Three simple lactones from Ranunculus japonicus
WANG Rong-le1, ZHOU Guang-xiong2, TAN Yu-zhi1, YE Wen-cai2, YAO Xin-sheng2(1. College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510224, China; 2. Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou 510632, China)
Objective To study the chemical constituents in the extract from Ranunculus japonicus. Methods Silica gel and Sephadex LH-20 open columns chromatography were used to isolate the cons-tituents from 85% alcoholic extract of the title plant. The structures of the isolated constituents were identified on the basis of spectral analyses. Results An oil sample was obtained, which showed a single spot by TLC with variety of the developing solvent systems. The oil was detected as a single peak by both GC-MS and RP-HPLC. However, analystic data of ESI-MS, 1D and 2D NMR revealed that the sample was the mixture of three compounds: ranunculinin (Ⅰ), isoranunculinin (Ⅱ), and dihydroranunculinin (Ⅲ) in the ratio of 2∶1∶1. Conclusion All of three compounds are obtained from the plant for the first time. Among them, compounds Ⅱ and Ⅲ are isolated as the natural products for the first time.