Oyama Manami, Tokiwano Tetsuo, Kawaii Satoru, Yoshida Yasunori, Mizuno Kouichi, Oh Keimei, Yoshizawa Yuko
Laboratory of Bio-organic Chemistry, Akita Prefectural University, Akita, 010-0195, Japan.
Laboratory of Bio-organic Chemistry, Tokyo Denki University, Hatoyama, Saitama, 350-0394, Japan.
Curr Bioact Compd. 2017 Jun;13(2):170-174. doi: 10.2174/1573407213666170113123428.
The rhizome of Oni-dokoro (a wild yam, Dioscorea tokoro) has extremely bitter taste and is not generally regarded edible;, however, in northern part of Japan, such as Iwate and a part of Aomori, it is used as health promoting food. To clarify the reason, we examined the biologically active compounds in the rhizome collected at Iwate and compared them from the other area in literature.
The acetonitrile extract from northern part of Japan was purified by bioassay-guided separation using antiproliferative activity to human leukemia HL-60 cell, and protodioscin (PD) was isolated and identified by instrumental analyses as the major active compound.
PD known as a saponin with four sugar moieties, an inhibitor for platelet aggregation, and a low density lipoprotein (LPL) lowering agent, displayed strong growth inhibitory effect to HL-60. The literature search suggested that the rhizome from other area contained dioscin and other saponins with three sugar moieties as their major component. We assume that the edible and health promoting effect of the rhizome in the particular area is partially derived from these different components.
We were interested in the differences of utilization in the rhizome of wild yam Dioscorea tokoro, and examined the chemical composition in the rhizome to find protodioscin as antiproliferative compound to HL-60. In the report from other area, the rhizome exhibited dioscin as the major compound. Our study indicated that the protodioscin/dioscin composition varied regionally, although the reason is still needs to be investigated.
鬼灯芋（一种野生山药，薯蓣科薯蓣属）的根茎味道极苦，一般不被视为可食用；然而，在日本北部，如岩手县和青森县的部分地区，它被用作促进健康的食品。为了阐明原因，我们研究了从岩手县采集的根茎中的生物活性化合物，并将其与文献中其他地区的进行了比较。
采用对人白血病HL-60细胞的抗增殖活性，通过生物测定引导分离法对日本北部的乙腈提取物进行纯化，通过仪器分析分离并鉴定出原薯蓣皂苷（PD）为主要活性化合物。
PD是一种具有四个糖基部分的皂苷，是血小板聚集抑制剂和低密度脂蛋白（LPL）降低剂，对HL-60显示出强烈的生长抑制作用。文献检索表明，其他地区的根茎中含有薯蓣皂苷和其他具有三个糖基部分的皂苷作为主要成分。我们推测，该特定地区根茎的可食用性和促进健康的作用部分源于这些不同的成分。
我们对野生山药薯蓣属根茎利用的差异感兴趣，并研究了根茎中的化学成分，发现原薯蓣皂苷是对HL-60具有抗增殖作用的化合物。在其他地区的报告中，根茎以薯蓣皂苷为主要化合物。我们的研究表明，原薯蓣皂苷/薯蓣皂苷的组成因地区而异，尽管原因仍有待研究。
