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Proteolysis-targeting chimera (PROTAC) is emerging as a promising technology in targeted protein degradation and drug discovery. However, there is still a lack of effective chemical tools to real-time detect and track the protein degradation. Herein, the first fluorescent and theranostic PROTACs were designed for imaging the degradation of nicotinamide phosphoribosyltransferase (NAMPT) in living cells. Compound

Proteolysis targeting chimaeras (PROTACs) is a cutting edge and rapidly growing technique for new drug discovery and development. Currently, the largest challenge in the molecular design and drug development of PROTACs is efficient identification of potent and drug-like degraders. This review aims to comprehensively summarize and analyse state-of-the-art methods and strategies in the design of PROTACs. We provide a detailed illustration of the general principles and tactics for designing potent PROTACs, highlight representative case studies, and discuss the advantages and limitations of these strategies. Particularly, structure-based rational PROTAC design and emerging new types of PROTACs (e.g., homo-PROTACs, multitargeting PROTACs, photo-control PROTACs and PROTAC-based conjugates) will be focused on.

Background Bone is the most common site of metastasis of prostate cancer (PCa). PCa invasion leads to a disruption of osteogenic-osteolytic balance and causes abnormal bone formation. The interaction between PCa and bone stromal cells, especially osteoblasts (OB), is considered essential for the disease progression. However, drugs that effectively block the cancer-bone interaction and regulate the osteogenic-osteolytic balance remain undiscovered. Methods A reporter gene system was constructed to screen compounds that could inhibit PCa-induced OB activation from 631 compounds. Then, the pharmacological effects of a candidate drug, Procoxacin (Pro), on OBs, osteoclasts (OCs) and cancer-bone interaction were studied in cellular models. Intratibial inoculation, micro-CT and histological analysis were used to explore the effect of Pro on osteogenic and osteolytic metastatic lesions. Bioinformatic analysis and experiments including qPCR, western blotting and ELISA assay were used to identify the effector molecules of Pro in the cancer-bone microenvironment. Virtual screening, molecular docking, surface plasmon resonance assay and RNA knockdown were utilized to identify the drug target of Pro. Experiments including co-IP, western blotting and immunofluorescence were performed to reveal the role of Pro binding to its target. Intracardiac inoculation metastasis model and survival analysis were used to investigate the therapeutic effect of Pro on metastatic cancer. Results Luciferase reporter gene consisted of Runx2 binding sequence, OSE2, and Alp promotor could sensitively reflect the intensity of PCa-OB interaction. Pro best matched the screening criteria among 631 compounds in drug screening. Further study demonstrated that Pro effectively inhibited the PCa-induced osteoblastic changes without killing OBs or PCa cells and directly killed OCs or suppressed osteoclastic functions at very low concentrations. Mechanism study revealed that Pro broke the feedback loop of TGF-β/C-Raf/MAPK pathway by sandwiching into 14–3-3ζ/C-Raf complex and prevented its disassociation. Pro treatment alleviated both osteogenic and osteolytic lesions in PCa-involved bones and reduced the number of metastases of PCa in vivo. Conclusions In summary, our study provides a drug screening strategy based on the cancer-host microenvironment and demonstrates that Pro effectively inhibits both osteoblastic and osteoclastic lesions in PCa-involved bones, which makes it a promising therapeutic agent for PCa bone metastasis. Graphical Abstract

Nicotinamide phosphoribosyltransferase (NAMPT) is identified as a promising target for cancer therapy. However, known NAMPT inhibitors are characterized by weak clinical efficacy and dose-dependent toxicity. There is an urgent need to develop new NAMPT intervention strategies. Using the proteolysis-targeting chimera (PROTAC) technology, we designed and synthesized a series of new von Hippel-Lindau (VHL)-recruiting NAMPT-targeting PROTACs. A highly potent NAMPT degrader (

The non-enzymatic functions of target proteins play key roles in the regulation of various cell signaling pathways and are closely related to numerous human diseases. However, traditional small-molecule inhibitors generally target the catalytic functional domain directly and work by inhibiting the enzymatic function of the target proteins without affecting the non-enzymatic function. The recently emerging proteolysis targeting chimera (PROTAC) technology has the advantage of simultaneously regulating the enzymatic and non-enzymatic functions of target proteins, thus providing a potential strategy to make up for the deficiency of inhibitors and explore the new therapeutic profile by the target degradation. This perspective aims to specifically summarize and analyze recent progress in blocking non-enzymatic functions of target proteins by PROTAC-mediated degradation, highlighting representative case studies and discussing the pharmacological features originating from inhibition of the non-enzymatic functions.

Development of proteolysis targeting chimeras (PROTACs) is emerging as a promising strategy for targeted protein degradation. However, the drug development using the heterobifunctional PROTAC molecules is generally limited by poor membrane permeability, low in vivo efficacy and indiscriminate distribution. Herein an aptamer-PROTAC conjugation approach was developed as a novel strategy to improve the tumor-specific targeting ability and in vivo antitumor potency of conventional PROTACs. As proof of concept, the first aptamer-PROTAC conjugate (APC) was designed by conjugating a BET-targeting PROTAC to the nucleic acid aptamer AS1411 (AS) via a cleavable linker. Compared with the unmodified BET PROTAC, the designed molecule (APR) showed improved tumor targeting ability in a MCF-7 xenograft model, leading to enhanced in vivo BET degradation and antitumor potency and decreased toxicity. Thus, the APC strategy may pave the way for the design of tumor-specific targeting PROTACs and have broad applications in the development of PROTAC-based drugs.

Targeted protein degradation is a promising area in the discovery and development of innovative therapeutics. Molecular glues mediate proximity-induced protein degradation and have intrinsic advantages over heterobifunctional proteolysis-targeting chimeras, including unprecedented mechanisms, distinct biological activities, and favorable physicochemical properties. Classical molecular glue degraders have been identified serendipitously, but rational discovery and design strategies are emerging rapidly. In this review, we aim to highlight the recent advances in molecular glues for targeted protein degradation and discuss the challenges in developing molecular glues into therapeutic agents. In particular, discovery strategies, action mechanisms, and representative case studies will be addressed.

The objective of this study is to synthesize a series of sesamol-based phenolic acid derivatives, which were designed by combination principle. The hypolipidemic activity of all these compounds was preliminarily screened by acute hyperlipidemic mice model induced by Triton WR 1339, in which compound T6 exhibited more significant reducing plasma TG and TC than fenofibrate. Compound T6 was also found to obviously decrease TG and TC both in the plasma and hepatic tissue of high-fat-diet-induced hyperlipidemic mice. Moreover, T6 showed hepatoprotective effects, which remarkable amelioration in characteristic liver enzymes was examined and the histopathological observation displayed that compound T6 inhibited lipids accumulation in the hepatic. The levels of PPAR-α receptor related to lipids metabolism in hepatic tissue were upregulated after T6 treatment. Other potent effects of T6 such as antioxidant and anti-inflammatory activity were also observed. On the bases of these findings, compound T6 may serve as an effective hypolipidemic and hepatoprotective agent.

Liver cancer stem cells (LCSCs) are regarded as the frequent cause of hepatocellular carcinoma (HCC) relapse and therapeutic resistance. The epithelial cell adhesion molecule (EpCAM) is one of the key biomarkers for LCSCs. EpCAMEpCAMMASM significantly inhibited proliferation without inducing apoptosis, down-regulated the expression of stemness-related genes, decreased the percentage of EpCAMMASM treatment is effective against EpCAM

Targeted protein degradation (TPD), represented by proteolysis-targeting chimera (PROTAC), has emerged as a novel therapeutic modality in drug discovery. However, the application of conventional PROTACs is limited to protein targets containing cytosolic domains with ligandable sites. Recently, nucleic-acid-based modalities, such as modified oligonucleotide mimics and aptamers, opened new avenues to degrade protein targets and greatly expanded the scope of TPD. Beyond constructing protein-degrading chimeras, nucleic acid motifs can also serve as substrates for targeted degradation. Particularly, the new type of chimeric RNA degrader termed ribonuclease-targeting chimera (RIBOTAC) has shown promising features in drug discovery. Here, we provide an overview of the newly emerging TPD strategies based on nucleic acids as well as new strategies for targeted degradation of nucleic acid (RNA) targets. The design strategies, case studies, potential applications, and challenges are focused on.

A visible-light-driven cascade radical cyclization process of N-methacryloyl-2-phenylbenzimidazole has been established with α-carbonyl alkyl bromide. This protocol provides an efficient and practical method for the synthesis of various α-carbonyl alkyl-substituted benzimidazo[2,1-α]isoquinolin-6(5H)-ones in outstanding yields, mild reaction conditions and excellent functional group tolerance.

The dose-related adverse effects of MDM2‒P53 inhibitors have caused significant concern in the development of clinical safe anticancer agents. Herein we report an unprecedented homo-PROTAC strategy for more effective disruption of MDM2‒P53 interaction. The design concept is inspired by the capacity of sub-stoichiometric catalytic PROTACs enabling to degrade an unwanted protein and the dual functions of MDM2 as an E3 ubiquitin ligase and a binding protein with tumor suppressor P53. The new homo-PROTACs are designed to induce self-degradation of MDM2. The results of the investigation have shown that PROTAC 11a efficiently dimerizes MDM2 with highly competitive binding activity and induces proteasome-dependent self-degradation of MDM2 in A549 non-small cell lung cancer cells. Furthermore, markedly, enantiomer 11a-1 exhibits potent in vivo antitumor activity in A549 xenograft nude mouse model, which is the first example of homo-PROTAC with in vivo therapeutic potency. This study demonstrates the potential of the homo-PROTAC as an alternative chemical tool for tumorigenic MDM2 knockdown, which could be developed into a safe therapy for cancer treatment., Graphical abstract “Suicide” cleavage of MDM2: a homo-PROTAC strategy possessing effective in vitro and in vivo antitumor activities is demonstrated for the first time. The approach may offer an opportunity to overcome the bottleneck of the dose-related adverse effects of MDM2‒P53 inhibitors in the development of clinical anticancer agents.Image 1

As one of the most aggressive and lethal human malignancies with extremely poor prognosis, there is an urgent demand of more effective therapy for the treatment of pancreatic cancer. Reported here is a new, effective therapeutic strategy and the design of small-molecule inhibitors that simultaneously target bromodomain and extra-terminal (BET) and histone deacetylase (HDAC), potentially serving as promising therapeutic agents for pancreatic cancer. A highly potent dual inhibitor (13 a) is identified to possess excellent and balanced activities against BRD4 BD1 (IC50 =11 nm) and HDAC1 (IC50 =21 nm). Notably, this compound shows higher in vitro and in vivo antitumor potency than the BET inhibitor (+)-JQ1 and the HDAC inhibitor vorinostat, either alone or and in combination, highlighting the advantages of BET/HDAC dual inhibitors for more effective treatment of pancreatic cancer.

Oxidative stress and inflammation were considered to be the major mechanisms in liver damage caused by clofibrate (CF). In order to obtain lipid-lowering drugs with less liver damage, the structure of clofibrate was optimized by O-desmethyl anetholtrithione and got the target compound clofibrate-O-desmethyl anetholtrithione (CF-ATT). CF-ATT significantly reduced the levels of plasma triglycerides (TG), total cholesterol (TC) in hyperlipidemia mice induced by Triton WR-1339. In addition, CF-ATT has a significantly protective effect on the liver compared with CF. The liver weight and liver coefficient were reduced. The hepatic function indexes were also decreased, such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). Histopathological examination of the liver revealed that inflammatory cell infiltration, nuclear degeneration, cytoplasmic loosening and hepatocyte necrosis were ameliorated by administration with CF-ATT. The hepatoprotective mechanism showed that CF-ATT significantly up-regulated Nrf2 and HO-1 protein expression and down-regulated p-NF-κB P65 expression in the liver. CF-ATT has obviously antioxidant and anti-inflammatory activity. These findings suggested that CF-ATT has significant hypolipidemia activity and exact hepatoprotective effect possibly through the Nrf2/NF-κB-mediated signal pathway.

Pancreatic carcinoma (PC) has one of the highest mortality-to-incidence ratios of any solid tumor worldwide. Although KRAS mutation is commonly found in 95% of PCs, directly targeting KRAS remains to be a highly challenging task because of its lacking catalytic pockets where molecule inhibitors can bind with. Proteolysis-targeting chimeric (PROTAC) represents an effective approach for specific degradation of disease-causing proteins by hijacking the endogenous ubiquitin-proteasome system (UPS). Previously, we designed a first-in-class PROTAC induced PDEδ degrader (PIPD), which demonstrated improved anti-tumor efficacy against KRAS mutant malignancies. However, translating cellular degradative effects from bench to beside remains a highly challenging task because of PROTAC’s poor penetration efficiency across target cytomembranes and non-targeting delivery induced undesired “off target” side-effects. Herein, a smart nano-drug delivery system (CM8988-PIPD) was successfully constructed by biomimetic strategy for targeted delivery of PIPD. The biomimetic nanoparticle showed well-defined regular spherical structure with an average particle size of approximately 124.8 nm. Cancer cytomembrane camouflage endows CM8988-PIPD with excellent in vivo serum stability, controlled drug release profile, favorable biocompatibility & immunocompatibility, and prominent targeting ability to homologous PC cells. Owing to these advantages, the smart DDS significantly enhanced PDEδ degrading efficacy, resulting in induced cellular apoptosis (more than 50% for both PC cells) and suppressed cell proliferation via the inhibition of RAS signaling. In vitro studies illustrated that CM8988-PIPD hold great potential for the treatment of PC, which merits further investigation in both pre-clinical and clinical investigations in the future.

The emergence of multi-drug resistant bacteria and the lack of novel antibiotics to combat them have led to the revival of polymyxin B, a previously abandoned antibiotic due to its potential nephrotoxicity and neurotoxicity. To facilitate its widely clinical applications, increasing effort has been devoted to molecularly engineer polymyxin B for the targeted imaging and effective treatment of bacterial infections. Herein, the molecular engineering strategies will be summarized in this mini review, with selected recent advances for illustration. Perspective of the challenges and trends in this exciting and eagerly anticipated research area will also be provided in the end. We hope this mini review will inspire researchers from diverse fields to bring forward the next wave of exploiting molecular engineering approaches to propel the “old” polymyxin B to “new” clinical significance in combating bacterial infections.

[Image: see text] The development of KRAS–PDEδ protein–protein interaction (PPI) inhibitors is generally hampered by limited antitumor activity. Herein, the first hydrophobic tagging (HyT)-based PDEδ degraders were designed. Compound 17c efficiently bound to PDEδ and induced degradation of PDEδ in SW480 colon cancer cells. As compared with PDEδ inhibitor deltazinone, HyT-based degrader 17c exhibited improved antitumor activity toward KRAS mutant cancer cells. This study highlighted the potential of HyT as a valuable chemical tool for tumorigenic PDEδ knockdown, which could be developed into a promising strategy for antitumor drug discovery.

Alyteserin-2a (ILGKLLSTAAGLLSNLNH

13-Aminomethyl-15-thiomatrine (M19) previously developed by our research group was a promising candidate for novel anti-osteoporosis drug development. However, the application of M19 was limited by its unsatisfactory druggability including poor chemical stability, excessively broad pharmacological activity and some degree of cytotoxicity. To solve these problems, M19-based bone targeting and cathepsin K sensitive peptide-drug conjugates (BTM19-1, BTM19-2 and BTM19-3) were developed to realize precise drug release in the bone tissue. Subsequent studies showed a rapid drug release process

A visible-light-driven cascade radical cyclization process of

Visible-light-driven sulfonylation/cyclization of N-methacryloyl-2-phenylbenzoimidazoles has been successfully developed. Using commercially available sulfonyl chloride as sulfonylation reagent, a wide range of sulfonylated benzo[4,5]imidazo[2,1-a]isoquinolin-6(5H)-ones with potential antitumor activity were provided in acceptable to excellent yields. This method has the advantages of mild reaction conditions and outstanding functional group tolerance, and provides a new strategy for the development of potential antitumor lead compounds.

As a promising targeted drug delivery system, aptamer-drug conjugates (ApDCs) can specifically bind with cognate molecular targets for improving therapeutic efficacy and reducing drug toxicity. However, current ApDC strategies suffer from problems caused by the complicated synthesis, relatively high cost, low controllability of drug binding sites and loading ratio. To solve these difficulties, we have designed and synthesized an artificial pharmaceutical solid-phase module of Combretastatin A-4 (CA-4), in which an inactive ingredient was selected as bonding moiety to incorporate with solid phase functionalities. Through solid-phase synthesis technology, this module was automatically and efficiently conjugated with an aptamer at predesigned positions. Biological studies revealed that these ApDCs can not only maintain excellent specific recognition ability, but also possess definite cytotoxicity against tumor cells.

Bromodomain-containing protein 4 (BRD4) has emerged as a promising treatment target for bone-related disorders. (+)-JQ1, a thienotriazolodiazepine compound, has been shown to inhibit pro-osteoclastic activity in a BRD4-dependent approach and impede bone loss caused by ovariectomy (OVX) in vivo. However, clinical trials of (+)-JQ1 are limited because of its poor druggability. In this study, we synthesized a new (+)-JQ1 derivative differing in structure and chirality. One such derivative, (+)-ND, exhibited higher solubility and excellent inhibitory activity against BRD4 compared with its analogue (+)-JQ1. Interestingly, (-)-JQ1 and (-)-ND exhibited low anti-proliferative activity and had no significant inhibitory effect on RANKL-induced osteoclastogenesis as compared with (+)-JQ1 and (+)-ND, suggesting the importance of chirality in the biological activity of compounds. Among these compounds, (+)-ND displayed the most prominent inhibitory effect on RANKL-induced osteoclastogenesis. Moreover, (+)-ND could inhibit osteoclast-specific gene expression, F‐actin ring generation, and bone resorption in vitro and prevent bone loss in OVX mice. Collectively, these findings indicated that (+)-ND represses RANKL‐stimulated osteoclastogenesis and averts OVX-triggered osteoporosis by suppressing MAPK and NF-κB signalling cascades, suggesting that it may be a prospective candidate for osteoporosis treatment.

A4K14-citropin 1.1 is a structurally optimized derivative derived from amphibians' skin secreta peptide Citropin, which exhibits broad biological activities. However, the application of A4K14-citropin 1.1 as a cancer therapeutic is restricted by its structural flexibility. In this study, a series of all-hydrocarbon stapled peptides derivatives of A4K14-citropin 1.1 were designed and synthesized, and their chemical and biological characteristics were also investigated. Among them, A4K14-citropin 1.1-Sp1 and A4K14-citropin 1.1-Sp4 displayed improved helicity levels, greater protease stability, and increased antitumor activity compared with the original peptide, which establishes them as promising lead compounds for novel cancer therapeutics development. These results revealed the important influence of all-hydrocarbon stapling side chain on the secondary structure, hydrolase stability, and biological activity of A4K14-citropin 1.1.

p53-Murine double minute 2 (MDM2) interaction and histone deacetylases (HDACs) are important targets in antitumor drug development. Inspired by the synergistic effects between MDM2 and HDACs, the first MDM2/HDACs dual inhibitors were identified, which showed excellent activities against both targets. In particular, compound 14d was proven to be a potent and orally active MDM2/HDAC dual inhibitor, whose antitumor mechanisms were validated in cancer cells. Compound 14d showed excellent in vivo antitumor potency in the A549 xenograft model, providing a promising lead compound for the development of novel antitumor agents. Also, this proof-of-concept study offers a novel and efficient strategy for multitargeting antitumor drug discovery.

[Image: see text] In order to take advantage of both immunotherapeutic and epigenetic antitumor agents, the first generation of dual indoleamine 2,3-dioxygenase 1 (IDO1) and histone deacetylase (HDAC) inhibitors were designed. The highly active dual inhibitor 10 showed excellent and balanced activity against both IDO1 (IC(50) = 69.0 nM) and HDAC1 (IC(50) = 66.5 nM), whose dual targeting mechanisms were validated in cancer cells. Compound 10 had good pharmacokinetic profiles as an orally active antitumor agent and significantly reduced the l-kynurenine level in plasma. In particular, it showed excellent in vivo antitumor efficacy in the murine LLC tumor model with low toxicity. This proof-of-concept study provided a novel strategy for cancer treatment. Compound 10 represents a promising lead compound for the development of novel antitumor agents and can also be used as a valuable probe to clarify the relationships and mechanisms between cancer immunotherapy and epigenetics.

The bis-benzodioxole-fibrate hybrids were designed by structural simplification and bioisostere principle. Lipids lowering activity was preliminarily screened by Triton WR 1339 induced hyperlipidemia mice model, in which T3 showed the best hypolipidemia, decreasing plasma triglyceride (TG) and total cholesterol (TC), which were better than sesamin and fenofibrate (FF). T3 was also found to significantly reduce TG, TC and low density lipoprotein cholesterin (LDL-C) both in plasma and liver tissue of high fat diet (HFD) induced hyperlipidemic mice. In addition, T3 showed hepatoprotective activity, which the noteworthy amelioration in liver aminotransferases (AST and ALT) was evaluated and the histopathological observation exhibited that T3 inhibited lipids accumulation in the hepatic and alleviated liver damage. The expression of PPAR-α receptor involved lipids metabolism in liver tissue significantly increased after T3 supplementation. Other potent activity, such as antioxidation and anti-inflammation, was also observed. The molecular docking study revealed that T3 has good affinity activity toward to the active site of PPAR-α receptor. Based on these findings, T3 may serve as an effective hypolipidemic agent with hepatoprotection.

Flood irrigation and over fertilization lead to a large amount of nitrogen (N) leaching in conventional plastic shed vegetable production systems, resulting in low N use efficiency and huge environmental costs. Drip fertilization can significantly reduce N leaching by reducing irrigation and N application; however, the respective roles of each factor in reducing N leaching remain unknown. In this study, structural equation modeling was carried out to determine the direct and indirect relationships among factors related to N leaching in plastic shed tomato production across six consecutive growing seasons. Treatments were as follows: conventional flooding irrigation and fertilization (CIF); CIF + corn straw (CIF + C); CIF + wheat straw (CIF + W); drip irrigation and fertilization (DIF); DIF + corn straw (DIF + C); and DIF + wheat straw (DIF + W). The results showed that the most important contributing factor to N leaching in this study was water percolation, which is mainly controlled by irrigation amount. This suggests that irrigation amount has a greater effect than N input rate and straw addition. Compared to CIF, DIF significantly reduced N leaching by an average of 63.9% without compromising tomato yield, with significant increases of 52.9% and 28.1% in the water use efficiency (WUE) and partial factor productivity of applied N (PFPN), respectively. Meanwhile, application of straw also resulted in a significant reduction in N leaching by reducing water percolation, with wheat straw having a greater effect than corn straw. Overall, excessive irrigation rather than N input was found to be the main cause of significant N leaching, highlighting the importance of optimal irrigation schemes. We therefore recommend precise drip irrigation and fertilization combined with straw addition for sustainable and environmentally-friendly plastic shed vegetable production.

Herein we report the first exploration of a dual-targeting drug design strategy to improve the efficacy of small-molecule cancer immunotherapy. New hybrids of indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors and DNA alkylating nitrogen mustards that respectively target IDO1 and DNA were rationally designed. As the first-in-class examples of such molecules, they were found to exhibit significantly enhanced anticancer activity in vitro and in vivo with low toxicity. This proof-of-concept study has established a critical step toward the development of a novel and effective immunotherapy for the treatment of cancers.

p53–MDM2 protein-protein interaction is a promising target for novel antitumor drug development. Previously, we identified a new class of spirotetrahydrothiopyran–oxindole p53–MDM2 inhibitors by novel organocatalytic enantioselective cascade reactions. Herein, a series of new derivatives were designed, synthesized and assayed to investigate the structure-activity relationships. Among them, compound B14 bearing a novel spiroindole–thiopyranopyridone scaffold exhibited potent MDM2 inhibitory activity as well as antitumor activity, which could effectively induce the apoptosis of A549 cancer cells. It represents a promising lead compound for the development of novel antitumor agents.

Sulfur containing spiroheterocyclic oxindoles are promising privileged scaffolds in medicinal chemistry and drug discovery. Previously, we identified a new class of spirodihydrothiopyran-oxindoles with good in vitro antitumor activity against A549 lung cancer cell line. Herein, various spirooxindole-dihydrothiopyrans with diverse substitutions were synthesized and assayed to investigate the structure-activity relationships. Among the derivatives, compounds 4b, 4i, 4m, 4n and 4q displayed superior or comparable antitumor activity than nutlin-3. Molecular mechanism study revealed this scaffold displayed moderate MDM2 inhibitory activity, significantly induced cancer cell apoptosis and arrested cell cycle at G0/G1 phase, which represented a good lead compound for antitumor drug discovery.

Using proline as the catalyst, an organocatalytic Michael–aldol cascade reaction was developed for the synthesis of spiro-tetrahydrothiopyran oxindoles. The highly functionalized scaffold was assembled in moderate to good yields (51–78%) and excellent diastereoselectivities (>20 : 1 dr). Interestingly, the oxindoles displayed moderate to good in vitro antitumor activities and were validated as p53-MDM2 inhibitors, which represented promising lead compounds for antitumor drug discovery.

A compact directional coupler with rectangular apertures, which are arranged in a fishbone configuration for high power systems, is designed. The proposed design can be applied to small size microwave interspaces and realize low coupling between waveguide and microstrip line with parallel axes by multi-aperture. In this paper, we present a C band novel directional coupler with low coupling of 40 dB with the deviation of 1 dB, directivity of 20 dB and low return loss over a operation band of 1.4 GHz.

Nicotinamide phosphoribosyltransferase (Nampt) is an attractive therapeutic target for cancer. A Nampt inhibitor with novel benzothiophene scaffold was discovered by high throughput screening. Herein the structure-activity relationship of the benzothiophene Nampt inhibitor was investigated. Several new inhibitors demonstrated potent activity in both biochemical and cell-based assays. In particular, compound 16b showed good Nampt inhibitory activity (IC50=0.17 μM) and in vitro antitumor activity (IC50=3.9 μM, HepG2 cancer cell line). Further investigation indicated that compound 16b could efficiently induce cancer cell apoptosis. Our findings provided a good starting point for the discovery of novel antitumor agents.

Designing multitarget drugs remains a significant challenge in current antitumor drug discovery. Because of the synergistic effect between topoisomerase and HDAC inhibitors, the present study reported the first-in-class triple inhibitors of topoisomerase I/II and HDAC. On the basis of 3-amino-10-hydroxylevodiamine and SAHA, a series of hybrid molecules was successfully designed and synthesized. In particular, compound 8c was proven to be a potent inhibitor of topoisomerase I/II and HDAC with good antiproliferative and apoptotic activities. This proof-of-concept study also validated the effectiveness of discovering triple topoisomerase I/II and HDAC inhibitors as novel antitumor agents.

Discovery of novel antifungal agents against Aspergillus fumigatus and Cryptococcus neoformans remains a significant challenge in current antifungal therapy. Herein the antifungal natural product sampangine was used as the lead compound for novel antifungal drug discovery. A series of D-ring scaffold hopping derivatives were designed and synthesized to improve antifungal activity and water solubility. Among them, the thiophene derivative S2 showed broad-spectrum antifungal activity, particularly for Aspergillus fumigatus and Cryptococcus neoformans. Moreover, compound S2 also revealed better water solubility than sampangine, which represents a promising antifungal lead compound for further structural optimization.

To analyze the binding of glycyrrhetic acid (GA) to angiotensin II type I (AT(1)) receptor and to explore the mechanisms underlying the binding, primary cell culture of rat vascular smooth muscle cell (VSMC), radioactive ligand-receptor binding assay, lascer confocal scanning microscope (LCSM), Northern blot, (3)H-TdR incorporation DNA assay were used in this study. The results suggest that specific binding of GA to AT(1) receptor (IC(50) value was 35.0 mumol/L) increases intracellular [Ca(2+)]i of VSMC, activates transcription factor c-myc and promotes the proliferation of VSMC, therefore GA was probably an agonist of AT(1) receptor, providing a new target for GA's pharmaceutical effects.