Quinone reductase inductive activity of capsicum annuum leaves and isolation of the active compounds

Although pepper leaves have been consumed as a traditional folk food in Korea, chemopreventive researches on pepper leaves are very rare. Thus, chemopreventive activity of pepper leaves was evaluated by isolating active compounds from pepper leaves. The methanol extract of pepper leaves showed significantly strong quinone reductase (QR) inductive activity compared to that of broccoli. Through partition and column chromatography, two major QR inducers were isolated from pepper leaves. Based on visible spectra, thin layer chromatography, solubility, chemical reactions, and DIP-MS, two major QR inducers from pepper leaves were identified as lutein and β- carotene. The concentration required to double the specific activity of QR (CD) values of lutein and β-carotene were 87.5 and 10.0 μM, respectively.