Flavonoid glycosides from Microtea debilis and their cytotoxic and anti-inflammatory effects

Two new 5-O-glucosylflavones, 5-O-β-D-glucopyranosyl cirsimaritin (1) and 5, 4'-O-β-D-diglucopyranosyl cirsimaritin (2), four known flavonoids, cirsimarin (3), cirsimaritin (4), salvigenin (5), 4', 5-dihydroxy-7-methoxyflavone (6), and a norisoprenoid, vomifoliol (7), have been isolated from the aerial parts of Microtea debilis. All isolates were tested for cytotoxicity in human cancer cell lines (Hep G2, COLO 205, and HL-60) and anti-inflammatory activities in LPS-treated RAW264.7 macrophages. Compound 6 was found to be a potent inhibitor to nitrite production in macrophages. Compounds 2, 4, 6, and 7 showed moderate anti-proliferative activity against COLO-205 cells with IC(50) values of 7.1, 13.1, 6.1, and 6.8 μM, respectively.