4种豆科牧草总皂苷含量的测定及其生长过程中含量的变化

Study on the total saponin measurement and variation in growth period of four legumes

以香草醛-冰醋酸为显色剂,采用分光光度法,测定三萜皂苷的含量,对波长、精密度、重现性和稳定性进行检测。并分别对鹰嘴紫云英Astragalus sinicus、红豆草Onobrychis viciaefolia、百脉根LotuscornicμLatus和小冠花Coronilla varia4种豆科牧草中皂苷的含量进行测定。结果表明,此方法简便易行,精密度高,重现性好,在25 min内测试结果稳定可靠。4种豆科牧草在整个生育时期总皂苷含量的变化不完全一致。鹰嘴紫云英和红豆草在初花期总皂苷含量最低,产草量较高,牧草品质优良,适宜青饲或调制干草;盛花期总皂苷含量丰富,产草量最高,宜作为生产中提取皂苷产品的原料。小冠花总皂苷含量始终较低,是一种优质的豆科牧草,不会使反刍家畜产生臌胀病。红豆草、鹰嘴紫云英、小冠花和百脉根4种豆科牧草在整个生育期皂苷含量均为叶中多于茎中。

The colorimetric method was used for quantification of triterpene saponin with vanillin reagents as colorant, and the accuracy, reproducibility and stability were tested. The contents of total saponin in 4 legumes （Astragalus sinicus, Onobrychis viciaefolia, Lotus corniculatus and Coronilla varia） were determined with the above method. The results showed that the method was simple with high accuracy and reproducibility, and very stable within 25 min. The variation of total saponin contents of 4 legumes was not same. A. sinicus and O. viciaefolia in early flowering stage were proper for feeding livestock or hay making because of the low saponin content, high yield and excellent quality, meanwhile, these two legumes were better be used as material for saponin extraction in flowering stage because of the high saponon content and the highest yield. C. varia, remained lower saponin content and no ruminant distension of abdomen, was a high-quality legume forage. The content of total saponin in leaf were much higher than in stem.