title: Enhanced cytotoxicity in a Z-photoisomer of a benzopyran derivative of propolis.
abstract: (Z)-2,2-Dimethyl-8-(3-methyl-2-butenyl)-benzopyran-6-propenoic acid (1) was isolated from Brazilian propolis, together with the known benzopyran derivative, (E)-2, 2-dimethyl-8-(3-methyl-2-butenyl)-benzopyran-6-propenoic acid (2). The structure was determined by spectroscopic analyses, which included 1D and 2D (1)H and (13)C NMR experiments, as well as MS, IR, and UV spectroscopy. Compound 2 rapidly changed to 1 under UV irradiation conditions (365 nm), and the reverse reaction was also observed. The ratio of 1 to 2 reached 2.3 when the reaction began from either 1 or 2, indicating a photostationary state. Compound 1 displayed an approximate 7-fold stronger cytotoxicity against human lung carcinoma cells (HLC-2) compared with 2.
authors.affiliation: Department of Preventive Medicine, Medical Research Institute, Tokyo Medical and Dental University, Kandasurugadai, Chiyoda-Ku, Tokyo 101-0062, Japan. mikaprm@mri.tmd.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Hirota
authors.forename: T
authors.initials: T
authors.lastname: Matsuno
authors.forename: T
authors.initials: T
authors.lastname: Fujiwara
authors.forename: H
authors.initials: H
authors.lastname: Sugiyama
authors.forename: S
authors.initials: S
authors.lastname: Mineshita
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D001578:Benzopyrans / Q000737:chemistry / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002264:Carboxylic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010777:Photochemistry; D011429:Propolis / Q000737:chemistry*; D014407:Tumor Cells, Cultured
chemical_list: C407784:2,2-dimethyl-8-(3-methyl-2-butenyl)-benzopyran-6-propenoic acid; C407786:3,3',5-trihydroxybiphenyl-2-carboxylic acid; D000972:Antineoplastic Agents, Phytogenic; D001578:Benzopyrans; D001713:Biphenyl Compounds; D002264:Carboxylic Acids; D011429:Propolis