title: New dihydrochalcones and anti-platelet aggregation constituents from the leaves of Muntingia calabura.
abstract: Two new dihydrochalcones, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone (1) and 4,2',4'-trihydroxy-3'-methoxydihydrochalcone (2), and a new flavanone, (2R,3R)-(-)-3,5-dihydroxy-6,7-dimethoxyflavanone (3), together with nineteen known compounds have been isolated from the leaves of Muntingia calabura. The structures of three new compounds were determined through spectral analyses including extensive 2D-NMR data. Among the isolates, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone, 5,7-dihydroxy-3-methoxyflavone, 5,7-dihydroxy-6-methoxyflavone, 5,4'-dihydroxy-3,7-dimethoxyflavone, (2S)-7,8,3',4',5'-pentamethoxyflavan, (2S)-5'-hydroxy-7,8,3',4'-tetramethoxyflavan, and methyl gallate exhibited significant anti-platelet aggregation activity in vitro.
authors.affiliation: Graduate Institute of Pharmaceutical Technology, Tajen University, Pingtung, Taiwan. jjchen@mail.tajen.edu.tw
authors.forename: Jih-Jung
authors.initials: JJ
authors.lastname: Chen
authors.forename: Hsinn-Hsing
authors.initials: HH
authors.lastname: Lee
authors.forename: Cheng-Dean
authors.initials: CD
authors.lastname: Shih
authors.forename: Chang-Hui
authors.initials: CH
authors.lastname: Liao
authors.forename: Ih-Sheng
authors.initials: IS
authors.lastname: Chen
authors.forename: Tsung-Hsien
authors.initials: TH
authors.lastname: Chou
mesh_terms: D000818:Animals; D047188:Chalcones / Q000737:chemistry; D006801:Humans; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D018515:Plant Leaves; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D011817:Rabbits; D029646:Tiliaceae
chemical_list: D047188:Chalcones; D010936:Plant Extracts; D010975:Platelet Aggregation Inhibitors; C015812:dihydrochalcone