benzofurans and orsellinic-acid

Rappiidic acid, a new o-orsellinic acid derivative, was isolated from the lichen Cladonia rappii. Its capability to scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) was investigated and compared with resveratrol and (+)-usnic acid. Usnic acid at 100 μM was the most efficient ROS scavenger, exhibiting activity 3-fold higher than that of resveratrol. At the same concentration, rappidic acid scavenged 23.1% of ROS formed, demonstrating that this compound is twice as active as resveratrol. Both compounds were shown to be poor RNS scavengers.

Topics: Benzofurans; Brazil; Free Radical Scavengers; Lichens; Molecular Structure; Resorcinols; Resveratrol

The major bioactive constituents of Usnea longissima Ach. are organic acids. However, few recent literatures involve the preparative separation of these organic acids. In the present study, pH zone-refining counter-current chromatography is used to separate organic acids from crude sample of U. longissima Ach. The crude extract was separated with the two-phase solvent system Pet-EtAc-MeOH-H2O (5:5:3:7, v/v) with 10mM TFA in organic stationary phase and different concentration of the eluter in aqueous mobile phase for the screening of the most suitable separation conditions. From the crude extract (1.2g), 74.0mg of orsellinic acid at 92.7% purity, 55.5mg of 4-O-methylorsellinic acid at 97.7% purity, 353.5mg of evernic acid at 93.8% purity, 102.0mg of barbatic acid at 94.8% purity, 19.4 mg of diffractaic acid at 92.2% purity, and 44.9 mg of usnic acid at 95.7% purity were obtained using the selected conditions in which the concentration of TFA in stationary phase was 10mM and the concentration of NaOH in mobile phase was 10-20mM. The purities of the separated organic acids were measured by HPLC. And the data of electrospray ionization-liquid chromatography/mass spectrometry (ESI-LC/MS), (1)H NMR, and (13)C NMR were used for confirming chemical structures.

Topics: Anisoles; Benzofurans; Chromatography, High Pressure Liquid; Countercurrent Distribution; Hydrogen-Ion Concentration; Hydroxybenzoates; Phthalic Acids; Resorcinols; Spectrometry, Mass, Electrospray Ionization; Usnea

Lecanoric acid (1), orsellinic acid methyl ester (2), orcinol (3), and usnic acid (4) were isolated from the lichen Parmelia subrudecta, collected on Palma of the Canary Islands, Spain. Compounds 1, 2, 3, and 4 were purified by solvent extraction, silica gel column chromatography, and preparative high-performance liquid chromatography (HPLC) consecutively. The structures of the four compounds were elucidated by one- and two-dimensional nuclear magnetic resonance (NMR) experiments and mass spectrometric investigations. These compounds showed activity against important gram-positive and gram-negative pathogens like mycobacteria and multiresistant staphylococci. This activity is combined with antiproliferative activity and cytotoxicity.

Topics: Anti-Infective Agents; Antineoplastic Agents; Bacteria; Bacterial Infections; Benzofurans; Cell Line, Tumor; Cell Proliferation; Humans; Lichens; Magnetic Resonance Spectroscopy; Molecular Structure; Neoplasms; Resorcinols; Salicylates; Spectrometry, Mass, Electrospray Ionization