Profiling of untargeted compounds from the ethanolic extract of green melinjo (Gnetum gnemon L.) peel

Melinjo (Gnetum gnemon) is one of the plants that is quite well known in Indonesia. The seeds of melinjo fruits are commonly processed as chips named as emping melinjo, while the fruit peel and leaves are consumed as vegetables. Extracts from melinjo peels have been reported to exhibit antioxidant activity and are utilized as ingredients in functional beverages. In addition, melinjo peel extracts have also been reported to have potential antihyperuricemic effects. The compounds suspected to contribute to antioxidant and antihyperuricemic activities belong to the phenolic compound group. Other compounds with potential antioxidant and antihyperuricemic properties from melinjo peel have not yet been identified. Therefore, this study aimed to explore the untargeted metabolite content in green melinjo peel. Ethanol extracts of green melinjo peel were analyzed using LC-HRMS. This analysis provides qualitative information for structural or molecular formula identification as well as quantitative data for each compound. The untargeted metabolites identified in retention time the ethanol extract of green melinjo peel were classified into 10 groups: amino acids-peptides, choline, vitamin, piperidines, phorbin, purines, phenolics, polyols, lipids, and alkaloid. The four dominant untargeted metabolites were choline (428.00 ppm), 2-hydroxy-2-butenedioicacid (213.20 ppm), phenylalanine (189.60 ppm), and TempolH (184.00 ppm). © The Authors, published by EDP Sciences.