title: Constituents of the Vietnamese medicinal plant Orthosiphon stamineus.
abstract: From the MeOH extract of the aerial part of Vietnamese Orthosiphon stamineus, five new isopimarane-type diterpenes [orthosiphols F-J (1-5)] and two new diterpenes [staminols A (6) and B (7)] with a novel carbon-framework, to which we proposed the name "staminane", and three new highly-oxygenated staminane-type diterpenes [staminolactones A (8) and B (9) and norstaminol A (10)1 were isolated. Moreover, staminolactone A (8) is 8,14-secostaminane-type and staminolactone B (9) is 13,14-secostaminane-type, while norstaminol A (10) is 14-norstaminen-type. Together with these new diterpenes, sixteen known compounds were also isolated and identified to be: 7,3',4'-tri-O-methylluteolin (11), eupatorin (12), sinensetin (13), 5-hydroxy-6,7,3',4'-tetramethoxyflavone (14), salvigenin (15), ladanein (16), tetramethylscutellarein (17), 6-hydroxy-5,7,4'-trimethoxyflavone (18), vomifoliol (19), aurantiamide acetate (20), rosmarinic acid (21), caffeic acid (22), oleanolic acid (23), ursolic acid (24), betulinic acid (25), and beta-sitosterol (26). All the isolated compounds were tested for their cytotoxicity towards highly liver metastatic murine colon 26-L5 carcinoma cells, and the new diterpenes, except for 4, and flavonoids (11, 12, 16, 18) showed cytotoxicity with an ED50 value between 10 and 90 microg/ml.
authors.affiliation: Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tezuka
authors.forename: P
authors.initials: P
authors.lastname: Stampoulis
authors.forename: A H
authors.initials: AH
authors.lastname: Banskota
authors.forename: S
authors.initials: S
authors.lastname: Awale
authors.forename: K Q
authors.initials: KQ
authors.lastname: Tran
authors.forename: I
authors.initials: I
authors.lastname: Saiki
authors.forename: S
authors.initials: S
authors.lastname: Kadota
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification* / Q000494:pharmacology; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D015394:Molecular Structure; D010936:Plant Extracts / Q000032:analysis; D010946:Plants, Medicinal / Q000737:chemistry*; D014407:Tumor Cells, Cultured; D014744:Vietnam
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004224:Diterpenes; D010936:Plant Extracts