Four constituents were isolated from Rhododendron micranthum Turcz . Their structures were identified ashyperin ,astragalin ,kaempferol ,and quercetin . Kaempferol wasisolated from the plantforthe firsttime . Hyperin wasthe main analgesic active constituent.
Three crystalline components, a new kaurane type diterpenoid named macrocalyxin H and two known diterpenoid oridonin and enmenol, were isolated from the leaves of Rabdosia macrocalyx (Dunn) Hara.Based on IR, MS, 1 H 1H COSY, 13 C 1H COSY and NOE spectroscopy, the structure of macrocalyxin H was determined as ent 7β 20 epoxy 1α, 6α, 7α, 15α, 16α pentahydroxy kaurene 17 acetate.
