Selective Cyclooxygenase-2 Inhibitors from Calophyllum membranaceum

Abstract

Chemical investigation of the anti-inflammatory Chinese folk medicine Calophyllum membranaceum has resulted in the isolation and characterization of three new xanthones (1-3), one new biphenyl C-glycoside (4), and one new phenylethanoid glycoside (5) along with 17 known compounds. Their structures were characterized on the basis of spectroscopic and chemical methods. Two xanthones, 2,6-dihydroxy-1,7-dimethoxyxanthone (1) and 3,4-dihydroxyxanthone, were found to exhibit selective inhibitory activity against cyclooxygenase-2 (IC(50)=2.99 and 1.80 microM) in vitro.

Chemical modifications of a natural xanthone and antimicrobial activity against multidrug resistant Staphylococcus aureus and cytotoxicity against human tumor cell lines

“…7 In recent years, xanthones and xanthone derivatives have been reported to have significant pharmacological activities based on their diverse structures. [8][9][10][11][12][13][14][15][16][17][18][19][20] Their interesting structural scaffold and the significant biological activities have led many scientists to isolate, modify or synthesize different xanthones for the development of prospective new drug candidates. 7 Many xanthones bearing nitrogenated side chains connected to the phenolic core in different positions by C, O or N atoms have been synthesized during the last 10 years, and this group of molecules have showed interesting biological effects 14,18,[21][22][23][24][25] including antibacterial 26 and cytotoxic activities.…”

“…1 H NMR spectrum of (15), 300 MHz, acetone-d 6 Figure 41S. 13 C NMR spectrum of (15) 1 H NMR spectrum of (17), 300 MHz, DMSO-d 6 Chemical modifications of a natural xanthone and antimicrobial activity S19 Vol. 34,No.…”

“…6 Figure 47S. 13 C NMR spectrum of (17), 75 MHz, DMSO-d 6 Figure 48S. EI/MS spectrum of (17) Micheletti et al…”

Prenylated xanthones from Hypericum ascyron

“…Various constituents of H. ascyron have been reported to date, and flavonoids [3][4][5][6] and xanthones [7] have been confirmed as components of this plant. The family Clusiaceae is a known rich source of xanthones [8,9], which have been shown to have various bioactivities, including those of anti-methicillin-resistant Staphylococcus aureus (MRSA) [10][11][12], anti-vancomycin-resistant Enterococci (VRE) [13], anti-malarial [14], tumor-promoting inhibition [15], selective cyclooxygenase-2 inhibition [16], and inhibitory effects on platelet-activating factor (PA-F)-induced hypotension [17]. In the course of our search for bioactive natural products from plants, we became interested in Hypericum plants and their chemical constituents.…”

Xanthones from Stems of Hypericum chinense

“…The family Clusiaceae is a rich source of xanthones, 1,2) which show various bioactivities: anti-methicillin-resistant Staphylococcus aureus (MRSA), [3][4][5] anti-vancomycin-resistant Enterococci (VRE), 6) anti-malarial, 7) tumor-promoting inhibition, 8) selective cyclooxygenase-2 inhibition, 9) inhibitory effects on PAF-induced hypotension.…”