Bioactivity-guided isolation of a bioactive compound with α-glucosidase inhibitory activity from the leaves extract of Sauropus androgynus

Naturally-derived antidiabetic medications have been explored as alternatives to the current widely-used drugs which can cause mild to severe side effects. Sauropus androgynus has been traditionally utilized to treat diabetes patients. In this report, a flavonoid glycoside, astragalin (1), was isolated from the leaves extract of S. androgynus using bioassay-guided isolation approach. Enrichment processes using macroporous resins resulted in two enriched fractions with 1 contents of 0.083% and 0.054% for PAD610 and PAD900 fractions, respectively. Compound 1 showed a higher α-glucosidase inhibitory (IC₅₀ = 55.03 ± 0.61 μg/mL) than that of acarbose. In vitro assay for antioxidant and α-glucosidase inhibitory activities showed the greatest inhibition by PAD 610 fractions which has 98.912% and 83.268%, respectively. These findings have shown promising results for further studies on S. androgynus as a potential herbal drug, particularly for the treatment of diabetes.