title: New metabolites of C-glycosidic ellagitannin from Japanese oak sapwood.
abstract: Two unusual ellagitannin metabolites, quercusnins A (3) and B (4), have been isolated from the sapwood of Quercus crispula, and their structures determined by spectroscopic methods, as well as DFT calculations of (1)H and (13)C NMR chemical shifts of the possible four diastereomers. Treatment of the major ellagitannin species, vescalagin, with Shiitake mushroom (Lentinula edodes) gave 3, which indicated that these unique ellagitannins were the fungal metabolites of ellagitannins.
authors.affiliation: Graduate School of Biomedical Sciences, Nagasaki University , 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Omar
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Hajime
authors.initials: H
authors.lastname: Maeda
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Saito
authors.forename: Takashi
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D047348:Hydrolyzable Tannins / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D029963:Quercus / Q000737:chemistry*; D014934:Wood / Q000737:chemistry
chemical_list: D047348:Hydrolyzable Tannins; C000588720:quercusnin A; C000588721:quercusnin B; C084709:vescalagin