA sarcoma genomic dataset on 262 affected patients, in order to corroborate the predictive significance of the identified early and metastatic MPNST driver genes. Specifically, the expression changes related to the mutated genes, such as in RBMX , PNPLA6 and AGAP2 , were associated with reduced patient survival, distinguishing them as potential prognostic biomarkers. This study underlines the relevance of integrating genomic results with clinical information for early diagnosis and prognostic understanding of tumor aggressiveness.

Molecular hybridization is a widely used strategy in drug discovery and development processes that consists of the combination of two bioactive compounds toward a novel entity. In the current study, two libraries of hybrid derivatives coming from the linkage of sesquiterpene counterparts dihydroartemisinin and artesunic acid, with a series of monoterpenes, were synthesized and evaluated by cell viability assay on primary and metastatic melanoma cell lines. Almost all the obtained compounds showed micromolar antimelanoma activity and selectivity toward the metastatic form of this cancer. Four hybrid derivatives containing perillyl alcohol, citronellol, and nerol as monoterpene counterpart emerged as the best compounds of the series, with nerol being active in combination with both sesquiterpenes, dihydroartemisinin and artesunic acid. Preliminary studies on the mechanism of action have shown the dependence of the pharmacological activity of newly synthesized hybrids on the formation of carbon- and oxygen-centered radical species. This study demonstrated the positive modulation of the pharmacodynamic effect of artemisinin semisynthetic derivatives dihydroartemisinin and artesunic acid due to the hybridization with monoterpene counterparts.

Leucine zipper-like transcription regulator 1 (LZTR1) acts as a negative factor that suppresses RAS function and MAPK signaling; mutations in this protein may dysregulate RAS ubiquitination and lead to impaired degradation of RAS superfamily proteins. Germline LZTR1 variants are reported in Noonan syndrome, either autosomal dominant or autosomal recessive, and in susceptibility to schwannomatosis. This article explores the genetic and phenotypic diversity of the autosomal dominant LZTR1 -related disorders, compiling a cohort of previously published patients (51 with the Noonan phenotype and 123 with schwannomatosis) and presenting two additional adult-onset cases: a male with schwannomatosis and Parkinson's disease and a female with Noonan syndrome, generalized joint hypermobility, and breast cancer. This review confirms that autosomal dominant LZTR1 -related disorders exhibit an extreme phenotypic variability, ranging from relatively mild manifestations to severe and multi-systemic involvement, and offers updated frequences of each clinical feature. The aim is to precisely define the clinical spectrum of LZTR1 -related diseases, using also two new emblematic clinical cases. Gaining insight into the mechanisms underneath this variability is crucial to achieve precision diagnostics and the development of therapeutic interventions.

The use of privileged scaffolds as a starting point for the construction of libraries of bioactive compounds is a widely used strategy in drug discovery and development. Scaffold decoration, morphing and hopping are additional techniques that enable the modification of the chosen privileged framework and better explore the chemical space around it. In this study, two series of highly functionalized pyrimidine and pyridine derivatives were synthesized using a scaffold morphing approach consisting of triazine compounds obtained previously as antiviral agents. Newly synthesized azines were evaluated against lymphoma, hepatocarcinoma, and colon epithelial carcinoma cells, showing in five cases acceptable to good anticancer activity associated with low cytotoxicity on healthy fibroblasts. Finally, ADME in vitro studies were conducted on the best derivatives of the two series showing good passive permeability and resistance to metabolic degradation.

Current therapy against melanoma relies on surgical treatment or, in alternative, on conventional drug therapy. Often these therapeutic agents are ineffective due to the development of resistance phenomena. For this purpose, chemical hybridization emerged as an effective strategy to overcome the development of drug resistance. In this study, a series of molecular hybrids were synthesized combining the sesquiterpene artesunic acid with a panel of phytochemical coumarins. Cytotoxicity, antimelanoma effect, and cancer selectivity of the novel compounds were evaluated by MTT assay on primary and metastatic cells and on healthy fibroblasts as a reference. The two most active compounds showed lower cytotoxicity and higher activity against metastatic melanoma than paclitaxel and artesunic acid. Further tests, including cellular proliferation, apoptosis, confocal microscopy, and MTT analyses in the presence of an iron chelating agent, were conducted with the aim of tentatively addressing the mode of action and the pharmacokinetic profile of selected compounds., Competing Interests: The authors declare no competing financial interest., (© 2023 American Chemical Society.)

Current therapy against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) are based on the use of Remdesivir 1 , Molnupiravir 2 , and the recently identified Nirmatrelvir 3 . Unfortunately, these three drugs showed some limitations regarding potency and possible drug-drug interactions. A series of derivatives coming from a decoration approach of the privileged scaffold s-triazines were synthesized and evaluated against SAR-CoV-2. One derivative emerged as the hit of the series for its micromolar antiviral activity and low cytotoxicity. Mode of action and pharmacokinetic in vitro preliminary studies further confirm the role as candidates for a future optimization campaign of the most active derivative identified with this work.

Background: Multicomponent reactions are one-pot processes for the synthesis of highly functionalized hetero-cyclic and hetero-acyclic compounds, often endowed with biological activity., Objective: Multicomponent reactions are considered green processes with a high atom economy. In addition, they present advantages compared to the classic synthetic methods, such as high efficiency and low waste production., Methods: In these reactions, two or more reagents are combined together in the same flask to yield a product containing almost all the atoms of the starting materials., Results: The scope of this review is to present an overview of the application of multicomponent reactions in the synthesis of compounds endowed with antiviral activity. The syntheses are classified depending on the viral target., Conclusion: Multicomponent reactions can be applied to all the stages of the drug discovery and development process, making them very useful in the search for new agents active against emerging (viral) pathogens., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Dendrimers are highly branched structures with a defined shape, dimension, and molecular weight. They consist of three major components: the central core, branches, and terminal groups. In recent years, dendrimers have received great attention in medicinal chemistry, diagnostic field, science of materials, electrochemistry, and catalysis. In addition, they are largely applied for the functionalization of biocompatible semiconductors, in gene transfection processes, as well as in the preparation of nano-devices, including heterogeneous catalysts. Here, we describe recent advances in the design and application of dendrimers in catalytic organic and inorganic processes, sustainable and low environmental impact, photosensitive materials, nano-delivery systems, and antiviral agents' dendrimers.

A library of five hybrids and six dimers of dihydroartemisinin and artesunic acid has been synthetized in a stereo-controlled manner and evaluated for the anticancer activity against metastatic melanoma cell line (RPMI7951). Among novel derivatives, three artesunic acid dimers showed antimelanoma activity and cancer selectivity, being not toxic on normal human fibroblast (C3PV) cell line. Among the three dimers, the one bearing 4-hydroxybenzyl alcohol as a spacer showed no cytotoxic effect (CC 50 >300 μM) and high antimelanoma activity (IC 50 =0.05 μM), which was two orders of magnitude higher than that of parent artesunic acid, and of the same order of commercial drug paclitaxel. In addition, this dimer showed cancer-type selectivity towards melanoma compared to prostate (PC3) and breast (MDA-MB-231) tumors. The occurrence of a radical mechanism was hypothesized by DFO and EPR analyses. Qualitative structure activity relationships highlighted the role of artesunic acid scaffold in the control of toxicity and antimelanoma activity., (© 2021 The Authors. ChemMedChem published by Wiley-VCH GmbH.)

Artesunic acid and artemisinin are natural substances with promiscuous anticancer activity against different types of cancer cell lines. The mechanism of action of these compounds is associated with the formation of reactive radical species by cleavage of the sesquiterpene pharmacophore endoperoxide bridge. Here we suggested topoisomerase 1 as a possible molecular target for the improvement of the anticancer activity of these compounds. In this context, we report that novel hybrid and dimer derivatives of artesunic acid and artemisinin, bearing camptothecin and SN38 as side-chain biological effectors, can inhibit growth of yeast cells overexpressing human topoisomerase 1 and its enzymatic activity in vitro . These derivatives showed also anticancer activity in melanoma cell lines higher than camptothecin and paclitaxel. In silico molecular docking calculations highlighted a common binding mode for the novel derivatives, with the sesquiterpene lactone scaffold being located near the traditional recognition site for camptothecin, while the bioactive side-chain effector laid in the camptothecin cleft., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

A group III metabotropic glutamate (mGlu) receptor agonist (PCEP) was identified by virtual HTS. This orthosteric ligand is composed by an l-AP4-derived fragment that mimics glutamate and a chain that binds into a neighboring pocket, offering possibilities to improve affinity and selectivity. Herein we describe a series of derivatives where the distal chain is replaced by an aromatic or heteroaromatic group. Potent agonists were identified, including some with a mGlu 4 subtype preference, e.g., 17m (LSP1-2111) and 16g (LSP4-2022). Molecular modeling suggests that aromatic functional groups may bind at either one of the two chloride regulatory sites. These agonists may thus be considered as particular bitopic/dualsteric ligands. 17m was shown to reduce GABAergic synaptic transmission at striatopallidal synapses. We now demonstrate its inhibitory effect at glutamatergic parallel fiber-Purkinje cell synapses in the cerebellar cortex. Although these ligands have physicochemical properties that are markedly different from typical CNS drugs, they hold significant therapeutic potential.

Previously isolated and characterized Pseudomonas lipases were immobilized in a low-cost MP-1000 support by a re-loading procedure that allowed a high activity per weight of support. Immobilized LipA, LipC, and LipCmut lipases, and commercial Novozym® 435 were tested for fatty acid methyl ester (FAMEs) synthesis using conventional and alternative feedstocks. Triolein and degummed soybean oils were used as model substrates, whereas waste cooking oil and M. circinelloides oil were assayed as alternative, low cost feedstocks, whose free fatty acid (FFA), and acylglyceride profile was characterized. The reaction conditions for FAMEs synthesis were initially established using degummed soybean oil, setting up the best water and methanol concentrations for optimum conversion. These conditions were further applied to the alternative feedstocks and the four lipases. The results revealed that Pseudomonas lipases were unable to use the FFAs, displaying a moderate FAMEs synthesis, whereas a 44% FAMEs production was obtained when M. circinelloides oil was used as a substrate in the reaction catalysed by Novozym® 435, used under the conditions established for degummed soybean oil. However, when Novozym® 435 was tested under previously described optimal conditions for this lipase, promising values of 85 and 76% FAMEs synthesis were obtained for waste cooking oil and M. circinelloides oil, respectively, which might result in promising, nonfood, alternative feedstocks for enzymatic biodiesel production. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1209-1217, 2017., (© 2017 American Institute of Chemical Engineers.)

Several Pseudomonas sp. CR611 Lip I.3 mutants with overall increased activity and a shift towards longer chain substrates were constructed. Substitution of residues Y29 and W310 by smaller amino acids provided increased activity on C18-substrates. Residues G152 and S154, modified to study their influence on interfacial activation, displayed a five and eleven fold increased activity.

Background: There is an increasing interest to seek new enzyme preparations for the development of new products derived from bioprocesses to obtain alternative bio-based materials. In this context, four non-commercial lipases from Pseudomonas species were prepared, immobilized on different low-cost supports, and examined for potential biotechnological applications., Results: To reduce costs of eventual scaling-up, the new lipases were obtained directly from crude cell extracts or from growth culture supernatants, and immobilized by simple adsorption on Accurel EP100, Accurel MP1000 and Celite®545. The enzymes evaluated were LipA and LipC from Pseudomonas sp. 42A2, a thermostable mutant of LipC, and LipI.3 from Pseudomonas CR611, which were produced in either homologous or heterologous hosts. Best immobilization results were obtained on Accurel EP100 for LipA and on Accurel MP1000 for LipC and its thermostable variant. Lip I.3, requiring a refolding step, was poorly immobilized on all supports tested (best results for Accurel MP1000). To test the behavior of immobilized lipases, they were assayed in triolein transesterification, where the best results were observed for lipases immobilized on Accurel MP1000., Conclusions: The suggested protocol does not require protein purification and uses crude enzymes immobilized by a fast adsorption technique on low-cost supports, which makes the method suitable for an eventual scaling up aimed at biotechnological applications. Therefore, a fast, simple and economic method for lipase preparation and immobilization has been set up. The low price of the supports tested and the simplicity of the procedure, skipping the tedious and expensive purification steps, will contribute to cost reduction in biotechnological lipase-catalyzed processes.

Background: Enzymatic biodiesel is becoming an increasingly popular topic in bioenergy literature because of its potential to overcome the problems posed by chemical processes. However, the high cost of the enzymatic process still remains the main drawback for its industrial application, mostly because of the high price of refined oils. Unfortunately, low cost substrates, such as crude soybean oil, often release a product that hardly accomplishes the final required biodiesel specifications and need an additional pretreatment for gums removal. In order to reduce costs and to make the enzymatic process more efficient, we developed an innovative system for enzymatic biodiesel production involving a combination of a lipase and two phospholipases. This allows performing the enzymatic degumming and transesterification in a single step, using crude soybean oil as feedstock, and converting part of the phospholipids into biodiesel. Since the two processes have never been studied together, an accurate analysis of the different reaction components and conditions was carried out., Results: Crude soybean oil, used as low cost feedstock, is characterized by a high content of phospholipids (900 ppm of phosphorus). However, after the combined activity of different phospholipases and liquid lipase Callera Trans L, a complete transformation into fatty acid methyl esters (FAMEs >95%) and a good reduction of phosphorus (P <5 ppm) was achieved. The combination of enzymes allowed avoidance of the acid treatment required for gums removal, the consequent caustic neutralization, and the high temperature commonly used in degumming systems, making the overall process more eco-friendly and with higher yield. Once the conditions were established, the process was also tested with different vegetable oils with variable phosphorus contents., Conclusions: Use of liquid lipase Callera Trans L in biodiesel production can provide numerous and sustainable benefits. Besides reducing the costs derived from enzyme immobilization, the lipase can be used in combination with other enzymes such as phospholipases for gums removal, thus allowing the use of much cheaper, non-refined oils. The possibility to perform degumming and transesterification in a single tank involves a great efficiency increase in the new era of enzymatic biodiesel production at industrial scale.

Background: A close association between maize roots and Burkholderia cepacia complex (BCC) bacteria has been observed in different locations globally. In this study we investigated by MultiLocus Restriction Typing (MLRT) the genetic diversity and relationships among Burkholderia cenocepacia IIIB and BCC6 populations associated with roots of maize plants cultivated in geographically distant countries (Italy and Mexico), in order to provide new insights into their population structure, evolution and ecology., Results: The 31 B. cenocepacia IIIB and 65 BCC6 isolates gave rise to 29 and 39 different restriction types (RTs), respectively. Two pairs of isolates of B. cenocepacia IIIB and BCC6, recovered from both Italian and Mexican maize rhizospheres, were found to share the same RT. The eBURST (Based Upon Related Sequence Types) analysis of MLRT data grouped all the B. cenocepacia IIIB isolates into four clonal complexes, with the RT-4-complex including the 42% of them, while the majority of the BCC6 isolates (94%) were grouped into the RT-104-complex. These two main clonal complexes included RTs shared by both Italian and Mexican maize rhizospheres and a clear relationship between grouping and maize variety was also found. Grouping established by eBURST correlated well with the assessment using unweighted-pair group method with arithmetic mean (UPGMA). The standardized index of association values obtained in both B. cenocepacia IIIB and BCC6 suggests an epidemic population structure in which occasional clones emerge and spread., Conclusions: Taken together our data demonstrate a wide dispersal of certain B. cenocepacia IIIB and BCC6 isolates in Mexican and Italian maize rhizospheres. Despite the clear relationship found between the geographic origin of isolates and grouping, identical RTs and closely related isolates were observed in geographically distant regions. Ecological factors and selective pressure may preferably promote some genotypes within each local microbial population, favouring the spread of a single clone above the rest of the recombinant population.

Novel classes of cannabinoid 2 receptor (CB2) agonists based on 1,2,3,4-tetrahydropyrrolo[3,4-b]indole and benzimidazole scaffolds have shown high binding affinity toward CB2 receptor and good selectivity over cannabinoid 1 receptor (CB1). A computational study of comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) was performed, initially on each series of agonists, and subsequently on all compounds together, in order to identify the key structural features impacting their binding affinity. The final CoMSIA model resulted to be the more predictive, showing cross-validated r2 (r(cv)2) = 0.680, non cross-validated r2 (r(ncv)2) = 0.97 and test set r²(r²(pred) = 0.93. The study provides useful suggestions for the design of new analogues with improved affinity.

(R)-PCEP (3-amino-3-carboxypropyl-2'-carboxyethyl phosphinic acid, 1), a new metabotropic glutamate receptor 4 (mGlu4R) agonist, was discovered in a previously reported virtual screening. The (S)-enantiomer and a series of derivatives were synthesized and tested on recombinant mGlu4 receptors. A large number of derivatives activated this receptor but was not able to discriminate between mGlu4 and mGlu8 receptors. The most potent ones 6 and 12 displayed an EC(50) of 1.0 +/- 0.2 microM at mGlu4R. Interestingly these agonists with longer alkyl chains revealed a new binding pocket adjacent to the glutamate binding site, which is lined with residues that differ among the mGluR subtypes and that will allow the design of more selective compounds. Additionally 6 was able to activate mGlu7 receptor with an EC(50) of 43 +/- 16 microM and is thus significantly more potent than L-AP4 (EC(50) of 249 +/- 106 microM).

Novel classes of CB2 agonists based on 4-oxo-1,4-dihydroquinoline and 4-oxo-1,4-dihydro-1,5-, -1,6- and -1,8-naphthyridine scaffolds have shown high binding affinity toward CB2 receptor and good selectivity over CB1. A computational study of comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) was performed, in order to identify the key structural features impacting their binding affinity. The final CoMSIA model resulted to be the more predictive, showing r(2)ncv=0.84, r(2)cv=0.619, SEE = 0.369, and r(2)pred=0.75. The study provides useful suggestions for the synthesis of new selective analogues with improved affinity.

Aim: To identify, by means of recA sequencing and multilocus sequence typing (MLST), Burkholderia cepacia complex (BCC) isolates of environmental and clinical origin, which failed to be identified by recA RFLP and species-specific PCR., Methods and Results: By using recA sequence-based identification, 17 out of 26 BCC isolates were resolved at the level of species and lineage (ten Burkholderia cenocepacia IIIB, two Burkholderia arboris and five Burkholderia lata). By using MLST method, 24 BCC isolates were identified. MLST confirmed recA sequence results, and, furthermore, enabled to identify isolates of the BCC5 group, and showed relatedness with Burkholderia contaminans for one of the two isolates not identified., Conclusions: recA sequence-based identification allowed to resolve, at the level of species and lineage, 65.4%, of the BCC isolates examined, whilst MLST increased this percentage to 88.5%., Significance and Impact of the Study: BCC isolates previously not resolved by recA RFLP and species-specific PCR were successfully identified by means of recA sequencing and MLST, which represent the most appropriate methods to identify difficult strains for epidemiological purposes and cystic fibrosis patients management.

Acylthiocarbamates (ATCs) have been identified as a class of potent non-nucleoside HIV-1 reverse transcriptase (RT) inhibitors. A computational strategy based on molecular docking studies followed by comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) was used to identify the most important features impacting ATC antiretroviral activity. The CoMSIA model proved to be the more predictive, with r(2)(ncv) = 0.89, r(cv)(2) = 0.38, standard error of estimate (SEE) = 0.494, F = 84, and r(2)(pred) = 0.81. The results of these studies will be useful in designing new ATCs with improved potency, also against clinically relevant resistant mutants.

In order to further explore the antiproliferative properties of O-phenoxyethyl and O-adamantyl acylthiocarbamates (ATCs), a series of 14 derivatives was prepared by a parallel adaptation of a highly convergent one-pot three-step procedure. Ten acylthiocarbamates were selected by the National Cancer Institute drug evaluation program and screened against a panel of 55 to 58 cell lines derived from nine different types of human cancers. In general, the tested compounds showed a widespread micromolar activity with some specificity against leukemia, renal UO-31, central nervous system (CNS) SNB-75, and non-small cell lung HOP-92 cancer cell lines. Bioinformatic COMPARE analyses were carried out to identify possible mechanism(s) of action for acylthiocarbamate antiproliferative activity.

A series of 6-amino-4-oxo-1,3-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonyl derivatives was synthesized. The compounds demonstrated to be novel, potent and selective inhibitors of Interleukin-8-induced human neutrophil chemotaxis. A SAR study was performed by varying the carbonyl function at position 5 and the chain linked to the amino group at position 6 of the scaffold. All the compounds of the series displayed inhibitory activity at nano- or picomolar concentrations against Interleukin-8-driven migration and no activity against fMLP- and C5a-induced chemotaxis. The binding tests of selected compounds on CXCR1 and CXCR2 receptors were negative. The most potent derivative showed in vivo efficacy in a mouse model of Zymosan-induced peritonitis.

Thiocarbamates (TCs) have been recently identified as a new class of potent non-nucleoside HIV-1 Reverse Transcriptase (RT) inhibitors. A computational strategy based on molecular docking studies, followed by CoMFA and CoMSIA analyses, has been used to elucidate the atomic details of the RT/TC interactions and to identify the most important features impacting the TC antiretroviral activity. The CoMFA model resulted to be the more predictive, and gave r(2)=0.93, r(cv)(2)=0.53, SEE=0.292, F=180, and r(test)(2)=0.70. The 3D-QSAR field contributions and the structural features of the RT binding site showed a good correlation. These studies will be useful to design new TCs with improved potency also against clinically relevant resistant mutants.

The structure-activity relationships (SARs) of acylthiocarbamates (ATCs), a new class of non-nucleoside HIV-1 reverse transcriptase inhibitors, have been expanded. Sixty-six new analogues were prepared by parallel solution-phase synthesis. In general, the potency of new ATCs was better than that of the first series and O-[2-phthalimidoethyl] 4-chlorophenyl(3-nitrobenzoyl) thiocarbamate turned out to be the most potent ATC so far synthesized (EC(50)=1.5nM). Several ATCs were active at micromolar concentrations against HIV-1 strains carrying the RT Y181C mutation and one of them was also moderately active against the K103R variant. Docking simulations were carried out to rationalize the most relevant SARs.

The structure-activity relationships (SARs) of N-aryl-O-(2-phthalimidoethyl)thiocarbamates (C-TCs) and their imide ring-opened congeners (O-TCs) as non-nucleoside HIV-1 reverse transcriptase inhibitors were further investigated. The SAR strategy involved modifications of the N-phenyl ring followed by the hybridization of the most promising N-aryl and O-(2-phthalimidoethyl) substructures. The role of stereochemistry and tert-butyl substitution of the phthalimidoethyl moiety on activity was also investigated. Seventy-six analogues were prepared by parallel solution-phase synthesis. Twenty-two C-TCs displayed nanomolar activity against wild-type HIV-1 and a number of analogues were effective against the Y181C mutant. Compound 56 combined the highest activity so far identified against Y181C (EC(50)=1.3 microM) with good potency against the K103R mutant (EC(50)=4.8 microM). Docking simulations helped to rationalize the SARs.

Symmetric formimidoester disulfides (DSs) have recently been identified as a new class of potent non-nucleoside HIV-1 reverse transcriptase (RT) inhibitors. Given that three geometric isomers for DSs are possible, a computational strategy based on molecular docking studies, followed by comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) was used in order to identify the most probable DS isomer interacting with RT, to elucidate the atomic details of the RT/DS interaction, and to identify key features impacting DS antiretroviral activity. The CoMFA model was found to be the more predictive, with values of r(2)ncv, r(2)cv, SEE = 0.264, F = 80, and r(2)pred=0.73.

Fifty-one acylthioureas (ATUs) incorporating imidazolidine-2-thione or its upper cyclohomologue were prepared by parallel synthesis and evaluated against a high number of human cancer cell lines for antiproliferative activity. ATUs 1o (3,5-dichlorobenzoyl), 1s (2-furoyl), 3s (2-furoyl) and 1t (2-thenoyl) displayed activity against leukemia, melanoma LOX IMVI, non-small cell lung NCI-H522, renal 786-0, CAKI-1, SN12C, UO-31 and breast MCF7, MDA-MB-435, T-47D cancer cell lines in the 0.3-9.7 microM concentration range. Compound 14s exhibited selectivity for melanoma SK-MEL-5 (GI(50)<5 nM); 1s for leukemia MOLT-4 (GI(50): 300 nM); 1q, 3b and 3q for renal cancer UO-31 (GI(50): 70-200 nM); 8s, 9s for non-small cell lung cancer EKVX (GI(50): 300, 10 nM) and 3j for HOP-92 (GI(50): 700 nM) cell line.

The molecular duplication of non-nucleoside reverse transcriptase inhibitor (NNRTI) O-(2-phthalimidoethyl)-N-arylthiocarbamates (C-TCs) led to the identification of symmetric formimidoester disulfides (DSs) as a novel class of potent NNRTIs. The lead compound 1 [dimer of the isothiocarbamic form of TC O-(2-phthalimidoethyl)-N-phenylthiocarbamate] turned out to prevent the wild-type HIV-1 multiplication in MT-4 cell culture with an EC(50) value of 0.35 microM. In order to perform a structure-activity relationship (SAR) study, we prepared 40 analogues of 1 by an unprecedented one-pot method of solution-phase parallel synthesis. The SAR strategy was focused on the variation of the N-aryl portion (mono-, di- and trisubstitution of the phenyl ring and its replacement with a 1-naphthyl, cyclopropyl or benzyl group) and of the 2-phthalimidoethyl moiety (introduction of a methyl on the phthalimide substructure, replacement of the phthalimide moiety with a phenyl ring and elongation of the ethyl linker). Most DSs proved to inhibit the wild-type HIV-1 replication in cell-based assays and 15 of them were active at nanomolar concentrations. The most potent congeners (11, 15, 16, 17, 18, 19, 20 and 32, EC(50): 10-70 nM) shared the N-para-substituted phenyl moiety. Compound 17 tested in enzyme assay against recombinant wild-type reverse transcriptase displayed an IC(50) value of 0.74 microM. Compounds 19 and 33 were active at micromolar concentrations against the clinically relevant Y181C and/or K103R resistant mutants.

To acquire further insight into the structure-activity relationship (SAR) of the thiocarbamates (TCs) described in the preceding work, 57 analogues of the lead compound O-(2-phenylethyl)-N-phenylthiocarbamate I were prepared by parallel solution-phase synthesis. We varied the 2-phenylethyl moiety (mono-substitution on the phenyl ring and modification of the ethyl linker), keeping constant the N-phenyl ring substitutions which have given the best results in the previous series. Most of the new TCs inhibited wild-type HIV-1 at micro- and nanomolar concentrations in MT-4 cell-based assays. Some TCs were also active at micromolar concentrations against the Y181C and/or K103N/Y181C resistant mutants. The SARs were rationalized by docking simulations.

In order to expand the structure-activity relationship (SAR) studies on Thiocarbamates (TCs), a recently discovered class of potent non-nucleoside HIV-1 reverse transcriptase inhibitors, 38 analogues of the lead O-[2-(2-pyridyl)ethyl]-N-phenylthiocarbamate 1 were prepared by parallel solution-phase synthesis. The SAR strategy was focused on the variation (mono- and disubstitution) of the N-phenyl ring and the replacement of the 2-pyridyl with 4-pyridyl, 2-thienyl and phenyl rings. The majority of the new TCs proved to prevent the wild-type HIV-1 multiplication in MT-4 cell culture and the most potent congeners displayed an EC(50) value of 100 nM. Two TCs were active also at micromolar concentrations against the Y181C- and/or K103N/Y181C-resistant mutants. Docking simulations helped to rationalize the SARs.

O-Phthalimidoethyl-N-arylthiocarbamates (TCs) have been recently identified as a new class of potent HIV-1 reverse transcriptase (RT) non-nucleoside inhibitors (NNRTIs), by means of computer-aided drug design techniques [Ranise A. Spallarossa, S. Cesarini, F. Bondavalli, S. Schenone, O. Bruno, G. Menozzi, P. Fossa, L. Mosti, M. La Colla, et al., Structure-based design, parallel synthesis, structure-activity relationship, and molecular modeling studies of thiocarbamates, new potent non-nucleoside HIV-1 reverse transcriptase inhibitor isosteres of phenethylthiazolylthiourea derivatives, J. Med. Chem. 48 (2005) 3858-3873]. To elucidate the atomic details of RT/TC interaction and validate an earlier TC docking model, the structures of three RT/TC complexes were determined at 2.8-3.0A resolution by X-ray crystallography. The conformations adopted by the enzyme-bound TCs were analyzed and compared with those of bioisosterically related NNRTIs.

Environment-friendly farming techniques seek to increase invertebrate biodiversity in part with the intention of encouraging greater numbers of predators that will help to control crop pests. However, in theory, this effect may be negated if the availability of a greater abundance and diversity of alternative prey diverts predators away from feeding on pests. The hypothesis that access to alternative prey can lead to reduced pest suppression under semi-field conditions was tested. Alternative prey type and diversity were manipulated in 70 mesocosms over 7+ weeks in the presence of the carabid Pterostichus melanarius (Illiger), a known predator of slugs, and reproducing populations of the slug Deroceras reticulatum (Müller). Significantly fewer slugs survived where no alternative prey were provided. Maximum slug numbers and biomass were found in treatments containing either carabids plus a high diversity of alternative prey (many species of earthworm and three of Diptera larvae) or a single additional prey (blowfly larvae, Calliphora vomitoria Linnaeus). In these treatments slug numbers and biomass were as high as in plots lacking predators. The effects of alternative prey were taxon-specific. Alternative prey strongly affected carabid fitness in terms of biomass and egg load. The fittest predators (those with access to high alternative prey diversity or C. vomitoria larvae) reduced slug numbers the least. The mean individual slug weights were greater in treatments with alternative prey than where no alternative prey were provided to the carabids. These results suggest that pests may survive and reproduce more rapidly in patches where predators have access to alternative prey.

In the crystal structure of the novel acylthiocarbamate derivative O-[2-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)ethyl] N-(4-methylphenyl)-N-(3-nitrobenzoyl)thiocarbamate, C25H19N3O6S, intra- and intermolecular pi-pi interactions occur between the phthalimide and N-benzoyl moieties. The partial atomic charges, calculated by ab initio methods, are consistent with the observed structure.

In this paper we describe our structure-based ligand design, synthetic strategy, and structure-activity relationship (SAR) studies that led to the identification of thiocarbamates (TCs), a novel class of non-nucleoside reverse transcriptase inhibitors (NNRTIs), isosteres of phenethylthiazolylthiourea (PETT) derivatives. Assuming as a lead compound O-[2-(phthalimido)ethyl]phenylthiocarbamate 12, one of the precursors of the previously described acylthiocarbamates (Ranise, A.; et al. J. Med. Chem. 2003, 46, 768-781), two targeted solution-phase TC libraries were prepared by parallel synthesis. The lead optimization strategy led to para-substituted TCs 31, 33, 34, 39, 40, 41, 44, 45, and 50, which were active against wild-type HIV-1 in MT-4-based assays at nanomolar concentrations (EC50 range: 0.04-0.01 microM). The most potent congener 50 (EC50 = 0.01 microM) bears a methyl group at position 4 of the phthalimide moiety and a nitro group at the para position of the N-phenyl ring. Most of the TCs showed good selectivity indices, since no cytotoxic effect was detected at concentrations as high as 100 microM. TCs 31, 37, 39, 40, and 44 significantly reduced the multiplication of the Y181C mutant, but they were inactive against K103R and K103N + Y181C mutants. Nevertheless, the fold increase in resistance of 41 was not greater than that of efavirenz against the K103R mutant in enzyme assays. The docking model predictions were consistent with in vitro biological assays of the anti-HIV-1 activity of the TCs and related compounds synthesized.