title: Dimeric proanthocyanidins from the roots of Ephedra sinica.
abstract: Two new dimeric proanthocyanidins, ephedrannin B ( 2) and mahuannin E ( 4), along with two known congeners, ephedrannin A ( 1) and mahuannin D ( 3), were isolated from the roots of Ephedra sinica Stapf. Based on NMR, MS, and CD analysis, the structures of the new compounds were deduced to be 5,7,4'-trihydroxyflavan-[4(alpha)-->8,2(alpha)-->O-->7]-kaempferol ( 2) and 5,7,4'-trihydroxyflavan-[4(beta)-->8,2(beta)-->O-->7]- EPI-afzelechin ( 4). The compounds 1 - 4 were evaluated for cytotoxicity against three tumor cell lines (SGC-7901, HepG2, and HeLa), and 2 was found to be significantly active.
authors.affiliation: College of Chemistry, Jilin University, Changchun, P. R. China.
authors.forename: Huaming
authors.initials: H
authors.lastname: Tao
authors.forename: Lishu
authors.initials: L
authors.lastname: Wang
authors.forename: Zhanchen
authors.initials: Z
authors.lastname: Cui
authors.forename: Daqing
authors.initials: D
authors.lastname: Zhao
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D003603:Cytotoxins / Q000302:isolation & purification / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D029790:Ephedra sinica / Q000737:chemistry*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D044945:Proanthocyanidins / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D003603:Cytotoxins; D010936:Plant Extracts; D044945:Proanthocyanidins; C539087:ephedrannin B