Kallappa M. Hosamani

In-vivo analgesic and anti-inflammatory activities of newly synthesized benzimidazole derivatives

A series of 2-methylaminobenzimidazole derivatives (1-11) were synthesized by the reaction of 2-(chloromethyl)-1H-benzimidazole derivatives with primary aromatic amines. All these compounds were characterized by IR, 1H NMR, 13C NMR, GC-MS and elemental analysis. The newly synthesized compounds were screened for analgesic and anti-inflammatory activities on acetic acid induced writhing in mice and carrageenan induced paw oedema in rats. Compounds (7) and (2) showed a potent analgesic (89% at 100 mg/kg b.w) and anti-inflammatory (100% at 100 mg/kg b.w) activities compared with standard drug Nimesulide (100% at 50 mg/kg b.w) respectively. The other compounds showed good analgesic and anti-inflammatory activities.

Derivatives of benzimidazole pharmacophore: Synthesis, anticonvulsant, antidiabetic and DNA cleavage studies

In seeking broad spectrum pharmacological activities of benzimidazole derivatives, a group of 4-thiazolidinones 5(a-j) and 1,3,4-oxadiazoles 6(a-j) containing 2-mercapto benzimidazole moiety were synthesized and screened for in vivo anticonvulsant activity by Maximal Electroshock (MES) model and antidiabetic activity using Oral Glucose Tolerance Test (OGTT). Compounds (5c), (5d), (5g) and (5i) exhibited potent anticonvulsant results and (6c), (6d), (6h) and (6i) showed excellent antidiabetic activities and also pharmacophore derived from active molecules suggested that presence of -OH group was a common feature in all active compounds. In DNA cleavage studies, compound (5d) cleaved DNA completely as no trace of DNA was found. On the other hand, a sharp streak was found for compounds (5c), (6a) and (6d).

Synthesis and evaluation of in vitro anti-microbial and anti-tubercular activity of 2-styryl benzimidazoles.

A new series of novel 5-(nitro/bromo)-styryl-2-benzimidazoles (1-12) has been synthesized by simple, mild and efficient synthetic protocol by attempted condensation of 5-(nitro/bromo)-o-phenylenediamine with trans-cinnamic acids in ethylene glycol. Screening for in vitro anti-tubercular activity against Mycobacterium tuberculosis H(37) Rv, anti-bacterial activity against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae bacterial strains and anti-fungal activity against Candida albicans and Asperigillus fumigatus fungal strains were carried out. Compounds 5, 7, 8, 9, 11 showed higher anti-tubercular activity and compounds 7, 8, 10, 11, 12 have proved to be effective with MIC (microg/ml) and emerged as lead molecules showing excellent activities against a panel of microorganisms. All synthesized compounds were characterized using IR, (1)H, (13)C NMR, GC-MS and elemental analysis.

Analgesic, anti-pyretic and DNA cleavage studies of novel pyrimidine derivatives of coumarin moiety.

A novel series of 4-[4-(6-phenyl-pyrimidin-4-yl)-phenoxymethyl]-chromen-2-ones [5-7(a-e)] were synthesized from various 4-bromomethyl coumarins 1(a-e). The synthesized compounds were screened for in-vivo analgesic and anti-pyretic activities at a dose of 25 and 100 mg/kg body weight (b.w), respectively. Among them, compounds 5(d), 6(c) and 7(d) exhibited significant analgesic activity comparable with standard drug analgin using Tail-flick model. Compounds 5(a) and 7(a-d) showed significant anti-pyretic activities comparable with standard drug aspirin using yeast-induced pyrexia model. DNA cleavage study by agarose gel electrophoresis method was also studied. Qualitative SAR studies indicate that, compounds with amino group at 2-position of pyrimidine ring enhances analgesic and anti-pyretic activities and compounds with hydroxyl and thio group at 2-position of pyrimidine ring increase DNA cleavage activities.

2-Azetidinone derivatives: design, synthesis, in vitro anti-microbial, cytotoxic activities and DNA cleavage study.

A novel series of 3-chloro-4-[4-(2-oxo-2H-chromen-4-ylmethoxy)-phenyl]-1-phenyl-azetidin-2-one derivatives (5a-j) have been synthesized from 4-aryloxymethylcoumarins (1a-e) and 4-aryliminomethyl-phenols (3a-b). The title compounds were screened for their in vitro anti-bacterial and anti-fungal activities. Results revealed that, compounds (5c), (5f), (5h) and (5j) showed excellent anti-microbial activity against a panel of microorganisms. Brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties among which (5h) and (5j) displayed potent cytotoxic activity against Artemia salina. The DNA cleavage activity of some compounds was studied by agarose gel electrophoresis method. All synthesized compounds were characterized using IR, (1)H NMR, (13)C NMR, MS and elemental analysis.

Microwave assisted, one-pot synthesis of 5-nitro- 2-aryl substituted-1H-benzimidazole libraries: Screening in vitro for antimicrobial activity

The efficient and rapid synthesis of 5-nitro-2-aryl substituted-1H-benzimidazole libraries (1a-1j) has been established. Thus, both microwave and conventional cyclo-condensation of 4-nitro ortho-phenylenediamine with various phenoxyacetic acids were carried out in the presence of HCl catalyst. The microwave synthesis route afforded advantages, such as good to excellent yields, shorter reaction time (2.5–3.5 min), readily available starting material, and simple purification procedure, which distinguish the present protocol from other existing methods used for the synthesis of benzimidazole libraries. Bioassay indicated that all the compounds showed in vitro antimicrobial activity against Vancomycin resistant enteroccoccus, Staphylococcus aureus, Micrococcus, Bacillus subtilis (gram-positive bacteria) and Shigella dysentery, Escherichia coli (gram-negative bacteria) and Candida albicans, Aspergillus niger, Penicillium (fungi). The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standards.

Industrial utilization of Rivea ornata seed oil: a moderate source of vernolic acid.

Rivea ornata seed oil was found to contain 12,13-epoxy-octadec-cis-9-enoic acid (vernolic acid, 22.0%) along with the other normal fatty acids like palmitic acid (24.2%), stearic acid (8.9%), oleic acid (17.1%) and linoleic acid (27.8%). The identification and characterization was based on Fourier transform infrared (FTIR), 1H-NMR, mass spectrometry (MS), gas–liquid chromatography (GLC)-techniques and chemical degradations.

Fatty acids in seed oil from Turnera ulmifolia

Abstract The seed oil from Turnera ulmifolia was found to contain the unusual fatty acids, 9,10-epoxy-octadec- cis -12-enoic acid (vernolic acid, 22.3%),

Cyclopropenoid fatty acids in leguminosae oils

Seed oils ofCassia grandis, Linn andDelonix elata, Gamble, Syn.Poinciana elata, Linn, belonging to the Leguminosae family contain small amounts of sterculic and malvalic acids as determined by conversion of esters with AgNO3/MeOH, NMR and IR.

Microwave-assisted synthesis of new fluorinated coumarin–pyrimidine hybrids as potent anticancer agents, their DNA cleavage and X-ray crystal studies

An efficient and rapid synthesis of 3-(2-(4-fluorobenzyl)-6-(substituted phenyl) pyrimidin-4-yl)-2H-chromen-2-one derivatives (1a–1l) under microwave-irradiation has been described in high yields. All the newly synthesized compounds (1a–1l) were characterized by elemental and spectroscopic analysis. In addition, the structure of compound (1a) and (1b) has been elucidated by the single crystal X-ray diffraction technique. The synthesized compounds (1a–1l) were evaluated for their anticancer activity against two human cancer cell lines viz., A-549 (human lung carcinoma) and MDA-MB-231 (human adenocarcinoma mammary gland). The results revealed that several synthesized compounds exhibit significant cytotoxicity against the two tested cancer cell lines with IC50 < 10 μM. Among these, compound (1j) exhibited potent activity against the A-549 cell line, which is comparable with standard drug Cisplatin, whereas compound (1b) was found extremely active against the MDA-MB-231 cell line and proved to be more potent than standard drug Cisplatin. DNA cleavage study by the gel electrophoresis method revealed that compounds (1b), (1e), (1g) and (1j) inhibit the growth of the pathogenic organism by cleaving the genome as no traces of DNA were found.