Design, synthesis, and biological evaluation of novel benzimidazole derivatives as sphingosine kinase 1 inhibitor.

Sphingosine kinase 1 (SphK1) has emerged as an attractive drug target for different diseases. Recently, discovered SphK1 inhibitors have been recommended in cancer therapeutics; however, selectivity and potency are great challenges. In this study, a novel series of benzimidazoles was synthesized and evaluated as SphK1 inhibitors.

Part III: Novel checkpoint kinase 2 (Chk2) inhibitors; design, synthesis and biological evaluation of pyrimidine-benzimidazole conjugates.

Recently a dramatic development of the cancer drug discovery has been shown in the field of targeted cancer therapy. Checkpoint kinase 2 (Chk2) inhibitors offer a promising approach to enhance the effectiveness of cancer chemotherapy. Accordingly, in this study many pyrimidine-benzimidazole conjugates were designed and twelve feasible derivatives were selected to be synthesized to investigate their activity against Chk2 and subjected to study their antitumor activity alone and in combination with the genotoxic anticancer drugs cisplatin and doxorubicin on breast carcinoma, (ER+) cell line (MCF-7).

Part II: New candidates of pyrazole-benzimidazole conjugates as checkpoint kinase 2 (Chk2) inhibitors.

The development of checkpoint kinase 2 (Chk2) inhibitors for the treatment of cancer has been an ongoing and attractive objective in drug discovery. In this study, twenty-one feasible pyrazole-benzimidazole conjugates were synthesized to study their effect against Chk2 activity using Checkpoint Kinase Assay. The antitumor activity of these compounds was investigated using SRB assay.

Part I: Design, synthesis and biological evaluation of novel pyrazole-benzimidazole conjugates as checkpoint kinase 2 (Chk2) inhibitors with studying their activities alone and in combination with genotoxic drugs.

Activated checkpoint kinase 2 (Chk2) is a tumor suppressor as one of the main enzymes that affect the cell cycle. 2-Biarylbenzimidazoles are potent selective class of Chk2 inhibitors; the structure-based design was applied to synthesize a new series of this class with replacing the lateral aryl group by substituted pyrazoles. Ten pyrazole-benzimidazole conjugates from the best fifty candidates according to docking programs have been subjected to chemical synthesis in this study.

Synthesis of (benzimidazol-2-yl)aniline derivatives as glycogen phosphorylase inhibitors.

A series of (benzimidazol-2-yl)-aniline (1) derivatives has been synthesized and evaluated as glycogen phosphorylase (GP) inhibitors. Kinetics studies revealed that compounds displaying a lateral heterocyclic residue with several heteroatoms (series 3 and 5) exhibited modest inhibitory properties with IC values in the 400-600μM range. Arylsulfonyl derivatives 7 (Ar: phenyl) and 9 (Ar: o-nitrophenyl) of 1 exhibited the highest activity (series 2) among the studied compounds (IC 324μM and 357μM, respectively) with stronger effect than the p-tolyl analogue 8.

New benzimidazoles and their antitumor effects with Aurora A kinase and KSP inhibitory activities.

A newly synthesized series of anticancer compounds comprising thiazolo[3,2-a]pyrimidine derivatives 6a-q bearing a benzimidazole moiety was produced via a one-pot reaction of N-(4-(1H-benzo[d]imidazol-2-yl)phenyl)-2-cyanoacetamide 5 with 2-aminothiazole and an appropriate aromatic aldehyde. Compound 7 was obtained via the reaction of 4-(1H-benzo[d]imidazol-2yl)benzenamide 1 with carbon disulphide and methyl iodide in the presence of concentrated aqueous solution of NaOH, then treated with o-phenylenediamine to give N-(4-1H-benzo[d]imidazol-2-yl)phenyl)-1H-benzo[d]imidazol-2-amine 8. The structures of the newly synthesized compounds were confirmed by analytical and spectroscopic measurements (IR, MS, and (1) H NMR).

Synthesis, molecular modeling, and biological evaluation of novel benzimidazole derivatives as inhibitors of hepatitis C virus RNA replication.

In this study, synthesis and docking studies of a series of new benzimidazole derivatives linked to substituted pyrimidines either through the methylenethio linkage or its bioisosteric methylene amino bridge were carried out. All the synthesized compounds were evaluated for their hepatitis C virus (HCV) RNA replication-inhibitory activity. Compounds 4d, 4f, and 4h were found to be more potent than VX-950 (IC50/90 of 4d=0.

Design, synthesis and molecular docking study of novel quinoxalin-2(1H)-ones as anti-tumor active agents with inhibition of tyrosine kinase receptor and studying their cyclooxygenase-2 activity.

On continuation to our work, new quinoxalin-2(1H)-ones were synthesized to study their cytotoxic effect against HepG-2 and MCF-7 with their effect on the human tyrosine kinase (TRK). Compounds 12, 18, 15, 13, 11a, 20 and 16, respectively, were found to be more potent than cisplatin against HepG2 and selective to TRK. Also, compounds 12, 18, 20, 13, 14, and 22, respectively, exhibited decidedly activity against MCF-7 and selectivity against human TRK compared to cisplatin.

Design, synthesis and structure-activity relationship of novel quinoxaline derivatives as cancer chemopreventive agent by inhibition of tyrosine kinase receptor.

The cancer chemopreventive activity of quinoxaline derivatives 1-20 has been evaluated by studying the inhibitory effect on Epstein-Barr virus early antigen (EBV-EA) activation. The quinoxaline derivatives 1-20 showed inhibitory effect on EBV-EA activation without cytotoxicity on Raji cells. All compounds exhibited dose dependent inhibitory activities, most of them showed significant activity at 1000 mol ratio/12-O-tetradecanoylphorbol-13-acetate (TPA).

Synthesis and docking studies of novel antitumor benzimidazoles.

In this work, the benzimidazole-pyrrole conjugates 6a-h and benzimidazole-tetracycles conjugates 12-14 were prepared. The cytotoxicity of the compounds 3, 4a-h, 6a-h, 8, 10 and 12-14 was tested against lung cancer cell line A549. Compound 6b exhibited higher activity than the bis-benzoxazole natural product (UK-1), the standard.

Part I: Synthesis, cancer chemopreventive activity and molecular docking study of novel quinoxaline derivatives.

The reaction of o-phenylene diamine and ethyl oxamate is reinvestigated and led to 3-aminoquinoxalin-2(1H)-one rather than benzimidazole-2-carboxamide as was previously reported. The structure of the obtained quinoxaline has been confirmed by X-ray. The anti-tumor activity of synthesized quinoxalines 1-21 has been evaluated by studying their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA).

Synthesis and antitumor activity of novel benzimidazole-5-carboxylic acid derivatives and their transition metal complexes as topoisomerease II inhibitors.

N-aminomethyl-1H-benzimidazole-5-carboxylic acid derivatives 2-5 and the ligand, 1-(5 (or 6-)-carboxy-1H-benzimidazol-2-ylmethyl)pyridinium chloride (6; H2L1) have been synthesized. New benzimidazole complexes 7-9 of the ligand 6; H2L1 with Cu2+, Co2 and Zn2+ were prepared. The growth-inhibitory against a panel of 21 human cancer cell lines of the synthesized compounds 1-9 was studied.

Novel antiviral benzofuran-transition metal complexes.

(5-(1H-benzo[d]imidazol-2-yl)-1H-pyrrol-3-yl)(6-hydroxy-4,7-dimethoxybenzofuran-5-yl)methanone (4) and 3-(6-hydroxy-4,7-dimethoxybenzofuran-5-carbonyl)-6H-pyrimido[1,6-a]pyrimidine-6,8(7H)-dione (5) were synthesized by the reaction of 4,7-dimethoxy-5-oxo-5H-furo[3,2-g]chromene-6-carbaldehyde (1) with (1H-benzo[d]imidazol-2-yl)methanamine dihydrochloride and 4-amino-2,6-dihydroxypyrimidine, respectively, via ROR in the presence of alcoholic KOH. The metal complexes 6-9 of compound 4; H(2)L(1) with (CuCl(2), FeCl(3), ZnCl(2), and LaCl(3)) and the metal complexes 10-13 of compound 5; H(2)L(2) with (CuCl(2), FeCl(3), CoCl(2) and LaCl(3)) were synthesized to form 1:1 or 1:2 (metal: ligand) complexes. The HIV inhibitory activity of all new compounds was tested.

Synthesis of potent antitumor and antiviral benzofuran derivatives.

A new series of potent antitumor and antiviral benzofuran derivatives was synthesized by the reaction of the furochromone-6-carboxaldehydes 1 and 2 with different heterocyclic amines to yield the benzofuran-5-carbonyl derivatives 4-11. The synthesized compounds 1, 3-11 were tested against twelve different human cancer cell lines and all of the compounds were more potent than the comparative standards. The HIV inhibitory activity of the tested compounds 1, 3-11 showed that they have higher potency than Atevirdine.

New transition metal ion complexes with benzimidazole-5-carboxylic acid hydrazides with antitumor activity.

Metal complexes of 2-methyl-1H-benzimidazole-5-carboxylic acid hydrazide (4a; L(1)) and its Schiff base 2-methyl-N-(propan-2-ylidene)-1H-benzimidazole-5-carbohydrazide (5a; L(2)) with transition metal ions e.g., copper, silver, nickel, iron and manganese were prepared.