Isolation of Oleanane Triterpenes and trans-Resveratrol from the Root of Peanut (Arachis hypogaea)

The methanolic extract of peanut root was consecutively partitioned with dichloromethane, ethyl acetate (EtOAc), and n-butanol. Three compounds were isolated from the EtOAc-soluble fraction by the repeated silica gel column chromatography. These compounds were identified as sophoradiol, soyasapogenol B, and trans-resveratrol based on ¹H- and ∨13C-NMR data. Sophoradiol and soyasapogenol B were isolated from the peanut for the first time. The trans-resveratrol content of the peanut root was 1.7 mg/g dry weight, which is more than 1,000 times higher than that of peanut.