GC‐MS‐Based Metabolite Profiling of Cosmos caudatus Leaves Possessing Alpha‐Glucosidase Inhibitory Activity

Cosmos caudatus, which is known as “Ulam Raja,” is an herbal plant used in Malaysia to enhance vitality. This study focused on the evaluation of the α‐glucosidase inhibitory activity of different ethanolic extracts of C. caudatus. Six series of samples extracted with water, 20%, 40%, 60%, 80%, and 100% ethanol (EtOH) were employed. Gas chromatography‐mass spectrometry (GC‐MS) and orthogonal partial least‐squares (OPLS) analysis was used to correlate bioactivity of different extracts to different metabolite profiles of C. caudatus. The obtained OPLS scores indicated a distinct and remarkable separation into 6 clusters, which were indicative of the 6 different ethanol concentrations. GC‐MS can be integrated with multivariate data analysis to identify compounds that inhibit α‐glucosidase activity. In addition, catechin, α‐linolenic acid, α‐D‐glucopyranoside, and vitamin E compounds were identified and indicate the potential α‐glucosidase inhibitory activity of this herb.