Detection of puerarin from pueraria mirifica tuber and its formulated cosmetic products

Abstract

Pueraria mirifica (PM) has traditionally been used to relieve postmenopausal symptoms. Recently, its extract has been developed into various cosmetic products to promote skin rejuvenation and youthfulness. This study investigated the phytochemicals of PM tuber and compared between the tuber flesh and its outer peel. Puerarin which is one of the major isoflavones and being considered as the marker compound was used to determine the presence of PM extract in local cosmetic products. Puerarin could be ionized by a mass spectrometer at both negative and positive modes. The peak ionized at the negative mode showed to have a narrower peak width (0.2 min) and higher signal-to-noise ratio (30) for pueararin (1 mg/L). The results also found PM extract contained many C- and O-glycosylated isoflavones, especially from its peel extract. This explains the peel extract showed to have four times higher antiradical activity than those of flesh extract. Puerarin from the cosmetic products was recovered via successive methanolic sonication and followed by liquid-liquid extraction using ethyl acetate. Puerarin was successfully partitioned from the highly complex chemical mixture of cosmetic products with the recovery ranged from 89.1 % to 115 %. Hence, isoflavones was found to be higher at the outer peels than its tuber flesh. A simple and reliable method has been developed to analyse the presence of PM extract in cosmetic products based on the detection of puerarin after successive extraction via methanolic sonication and ethyl acetate partition.