title: 19-Nor- and 18,20-epoxy-cardenolides from the leaves of Calotropis gigantea.
abstract: Two new cardenolides (1 and 2) along with 12 known compounds were isolated from the dichloromethane extract of the leaves of Calotropis gigantea. The structural elucidation was accomplished by spectroscopic methods. Some of the isolates were evaluated for cytotoxic activity against KB, BC, and NCI-H187 cancer cell lines, and all cardenolides tested were found to possess strong inhibitory effects. The presence of a deoxysugar at C-3, a formyl group at C-10, and an alpha,beta-unsaturated gamma-lactone was crucial for cytotoxic activity.
authors.affiliation: Department of Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkapi, Bangkok 10240, Thailand.
authors.forename: Thitima
authors.initials: T
authors.lastname: Lhinhatrakool
authors.forename: Somyote
authors.initials: S
authors.lastname: Sutthivaiyakit
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D031107:Calotropis / Q000737:chemistry*; D002298:Cardenolides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007624:KB Cells; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: C513717:18,20-epoxycalotropin; C513716:19-nor-10-hydrocalactinic acid methyl ester; D000972:Antineoplastic Agents, Phytogenic; D002298:Cardenolides