S. B. Benaka Prasad

Synthesis and in vitro antiproliferative activity against human cancer cell lines of novel 5-(4-methyl-benzylidene)-thiazolidine-2,4-diones

SummaryA series of novel 5-(4-methyl-benzylidene)-thiazolidine-2,4-dione derivatives 6 (a–d) and 7 (a–g) were synthesized with different substituted aromatic sulfonyl chlorides (R–SO2–Cl) and alkyl halides (R–X) and were characterized by 1H NMR, LC/MS, FTIR and elemental analyses. All the compounds synthesised were evaluated for their cell antiproliferation activity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The antiproliferative effects of the synthesised compounds were tested against viable human skin fibroblast cell line and carcinoma cell lines namely HeLa cells, HT-29 cells, MCF-7 cells, HepG-2 cells by adopting positive and negative control. The importance of the nitro group on thiazolidinone moiety was confirmed and it was concluded that the fourth position of the substituted aryl ring plays a dominant role and was responsible for the antiproliferative activity. Among the synthesized compounds only 6a, 7e and 7g have potent antiproliferative activity on all the carcinoma cell lines tested.

Synthesis and in vitro antiproliferative activity of novel 1-benzhydrylpiperazine derivatives against human cancer cell lines

In order to explore the antiproliferative effect associated with the piperazine framework, several 1-benzhydrylpiperazine derivatives 8(a-d), 9(a-d) and 10(a-h) were synthesized. Variation in the functional group at N-terminal of the piperazine led to three sets of compounds, bearing the sulfonyl, amide and thiourea, respectively. Their chemical structures were confirmed by (1)H NMR, LCMS, IR and elemental analysis. The antiproliferative effect of the compounds were evaluated in vitro using the MTT colorimetric method against one normal cell line (NF-103 skin fibroblast cells) and four human cancer cell lines (MCF-7 breast carcinoma cell line, HepG-2 hepatocellular carcinoma cell line, HeLa cervix carcinoma cell line and HT-29 colon carcinoma cell line) for the time period of 24 h. Among the series, four compounds exhibited interesting growth inhibitory effects against all four cell lines.

Synthesis and evaluation of 1-benzhydryl-sulfonyl-piperazine derivatives as inhibitors of MDA-MB-231 human breast cancer cell proliferation

A series of novel 1-benzhydryl-sulfonyl-piperazine derivatives 7(a-e) were designed by a nucleophilic substitution reaction of 1-benzhydryl-piperazine with various sulfonyl chlorides and characterized by 1H nuclear magnetic resonance (NMR), liquid chromatography mass spectrometry (LC/MS), Fourier-transform infrared (FTIR), and elemental analysis. Our research is focused on identifying synthetically occurring chemotherapeutic substances capable of inhibiting, retarding, or reversing the process of multistage carcinogenesis. The title compounds were evaluated for their efficacy in inhibiting MDA-MB-231 breast cancer cell proliferation. Compound 1-benzhydryl-4-(4-tert-butyl-benzenesulfonyl)-piperazine (7d) showed significant inhibitory activity.

Synthesis and antimicrobial studies of novel 1-benzhydryl-piperazine sulfonamide and carboxamide derivatives

A series of novel substituted 1-benzhydryl-piperazine sulfonamide 8(a–f) and benzamides 9(a–h) were synthesized and their antimicrobial activities evaluated in vitro by paper disc diffusion and micro dilution method against standard strains of Gram-positive (Staphylococcus aureus ATCC 25953, Staphylococcus epidermis 25212, Bacillus cereus 11778, Bacillus substilis 6051) and Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 2853, Proteus vulgaris ATCC 2853 and Salmonella typhi ATCC 9484) bacteria. Among the synthesized new compounds 8d, 8e, 9c, 9e, 9f and 9 h showed potent antimicrobial activities compared to the standard drug streptomycin.

Effect of novel N-aryl sulfonamide substituted 3-morpholino arecoline derivatives as muscarinic receptor 1 agonists in Alzheimer’s dementia models

A series of novel, potent, and selective muscarinic receptor 1 agonists (M1 receptor agonists) that employ a key N-substituted morpholine Arecoline moiety has been synthesized as part of research effort for the therapy of Alzheimers diseases. The ester group of arecoline (which is reported as muscarinic agonist) has been replaced by N-substituted morpholine ring. The structure-activity relationship reveals that the electron donating 4-substituted sulfonyl derivatives (9a, 9b, 9c, and 9e) on the nitrogen atom of the morpholine ring increases the affinity of M1 receptor binding 50- to 80-fold greater than the corresponding arecoline. Other derivatives also showed considerable M1 receptor binding affinity.

Evaluation of in vivo wound-healing potential of 2-[4-(2,4-dimethoxy-benzoyl)-phenoxy]-1-[4-(3-piperidin-4-yl-propyl)-piperidin-1-yl]-ethanone derivatives

Series of 2-[4-(2,4-dimethoxy-benzoyl)-phenoxy]-1-[4-(3-piperidin-4-yl-propyl)-piperidin-1-yl]-ethanone derivatives 9(a-d) and 10(a-d) were synthesized in good yield. The synthesized compounds were characterized by (1)H NMR, LC-MS, FTIR and elemental analysis. All the compounds were screened for in vivo wound-healing activity by incision and dead space wound models on Swiss albino rats. Significant wound healing was observed in 10b and 10d treated groups as also the epithelialization of the incision wound was faster with a high rate of wound contraction in these groups. The tensile strength of the incision wound was significantly increased in 10b and 10d compared to the Nitrofurazone, the standard skin ointment. In dead space wound model also the weight of the granulation was higher indicating increase in collagenation. The SAR correlation studies revealed that the thioamide functional linkage and electron withdrawing groups influence the wound-healing activity.

Synthesis and in vitro antiproliferative activity of diphenyl(sulphonylpiperidin-4-yl)methanol derivatives

A series of novel diphenyl(piperidin-4-yl)methanol derivatives 10(a–n) were synthesized and characterized by 1H NMR, LC/MS, FTIR, and elemental analyses. All the synthesized compounds were evaluated for cell proliferation by MTT assay. The antiproliferative effects of the synthesized compounds were tested against viable human skin fibroblast cell line and carcinoma cell lines, namely HeLa cells, HT-29 cells, MCF-7 cells, and HepG-2 cells in comparing the positive and negative control. Among the synthesized compounds, (10b) and (10g) have been identified as potent antiproliferative agents.

Synthesis of novel 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole derivatives as antiproliferative agents: A structure–activity relationship study

SummaryA series of novel 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole derivatives 5(a–m) were synthesized with different substituted aromatic/heterocyclic acid chlorides (R-CO-Cl) and characterized by 1H NMR, LC/MS, FTIR and elemental analyses. All the compounds synthesised were evaluated for their antiproliferative activity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The antiproliferative effects of the synthesised compounds were tested against viable human skin fibroblast cells and carcinoma cells namely HeLa cells, HT-29 cells, MCF-7 cells, HepG-2 cells by adopting positive and negative control. The importance of the aromatic and heterocyclic moiety was confirmed. From the SAR studies, it reveals that, the substitution at N-terminal of 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole by the heterocyclic ring plays a dominant role and was responsible for the antiproliferative activity. Among the synthesized compounds 5a, 5d and 5k have showed potent antiproliferative activity on all the carcinoma cells tested.

Synthesis and antimicrobial activity of 1-benzhydryl-sulfonyl-4-(3-(piperidin-4-yl) propyl)piperidine derivatives against pathogens of Lycopersicon esculentum: a structure-activity evaluation study.

Several 1-benzhydryl-sulfonyl-4-(3-(piperidin-4-yl)propyl)piperidine derivatives 8(a–j) were prepared by the treatment of substituted benzhydryl chlorides with 4-(3-(piperidin-4-yl)propyl)piperidine followed by N-sulfonation with sulfonyl chlorides in the presence of dry methylene dichloride and triethyl amine. The synthesized compounds were characterized by 1H-NMR, IR, and elemental analysis. All the synthesized compounds were evaluated in vitro for their efficacy as antimicrobial agents by artificial inoculation technique against standard strains of two important bacterial viz., Xanthomonas axonopodis pv. vesicatoria and Ralstonia solanacearum as well as and two fungal pathogens namely Alternaria solani and Fusarium solani of tomato plants. We have briefly investigated the structure-activity relation studies and reveal that the nature of substitutions on benzhydryl ring and sulfonamide ring influences the antibacterial activity. Among the synthesized new compounds 8b, 8d, 8g, 8h, 8i, and 8j were showed significant potent antimicrobial activities compared to the standard drugs Chloramphenicol, Mancozeb.

Synthesis and Evaluation of 1-Benzhydryl-sulfonyl-piperazine Derivatives as Inhibitors of Tumor Growth and Tumor Angiogenesis of Mouse Ehrlich Ascites Tumor In Vivo

A series of novel 1-benzhydryl-sulfonyl-piperazine derivatives 3(a-e) were synthesized by nucleophilic substitution reaction of 1-benzhydryl-piperazine with different sulfonyl chlorides and were characterized by 1H NMR, LC/MS, FTIR and elemental analysis. In the present study, the compounds 3(a-e) exhibited in vivo inhibition of Ehrlich ascites tumor (EAT) cell growth and increased the Median Survival Time (MST) and %ILS of EAT bearing mice. Further treatment of derivatives in vivo resulted in reduction of EAT cell number and ascites formation. The efficacy of the derivatives to inhibit the angiogenesis in vivo was evaluated in tumor bearing mice peritoneum and chorio allantoic membrane (CAM) model. The compounds suppressed the blood vessel formation in vivo in mice peritoneum and in CAM. Among the compounds studied, 3e demonstrated highest tumor inhibitory and anti-angiogenic effects against mouse tumor. However, this phenomenon needs detailed investigation.