Flavan and procyanidin glycosides from the bark of blackjack oak.
The bark of blackjack oak contains (+)-catechin, (-)-epicatechin, (+)-3-O-[beta-D-glucopyranosyl]-catechin, catechin-(4 alpha-->8)-catechin, epicatechin-(4 beta-->8)-catechin as well as the novel 3-O-[beta-D-glucopyranosyl]-catechin-(4 alpha-->8)-catechin and 3-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl]-catechin, as major components. The latter rutinoside of catechin is especially interesting because of the exceptionally small J2,3 C-ring coupling. The glucoside of catechin-(4 alpha-->8)-catechin is only the second proanthocyanidin found in nature in which a 3-O-glycoside is present in the upper 'extender unit' of a dimer.
Bae
Y S
YS
Southern Forest Experiment Station, USDA Forest Service, Pineville, LA 71360.
Burger
J F
JF
Steynberg
J P
JP
Ferreira
D
D
Hemingway
R W
RW
D044946:Biflavonoids; D002240:Carbohydrate Sequence; D002392:Catechin / Q000737:chemistry / Q000302:isolation & purification*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D044945:Proanthocyanidins; D014197:Trees / Q000737:chemistry*
D044946:Biflavonoids; D005419:Flavonoids; D006027:Glycosides; D044945:Proanthocyanidins; C017674:procyanidin; D002392:Catechin