Comparative analysis of isoflavones in Pueraria lobata from different regions in China

Abstract

Pueraria lobata (P. lobata) is a Chinese traditional produce with various biological activities. An high performance liquid chromatography-mass spectrometry (HPLC-MS) method for the detections of isoflavonoids was established. 11 isoflavonoids in 80 P. lobata samples from eight different production regions in China were determined quantitatively. The P. lobata sample from the Shaanxi had the highest total isoflavonoid content, at 106.11 mg/g, and the profile of that from the Sichuan Province was the lowest, at 69.40 mg/g. Among the 11 isoflavonoids, the content of puerarin was the highest, ranging from 44.54 to 66.58 mg/g. Principal component analysis (PCA), hierarchical cluster analysis (HCA), and discriminant analysis (DA) were conducted to evaluate the effects of geographical regions on the contents of isoflavonoids in P. lobata. The samples were classified into three groups on the basis of the content of puerarin, and the samples from Shaanxi and Guangdong had obvious regional characteristics. Combined with ABTS and DPPH free radical scavenging tests, the antioxidant capacities of P. lobata from different regions were evaluated in vitro. P. lobata samples from Jiangsu had the highest antioxidant capacity, and the ABTS and DPPH free radical scavenging abilities were 1.22 and 1.52 times than those of Sichuan samples, respectively. The puerarin was the principal but not the only influencing factor on the antioxidant capacity of P. lobata.