Cytotoxic chalcones and antioxidants from the fruits of a Syzygium samarangense (Wax Jambu)

摘要

Bioassay-guided fractionation of the methanolic extracts of the pulp and seeds of the fruits of Syzygium samarangense Merr. & Perry (Blume) led to the identification of four cytotoxic compounds and eight antioxidants on the basis of HPLC-PDA analysis, MS, and various NMR spectroscopic techniques. Three C-methylated chalcones, 2′,4′-dihydroxy-3′,5′-dimethyl-6′-methoxychalcone (>1), 2′,4′-dihydroxy-3′-methyl-6′-methoxychalcone (stercurensin, >2), and 2′,4′-dihydroxy-6′-methoxychalcone (cardamonin, >3), were isolated and displayed cytotoxic activity (IC50 = 10, 35, and 35 μM, respectively) against the SW-480 human colon cancer cell line. Also a number of known antioxidants were obtained including six quercetin glycosides: reynoutrin (>4), hyperin (>5), myricitrin (>6), quercitrin (>7), quercetin (>9), and guaijaverin (>10), one flavanone: (S)-pinocembrin (>8), and two phenolic acids: gallic acid (>11) and ellagic acid (>12).