title: Tetrapetalone A, a novel lipoxygenase inhibitor from Streptomyces sp.
abstract: A simple new assay was designed for lipoxygenase inhibitors. This assay was used to find the novel lipoxygenase inhibitor, tetrapetalone A (1). Tetrapetalone A (1), C26H33NO7, was isolated from Streptomyces sp. USF-4727 strain. Its planar structure was determined by spectroscopic evidence and by methylating with diazomethane to show the presence of a novel tetracyclic skeleton and a beta-D-rhodinosyl moiety. The stereochemistry of 1 was investigated by the coupling constant in the 1H-NMR spectrum, NOE correlations, modified Mosher's method and derivation. We have reported the structural elucidation of 1 in our previous paper. However, further investigation gave another structure for 1, which is described in this paper. Tetrapetalone A showed similar inhibitory activity against soybean lipoxygenase to the two well-known lipoxygenase inhibitors, kojic acid and NDGA, while methylated tetrapetalone A (2) showed little inhibitory activity, even at a concentration of 1 mM.
authors.affiliation: Laboratory of Applied Microbiology, School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan.
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Komoda
authors.forename: Kayo
authors.initials: K
authors.lastname: Yoshida
authors.forename: Naoki
authors.initials: N
authors.lastname: Abe
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Misako
authors.initials: M
authors.lastname: Imachi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hirota
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koshino
authors.forename: Akira
authors.initials: A
authors.lastname: Hirota
mesh_terms: D004353:Drug Evaluation, Preclinical / Q000379:methods*; D006027:Glycosides / Q000737:chemistry* / Q000494:pharmacology*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry* / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D016859:Lipoxygenase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D009637:Masoprocol / Q000494:pharmacology; D008968:Molecular Conformation; D015394:Molecular Structure; D011753:Pyrones / Q000494:pharmacology; D013025:Glycine max / Q000201:enzymology; D013237:Stereoisomerism; D013302:Streptomyces
chemical_list: D006027:Glycosides; D006576:Heterocyclic Compounds, 4 or More Rings; D016859:Lipoxygenase Inhibitors; D011753:Pyrones; C492598:tetrapetalone A; C011890:kojic acid; D009637:Masoprocol