Chemical constituents in flowers of Rhododendron lapponicum
LI Gan-peng;LUO Yang;LI Shang-xiu;YANG Cui;TIAN Qian;ZUO Ma-yi;Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethic Affairs Commission & Ministry of Education, Yunnan University of Nationalities;
Objective To study the chemical constituents in the flowers of Rhododenron parvifolium, which is a traditional Tibet medicine. Methods Silica gel column chromatography, HPLC, and Sephadex LH-20 column chromatography techniques were used for the separation and purification of the compounds. Their structures were determined on the basis of IR, MS, 1D, and 2D NMR spectral evidences. Results Thirteen compounds were isolated from methanol extract in the flowers of R. parvifolium, and their structures were identified as parvifoliumol I(1), umbelliferone(2), scopoletin(3), 4′, 5, 7-trihydroxyflavanone(4), 8-demethylfarrerol(5), farrerol(6), quercetin(7), rutin(8), eudesmin A(9), 4-hydroxybenzoic acid(10), 3, 5-dihydroxy toluene(11), oleanane(12), and kojic acid(13). Conclusion Compound 1 is a new compound, which has a hexahydroxanthene skeleton. Compounds 9, 11, and 13 are obtained from the plants of Rhododendron L. for the first time.