A new oleanane-type triterpenoid saponin with α-glucosidase inhibitory activity from Camellia nitidissima

Natural products with potential hypoglycemic activity in T2DM: 2019-2023

As currently the most common metabolic disease, type 2 diabetes mellitus (T2DM) has shown a continuous increase in the number of patients in recent decades. Most anti-T2DM drugs tend to cause some side effects. Given the pathogenesis of T2DM, natural products have emerged as an important source of anti-T2DM drugs. This article reviews natural products with potential hypoglycemic activity from 2019 to 2023. A total of 200 previously natural products were discovered on SciFinder, PubMed and Web of Science. These products were categorized based on their structural frameworks and their biological activities were summarized. Although the mechanisms of action of most compounds are unclear, these compounds could still serve as candidates for the development of lead compounds. Therefore, further structure and activity research of natural products will significantly contribute to the development of potential anti-T2DM drugs.

Glycoside constituents of Camellia amplexicaulis and their α-glucosidase inhibitory activity

Four new glycosides, named amplexicosides A-D (1-4), and five known compounds: benzyl 2-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyloxy]-benzoate (5), benzyl 2-neohesperidosyloxy-6-hydroxybenzoate (6), chrysandroside A (7), chrysandroside B (8) and camelliquercetiside C (9) were isolated from the branches and leaves of Camellia amplexicaulis (Pit.) Cohen-Stuart. Their structures were elucidated using HR-ESI-MS and 1D- and 2D-NMR spectra and compared to reported NMR data. All of the isolated compounds were screened in an α-glucosidase assay. Compounds 4, 8, and 9 significantly inhibited α-glucosidase with respective IC50 values of 254.9 ± 4.2, 304.8 ± 11.9 and 228.1 ± 16.4 μM.