Liza Md Salleh, Russly Abdul Rahman, Jinap Selamat, Azizah Hamid and Md Zaidul Islam Sarker
Supercritical carbon dioxide (SC-CO2) extraction was used to obtain the bioactive flavonoid compounds of Strobilanthes crispus (Pecah Kaca). Process variables namely pressure, temperature and co-solvent flow rate were studied for optimization of the extraction yield and bioactive flavonoid compound of S. crispus by response surface methodology following a Box Behnken design of experiments. HPLC was performed to determine the major bioactive flavonoid compounds from S. crispus. The optimum value of yield extraction (6.55%) was obtained at pressure 200 bar, 50°C temperature and co-solvent flow rate of 5 g/min. Under the optimum conditions, eight flavonoid compounds were identified namely (+)-catechin, (-) epicatechin, rutin, myricetin, luteolin, apigenin, naringenin and kaempferol. The experimental extraction yield is in good agreement with the predicted one. The response surface methodology used in this study was able to predict the optimal extraction conditions for the extraction yield of bioactive flavonoid compounds from S.crispus leaves extract.