5-Deoxyflavones with Cytotoxic Activity from Mimosa diplotricha

Bioassay-guided isolation of Mimosa diplotrichaled to the isolation of four new 5-deoxyflavones, diplotrins A–C (1–3) and diplotasin (4), together with 12 known flavonoids, flavonolignans, and triterpenoids. On the basis of spectroscopic evidence, compounds 1–4were characterized as 2′,5′-dihydroxy-3,7,8,4′-tetramethoxyflavone (1), 3′-hydroxy-3,7,8,4′-tetramethoxyflavone (2), 2′-hydroxy-7,4′,5′-trimethoxyflavone (3), and 4-hydroxy-3,10,11-trimethoxyisochromeno-[4,3-b]-chromen-7(5H)-one (4). The cytotoxic effects of these isolated compounds were evaluated against the A549, AGS, HT-29, and PC3 human cancer cell lines. Compounds 2and 5″-methoxyhydnocarpin-D (5) showed the most potent antiproliferative activity.