Unraveling Cultivar-Dependent Resin Glycoside Profiles and Pancreatic Lipase Inhibitory Activity in Aerial Parts of Commonly Cultivated Sweetpotatoes (Ipomoea batatas) in China

Sweetpotato ( Ipomoea batatas (L.) Lam.) is one of the most important crops in the world, which produces not only tubers but edible and nutritious aerial parts. The aerial parts, largely discarded as agricultural biomass, are rich sources of resin glycosides (RGs), a class of natural pancreatic lipase (PL) inhibitors. However, this activity is highly cultivar-dependent. In this study, the aerial parts of sweetpotato from 22 commonly grown cultivars in China, the world’s largest sweetpotato producer, were evaluated for PL inhibitory activity. Among them, Yanshu 25 was the strongest PL inhibitor, with an orlistat equivalent (OE) of 1.599 ± 0.068 ng orlistat/μg extracts. Further profiling by UHPLC-QTOF-MS/MS combined with multivariate analysis revealed 15 differential RGs enriched in those high-activity cultivars, characterized by tetra- or pentasaccharide cores with frequent 2-methylbutyryl (2-mba), cinnamoyl (Cna), and dodecanoyl (Dodeca) substitutions. Our results represent a further step toward systematically mapping cultivar-dependent RG diversity and bioactivity in sweetpotato, ultimately supporting germplasm selection and the valorization of underutilized aerial biomass.