title: Synthesis and antibacterial screening of hydrazones, Schiff and Mannich bases of isatin derivatives.
abstract: Schiff bases and hydrazones of substituted isatins (1-28) were prepared by reacting isatin and aromatic primary amines/hydrazines. A new series of the corresponding N-Mannich base (29-35) was synthesised by reacting them with formaldehyde and diphenyl amine. The chemical structures were confirmed by means of 1H-NMR, IR spectral data and elemental analysis. The compounds were screened for antibacterial activity against seven Gram (+) and seven Gram (-) standard and pathological bacterial strains by the paper disc diffusion technique. The minimum inhibitory concentrations of the active compounds were determined. 1-Diphenyl amino-methyl-3-(4-bromo phenylimino)-1,3-dihydro-indol-3-one (30) and 3-(4-bromo phenylimino)-5-nitro-1,3-dihydro-indol-3-one (13) were found to be the most active compounds of the series. Mannich bases exhibited higher activity than the corresponding Schiff bases.
authors.affiliation: Department of Pharmaceutical Chemistry, Vel's College of Pharmacy, 600 117, Chennai, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Sridhar
authors.forename: M
authors.initials: M
authors.lastname: Saravanan
authors.forename: A
authors.initials: A
authors.lastname: Ramesh
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D004353:Drug Evaluation, Preclinical / Q000379:methods; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006835:Hydrazones / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis / Q000494:pharmacology*; D007510:Isatin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology*; D008352:Mannich Bases / Q000737:chemistry*; D008826:Microbial Sensitivity Tests / Q000379:methods; D012545:Schiff Bases / Q000737:chemistry*
chemical_list: C445520:1-diphenyl amino-methyl-3-(4-bromo phenylimino)-1,3-dihydro-indol-3-one; C445521:3-(4-bromo phenylimino)-5-nitro-1,3-dihydro-indol-3-one; D000900:Anti-Bacterial Agents; D006835:Hydrazones; D007211:Indoles; D008352:Mannich Bases; D012545:Schiff Bases; D007510:Isatin