Flavonoids and their cytotoxic activity from Tithonia diversifolia

Three flavones (1-3) were isolated from the aerial part of Tithonia diversifolia (Hemsl.) A. Gray growing in Hoa Binh province, Vietnam. Their structures were identified as hispidulin (1), nepetin (2) and luteotin (3) by analysis of these spectroscopic MS, NMR data and comparison with reported data.