title: A new pentacyclic triterpene with potent antibacterial activity from Limnophila indica Linn. (Druce).
abstract: A new pentacyclic triterpenoid constituent, characterized as 3-oxo-olean-12(13),18(19)-dien-29α-carboxylic acid (1) on the basis of detailed spectral studies, was isolated from the aerial parts and roots of Limnophila indica (Scrophulariaceae). Compound 1 exhibited considerable antibacterial activity against three Gram-positive bacteria viz. Bacillus subtilis, Staphylococcus aureus and Listeria monocytogenes (MICs within a range of 25-30 μg/ml) and moderate activity against four Gram-negative bacteria Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, and Pantoea ananatis (MICs within a range of 30-100 μg/ml). The plant pathogenic bacterium P. ananatis and human pathogenic S. typhimurium responded at comparatively higher concentrations of the compound 1, which were 75 and 100 μg/ml respectively. The compound inhibited the growth of Gram-positive B. subtilis and Gram-negative P. aeruginosa completely with a clear bactericidal mode of action at their MIC values. The compound upon treatment on both B. subtilis and P. aeruginosa released substantial amount of nucleic acid in the external medium and also effected the change of morphology towards pleomorphicity, thereby indicating its probable action on cell membrane. Furthermore, the triterpenoid 1 was found not to inhibit a probiotic lactic acid bacterium Lactococcus lactis subsp. lactis LABW4 under in vitro condition and to possess no toxicity in Swiss albino mice.
authors.affiliation: Laboratory of Natural Products and Organic Synthesis, Department of Chemistry, Visva-Bharati University, Santiniketan 731 235, West Bengal, India. Electronic address: brahmg2001@yahoo.co.in.
authors.forename: Goutam
authors.initials: G
authors.lastname: Brahmachari
authors.forename: Narayan C
authors.initials: NC
authors.lastname: Mandal
authors.forename: Rajiv
authors.initials: R
authors.lastname: Roy
authors.forename: Ranjan
authors.initials: R
authors.lastname: Ghosh
authors.forename: Soma
authors.initials: S
authors.lastname: Barman
authors.forename: Sajal
authors.initials: S
authors.lastname: Sarkar
authors.forename: Shyamal K
authors.initials: SK
authors.lastname: Jash
authors.forename: Sadhan
authors.initials: S
authors.lastname: Mondal
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots; D028083:Scrophulariaceae / Q000737:chemistry*
chemical_list: C000588607:3-oxo-olean-12(13),18(19)-dien-29alpha-carboxylic acid; D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D009828:Oleanolic Acid
keywords: 18(19)-dien-29α-carboxylic acid; 3-Oxo-olean-12(13),; Antibacterial activity; CC; CFU; CLSI; Clinical and Laboratory Standards Institute; DMSO; GCMS; Limnophila indica; MIC; MTCC; OA; Pentacyclic triterpene; SEM; SGOT; SGPT; Scrophulariaceae; colony forming units; column chromatography; dimethyl sulphoxide; gas chromatographic mass spectrophotometer; microbial type culture collection; minimum inhibitory concentration; oleanolic acid; scanning electron microscopy; serum glutamic pyruvic transaminase; serum glutamic-oxaloacetic transaminase