title: Two novel norwithasteroids with unusual six- and seven-membered ether rings in side chain from flos daturae.
abstract: Chemical investigation of 50% ethanol eluate fraction of macroporous resin for the flower of Datura metel L. collected in Jiangsu province of China resulted in the isolation of two novel naturally occurring norwithasteroids, baimantuoluoline I (1) and baimantuoluoside J (2). Their structures were elucidated as 5 α , 6 β , 12 β -trihydroxy-1-oxo-2-en-ergosta-21,24;22,29-diepoxy-26-carboxylic acid (1) and 5 α , 6 β , 12 β , 25-tetrahydroxy-1-oxo-2-en-ergosta-21,24;22,29-diepoxy-26-carboxylic acid (2) on the basis of extensive spectroscopic analysis, including 1D, 2D-NMR, and HR-ESI-MS. According to the literatures, this study represents the first report of the norwithasteroids in the side chain with unusual six- and seven-membered ether rings instead of those with an unmodified skeleton (δ-lactone or δ-lactol side chain) and a modified skeleton ( γ -lactone or γ -lactol side chain) in the family of withanolides. Meanwhile, compounds 1 and 2 were evaluated for their immunosuppressive activity against mice splenocyte proliferation in vitro.
authors.affiliation: Key Laboratory of Chinese Materia Medica of Ministry of Education, Heilongjiang University of Chinese Medicine, Harbin 150040, China.
authors.forename: Bing-You
authors.initials: BY
authors.lastname: Yang
authors.forename: Yong-Gang
authors.initials: YG
authors.lastname: Xia
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Wang
authors.forename: Qiu-Hong
authors.initials: QH
authors.lastname: Wang
authors.forename: Hai-Xue
authors.initials: HX
authors.lastname: Kuang