Objective To investigate the chemical constituents of the fruits of Phyllanthus emblica and evaluate their antioxidant and hypoglycemic activities. Methods Compounds were isolated and purified using silica gel and reversed-phase silica gel RP-18 column chromatography, followed with semi-preparative high-performance liquid chromatography (HPLC). The chemical structures were elucidated based on physicochemical properties, together with UV, NMR, HR-ESI-MS, and X-ray single-crystal diffraction methods, and comparison with literature data. Antioxidant and hypoglycemic activities were assessed by DPPH free radical scavenging and α-glucosidase inhibitory assays. Results Nine compounds were isolated from the ethyl acetate fraction of the methanol extract of P. emblica fruits and identified as 1-(2-aminobenzofuran-3-yl)-2-(2-methoxyphenyl)ethan-1-one (1), methyl dioxindole-3-acetate (2), aurantiamide (3), phyllaemblicin G3 (4), mucic acid dimethyl ester 2-O-gallate (5), chebulic acid trimethyl ester (6), 3,4,8,9,10-pentahydroxydibenzo[b,d]pyran-6-one (7), ellagic acid (8), and methyl 1-O-benzoyl-3-α- glucuronosyl glycerol (9), respectively. The bioassay showed that compounds 5-8 exhibited significant DPPH radical scavenging capacity (scavenging rates = 86.59% − 90.75%), and 1, 7, and 8 displayed inhibitory activity against α-glucosidase with IC₅₀ values ranging from 1.44 to 33.06 μmol/L. Among them, compound 7 showed the strongest inhibition, which was superior to the positive control quercetin (IC₅₀ = 4.96 μmol/L). Conclusion Compound 1 is a new alkaloid, named emblicine A, while 2, 3, and 9 are reported from the titled plant for the first time. It is the first study to identify alkaloid with hypoglycemic activity from P. emblica, providing a scientific basis for its traditional use in glycemic control and antioxidant defense.

Phyllanthus emblica L.  /  alkaloid  /  emblicine A  /  antioxidant  /  α-glucosidase inhibitory activity  /  aurantiamide  /  methyl 1-O-benzoyl-3-α- glucuronosyl glycerol