通过正离子和负离子液相色谱-串联质谱法对白芒柄花种子粕中的植物蜕皮甾体糖苷进行表征。

Characterization of phytoecdysteroid glycosides in Meadowfoam (Limnanthes alba) seed meal by positive and negative ion LC-MS/MS.

作者信息

Stevens Jan F, Reed Ralph L, Morré Jeffrey T

机构信息

Department of Pharmaceutical Sciences and Chemistry, Oregon State University, Corvallis, OR 97331, USA.

出版信息

J Agric Food Chem. 2008 Jun 11;56(11):3945-52. doi: 10.1021/jf800211k. Epub 2008 May 10.

Meadowfoam ( Limnanthes alba) is an oilseed crop grown in western Oregon. The seed meal has potential value as a biopesticide due to glucosinolate degradation products and phytoecdysteroids, a group of polyhydroxylated triterpenoids with potent activities as arthropod molting hormones. Liquid chromatography in combination with tandem mass spectrometry operated in the precursor ion mode revealed the presence of four ecdysteroid glycosides in meadowfoam seed meal. The carbohydrate sequence and the identity of the ecdysteroid aglycones, ponasterone A and 20-hydroxyecdysone, were determined by product ion scanning. Ecdysteroids were detected in the negative ion mode as [M + formate] (-) ions, which yielded [M - H] (-) and alpha-cleavage fragments with retention of hydroxyl groups in MS/MS experiments (not seen in the positive ion mode), allowing the determination of the number of hydroxyl groups in the side chain and in the steroid ring system. MS/MS of glycoside ions ([MH] (+) or [M + formate] (-)) provided carbohydrate sequence information.

白芒花（Limnanthes alba）是一种在俄勒冈州西部种植的油料作物。由于硫代葡萄糖苷降解产物和植物蜕皮甾体（一类具有作为节肢动物蜕皮激素的强大活性的多羟基三萜类化合物），种子粕具有作为生物农药的潜在价值。液相色谱结合以前体离子模式运行的串联质谱法显示白芒花种子粕中存在四种蜕皮甾体糖苷。通过产物离子扫描确定了碳水化合物序列以及蜕皮甾体苷元（蜕皮甾酮A和20-羟基蜕皮酮）的身份。蜕皮甾体在负离子模式下以[M + 甲酸根] (-)离子被检测到，在MS/MS实验中产生[M - H] (-)和保留羟基的α-裂解碎片（在正离子模式下未观察到），从而能够确定侧链和甾体环系统中的羟基数量。糖苷离子（[MH] (+)或[M + 甲酸根] (-)）的MS/MS提供了碳水化合物序列信息。