Isolation, identification of polymethoxy flavonoids from mentha dumetorum and investigation of their antiproliferative activities

In this study; Aerial part of Mentha dumetorum was boiled in water. After cooling and filtered, the liquid part was partitioned with hexane. Hexane phase was separated by separatory funnel then; the solvent was removed under reduced pressure to yield the crude extract which was subjected to chromatographic techniques (sephadex LH-20, silica gel, preparative TLC and HPLC) to isolate seven polymethoxy flavonoids. The isolated compounds, xanthomicrol (MD-1), 5-hydroxy-6,7,8,4'-tetramethoxy flavonone (MD-2), 5-desmethyl sinensetin (MD-3), 5-demethyl nobiletin (MD-4), gardenin B (MD-5), 5-hidroxy-6,7,8,3',4'-penta methoxy flavanone (MD-6) and 5-hidroxy-6,7,4'-trimethoxy flavone (MD-7) were elucidated by spectroscopic techniques (1H and 13C-NMR, LC-TOF-MS ve UV). Isolated compounds were quantified using a LC-TOF-MS instrument. The total amount of isolated polymethoxylated flavones was calculated as % 6.2 of hexane extract and % 0.12 of dry biomass. The anti-cancer effects of isolated compounds were evaluated using a real-time cell analyzer–single plate (RTCA-SP) instrument against HeLA (Human Cervix Carcinoma) and HT29 (Human Colorectal Adenocarcinoma) cell lines. MD-2 and MD-5 were found to reveal the most activity against both cell lines compared the all other isolated polymethoxylated flavones.