Optimized extraction, enrichment, identification and hypoglycemic effects of triterpenoid acids from Hippophae...

The Hippophae rhamnoides L. pomace was generated in the production process for juice, wine of food industry. To expand the application of pomace, the extraction process optimization, enrichment and identification of triterpene acids were performed in this study. The extraction yield was 14.87% under optimal ultrasound-assisted extraction techniques performed via response surface methodology. The extract was subsequently purified to obtain the triterpenoid acid enrichment fraction (TPF) with the content of 75.23% ± 1.45%. 13 triterpenoid acids were identified via UPLC-Triple-TOF MS/MS and further semi-quantified through comparison with triterpenoid acid standards. TPF exhibited a strong inhibitory effect on α-glucosidase with IC₅₀ value of 5.027 ± 0.375 μg/mL, as determined via enzyme inhibition experiment and molecular docking. Additionally, the TPF significantly reduced postprandial glucose levels, as revealed via carbohydrate tolerance tests, as well as ameliorate serum lipid profiles. Therefore, pomace may be a promising resource of functional food components with therapeutic and commercial values.