Radical-scavenging activity of orsellinates.
Lichens are an important source of phenolic compounds and have been intensively investigated for their biological and pharmacological activities. Lecanoric acid (1), a lichen depside, was isolated from a Parmotrema tinctorum specimen and treated with alcohols to produce orsellinic acid (2) and orsellinates (3) to (9) (2,4-dihydroxy-6-n-methyl benzoates). Free radical scavenging activity of methyl (3), ethyl (4), n-propyl (5), n-butyl (6), iso-propyl (7), sec-butyl (8), tert-butyl (9) orsellinates was evaluated using 2,2'-diphenyl-1-picrylhydrazyl (DPPH) method. Results showed that chain elongation of methyl (3) to n-butyl (6) causes a rise in the antioxidant activity. However, iso-propyl (7) and tert-butyl (9) were more active than the correspondent linear compounds, although sec-butyl (8) was less active among the chain ramified compounds. All the orsellinates were less active than lecanoric acid (1) and orsellinic acid (2). Orcinol (10) and resorcinol (11) were also determined for comparison with activities of orsellinates. Gallic acid (12) was used as control.
Lopes
Thiago Inácio Barros
TI
Departamento de Química, Universidade Federal de Mato Grosso do Sul, Brazil.
Coelho
Roberta Gomes
RG
Yoshida
Nídia Cristiane
NC
Honda
Neli Kika
NK
D001713:Biphenyl Compounds; D016166:Free Radical Scavengers / Q000494:pharmacology*; D008011:Lichens / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010851:Picrates / Q000737:chemistry; D012118:Resorcinols / Q000494:pharmacology*; D021241:Spectrometry, Mass, Electrospray Ionization; D013329:Structure-Activity Relationship
D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D012118:Resorcinols; C501612:orsellinic acid; C004931:1,1-diphenyl-2-picrylhydrazyl