title: A new xanthone from the bark of Calophyllum thorelii.
abstract: A new xanthone, calothorexanthone, together with five known compounds, garbogiol, 1,4,8-trihydroxyxanthone, δ-tocotrienol, 1,7-dihydroxyxanthone and globuxanthone, was isolated from a petroleum ether extract of the bark of Calophyllum thorelii. Their structures were established on the basis of spectroscopic methods, mainly one- and two-dimensional NMR. Antioxidant activity of the isolated compounds was tested using DPPH free radical scavenging assay and some exhibited remarkable effects with IC₅₀ of 13.63-17.46 µg mL(-1).
authors.affiliation: Natural Product and Medicinal Chemistry Lab, Faculty of Chemistry, Ho Chi Minh City University of Science, 227 Nguyen Van Cu, Ho Chi Minh City, Vietnam.
authors.forename: Le-Thu Thi
authors.initials: LT
authors.lastname: Nguyen
authors.forename: Duc Minh
authors.initials: DM
authors.lastname: Nguyen
authors.forename: Lien-Hoa Dieu
authors.initials: LH
authors.lastname: Nguyen
mesh_terms: D029759:Calophyllum / Q000737:chemistry*; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry*; D044004:Xanthones / Q000737:chemistry*
chemical_list: D044004:Xanthones; C009689:xanthone