Synthesis of xanthoneO-glycosides. Part III. Synthesis of 1- and 8-O-?-D-glycosides of 5-O-methyl- and de-O-methylbellidifolin
作者:Barbara Vermes、Otto Seligmann、Hildebert Wagner
DOI:10.1002/hlca.19850680832
日期:1985.12.18
The unambiguous synthesis of three naturally occurring and biologically active xanthone 1-O and 8-O-β-D-glucosides of 5-O-methyl- and de-O-methylbellidifolin (2–4) was accomplished. The protected xanthone aglycones having only a single reactive OH group were prepared by selective benzylation, methylation, and debenzoylation reactions. An unexpected stability of the 1-MeO group towards demethylation
完成了3种天然存在且具有生物活性的蒽酮1- O和8 - O -β-D-葡萄糖苷(5- O-甲基-和去-O-甲基bellidifolin(2-4)的明确合成)。通过选择性苄基化,甲基化和脱苯甲酰化反应制备仅具有单个反应性OH基团的被保护的蒽酮苷元。观察到1-MeO基团对去甲基化的出乎意料的稳定性。
Studies on the Constituents of Swertia japonica. IV. Isolation and Structure of Xanthones
作者:MANKI KOMATSU、TSUYOSHI TOMIMORI、NAOKO MIKURIYA
DOI:10.1248/cpb.17.155
日期:——
The chemical constituents of Swertia japonica MAKINO were studied. Three kinds of new natural xanthones, named norswertianin (I), swertianin (III) and methylswertianin (V), were isolated from the whole herb of this plant, together with desmethylbellidifolin (X) and bellidifolin (XII). I was identified as 1, 3, 7, 8-tetrahydroxyxanthone. The direct isolation of I from natural source has never been published, although it has derived from decussatin (VII) and/or swertinin (VIII) by demethylation. The structure of III and V were shown to be 1, 7, 8-trihydroxy-3-methoxyxanthone and 1, 8-dihydroxy-3, 7-dimethoxy-xanthone, respectively. At the same time, "swertianol"was revised the structure to 1, 5, 8-trihydroxy-3-methoxyxanthone, which was proved to be identical with bellidifolin.
对獐牙菜MAKINO的化学成分进行了研究。从该植物全草中分离得到三种新的天然呫吨酮,分别命名为norswertianin (I)、swertianin (III)和methylswertianin (V),以及去甲基bellidifolin (X)和bellidifolin (XII)。我被鉴定为1,3,7,8-四羟基氧杂蒽酮。尽管 I 是通过去甲基化从 decussatin (VII) 和/或 swertinin (VIII) 衍生而来,但从未发表过从天然来源直接分离 I 的方法。 III和V的结构分别为1,7,8-三羟基-3-甲氧基呫吨酮和1,8-二羟基-3,7-二甲氧基-呫吨酮。同时,将“獐牙菜醇”的结构修改为1,5,8-三羟基-3-甲氧基呫吨酮,并证明其与桔梗素相同。
Xanthone and flavonol constituents of Swertia hookeri
作者:Shibnath Ghosal、Kanika Biswas、Dinesh K. Jaiswal
DOI:10.1016/0031-9422(80)85027-8
日期:1980.1
Abstract The whole plant of Swertiahookeri , collected at flowering has been shown to contain two tri- and nine tetraoxygenated free, glucosyloxy, and stearyl ester xanthones and one flavonol stearyl ester. Among these, three are previously unreported in nature and one was known previously only as a synthetic compound. The xanthones are based on 1,3,5,-, 1,3,5,8- and 1,3,7,8-oxygenated systems with