Design,synthesis and biological evaluation of indole derivatives as Vif inhibitors

The crystal structure of viral infectivity factor (Vif) was reported recently, which makes it possible to design new inhibitors against Vif by structure-based drug design. Through analysis of the protein surface of Vif, the C2 pocket located in the N-terminal was found, which is suit for developing small molecular inhibitors. Then, in our article, fragment-based virtual screening (FBVS) was conducted and a series of fragments was obtained, among which, Zif-1 bearing indole scaffold and pyridine ring can form H-bonds with Tyr148 and Ile155. Subsequently, 19 derivatives of Zif-1 were synthesized. Through the immune-fluorescence staining and Western blot assays, Zif-15 shows potent activity in inhibiting Vif-mediated A3G degradation. Further docking experiment shows that Zif-15 form H-bond interactions with residues His139, Tyr148 and Ile155. Therefore, Zif-15 is a promising lead compound against Vif that can be used to treat AIDS.     

Design,synthesis and biological evaluation of novel hydroxamic acid based histone deacetylase 6 selective inhibitors bearing phenylpyrazol scaffold as surface recognition motif

In recent years, inhibition of HDAC6 became a promising therapeutic strategy for the treatment of cancer and HDAC6 inhibitors were considered to be potent anti-cancer agents. In this work, celecoxib showed moderate degree of HDAC6 inhibition activity and selectivity in preliminary enzyme inhibition activity assay. A series of hydroxamic acid derivatives bearing phenylpyrazol moiety were designed and synthesized as HDAC6 inhibitors. Most compounds showed potent HDAC6 inhibition activity. 11i was the most selective compound against HDAC6 with IC₅₀ values of 0.020 µM and selective factor of 101.1. Structure-activity relationship analysis indicated that locating the linker group at 1′ of pyrazol gave the most selectivity. The most compounds 11i (GI₅₀ = 3.63 μM) exhibited 6-fold more potent than vorinostat in HepG2 cells. Considering of the high selectivity against HDAC6 and anti-proliferation activity, such compounds have potential to be developed as anti-cancer agents.     

Design,synthesis and biological evaluation of lapachol derivatives possessing indole scaffolds as topoisomerase I inhibitors

A series of novel lapachol derivatives possessing indole scaffolds was designed and synthesized. The in vitro anti-proliferative activity of these novel compounds was evaluated in Eca109 and Hela cell lines. Almost all the tested compounds showed manifested potent inhibitory activity against the two tested cancer cell lines. Topo I-mediated DNA relaxation activity indicated that these novel compounds have potent Topoisomerase I inhibition activity. The most potent compounds 4n and 4k demonstrated more cytotoxicity than camptothecin and was comparable to camptothecin in inhibitory activities on Topoisomerase I in our biological assay. In addition, the Hoechst 33342 staining method also showed that the complex can induce Hela cell apoptosis.     

Design,synthesis, docking studies and biological evaluation of novel chalcone derivatives as potential histone deacetylase inhibitors

A group of novel chalcone derivatives comprising hydroxamic acid or 2-aminobenzamide group as zinc binding groups (ZBG) were synthesized. The structure of the prepared compounds was fully characterized by IR, NMR and elemental microanalyses. Most of the tested compounds displayed strong to moderate HDAC inhibitory activity. Some of these compounds showed potent anti-proliferative activity against human HepG2, MCF-7 and HCT-116 cell lines. In particular, compounds 4a and 4b exhibited significant anti-proliferative activity against the three cell lines compared to SAHA as reference drug and displayed promising profile as anti-tumor candidates. The results indicated that these chalcone derivatives could serve as a promising lead compounds for further optimization as antitumor agents.     

Synthesis and biological evaluation of quinoline derivatives as potential anti-prostate cancer agents and Pim-1 kinase inhibitors

In this work, a series of quinoline derivatives were designed and synthesized as antitumor agents. Most quinolines showed potent anti-proliferative activity against human prostatic cancer PC-3 cell line. Among which, 9d, 9f and 9g were the most effective compounds with GI₅₀ values of 2.60, 2.81 and 1.29 μM, respectively. Structure–activity relationship analysis indicated that the secondary amine linked quinoline and pyridine ring played an important role in the anti-proliferative effects. Mechanistic studies revealed that 9g was a potential Pim-1 kinase inhibitor with abilities of cell cycle arrest and apoptosis induction. Considering of the increased activity of Pim-1 in prostate cancer, such compounds have potential to be developed as anti-prostate cancer agents.     

Binding pocket-based design,synthesis and biological evaluation of novel selective BRD4-BD1 inhibitors

Bromodomain-containing protein 4 (BRD4), consisting of two tandem bromodomains (BD1 and BD2), is key epigenetic regulator in fibrosis and cancer, which has been reported that BD1 and BD2 have distinct roles in post-translational modification. But there are few selective inhibitors toward those two domains. Herein, this study designed and synthesized a series of novel selective BRD4-BD1 inhibitors, using computer-aided drug design (CADD) approach focused on exploring the difference of the binding pockets of BD1 and BD2, and finding the His437 a crucial way to achieve BRD4-BD1 selectivity. Our results revealed that the compound 3u is a potent selective BRD4-BD1 inhibitor with IC₅₀ values of 0.56?μM for BD1 but >100?μM for BD2. The compound exhibited a broad spectrum of anti-proliferative activity against several human cancer and fibroblastic cell lines, which might be related to its capability of reducing the expression of c-Myc and collagen I. Furthermore, it could induce apoptosis in A375 cells. To the contrary, the selective BD2 inhibitor, RVX-208, did not indicate any of these activities. Our findings highlight that the function of BRD4-BD1 might be predominant in fibrosis and cancer. And it is rational to further develop novel selective BRD4-BD1 inhibitors.     

Discovery of novel phenoxybenzamide analogues as Raf/HDAC dual inhibitors

Histone deacetylase (HDAC) inhibitors as an important epigenetic therapeutic strategy affect signaling networks and act synergistically with kinase inhibitors for the treatment of cancer. Herein we presented a series of novel phenoxybenzamide analogues with inhibition of Raf and HDAC. Among them, compound 10e showed potent antiproliferative activities against Hepg2 and MDA-MB-468 in cellular assays. This work may lay the foundation for developing novel dual Raf/HDAC inhibitors as potential anticancer therapeutics.     

Design,synthesis and biological evaluation of novel 4,5-dihydro-[1,2,4]triazolo[4,3-f]pteridine derivatives as potential BRD4 inhibitors

Recently, diverse kinase inhibitors were reported having interaction with BRD4. It provided a strategy for developing a new structural framework for the next-generation BRD4-selective inhibitors. Starting from PLK1 kinase inhibitor BI-2536, we designed 18 compounds by modifying dihydropteridine core. Compound 23 showed potent BRD4 inhibitory activities with IC₅₀ of 79 nM and no inhibitory activities for PLK1. Cell antiproliferation assay was performed and potent inhibitory activity against MV4;11 with IC₅₀ of 1.53 μM. Cell apoptosis and western blotting indicated compound 23 induced apoptosis by down-regulating c-Myc. These novel selective BRD4 inhibitors provided new lead compounds for further drug development.     

Design,synthesis and biological evaluation of novel pyrimidinedione derivatives as DPP-4 inhibitors

A series of novel pyrimidinedione derivatives were designed and evaluated for in vitro dipeptidyl peptidase-4 (DPP-4) inhibitory activity and in vivo anti-hyperglycemic efficacy. Among them, the representative compounds 11, 15 and 16 showed excellent inhibitory activity of DPP-4 with IC₅₀ values of 64.47?nM, 188.7?nM and 65.36?nM, respectively. Further studies revealed that compound 11 was potent in vivo hypoglycemic effect. The structure–activity relationships of these pyrimidinedione derivatives had been discussed, which would be useful for developing novel DPP-4 inhibitors as treating type 2 diabetes.     

Structure-based design,synthesis and in vitro antiproliferative effects studies of novel dual BRD4/HDAC inhibitors

Histone acetylation marks play important roles in controlling gene expressions and are removed by histone deacetylases (HDACs). These marks are read by bromodomain and extra-terminal (BET) proteins, whose targeted inhibitors are under clinical investigation. BET and HDAC inhibitors have been demonstrated to be synergistically killing in Mycinduced murine lymphoma. Herein, we combine the inhibitory activities of BET and HDAC into one molecule through structure-based design method and evaluate its function. The majority of these synthesized compounds showed inhibitory activity against second bromdomains(BRD) of BRD4 and HDAC1. Among them, 16ae presented anti-proliferative effects against human acute myelogenous leukemia (AML) cell lines in vitro, and 16ae is confirmed to reduce the expression of Myc by Western blot analysis. Those results indicated that 16ae is a potent dual BRD4/HDAC inhibitor and deserves further investigation.     

Design,synthesis and biological evaluation of novel zanamivir derivatives as potent neuraminidase inhibitors

Neuraminidase (NA) is an important antiviral drug target. Zanamivir is one of the most potent NA inhibitors. In this paper, a series of zanamivir derivatives as potential NA inhibitors were studied by combination of molecular modeling techniques including 3D-QSAR, molecular docking, and molecular dynamics (MD) simulation. The results show that the best CoMFA (comparative molecular field analysis) model has q²?=?0.728 and r²?=?0.988, and the best CoMSIA (comparative molecular similarity indices analysis) model has q²?=?0.750 and r²?=?0.981, respectively. The built 3D-QSAR models show significant statistical quality and excellent predictive ability. Seven new NA inhibitors were designed and predicted. 20?ns of MD simulations were carried out and their binding free energies were calculated. Two designed compounds were selected to be synthesized and biologically evaluated by NA inhibition and virus inhibition assays. One compound (IC₅₀?=?0.670?µM, SI?>?149) exhibits excellent antiviral activity against A/WSN/33 H1N1, which is superior to the reference drug zanamivir (IC₅₀?=?0.873?µM, SI?>?115). The theoretical and experimental results may provide reference for development of new anti-influenza drugs.     

Design,synthesis and biological evaluation of novel 6-phenyl-1,3a,4,10b-tetrahydro-2H-benzo[c]thiazolo[4,5-e]azepin-2-one derivatives as potential BRD4 inhibitors

Bromodomain-containing protein 4 (BRD4) is a key epigenetic regulator in cancer, and inhibitors targeting BRD4 exhibit great anticancer activity. By replacing the methyltriazole ring of the BRD4 inhibitor I-BET-762 with an N-methylthiazolidone heterocyclic ring, fifteen novel BRD4 inhibitors were designed and synthesized. Compound 13f had a hydrophobic acetylcyclopentanyl side chain, showing the most potent BRD4 inhibitory activity in the BRD4-BD1 inhibition assay (IC₅₀ value of 110 nM), it also significantly suppressed the proliferation of MV-4-11 cells with high BRD4 level (IC₅₀ value of 0.42 μM). Furthermore, the potent apoptosis-promoting and G0/G1 cycle-arresting activity of compound 13f were indicated by flow cytometry. As the downstream-protein of BRD4, c-Myc was in significantly low expression by compound 13f treatment in a dose-dependent manner. All the findings supported that this novel compound 13f provided a perspective for developing effective BRD4 inhibitors.     

Design,synthesis and biological evaluation of a series of pyrano chalcone derivatives containing indole moiety as novel anti-tubulin agents

A new series of pyrano chalcone derivatives containing indole moiety (3–42, 49a–49r) were synthesized and evaluated for their antiproliferative activities. Among all the compounds, compound 49b with a propionyloxy group at the 4-position of the left phenyl ring and N-methyl-5-indoly on the right ring displayed the most potent cytotoxic activity against all tested cancer cell lines including multidrug resistant phenotype, which inhibits cancer cell growth with IC₅₀ values ranging from 0.22 to 1.80 μM. Furthermore, 49b significantly induced cell cycle arrest in G2/M phase and inhibited the polymerization of tubulin. Molecular docking analysis demonstrated the interaction of 49b at the colchicine binding site of tubulin. In experiments in vivo, 49b exerted potent anticancer activity in HepG2 human liver carcinoma in BALB/c nude mice. These results indicated these compounds are promising inhibitors of tubulin polymerization for the potential treatment of cancer.     

Design,synthesis and biological evaluation of novel 6,7-disubstituted-4-phenoxyquinoline derivatives bearing 4-oxo-3,4-dihydrophthalazine-1-carboxamide moieties as c-Met kinase inhibitors

A series of 6,7-disubstituted-4-phenoxyquinoline derivatives bearing 4-oxo-3,4-dihydrophthalazine-1-carboxamide moieties were designed, synthesized and evaluated for their c-Met kinase inhibition and cytotoxicity against H460, MKN-45, HT-29 and MDA-MB-231 cancer cell lines in vitro. Most compounds displayed good to excellent potency against four tested cancer cell lines as compared with foretinib. The SAR analyses indicated that compounds with halogen groups, especially fluoro groups at 4-position on the phenyl ring (moiety B) were more effective than those with nitro groups or methoxy groups. In this study, a promising compound 33 (c-Met IC₅₀ = 1.63 nM) was identified, which showed the most potent antitumor activities with IC₅₀ values of 0.055 μM, 0.071 μM, 0.13 μM, and 0.43 μM against H460, MKN-45, HT-29 and MDA-MB-231 cell lines, respectively.     

Design and synthesis of aminocoumarin derivatives as DPP-IV inhibitors and anticancer agents

DPP-IV “a moonlighting protein” has immerged as promising pathway to control Type 2 diabetes as well as found to play key role in earlier stages of cancer. Here we have reported design, synthesis and applications of aminocoumarin derivatives as DPP-IV inhibitors. Compounds have been synthesized and studied for their DPP-IV inhibition activity. Three compounds have shown moderate inhibition at 100 µM concentration. All compounds were also screened for their anticancer activity against A549 (Lung cancer cell line), MCF-7 (Breast cancer cell line) using MTT assay. One of the compounds has shown very good anticancer activity with IC₅₀ value 24 ± 0.1 nM against A549 cell line.     

Design,synthesis and biological evaluation of pyrimidine derivatives as novel CDK2 inhibitors that induce apoptosis and cell cycle arrest in breast cancer cells

Cyclin-dependent kinase 2 (CDK2) plays a key role in eukaryotic cell cycle progression which could facilitate the transition from G1 to S phase. The dysregulation of CDK2 is closely related to many cancers. CDK2 is utilized as one of the most studied kinase targets in oncology. In this article, 24 benzamide derivatives were designed, synthesized and investigated for the inhibition activity against CDK2. Our results revealed that the compound 25 is a potent CDK2 inhibitor exhibiting a broad spectrum anti-proliferative activity against several human breast cancer cells. Additionally, compound 25 could block cell cycle at G0 or G1 and induce significant apoptosis in MDA-MB-468 cells. These findings highlight a rationale for further development of CDK2 inhibitors to treat human breast cancer.     

Design,synthesis and evaluation of novel HDAC inhibitors as potential antitumor agents

Phenyl imidazolidin-2-one was introduced as the linker for novel HDAC inhibitors. A focused library of 20 compounds was designed and synthesized, among which eight compounds showed equivalent or higher potencies against HDAC1 as compared to vorinostat. In vitro antitumor activity assays in HCT-116, PC-3 and HL-60 cancer cells revealed six compounds with potent antitumor activities, and compound 1o showed 6- to 9-fold higher potencies compared to vorinostat. In an HCT-116 nude mice xenograft model, compound 1o displayed significant antitumor activity in both continuous and intermittent dosing schedules.