Chemical constituents in flowers of Rhododendron lapponicum / 中草药

ABSTRACT

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.