title: New resveratrol tetramers from the stem bark of Upuna borneensis.
abstract: Five new resveratrol (=5-[(E)-2-(4-hydroxyphenyl)ethenyl]benzene-1,3-diol) tetramers, upunaphenols H-J (1-3) and trans-(4) and cis-upunaphenol K (5), were isolated from the stem of Upuna borneensis (Dipterocarpaceae). Their structures were elucidated on the basis of 1D- and 2D-NMR as well as FAB-MS data. Compounds 1-3 bear a rare biphenyl bond in their frameworks. Compounds 1 and 2 have an unprecedented nonacyclic fused ring system, and compounds 2 and 3 have symmetrical structures.
authors.affiliation: Gifu Prefectural Institute of Health and Environmental Sciences, 1-1 Naka-fudogaoka, Kakamigahara 504-0838, Japan. zvn00510@nifty.ne.jp
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ito
authors.forename: Zulfiqar
authors.initials: Z
authors.lastname: Ali
authors.forename: Miyuki
authors.initials: M
authors.lastname: Furusawa
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Iliya
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Nakaya
authors.forename: Jin
authors.initials: J
authors.lastname: Murata
authors.forename: Dedy
authors.initials: D
authors.lastname: Darnaedi
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Oyama
authors.forename: Munekazu
authors.initials: M
authors.lastname: Iinuma
mesh_terms: D020448:Ericales; D015394:Molecular Structure; D024301:Plant Bark; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D018547:Plant Stems; D000077185:Resveratrol; D013267:Stilbenes / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D010936:Plant Extracts; D013267:Stilbenes; D000077185:Resveratrol