title: Polyanthumin, a novel cyclobutane chalcone trimmer from Memecylon polyanthum.
abstract: A novel unusual trimmer chalcone, polyanthumin (1), together with five known compounds myricetin 3-O-(3″-O-galloyl)-α-l-rhamnopyranoside (2), sulfuretin (3), fustin (4), gallic acid (5), and ethyl gallate (6), was isolated from the dry stems of Memecylon polyanthum H.L. Li. Among them, compound 1 is a new chalcone trimmer with a novel cyclobutane skeleton in nature. Compounds 3 and 4 are flavonoids carrying a single 7-OH in A ring, which provided the first example of these class flavonoids from the family Melastomataceae. In addition, the antitumor activities for 2-4 were reported for the first time in this study. The antitumor effects of the isolated compounds 1-6 in vitro were assayed by the SRB method using human cancer K562 cells, with the inhibition rates ranging from 39.4% to 54.5% at 100 μg/ml. The IC50 values of compounds 1 and 3 for the inhibition of K562 cell proliferation were determined to be 45.4 and 30.5 μg/ml, respectively. To the best of our knowledge, compound 1 was the second sample as chalcone trimer. In addition, the antitumor activities for 2-4 were reported for the first time in this study.
authors.affiliation: a Beijing Institute of Pharmacology and Toxicology , Beijing 100850 , China.
authors.forename: Guan
authors.initials: G
authors.lastname: Chen
authors.forename: Cheng-Bin
authors.initials: CB
authors.lastname: Cui
authors.forename: Ai-Di
authors.initials: AD
authors.lastname: Qi
authors.forename: Chang-Wei
authors.initials: CW
authors.lastname: Li
authors.forename: Zun-Wei
authors.initials: ZW
authors.lastname: Tao
authors.forename: Rong
authors.initials: R
authors.lastname: Ren
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001572:Benzofurans / Q000302:isolation & purification; D002599:Chalcone / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D047188:Chalcones; D003503:Cyclobutanes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005419:Flavonoids / Q000302:isolation & purification; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000302:isolation & purification; D006801:Humans; D020014:K562 Cells; D035322:Melastomataceae / Q000737:chemistry*; D015394:Molecular Structure; D018547:Plant Stems / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000970:Antineoplastic Agents; D001572:Benzofurans; D047188:Chalcones; D003503:Cyclobutanes; D004365:Drugs, Chinese Herbal; D005419:Flavonoids; C000598654:polyanthumin; C048734:ethyl gallate; C522894:fustin; D002599:Chalcone; D005707:Gallic Acid; C040015:myricetin; C054989:sulfuretin
keywords: Melastomataceae; Memecylon polyanthum; antitumor activity; cyclobutane chalcone trimmer; structure determination