Bae Y S, Burger J F, Steynberg J P, Ferreira D, Hemingway R W
Southern Forest Experiment Station, USDA Forest Service, Pineville, LA 71360.
Phytochemistry. 1994 Jan;35(2):473-8. doi: 10.1016/s0031-9422(00)94785-x.
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.
黑杰克橡木的树皮含有（+）-儿茶素、（-）-表儿茶素、（+）-3-O-[β-D-吡喃葡萄糖基]-儿茶素、儿茶素-（4α→8）-儿茶素、表儿茶素-（4β→8）-儿茶素，以及新型的3-O-[β-D-吡喃葡萄糖基]-儿茶素-（4α→8）-儿茶素和3-O-[α-L-鼠李糖基-（1→6）-β-D-吡喃葡萄糖基]-儿茶素作为主要成分。儿茶素的后者芸香糖苷特别有趣，因为其J2,3 C环偶联异常小。儿茶素-（4α→8）-儿茶素的葡萄糖苷是自然界中发现的第二种原花青素，其中3-O-糖苷存在于二聚体的上部“延伸单元”中。
