Synthesis and biological evaluation of CHX-DAPYs as HIV-1 non-nucleoside reverse transcriptase inhibitors

A series of new diarylpyrimidines (DAPYs) characterized by a halogen atom on the methylene linker between wing I and the central pyrimidine ring was synthesized and evaluated for their anti-HIV activity in MT-4 cell cultures. The two most promising compounds 7f and 7g showed excellent activity against wild-type HIV-1 with low nanomolar EC₅₀ values of 0.005 and 0.009 μM, respectively, which were comparable to or more potent than all the reference drugs zidovudine (AZT), lamivudine (3TC), nevirapine (NEV), efavirenz (EFV), delaviridine (DLV) and etravirine (ETV). In particular, 7g also displayed strong activity against the double mutant strain 103N + 181C with an EC₅₀ value of 8.2 μM. The preliminary structure–activity relationship (SAR) and molecular docking analysis of this new series of CHX-DAPYs were also investigated.     

Synthesis and bioevaluation of substituted chalcones,coumaranones and other flavonoids as anti-HIV agents

A series of chalcone, flavone, coumaranone and other flavonoid compounds were screened for their anti HIV-1 activity in two cell culture models using TZM-bl and PM1 cells. Within the systems evaluated, the most promising compounds contained either an α- or β-hydroxy-carbonyl motif within their structure (e.g., 8 and 9). Efficacious substituents were identified and used to design new HIV inhibitors with increased potency and lower cytotoxicity. Of the scaffolds evaluated, specific chalcones were found to provide the best balance between anti-HIV potency and low host cell toxicity. Chalcone 8l was shown to inhibit different clinical isolates of HIV in a dose-dependent manner (e.g., IC₅₀ typically ⩽ 5 μM). Inhibition of HIV infection experiments using TZM-bl cells demonstrated that chalcone 8l and flavonol 9c had IC₅₀ values of 4.7 μM and 10.4 μM, respectively. These insights were used to design new chalcones 8o and 8p. Rewardingly, chalcones 8o and 8p (at 10 μM) each gave >92% inhibition of viral propagation without impacting PM1 host cell viability. Inhibition of viral propagation significantly increased (60–90%) when PM1 cells were pre-incubated with chalcone 8o, but not with the related flavonol 9c. These results suggested that chalcone 8o may be of value as both a HIV prophylactic and therapy. In summary, O-benzyl-substituted chalcones were identified as promising anti-HIV agents for future investigation.     

Synthesis and biological evaluation of novel C6-amino substituted 4-azasteroidal purine nucleoside analogues

Novel C6-amino substituted purine nucleoside analogues (2–12) bearing a modified pyranose-like D ring of the 4-azasteroid moiety were efficiently synthesized through nucleophilic substitution at C6 position of the steroidal nucleoside precursors (1a, b) with versatile amines. All the synthesized new compounds were evaluated for their anticancer activity in vitro against Hela, PC-3 and MCF-7 cell lines. Among them, compounds 4b, 7b and 9b exhibited significant cytotoxicity with the IC₅₀ values of 2.99 μM (PC-3), 2.84 μM, (PC-3) and 2.69 μM (Hela), respectively.     

Design,synthesis and biological evaluation of 3-benzyloxy-linked pyrimidinylphenylamine derivatives as potent HIV-1 NNRTIs

A novel series of 3-benzyloxy-linked pyrimidinylphenylamine derivatives (8a–8s) was designed, synthesized and evaluated for their in vitro anti-HIV activity in MT-4 cell cultures. Most of the compounds inhibited wild-type (wt) HIV-1 replication in the lower micromolar concentration range (EC₅₀ = 0.05–35 μM) with high selectivity index (SI) values (ranged from 10 to >4870). In particular, 8h and 8g displayed excellent antiretroviral activity against wt HIV-1 with low cytotoxicity (EC₅₀ = 0.07 μM, CC₅₀ >347 μM, SI >4870; EC₅₀ = 0.05 μM, CC₅₀ = 42 μM, SI = 777, respectively), comparable to that of the marked drug nevirapine (EC₅₀ = 0.113 μM, CC₅₀ >15 μM, SI >133). In order to confirm the binding target, 8h was selected to perform the anti-HIV-1 RT assay. Additionally, preliminary structure activity relationship (SAR) analysis and molecular docking studies of newly synthesized compounds were also discussed, as well as the predicted physicochemical properties.     

Synthesis,anti-HIV activity,integrase enzyme inhibition and molecular modeling of catechol,hydroquinone and quinol labdane analogs

Labdane analogs with o-quinol, catechol and hydroquinone moiety have been synthesized using Diels–Alder reaction of methyl 3,4-dioxocyclohexa-1,5-diene-carboxylate, 3,4-dioxocyclohexa-1,5-diene-carboxylic acid and 3,6-dioxocyclohexa-1,4-dienecarboxylic acid with mono terpene 1,3-dienes, namely ocimene and myrcene. The resulting molecules and their derivatives were evaluated for their anti-HIV-1 activity using TZM-bl cell based virus infectivity assay. Two molecules 13 and 18 showed anti-HIV activity with IC₅₀ values 5.0 (TI = 11) and 4.6 (TI = 46) μM, respectively. The compounds 17, 18 and 20 showed efficacy against HIV-1 integrase activity and showed inhibition with IC₅₀ 13.4, 11.1 and 11.5 μM, respectively. The HIV-1 integrase inhibition activity of these synthetic molecules was comparable with integric acid, the natural fungal metabolite. Molecular modeling studies for the HIV-1 integrase inhibition of these active synthetic molecules indicated the binding to the active site residues of the enzyme.     

Aminoparthenolides as novel anti-leukemic agents: Discovery of the NF-κB inhibitor,DMAPT (LC-1)

A series of aminoparthenolide analogs (6–37) were synthesized and evaluated for their anti-leukemic activity. Eight compounds exhibited good anti-leukemic activity with LD₅₀’s in the low μM range (1.5–3.0 μM). Compounds 16, 24 and 30 were the most potent compounds in the series, causing greater than 90% cell death at 10 μM concentration against primary AML cells in culture, with LD₅₀ values of 1.7, 1.8 and 1.6 μM.     

Synthesis and anti-HIV activity of alkylated quinoline 2,4-diols

Naturally occurring quinolone alkaloids, buchapine (1) and compound 2 were synthesized as reported in literature and evaluated for anti-HIV potential in human CD4+ T cell line CEM-GFP, infected with HIV-1_NL4.3 virus by p24 antigen capture ELISA assay. The compounds 1 and 2 showed potent inhibitory activity with IC₅₀ value of 2.99 and 3.80 μM, respectively. Further, 45 alkylated derivatives of quinoline 2,4-diol were synthesized and tested for anti-HIV potential in human CD4+ T cell line CEM-GFP. Among these, 13 derivatives have shown more than 60% inhibition. We have identified three most potent inhibitors 6, 9 and 23; compound 6 was found to be more potent than lead molecule 1 with IC₅₀ value of 2.35 μM and had better therapeutic index (26.64) as compared to AZT (23.07). Five derivatives 7, 19a, 19d, 21 and 24 have displayed good noticeable anti-HIV activity. All active compounds showed higher CC₅₀ values which indicate that they have better therapeutic indices.     

Synthesis and evaluation of novel triazoles and mannich bases functionalized 1,4-dihydropyridine as angiotensin converting enzyme (ACE) inhibitors

A series of novel diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate embedded triazole and mannich bases were synthesized, and evaluated for their angiotensin converting enzyme (ACE) inhibitory activity. Screening of above synthesized compounds for ACE inhibition showed that triazoles functionalized compounds have better ACE inhibitory activity compared to that of mannich bases analogues. Among all triazoles we found 6h, 6i and 6j to have good ACE inhibition activity with IC₅₀ values 0.713 μM, 0.409 μM and 0.653 μM, respectively. Among mannich bases series compounds, only 7c resulted as most active ACE inhibitor with IC₅₀ value of 0.928 μM.     

Design,synthesis, and docking studies of afatinib analogs bearing cinnamamide moiety as potent EGFR inhibitors

Two series of afatinib derivatives bearing cinnamamide moiety (10a–n and 11a–h) were designed, synthesized and evaluated for the IC₅₀ values against four cancer cell lines (A549, PC-3, MCF-7 and Hela). Two selected compounds (10e, 10k) were further evaluated for the inhibitory activity against EGFR and VEGFR2/KDR kinases. Seven of the compounds showed excellent cytotoxicity activity and selectivity with the IC₅₀ values in single-digit μM to nanomole range. Three of them are equal to more active than positive control afatinib against one or more cell lines. The most promising compound 10k showed the best activity against A549, PC-3, MCF-7 and Hela cancer cell lines and EGFR kinase, with the IC₅₀ values of 0.07 ± 0.02 μM, 7.67 ± 0.97 μM, 4.65 ± 0.90 μM and 4.83 ± 1.28 μM, which were equal to more active than afatinib (0.05 ± 0.01 μM, 4.1 ± 2.47 μM, 5.83 ± 1.89 μM and 6.81 ± 1.77 μM), respectively. Activity of compounds 10e (IC₅₀ 9.1 nM) and 10k (IC₅₀ 3.6 nM) against EGFR kinase were equal to the reference compound afatinib (IC₅₀ 1.6 nM). Structure–activity relationships (SARs) and docking studies indicated that replacement of the aqueous solubility 4-(dimethylamino)but-2-enamide group by cinnamamide moiety didn’t decrease the antitumor activity. The results suggested that methoxy substitution had a significant impact on the activity and methoxy substituted on C-4 or C-2,3,4 position was benefit for the activity.     

Synthesis and biological evaluation of novel 2-(substituted phenylaminocarbonylmethylthio)-6-(2,6-dichlorobenzyl)-pyrimidin-4(3H)-ones as potent HIV-1 NNRTIs

A series of novel 2-(phenylaminocarbonylmethylthio)-6-(2,6-dichlorobenzyl)-pyrimidin-4(3H)-ones have been designed and synthesized. All of the new compounds were evaluated for their anti-HIV activities in MT-4 cells. Most of these new compounds showed moderate to potent activities against wild-type HIV-1 with an EC₅₀ ranging from 4.48 μM to 0.18 μM. Among them, 2-[(4-bromophenylamino)carbonylmethylthio]-6-(2,6-dichlorobenzyl)-5-methylpyrimidin-4(3H)-one 4b3 was identified as the most promising compound (EC₅₀ = 0.18 ± 0.06 μM, CC₅₀ >243.56 μM, SI >1326). The structure–activity relationship (SAR) of these new congeners is discussed.     

Structural modifications of 5,6-dihydroxypyrimidines with anti-HIV activity

A series of 5,6-dihydroxypyrimidine analogs were synthesized and evaluated for their anti-HIV activity in vitro. Among all of the analogs, several compounds exhibited significant anti-HIV activity, especially 1b and 1e, which showed the most potent anti-HIV activity with EC₅₀ values of 0.14 and 0.15 μM, and TI (therapeutic index) values of >300 and >900, respectively. Further docking studies revealed that the representative compounds 1e and 3a could meet the HIV-1 integrase inhibition minimal requirements of a chelating domain (two metal ions) and an aromatic domain (π–π stacking interactions).     

Synthesis and antiproliferative activities of quebecol and its analogs

Simple and efficient synthesis of quebecol and a number of its analogs was accomplished in five steps. The synthesized compounds were evaluated for antiproliferative activities against human cervix adenocarcinoma (HeLa), human ovarian carcinoma (SK-OV-3), human colon carcinoma (HT-29), and human breast adenocarcinoma (MCF-7) cancer cell lines. Among all the compounds, 7c, 7d, 7f, and 8f exhibited antiproliferative activities against four tested cell lines with inhibition over 80% at 75 μM after 72 h, whereas, compound 7b and 7g were more selective towards MCF-7 cell line. The IC₅₀ values for compounds 7c, 7d, and 7f were 85.1 μM, 78.7 μM, and 80.6 μM against MCF-7 cell line, respectively, showing slightly higher antiproliferative activtiy than the synthesized and isolated quebecol with an IC₅₀ value of 104.2 μM against MCF-7.     

Design,synthesis, anticancer activity and docking studies of novel 4-morpholino-7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine derivatives as mTOR inhibitors

A series of 7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine derivatives (7a–q, 10a–q) were designed, synthesized and their chemical structures were confirmed by ¹H NMR, ¹³C NMR, MS and HRMS spectrum. All the compounds were evaluated for the inhibitory activity against mTOR kinase at 10 μM level. Five selected compounds (7b, 7e, 7h, 10b and 10e) were further evaluated for the inhibitory activity against PI3Kα at 10 μM level, and the IC₅₀ values against mTOR kinase and two cancer cell lines. Twelve of the target compounds exhibited moderate antitumor activities. The most promising compound 7e showed strong antitumor activities against mTOR kinase, H460 and PC-3 cell lines with IC₅₀ values of 0.80 ± 0.15 μM, 7.43 ± 1.45 μM and 11.90 ± 0.94 μM, which were 1.28 to 1.71-fold more active than BMCL-200908069-1 (1.37 ± 0.07 μM, 9.52 ± 0.29 μM, 16.27 ± 0.54 μM), respectively. Structure–activity relationships (SARs) and docking studies indicated that the thiopyrano[4,3-d]pyrimidine scaffolds exerted little effect on antitumor activities of target compounds. Substitutions of aryl group at C-4 position had a significant impact on the antitumor activities, and 4-OH substitution produced the best potency.     

Synthesis,and docking studies of phenylpyrimidine-carboxamide derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety as c-Met inhibitors

Four series of phenylpyrimidine-carboxamide derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety (14a–e, 15a–g, 16a–e and 17a–g) were designed, synthesized and evaluated for the IC₅₀ values against three cancer cell lines (A549, PC-3 and MCF-7). Four selected compounds (15e, 16a–b and 17a) were further evaluated for the activity against c-Met kinase, HepG2 and Hela cell lines. Most of the compounds showed excellent cytotoxicity activity and selectivity with the IC₅₀ valuables in single-digit μM to nanomole range. Eleven of them are equal to more active than positive control Foretinib against one or more cell lines. The most promising compound 15e showed superior activity to Foretinib against A549, PC-3 and MCF-7 cell lines, with the IC₅₀ values of 0.14 ± 0.08 μM, 0.24 ± 0.07 μM and 0.02 ± 0.01 μM, which were 4.6, 1.6 and 473.5 times more active than Foretinib (0.64 ± 0.26 μM, 0.39 ± 0.11 μM, 9.47 ± 0.22 μM), respectively. Structure–activity relationships (SARs) and docking studies indicated that the replacement of phenylpicolinamide scaffold with phenylpyrimidine fragment of the target compounds was benefit for the activity. What’s more, the introduction of fluoro atom to the aminophenoxy part played no significant impact on the activity and any substituent group on aryl group is unfavourable for the activity.     

Synthesis,biological evaluation and molecular modeling of 1,3,4-thiadiazol-2-amide derivatives as novel antitubulin agents

A series of 1,3,4-thiadiazol-2-amide derivatives (6a–w) were designed and synthesized as potential inhibitors of tubulin polymerization and as anticancer agents. The in vitro anticancer activities of these compounds were evaluated against three cancer cell lines by the MTT method. Among all the designed compounds, compound 6f exhibited the most potent anticancer activity against A549, MCF-7 and HepG2 cancer cell lines with IC₅₀ values of 0.03 μM, 0.06 μM and 0.05 μM, respectively. Compound 6f also exhibited significant tubulin polymerization inhibitory activity (IC₅₀ = 1.73 μM), which was superior to the positive control. The obtained results, along with a 3D-QSAR study and molecular docking that were used for investigating the probable binding mode, could provide an important basis for further optimization of compound 6f as a novel anticancer agent.     

Design,synthesis, and docking studies of phenylpicolinamide derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety as c-Met inhibitors

Four series of phenylpicolinamide derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety (12a–e, 13a–f, 14a–f and 15a–i) were designed, synthesized and evaluated for the IC₅₀ values against three cancer cell lines (A549, PC-3 and MCF-7) and c-Met kinase. Five selected compounds (13b, 15b, 15d, 15e and 15f) were further evaluated for the activity against HepG2 and Hela cell lines. Eighteen of the compounds showed excellent cytotoxicity activity and selectivity with the IC₅₀ valuables in single-digit μM to nanomole range. Seven of them are equal to more active than positive control Foretinib against one or more cell lines. The most promising compound 15f showed superior activity to Foretinib, with the IC₅₀ values of 1.04 ± 0.11 μM, 0.02 ± 0.01 μM and 9.11 ± 0.55 μM against A549, PC-3 and MCF-7 cell lines, which were 0.62 to 19.5 times more active than Foretinib (IC₅₀ values: 0.64 ± 0.26 μM, 0.39 ± 0.11 μM, 9.47 ± 0.22 μM), respectively. Structure–activity relationships (SARs) and docking studies indicated that replacement of quinoline nucleus of the previous active compounds with 1H-pyrrolo[2,3-b]pyridine moiety maintained even improved the potent cytotoxic activity. The results suggested that the introduction of fluoro atoms to the aminophenoxy part of target compounds or the phenyl group of pyrimidine substituted on C-4 position was benefit for the activity.     

Structural modifications of CH(OH)-DAPYs as new HIV-1 non-nucleoside reverse transcriptase inhibitors

A series of CR₂(OH)-diarylpyrimidine derivatives (CR₂(OH)-DAPYs) featuring a hydrophobic group at CH(OH) linker between wing I and the central pyrimidine were synthesized and evaluated for their anti-HIV activity in MT-4 cell cultures. All the target compounds except for compound 3k displayed inhibitory activity against HIV-1 wild-type with EC₅₀ values ranging from 7.21 ± 1.99 to 0.067 ± 0.006 μM. Among them, compound 3d showed the most potent anti-HIV-1 activity (EC₅₀ = 0.067 ± 0.006 μM, SI > 592), which was approximately 2-fold more potent than the reference drugs nevirapine (NVP) and delaviridine (DLV) in the same assay. In addition, the binding modes with HIV-1 RT and the preliminary SAR studies of these new derivatives were also investigated.     

Synthesis and evaluation of β-carboline derivatives as inhibitors of human immunodeficiency virus

A series of β-carboline derivatives were synthesized by utilizing aromatization and chemoselective alkylation method recently reported from our laboratory. Synthesized derivatives were evaluated for anti-HIV activity in human CD4+ T cell line (CEM-GFP) infected with HIV-1 NL_4.3 virus. 1-Formyl-β-carboline-3-carbxylic acid methyl ester (15) showed inhibition of human immunodeficiency virus at IC₅₀ = 2.9 μM.     

Design,synthesis and biological evaluation of novel 4-anilinoquinazolines with C-6 urea-linked side chains as inhibitors of the epidermal growth factor receptor

A novel series of anilinoquinazoline compounds with C-6 urea-linked side chains was designed and synthesized as reversible inhibitors of epidermal growth factor receptor (EGFR) based on the structure–activity relationships (SARs) of anilinoquinazoline inhibitors. All compounds demonstrated good inhibition of EGFR wild type (EGFR wt) (IC₅₀ = 0.024–1.715 μM) and inhibited proliferation of A431cell line (IC₅₀ = 0.116–22.008 μM). The binding mode of compounds 8a, 8d, 8k and 8o was consistent with the biological results. Moreover, compounds 8k and 8l almost completely blocked the phosphorylation of EGFR in A431 cell line at 0.01 μM. Interestingly, all of the compounds also demonstrated moderate inhibition of EGFR/T790M/L858R (IC₅₀ = 0.049–5.578 μM). In addition, compounds 8f and 8h blocked the autophosphorylation of EGFR in NCI-H1975 cells at high concentration (10 μM), and compound 8f was confirmed to be an irreversible inhibitor through the dilution method. Importantly, the compounds with C-6 urea-linked side chains which did not contain Michael acceptors demonstrated moderate to strong irreversible EGFR inhibition.