Bai, L; Kato, T; Inoue, K; Yamaki, M; Takagi, S
Three biphenanthrenes, blestrianol A, B and C and one dibenzylphenanthrene were isolated from tubers of Bletilla striata. The structures were elucidated as 4,4â²-dimethoxy-9,9â²,10,10â²-tetrahydro-[1â²,3-biphenanthrene]-2,2â²,7,7â²-tetraol, 4â²,5-dimethoxy-8-(4-hydroxybenzyl)-9,9â²,10,10â²-tetrahydro-[1â²,3-biphenanthrene]-2,2â²,7,7â²-tetraol,4â²,5-dimethoxy-8-(4-hydroxybenzyl)-9,10-dihydro-[1â²,3-biphenanthrene]-2,2â²,7,7â²-tetraol and 1,8-bi(4-hydroxybenzyl)-4-methoxy-phenanthrene-2,7-diol by their spectroscopic data. © 1991.