title: New antimicrobial alkaloids from the roots of Polyalthia longifolia var. pendula.
abstract: Bioassay-guided isolation studies on the root extract of Polyalthia longifolia var. pendula possessing significant antibacterial activity led to the isolation of three new alkaloids pendulamine A (1), pendulamine B (2) and penduline (3) along with stigmasterol 3-O-beta-D-glucoside, allantoin, the known diterpenoid kolavenic acid, and the azafluorene alkaloid isoursuline. The structures of these compounds have been elucidated with the help of spectroscopic studies including 2D NMR experiments. Compounds 1 and 2, which are the only protoberberine alkaloids having a monosubstituted A ring with a hydroxy group at C-3, were found to be the active antibacterial principles of the roots. Their MIC values ranged between 0.02-20 microg against the tested bacteria.
authors.affiliation: H.E.J. Research Institute of Chemistry, International Center for Chemical Sciences, University of Karachi, Karachi, Pakistan. shaheen@khi.comsats.net.pk
authors.forename: Shaheen
authors.initials: S
authors.lastname: Faizi
authors.forename: Rashid Ali
authors.initials: RA
authors.lastname: Khan
authors.forename: Soobia
authors.initials: S
authors.lastname: Azher
authors.forename: Shakeel Ahmed
authors.initials: SA
authors.lastname: Khan
authors.forename: Saima
authors.initials: S
authors.lastname: Tauseef
authors.forename: Aqeel
authors.initials: A
authors.lastname: Ahmad
mesh_terms: D000470:Alkaloids / Q000008:administration & dosage / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D018517:Plant Roots; D031044:Polyalthia
chemical_list: D000470:Alkaloids; D000900:Anti-Bacterial Agents; D010936:Plant Extracts