BERGENIN, A C-GLYCOPYRANOSYL DERIVATIVE OF 4-0-METHYLGALLIC ACID
BERGENIN, A C-GLYCOPYRANOSYL DERIVATIVE OF 4-0-METHYLGALLIC ACID
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DOI：
10.1039/jr9580002231
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发表时间：
1958-01-01
期刊：
影响因子：
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通讯作者：
HAYNES, LJ
中科院分区：
文献类型：
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作者：
HAY, JE;HAYNES, LJ
2232 Hay和Haynes：Bergenirt，一种C-吡喃葡萄糖基解释了对完全乙酰化的抗性，并受到Shimokariyama的批评，他提出了五羟基结构（11）。这方面的证据似乎完全基于岩白菜素容易还原费林溶液的事实。ShimokGriyama表明岩白菜素的还原能力与葡萄糖相当，他通过开环岩白菜素（V）中形成己酮糖侧链来解释。由此可以预期，二-O-甲基岩白菜素仍具有可观的还原能力。事实并非如此，因此岩白菜素本身的还原性质必须完全归因于两个游离酚基的存在，而不是侧链中的潜在还原基团。此外，开环的二-O-甲基岩白菜素不与苯肼形成衍生物。由于二-O-甲基岩白菜素没有还原性，结构（Ⅰ）和（11）都不正确，因为结构（Ⅰ）在内酯环的开环上也应该得到己酮糖（Ⅴ），由Tschitlobbabin提出的分子式C，H，O，H，O已通过分析和X-射线分子量测定得到证实，其值为344 & 4（必填，346）。岩白菜素及其衍生物的红外光谱中的羰基伸缩频率见表1。值得注意的是
2232 Hay and Haynes: Bergenirt, a C-Glycopyranosyl explain the resistance to full acetylation and was criticised by Shimokariyama who proposed the pentahydroxylic structure (11). The evidence for this appears to be based entirely on the fact that bergenin readily reduces Fehling's solution. ShimokGriyama showed that the reducing power of bergenin is comparable with that of glucose, which he explained by formation of a keto-hexose side-chain in ring-opened bergenin (V). It is to be expected from this that di-O-methylbergenin would still possess appreciable reducing power. This is not so, and therefore the reducing properties of bergenin itself must be due solely to the presence of the two free phenolic groups and not to a potential reducing group in the side-chain. Moreover, ring-opened di-O-methylbergenin does not form a derivative with phenylhydrazine. Since di-0-methylbergenin shows no reducing properties, neither structure (I) nor (11) can be correct, since structure (I) should also give the ketohexose (V) on opening of the lactone ring.The molecular formula C,, H,, O,, H, O proposed by Tschitschibabin has been confirmed by analysis and by an X-ray molecular-weight determination which gave the value 344 & 4 (required, 346). The carbonyl stretching frequencies in the infrared spectra of bergenin and a number of its derivatives are given in Table 1. It is noteworthy that the