Cyclopeptide Alkaloids and Vitamin C Derivatives With Antioxidant Activity From the Twigs of <i>Antidesma fordii</i>

Antidesma fordii Hemsl., a medicinal treelet native to southern China and Southeast Asia, has received limited scientific investigation despite its ethnopharmacological significance. This study reported the isolation of four previously unreported 4(14)-integerrine-type cyclopeptide alkaloids (1-4) and two vitamin C derivatives (5-6), along with the known compound scutianine M (7) from A. fordii twigs. The structures of compounds 1-6 were determined by spectroscopic data analysis, electronic circular dichroism (ECD) calculations, and X-ray crystallography. Compound 5 displayed obvious antioxidant capacities in ABTS and FRAP assays. This study not only filled the phytochemical knowledge gap for A. fordii, but also identified the antioxidant potential of some compounds.