Alangionosides E (5) and O (6), isolated from the leaves of Alangiumpremnifolium, are also megastigmane glucosides, and the latter is closely related to 1 and actinidioionoside (4). However, the absolute configurations of the 9-position remained to be determined. They were analyzed to be R by means of a modified Mosher's method. Alangionoside E (5) is identical with corchoionoside A in all aspects. The name
来自 Glochidion zeylanicum,两种 megastigmane 葡萄糖苷,3- 和 9-O-β-D-吡喃葡萄糖苷 (3S,5R,6R,7E,9S)-megastigman-7-ene-3,5,6,9-tetrol (1和 2 个),分别被隔离。它们的结构在 9 位立体化学上与分别从中国猕猴桃和一头猕猴桃中分离的奇异果苷 (3) 和猕猴桃苷 (4) 不同。从 Alangium premnifolium 的叶子中分离出来的 Alangionosides E (5) 和 O (6) 也是巨豆苷,后者与 1 和actinidioionoside (4) 密切相关。然而,9位的绝对构型仍有待确定。通过改进的 Mosher 方法将它们分析为 R。Alangionoside E (5) 在所有方面都与 corchoionoside A 相同。此后必须保留 corchoionoside A
Megastigmanes from the aerial part of Euphorbia heterophylla
Three unprecedented megastigmanes together with twelve known compounds were isolated from the aerial part of Euphorbia heterophylla. The structural elucidation was based on extensive uses of spectroscopic data. The absolute configuration assignment of 1 was based on NOESY correlations and comparison of the experimental and calculated ECD spectra. Selected isolates obtained in sufficient quantity were