我国野生大豆的皂角苷成分研究进展

Research Progress in Soysaponin in Chinese Wild Soybean

大豆皂角苷具有增强人体免疫力、降血脂、养肝、抗癌等功效。在国家自然基金资助下,近年来我们对中国野生大豆皂角苷进行了初步研究,结果如下:(1)在国际上已知的5组类别大豆皂角苷之外,从中国野生大豆中鉴定出第6组,即β组新类别,同时发现4个新皂角苷成分A-αg、K-αg、KA-αg和HAb-αg,其中A-αg化合物被确认是A组、α组和β组皂角苷的总前体;(2)发现了控制C-22碳位阿拉伯糖结合的Sg-7位点;(3)鉴定出若干A0突变体、稀有的AuAe表型和高Bd含量的变异种质,并发现α组皂角苷成分的单独存在个体;(4)皂角苷成分表型及基因可以作为新的化学成分有关的遗传标记,通过此标记分析了中国野生大豆的遗传多样性及地理分化;(5)我国南方区域野生大豆AaBc表型及Sg-4基因具有东亚最高频率,意味着是更具有原始祖本特征的区域群体,东亚野生大豆皆来源于我国华南及南方地区野生大豆扩散。

Soysaponin has the functions of enhancing human immunity,reducing blood lipid,nourishing liver and anti-cancer.In recent years,our researches on soyasaponin in Chinese wild soybean have achieved some preliminary progresses supported by the NSFC,showing that Chinese wild soybeans were rich in the components and genetic variation of saponin composition.These progresses were as followings:(i)a new category of group-βwas identified in addition to reported five groups of soyasaponin and four new components A-αg,K-αg,KA-αg and HAb-αg were found,of which the A-αg component was first recognized to be the total precursor of the groups A,αandβ;(ii)a Sg-7 locus controlling arabinose bonding to the C-22 position of the aglycone was discovered;(iii)a number of A0 mutants and rare accessions with AuAe phenotype and high-content Bd component,as well as the individuals with separate groupαcomponents in Chinese wild soybeans were identified;(iv)soyasaponin phenotypes and genes could be used as genetic markers of chemical composition,by which the genetic diversity and geographical differentiation were analyzed in Chinese wild soybeans;(v)wild soybeans in South China had the highest frequencies of AaBc phenotype and Sg-4 gene in eastern Asia,which implied that the southern wild soybeans were a regional population possessing more primitive ancestral characteristics,and that eastern Asian wild soybeans originally came from southern China.