Simultaneous high‐performance liquid chromatography analysis of anthraquinones in sicklepod sprouts with α‐glucosidase inhibitory activity

Abstract

IntroductionSicklepod [Cassia obtusifolia L. syn Senna obtusifolia (L.) H.S. Irwin & Barneby, Fabaceae] sprouts are promising ingredients with health‐promoting benefits. Notwithstanding, the pharmacologically active compounds in sicklepod sprouts have not been studied or analysed in detail.ObjectiveThis study aimed to isolate and structurally identify phytochemicals showing α‐glucosidase inhibitory activity in sicklepod sprouts and simultaneously quantify the compounds in the sprouts to determine the optimal cultivation method and germination time to maximise active compounds.MethodA simultaneous high‐performance liquid chromatography‐ultraviolet (HPLC‐UV) method with high sensitivity and accuracy was developed and used to analyse time‐dependent changes in anthraquinone content during sicklepod germination.ResultsThirteen anthraquinones were isolated and identified, of which six—chrysoobtusin, emodin, 1‐O‐methyl‐2‐methoxychrysophanol, 7‐O‐methylobtusin, chrysophanol, and physcion—showed moderate α‐glucosidase inhibitory activity. The maximum content of anthraquinones in a sprout was observed on Day 5 under both light and dark conditions.ConclusionThe findings of this study revealed that sicklepod sprouts which are promising functional food materials contain a variety of anthraquinones.