title: Bioenhancing and antimycobacterial agents from Ammannia multiflora.
abstract: The methanolic extract of Ammannia multiflora (Lythraceae) showed significant bioenhancing activity with the antibiotic nalidixic acid. Bioassay-guided fractionation of MeOH extract resulted in the isolation of a novel compound, 2,5-bis-(3,3'-hydroxyaryl)tetrahydrofuran, named as ammaniol (5), along with 9 other known compounds (1-4, 6-10). Furthermore, compound 4-hydroxy- α-tetralone (1) was converted into five semisynthetic acyl derivatives, 1A-1E, which were evaluated along with compounds 1, 5, 6, 9, and 10 for their bioenhancing activity in combination with nalidixic acid against the two strains, CA8000 and DH5 α, of Escherichia coli. The results showed that the methanolic extract of A. multiflora and compounds 1 and 9 possessed significant bioenhancing activity and reduced the dose of nalidixic acid fourfold while compounds 5, 6, 10 and semisynthetic derivatives 1A- 1E reduced the dose of nalidixic acid twofold. Compound 5 was also tested for antimycobacterial activity against Mycobacterium H37Rv and was found to show moderate activity (MIC 25 µg/mL) against this pathogen.
authors.affiliation: Analytical Chemistry Division, Central Institute of Medicinal and Aromatic Plants, P. O. CIMAP, Lucknow, India.
authors.forename: Harish C
authors.initials: HC
authors.lastname: Upadhyay
authors.forename: Gaurav R
authors.initials: GR
authors.lastname: Dwivedi
authors.forename: Mahendra P
authors.initials: MP
authors.lastname: Darokar
authors.forename: Vinita
authors.initials: V
authors.lastname: Chaturvedi
authors.forename: Santosh K
authors.initials: SK
authors.lastname: Srivastava
mesh_terms: D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000302:isolation & purification / Q000494:pharmacology; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects*; D005663:Furans / Q000302:isolation & purification / Q000494:pharmacology*; D041743:Herb-Drug Interactions; D029561:Lythraceae / Q000737:chemistry*; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D009268:Nalidixic Acid / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D044024:Tetralones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: C572587:4-hydroxy-alpha-tetralone; D000890:Anti-Infective Agents; D000995:Antitubercular Agents; D005663:Furans; D010936:Plant Extracts; D044024:Tetralones; C572586:ammaniol; D009268:Nalidixic Acid