“彩色马铃薯”块茎花色苷分子结构研究进展

Research Advances in the Molecular Structures of the Stem Tuber Anthocyanins of "Colored Potatoes"

"彩色马铃薯"是指块茎的"皮"和/或"肉"为红、紫、蓝或橙色的马铃薯,其块茎"皮"和"肉"变化多端的着色模式源于花色苷的积累,块茎各种颜色在根本上由花色素决定。在"彩色马铃薯"块茎中已发现6种花色素,即矮牵牛色素、花葵素、锦葵色素、芍药色素、花青素和花翠素;不同颜色块茎所含的花色素种类不同,同一颜色块茎所含花色素种类也可能不同;紫色块茎所含的花色素种类最为多样化。"彩色马铃薯"块茎的各种花色素一般在C3位经过氧-糖苷键实现1个芸香糖基取代,在苷元的C5位,要么以氧-糖苷键实现单葡萄糖基取代,要么不发生取代。"彩色马铃薯"块茎花色苷常在花色素C3位二糖取代基上或在C5位的单糖取代基上进一步发生反式单酰基取代,实现酰基取代的酚酸多为对香豆酸,其次为阿魏酸和咖啡酸。"彩色马铃薯"块茎矮牵牛素、锦葵色素、花葵素和芍药色素的对香豆酸酰化衍生物的惯用名分别为"petanin","malvanin","pelanin"和"peonanin"。本文可以为"彩色马铃薯"块茎颜色呈现的机理探索及其花色苷的分子结构鉴定提供参考。

＂ Colored potatoes＂ refer to the special potato cuhivars in which the stem tuber ＂skins＂ and/or ＂fleshes＂ are red, purple, blue or orange. The various coloration patterns of tile ＂skins＂ and/or ＂fleshes＂ result from the accumulation of the anthocyanins in the tuber, and the tuber colors are fundamentally determined by the anthocyanidins. Six anthocyanidins have been found in the tubers of ＂colored potatoes＂, namely petunidin, polargonidin, malvidin, peonidin, cyanidin and delphinidin. The tubers with different colors contain different kinds of anthocyanidins, and the tubers with the same color may contain different anthocyanidins. The anthocyanidins discovered in the purple tubers are the most diverse. Gen- erally,the anthocyanidins in the tubers of ＂colored potatoes＂ realize a rutinosyl substitution at the C3 site by O-glycosidic bond, and either a glucosyl linked by O-glycosidic bond or no substituent group exists at the C5 site. Furthermore, a trans monoacyl usually exists at the disacharide substitution group at the C3 site or the monosaccharide substitution group at the C5 site of the anthocyanidins, and the phenolic acid acylating the stem tuber anthocyanins is often p-coumaric acid, next are the ferulic and caffeic acids. The trivial names of the p-coumaric acid acylated derivatives from petunidin, malvidin, pelargonidin, and peonidin of the stem tuber of ＂colored potatoes＂ are ＂petanin＂, ＂malvanin＂, ＂pelanin＂ and ＂peonanin＂, respectively. This review can provide a reference for the exploration on the mechanism of the tuber coloration and the identification of the molecular structures of the stem tuber anthocyanins of ＂colored potatoes＂.