Studies on the Constituents of Orchidaceous Plants. IX.1)Constituents of Spiranthes sinensis (PERS.) AMes var. amoena (M. BIEBERSON) HAra. (2). Structures of Spiranthesol, Spiranthoquinone, Spiranthol-C, and Spirasineol-B, New Isopentenyldihydrophenanthrenes2)

Abstract

Four new dihydrophenanthrene derivatives, spiranthesol, spiranthoquinone, spiranthol-C, and spirasineol-B, were isolated from the roots of Spiranthes sinensis (PERS.) Ames var. amoena (M. BIEBERSON) Hara (Japanese name “nezibana”). The structures 1, 2, 3, and 4 were proposed for these compounds, respectively, on the basis of spectroscopic data obtained by various methods including 1H-detected heteronuclear multiple-bond multiple-quantum coherence (HMBC) spectroscopy. Chemical conversions of spiranthol-A to spiranthol-C and spiranthoquinone and of spirasineol-A to spirasineol-B are also described. © 1990, The Pharmaceutical Society of Japan. All rights reserved.