演題概要

2P-36

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ステビア葉中のキシロース含有ステビオール配糖体の探索と構造推定

(¹サントリー生科財団・ ²サントリー・ ³サントリー食品・ ⁴サントリーグローバルイノベーションセンター)
^o渡辺健宏¹・ 藤川紘樹¹・ 浦井聡一郎²・ 岩城一考³・ 平井正良⁴・ 宮川克郎⁴・ 浦谷宏¹・ 山垣亮¹・ 長尾浩二³・ 横尾芳明³・ 島本啓子¹

Some steviol glycosides obtained from Stevia rebaudiana leaves exhibit sweetness that is nearly 250-300 times higher than that of sucrose and they are therefore utilized as a low-calorie sweetener in the food industry. Among them, the sweetness of major glycosides composed of glucose residues (e.g., stevioside and rebaudioside A), in which all residues consist of glucose, has been widely studied. However, the properties of minor natural products containing rhamnose (Rha) or xylose (Xyl) residues are poorly investigated. In this study, we report investigation and structure estimation method to identify trace amounts of highly glycosylated steviol containing Rha or Xyl in stevia leaves and to verify what taste qualities they individually impart. First, elution trends of LC separations of available authentic samples and MS/MS fragment pattern analysis are performed. Next, stevia leaf extract was analyzed by LC-MS/MS. As a result, 18 peaks corresponding to steviol glycosides were obtained, and the structures of five new steviol glycosides were estimated, naming those containing Rha the "dulcoside" series and those containing Xyl the "rebaudioside FX" series.