title: Triterpenoids from the leaves of Psidium guajava.
abstract: Two triterpenoids, 20beta-acetoxy-2alpha,3beta-dihydroxyurs-12-en-28-oic acid (guavanoic acid, 3), and 2alpha,3beta-dihydroxy-24-p-z-coumaroyloxyurs-12-en-28-oic acid (guavacoumaric acid, 7), along with six known compounds 2alpha-hydroxyursolic acid (1), jacoumaric acid (2), isoneriucoumaric acid (4), asiatic acid (5), ilelatifol D (6) and beta-sitosterol-3-O-beta-D-glucopyranoside (8), have been isolated from the leaves of Psidium guajava. Their structures were determined through spectroscopic methods. Compound 5 showed dose-dependent (10-500 microg/ml) spasmolytic activity in spontaneously contracting isolated rabbit jejunum preparations.
authors.affiliation: H.E.J. Research Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan. sabira@khi.comsaats.net.pk
authors.forename: Sabira
authors.initials: S
authors.lastname: Begum
authors.forename: Syed Imran
authors.initials: SI
authors.lastname: Hassan
authors.forename: Bina S
authors.initials: BS
authors.lastname: Siddiqui
authors.forename: Farhana
authors.initials: F
authors.lastname: Shaheen
authors.forename: M Nabeel
authors.initials: MN
authors.lastname: Ghayur
authors.forename: Anwar H
authors.initials: AH
authors.lastname: Gilani
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*; D031647:Psidium / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D014315:Triterpenes; C473527:guavacoumaric acid; C473526:guavanoic acid