Y. Kashiwada, Kimihisa Yamazaki, Y. Ikeshiro
Feb 18, 2001
Citations
2
Influential Citations
170
Citations
Quality indicators
Journal
Tetrahedron
Abstract
Abstract—Two novel chromane derivatives (1 and 2) and the known chromene (3) were isolated from the leaves and twigs of Rhodo-dendron dauricum. The absolute stereostructure of 1 was established by spectroscopic examination and X-ray crystallographic analysis. Theabsolute stereostructures of 2 and 3 were also confirmed by photochemical conversion of 3 into 1 and 2. Daurichromenic acid (3)demonstrated potent anti-HIV activity with an EC 50 value of 0.00567 mg/mL and therapeutic index (TI) of 3,710. Rhododaurichromanicacid A (1) also showed relatively potent anti-HIV activity with an EC 50 value of 0.37 mg/mL, and a TI of 91.9, whereas rhododaurichromanicacid B (1) displayed no anti-HIV activity. q 2001 Elsevier Science Ltd. All rights reserved. 1. IntroductionRhododendron dauricum is distributed in the northern partof China, eastern part of Siberia, and Hokkaido. The driedleaves of this plant are known in China as ‘Manshanfong,’and are used medicinally as an expectorant and totreat acute–chronic bronchitis.