title: Hantzsch reaction: synthesis and characterization of some new 1,4-dihydropyridine derivatives as potent antimicrobial and antioxidant agents.
abstract: In the present study two new series of Hantzsch 1,4-dihydropyridine derivatives (1,4-DHPs) containing substituted pyrazole moiety (4a-f and 5a-f) were synthesized by the reaction of 3-aryl-1H-pyrazole-4-carbaldehydes with 1,3-dicarbonylcompounds (ethylacetoacetate and methylacetoacetate) and ammonium acetate. The newly synthesized compounds were characterized by IR, NMR, mass spectral study and also by C, H, N analyses. New compounds were screened for their antimicrobial activity by well plate method (zone of inhibition). Antioxidant studies of the synthesized compounds were also performed by measuring the DPPH radical scavenging assay. Compounds 4c, 4e and 4f were found to be potent antibacterial and antioxidant agents. The acute oral toxicity study for the compounds 4c, 4e and 4f were carried out and the experimental studies revealed that compounds 4c and 4e is safe up to 3000 mg/kg and no death of animals were recorded. However in compound 4f, we found mortality above 2000 mg and also significant behavioral changes in experimental animals.
authors.affiliation: SeQuent Scientific Ltd, No 120 A & B, Industrial Area, Baikampady, New Mangalore, Karnataka 575 011, India.
authors.forename: A M
authors.initials: AM
authors.lastname: Vijesh
authors.forename: Arun M
authors.initials: AM
authors.lastname: Isloor
authors.forename: S K
authors.initials: SK
authors.lastname: Peethambar
authors.forename: K N
authors.initials: KN
authors.lastname: Shivananda
authors.forename: T
authors.initials: T
authors.lastname: Arulmoli
authors.forename: Nishitha A
authors.initials: NA
authors.lastname: Isloor
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D001419:Bacteria / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D001713:Biphenyl Compounds / Q000737:chemistry; D060326:Chemistry Techniques, Synthetic / Q000379:methods*; D004095:Dihydropyridines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D005260:Female; D016166:Free Radical Scavengers / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D005658:Fungi / Q000187:drug effects; D051379:Mice; D010851:Picrates / Q000737:chemistry
chemical_list: D000890:Anti-Infective Agents; D001713:Biphenyl Compounds; D004095:Dihydropyridines; D016166:Free Radical Scavengers; D010851:Picrates; C038806:1,4-dihydropyridine; C004931:1,1-diphenyl-2-picrylhydrazyl