Quinazoline-1-deoxynojirimycin hybrids as high active dual inhibitors of EGFR and α-glucosidase

A series of novel quinazoline-1-deoxynojirimycin hybrids were designed, synthesized and evaluated for their inhibitory activities against two drug target enzymes, epidermal growth factor receptor (EGFR) tyrosine kinase and α-glucosidase. Some synthesized compounds exhibited significantly inhibitory activities against the tested enzymes. Comparing with reference compounds gefitinib and lapatinib, compounds 7d, 8d, 9b and 9d showed higher inhibitory activities against EGFR (IC₅₀: 1.79–10.71 nM). Meanwhile the inhibitory activities of 7d, 8d and 9c against α-glucosidase (IC₅₀ = 0.14, 0.09 and 0.25 µM, respectively) were obvious higher than that of miglitol (IC₅₀ = 2.43 µM), a clinical using α-glucosidase inhibitor. Interestingly, compound 9d as a dual inhibitor showed high inhibitory activity to EGFR^wt tyrosine kinase (IC₅₀ = 1.79 nM), also to α-glucosidase (IC₅₀ = 0.39 µM). The work could be very useful starting point for developing a new series of enzyme inhibitors targeting EGFR and/or α-glucosidase.     

C-2 (E)-4-(Styryl)aniline substituted diphenylpyrimidine derivatives (Sty-DPPYs) as specific kinase inhibitors targeting clinical resistance related EGFRT790M mutant

With the aim to overcome the drug resistance induced by the EGFR T790M mutation (EGFR^T790M), herein, a family of diphenylpyrimidine derivatives (Sty-DPPYs) bearing a C-2 (E)-4-(styryl)aniline functionality were designed and synthesized as potential EGFR^T790M inhibitors. Among them, the compound 10e displayed strong potency against the EGFR^T790M enzyme, with the IC₅₀ of 11.0 nM. Compound 10e also showed a higher SI value (SI = 49.0) than rociletinib (SI = 21.4), indicating its less side effect. In addition, compound 10e could effectively inhibit the proliferation of H1975 cells harboring the EGFR^T790M mutation, within the concentration of 2.91 μM. Significantly, compound 10e has low toxicity against the normal HBE cell (IC₅₀ = 22.48 μM). This work provided new insights into the discovery of potent and selective inhibitor against EGFR^T790M over wild-type (EGFR^WT).     

Development and evaluation of 4-(pyrrolidin-3-yl)benzonitrile derivatives as inhibitors of lysine specific demethylase 1

As part of our ongoing efforts to develop reversible inhibitors of LSD1, we identified a series of 4-(pyrrolidin-3-yl)benzonitrile derivatives that act as successful scaffold-hops of the literature inhibitor GSK-690. The most active compound, 21g, demonstrated a K_d value of 22 nM and a biochemical IC₅₀ of 57 nM. In addition, this compound displayed improved selectivity over the hERG ion channel compared to GSK-690, and no activity against the related enzymes MAO-A and B. In human THP-1 acute myeloid leukaemia cells, 21g was found to increase the expression of the surrogate cellular biomarker CD86. This work further demonstrates the versatility of scaffold-hopping as a method to develop structurally diverse, potent inhibitors of LSD1.     

Substituted 4-amino-1H-pyrazolo[3,4-d]pyrimidines as multi-targeted inhibitors of insulin-like growth factor-1 receptor (IGF1R) and members of ErbB-family receptor kinases

This Letter describes the lead discovery, optimization, and biological characterization of a series of substituted 4-amino-1H-pyrazolo[3,4-d]pyrimidines as potent inhibitors of IGF1R, EGFR, and ErbB2. The leading compound 11 showed an IGF1R IC₅₀ of 12 nM, an EGFR (L858R) IC₅₀ of 31 nM, and an ErbB2 IC₅₀ of 11 nM, potent activity in cellular functional and anti-proliferation assays, as well as activity in an in vivo pharmacodynamic assay.     

Design and synthesis of pyrrolo[3,2-d]pyrimidine HER2/EGFR dual inhibitors: Improvement of the physicochemical and pharmacokinetic profiles for potent in vivo anti-tumor efficacy

During the course of our studies on a novel HER2/EGFR dual inhibitor (TAK-285), we found an alternative potent pyrrolo[3,2-d]pyrimidine compound (1a). To enhance the pharmacokinetic (PK) profile of this compound, we conducted chemical modifications into its N-5 side chain and conversion of the chemically modified compounds into their salts. Among them, 2cb, the tosylate salt of compound 2c, showed potent HER2/EGFR kinase inhibitory activity (IC₅₀: 11/11 nM) and cellular growth inhibitory activity (BT-474 cell GI₅₀: 56 nM) with a good drug metabolism and PK (DMPK) profile. Furthermore, 2cb exhibited significant in vivo antitumor efficacy in both mouse and rat xenograft models with transplanted 4-1ST gastric cancer cell lines (mouse, T/C = 0%, 2cb po bid at 100 mg/kg; rat, T/C: -1%, 2cb po bid at 25 mg/kg).     

Synthesis and structure–activity relationships of N-benzyl-N-(X-2-hydroxybenzyl)-N′-phenylureas and thioureas as antitumor agents

Two series of novel N-benzyl-N-(X-2-hydroxybenzyl)-N′-phenylureas and thioureas (1a–18a; 1b–18b) as potential EGFR and HER-2 kinase inhibitors have been discovered. These compounds displayed good EGFR and HER-2 inhibitory activity and the SARs are also been studied. Especially compound 7b demonstrated significant EGFR and HER-2 inhibitory activity (IC₅₀ = 0.08 μM for EGFR and IC₅₀ = 0.35 μM for HER-2). Docking simulation was performed to position compound 7b into the EGFR active site to determine the probable binding conformation and antiproliferative assay results indicating that these series of urea and thioureas own high antiproliferative activity against MCF-7. Above all, thiourea 7b would be a potential anticancer agent deserves further research.     

Design,synthesis and biological evaluation of 4-anilinothieno[2,3-d]pyrimidine-based hydroxamic acid derivatives as novel histone deacetylase inhibitors

A series of 4-anilinothieno[2,3-d]pyrimidine-based hydroxamic acid derivatives as novel HDACs inhibitors were designed, synthesized and evaluated. Most of these compounds displayed good to excellent inhibitory activities against HDAC1, 3, 6. The IC₅₀ values of compound 10r against HDAC1, HDAC3, HDAC6 was 1.14 ± 0.03 nM, 3.56 ± 0.08 nM, 11.43 ± 0.12 nM. Compound 10r noticeably up-regulated the level of histone H3 acetylation compared to the SAHA. Most of the compounds showed the strong anti-proliferative activity against human cancer cell lines including RMPI8226 and HCT-116. The IC₅₀ values of Compounds 10r and 10t against RPMI8226 was 2.39 ± 0.20 μM, 1.41 ± 0.44 μM, respectively, and the HCT-116 was sensitive to the compounds 10h, 10m, 10r, 10w with the IC₅₀ values <1.9 μM.     

Toward discovery of mutant EGFR inhibitors; Design,synthesis and in vitro biological evaluation of potent 4-arylamino-6-ureido and thioureido-quinazoline derivatives

A new series of 4-anilinoquinazolines with C-6 ureido and thioureido side chains and various substituents at the C-4 anilino moiety was designed, synthesized and evaluated as wild type (WT) and mutant EGFR inhibitors. Most of the compounds inhibited EGFR kinase wild type (EGFR WT) with IC₅₀ values in the low nanomolar range (<0.495–9.05 nM) and displayed more potent cytotoxic effect in BaF/3 expressing EGFR WT than reference compound gefitinib. The anti-proliferative effect of all synthesized compounds against gefitinib insensitive double mutant cell lines Ba/F3 expressing Del19/T790M and Ba/F3 expressing L858R/T790M were assayed. Compounds 4d, 6f, 7e showed significant inhibition (IC₅₀ = 1.76–2.38 μM) in these mutant lines and significant Her2 enzyme inhibition (IC₅₀ = 19.2–40.6 nM) compared to lapatinib (60.1 nM). The Binding mode of compounds 6d, 6f, 7a, 7b and 8b were demonstrated. Furthermore, growth inhibition against gefitinib insensitive cell lines PC9-GR4 (Del19/T790M) were tested, compounds 6f and 7e showed about eight and three folds respectively greater potency than gefitinib. Our structure–activity relationships (SAR) studies suggested that presence of ethyl piperidino urea/thiourea at 6-position and bulky group of (3-chloro-4-(3-fluorobenzyloxy)phenyl)amino at 4-position of quinazoline may serve as promising scaffold for developing inhibitors against wild type and mutant EGFR.     

Discovery of novel 9H-purin derivatives as dual inhibitors of HDAC1 and CDK2

HDAC and CDK inhibitors have been demonstrated to be synergistically in suppressing cancer cell proliferation and inducing apoptosis. In this work, we incorporated the pharmacophore groups of HDACs and CDKs inhibitors into one molecule to design and synthesize a series of purin derivatives as HDAC/CDK dual inhibitors. The lead compound 6d, showing good HDAC1 and CDK2 inhibitory activity with IC₅₀ values of 5.8 and 56 nM, respectively, exhibited attractive potency against several cancer cell lines in vitro. This work may lead to the discovery of a novel scaffold and potential dual HDAC/CDK inhibitors.     

Discovery of a highly potent,selective and novel CDK9 inhibitor as an anticancer drug candidate

A series of novel hybrid structure derivatives, containing both LEE011 and Cabozantinib pharmacophore, were designed, synthesized and evaluated. Surprisingly, a compound 4d was discovered that highly exhibited effective and selective activity of CDK9 inhibition with IC₅₀ = 12 nM. It effectively induced apoptosis in breast and lung cancer cell lines at nanomolar level. Molecular docking of 4d to ATP binding site of CDK9 kinase demonstrated a new hydrogen bonding between F atom of 4-(3-fluorobenzyloxy) group and ASN116 residue, compared with the positive control, LEE011. The compound 4d could block the cell cycle both in G0/G1 and G2/M phase to prevent the proliferation and differentiation of cancer cells. Mice bared-breast cancer treated with compound 4d showed significant suppression of cancer with low toxicity. Taken together, this novel compound 4d could be a promising drug candidate for clinical application.     

Design,synthesis and biological evaluation of thiazolidinone derivatives as potential EGFR and HER-2 kinase inhibitors

Two series of thiazolidinone derivatives designing for potential EGFR and HER-2 kinase inhibitors have been discovered. Some of them exhibited significant EGFR and HER-2 inhibitory activity. Compound 2-(2-(5-bromo-2-hydroxybenzylidene)hydrazinyl)thiazol-4(5H)-one (12) displayed the most potent inhibitory activity (IC₅₀ = 0.09 μM for EGFR and IC₅₀ = 0.42 μM for HER-2), comparable to the positive control erlotinib. Docking simulation was performed to position compound 12 into the EGFR active site to determine the probable binding model. Antiproliferative assay results indicating that some of the thiazolidinone derivatives own high antiproliferative activity against MCF-7. Compound 12 with potent inhibitory activity in tumor growth inhibition would be a potential anticancer agent.     

Synthesis,molecular modeling,and biological evaluation of cinnamic acid metronidazole ester derivatives as novel anticancer agents

A series of novel cinnamic acid metronidazole ester derivatives have been designed and synthesized, and their biological activities were also evaluated as potential EGFR and HER-2 kinase inhibitors. Compound 3h showed the most potent biological activity (IC₅₀ = 0.62 μM for EGFR and IC₅₀ = 2.15 μM for HER-2). Docking simulation was performed to position compound 3h into the EGFR active site to determine the probable binding model. Antiproliferative assay results demonstrated that some of these compounds possessed good antiproliferative activity against MCF-7. Compound 3h with potent inhibitory activity in tumor growth inhibition may be a potential anticancer agent.     

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.     

Synthesis,biological evaluation and molecular docking studies of chromone hydrazone derivatives as α-glucosidase inhibitors

A series of chromone hydrazone derivatives 4a–4p have been synthesized, characterized by ¹H NMR and ¹³C NMR and evaluated for their in vitro α-glucosidase inhibitory activity. Out of these tested compounds, six (4a, 4b, 4d, 4j, 4o and 4p) displayed potent α-glucosidase inhibitory activity with IC₅₀ values in the range of 20.1 ± 0.19 μM to 45.7 ± 0.23 μM, as compared to the standard drug acarbose (IC₅₀ = 817.38 ± 6.27 μM). Among this series, compound 4d (IC₅₀ = 20.1 ± 0.19 μM) with 4-sulfonamide substitution at phenyl part of hydrazide was found to be the most active compound. Lineweaver-Burk plot analysis indicated that compound 4d is a non-competitive inhibitor of α-glucosidase. The binding interactions of the most active analogs were confirmed through molecular docking studies. Docking studies showed 4d are interacting with the residues Glu-276, Asp-214, Asp-349 and Arg-439 through hydrogen bonds, arene-anion and arene-cation interactions. In summary, our studies shown that these chromone hydrazone derivatives are a new class of α-glucosidase inhibitors.     

Discovery of (R)-5-(benzo[d][1,3]dioxol-5-yl)-7-((1-(vinylsulfonyl)pyrrolidin-2-yl)methyl)-7H-pyrrolo[2,3-d]pyrimidin-4-amine (B6) as a potent Bmx inhibitor for the treatment of NSCLC

Described as a Btk inhibitor, ibrutinib also potently inhibits Bmx and EGFR, two good targets for lung cancer. Owing to its high CLogP (4.07) and low aqueous solubility (<0.01 mg/ml), resulting in unfavorable bioavailability, ibrutinib requires high dosages to achieve good clinical response in the treatment of non-small cell lung cancer (NSCLC). In our effort to improve the CLogP of ibrutinib by structural optimization led to the discovery of a potent anti-cancer agent B6, with beneficial physicochemical parameters (CLogP = 2.56, solubility in water ≈ 0.1 mg/ml) meeting the principles of oral drugs. B6 exhibited anti-proliferation activities against EGFR-expressing cells, especially the mutant ones, such as H1975 (L858R/T790M, IC₅₀ = 0.92 ± 0.19 μM) and HCC827 (Del119 IC₅₀ = 0.014 ± 0.01 μM). Moreover, B6 significantly slowed down H1975 tumor growth with anti-tumor rate of 73.9% (p < 0.01). Enzyme potencies assay demonstrated B6 moderately selectively inhibited Bmx (IC₅₀ = 35.7 ± 0.1 nM) over other kinases. So, as a potent Bmx inhibitor, B6 has the potential to be an efficacious treatment for NSCLC with acquired drug resistance.     

Novel inhibitors of epidermal growth factor receptor: (4-(Arylamino)-7H-pyrrolo[2,3-d]pyrimidin-6-yl)(1H-indol-2-yl)methanones and (1H-indol-2-yl)(4-(phenylamino)thieno[2,3-d]pyrimidin-6-yl)methanones

Several members of the quinazoline class of known tyrosine kinase inhibitors are approved anticancer agents, often showing selectivity for receptors of the HER/ErbB-family. Combining structural elements of this class with the bisindolylmethanone-structure led to a series of novel compounds. These compounds inhibited EGFR in the nanomolar range. Moreover, inhibition of EGFR autophosphorylation in intact A431 cells was shown, with IC₅₀ values ranging form 0.3–1 μM for compound 42, and 0.1–0.3 μM for 45. In a panel of 42 human tumor cell lines the sensitivity profile of the novel compounds was shown to be similar to that of the quinazoline class of tyrosine kinase inhibitors lapatinib and erlotinib (Tarceva®).     

Design,synthesis and biological evaluation of novel 6-alkenylamides substituted of 4-anilinothieno[2,3-d]pyrimidines as irreversible epidermal growth factor receptor inhibitors

A novel series of 6-alkenylamides of 4-anilinothieno[2,3-d]pyrimidine derivatives was designed, synthesized and evaluated as irreversible inhibitors of the epidermal growth factor receptor (EGFR). Most of the compounds exhibited good potency against EGFR wild type (EGFR wt) and EGFR T790M/L858R. Among these, the half-maximal inhibitory concentration (IC₅₀) values of 17 compounds against EGFR wt were less than 0.020 μM, and those of 12 compounds were less than 0.010 μM. The IC₅₀ values of 10 compounds against EGFR T790M/L858R were less than 0.005 μM. Compounds 8l, 9n, 9o, 9q and 9v almost completely blocked the phosphorylation of EGFR in the A431 cell line at 1 μM. Compounds 8l, 9n, 9o, 9q and 9v blocked the autophosphorylation of EGFR in NCI-H1975 cells at high concentration (1 μM), and compound 8l was confirmed to be an irreversible inhibitor through the dilution method.     

Design,synthesis, docking and biological evaluation of 4-phenyl-thiazole derivatives as autotaxin (ATX) inhibitors

The autotaxin-lysophophatidic acid (ATX-LPA) signaling pathway is involved in several human diseases such as cancer, autoimmune diseases, inflammatory diseases neurodegenerative diseases and fibrotic diseases. Herein, a series of 4-phenyl-thiazole based compounds was designed and synthesized. Compounds were evaluated for their ATX inhibitory activity using FS-3 and human plasma assays. In the FS-3 assay, compounds 20 and 21 significantly inhibited the ATX at low nanomolar level (IC₅₀ = 2.99 and 2.19 nM, respectively). Inhibitory activity of 21 was found to be slightly better than PF-8380 (IC₅₀ = 2.80 nM), which is one of the most potent ATX inhibitors reported till date. Furthermore, 21 displayed higher potency (IC₅₀ = 14.99 nM) than the first clinical ATX inhibitor, GLPG1690 (IC₅₀ = 242.00 nM) in the human plasma assay. Molecular docking studies were carried out to explore the binding pattern of newly synthesized compounds within active site of ATX. Docking studies suggested the putative binding mode of the novel compounds. Good ATX inhibitory activity of 21 was attributed to the hydrogen bonding interactions with Asn230, Trp275 and active site water molecules; electrostatic interaction with catalytic zinc ion and hydrophobic interactions with amino acids of the hydrophobic pocket.     

Design,synthesis, X-ray studies,and biological evaluation of novel macrocyclic HIV-1 protease inhibitors involving the P1′-P2′ ligands

Design, synthesis, and evaluation of a new class of HIV-1 protease inhibitors containing diverse flexible macrocyclic P1′-P2′ tethers are reported. Inhibitor 5a with a pyrrolidinone-derived macrocycle exhibited favorable enzyme inhibitory and antiviral activity (K_i = 13.2 nM, IC₅₀ = 22 nM). Further incorporation of heteroatoms in the macrocyclic skeleton provided macrocyclic inhibitors 5m and 5o. These compounds showed excellent HIV-1 protease inhibitory (K_i = 62 pM and 14 pM, respectively) and antiviral activity (IC₅₀ = 5.3 nM and 2.0 nM, respectively). Inhibitor 5o also remained highly potent against a DRV-resistant HIV-1 variant.     

Synthesis and biological evaluation of novel hydroxybenzaldehyde-based kojic acid analogues as inhibitors of mushroom tyrosinase

Two series of novel kojic acid analogues (4a–j) and (5a–d) were designed and synthesized, and their mushroom tyrosinase inhibitory activities was evaluated. The result indicated that all the synthesized derivatives exhibited excellent tyrosinase inhibitory properties having IC₅₀ values in the range of 1.35 ± 2.15–17.50 ± 2.75 μM, whereas standard inhibitor kojic acid have IC₅₀ values 20.00 ± 1.08 μM. Specifically, 5-phenyl-3-[5-hydroxy-4-pyrone-2-yl-methylmercap-to]-4-(2,4-dihydroxyl-benzylamino)-1,2,4-triazole (4f) exhibited the most potent tyrosinase inhibitory activity with IC₅₀ value of 1.35 ± 2.15 μM. The kinetic studies of the compound (4f) demonstrated that the inhibitory effects of the compound on the tyrosinase were belonging to competitive inhibitors. Meanwhile, the structure-activity relationship was discussed.