燕麦发芽前后酚类物质的组成变化及结构鉴定

Composition Change and Structure Identification of Phenols in Oat After Germination

【目的】对燕麦发芽前后酚类物质的组成变化进行分析,对疑似燕麦蒽酰胺的组分进行结构鉴定。【方法】通过高效液相色谱分析未发芽燕麦、发芽6 d燕麦籽粒、芽和根提取物的多酚组成,利用高效液相色谱与串联四级杆飞行时间质谱仪联用技术(HPLC/Q-TOF-MS)获得燕麦蒽酰胺的精确分子量。【结果】燕麦发芽后籽粒中酚酸的种类和数量明显减少,相对含量由32.14%下降至5%以下,而燕麦蒽酰胺的相对含量由45.52%上升至79.21%。2c、2p、2f、t2和t3是原样和6 d籽粒中共有的主要蒽酰胺,其分子式(分子量)分别为C16H13O6N(315.0753)、C16H13O5N(299.0818)、C17H15O6N(329.0912)、C18H15O5N(325.0968)和C19H17O6N(355.1077),其中t2和t3是发芽过程中含量上升最显著的组分。6 d芽和6 d根提取物中的成分与籽粒存在显著差异,主要组分w6—w10的分子量分别为564.1498、592.1808、494.1781、710.1834和192.0433。【结论】燕麦发芽前后酚类物质的组成产生了很大变化,明确了6种蒽酰胺的结构信息以及4种未知物质的精确分子量,为发芽燕麦的研究提供了新的理论依据。

[ Objective] Changes of phenols composition after oat germination and structure identification of possible avenanthramides were studied. [ Method] HPLC was used to analyze the phenol composition of extracts from ungerminated oat seeds, 6-day germinated oat grains, buds and roots. HPLC/Q-TOF-MS was chosen to detect the molecular weight of avenanthramides [ Result ] The results indicated that the kind and content of phenolic acid in 6-day germinated oat grains were reduced. The relative content of phenolic acid was reduced from 32.14% to lower than 5%, while the relative content avenanthramide was increased from 45.52% to 79.21%. A group of avenanthramides such as 2c, 2p, 2f, t2, and t3 were both in ungerminated oat seeds and 6-day germinated oat grains. The molecular formula （molecular weight） of 2c, 2p, 2f, t2 and t3 were, respectively, C16H1306N（315.0753）, Ct6H13OsN（299.0818）, CI7HlsOtN（329.0912）, C1sHlsOsN（325.0968） and C19H17OtN（355.1077）. Avenanthramides t2 and t3 increased drastically during oat germination. The composition of 6-day germinated oat buds and roots extracts was different from oat grain extract. The molecular weight of w6-wl0 were, respectively, 564.1498, 592.1808, 494.1781, 710.1834 and 192.0433. [ Conclusion ] Phenol composition changed obviously after oat germination. The structure of six avenanthramides and the molecular weight of four possible avenanthramides were identified, thus offering a theoretical theory evidence for the study of germinated oat.