Chemical structure and selected biological properties of a glucomannan from the lichenized fungus Heterodermia obscurata.
Successive aqueous and alkaline extraction of the thallus of the lichenized fungus Heterodermia obscurata provided a highly branched glucomannan fraction (GM), whose chemical structure was determined. This was based on monosaccharide composition, methylation, partial acid hydrolysis, and NMR spectroscopic analysis. It consisted of a main chain of (1→6)-linked α-D-mannopyranosyl units, almost all being substituted at O-2 with α-D-glucopyranosyl, α-D-mannopyranosyl, and 4-O-substituted α-D-mannopyranosyl groups. Intra-peritoneal administration of this GM induced a marked and dose-dependent inhibition of acetic acid-induced visceral pain with an ID(50) of 0.6 (0.2-2.0) mg/kg and inhibition of 88±4%. It also reduced leukocyte migration by 58±4%, but did not alter plasmatic extravasation to the peritoneal cavity. The results suggest that the glucomannan from the H. obscurata might have potential for antinociceptive and anti-inflammatory utilization.
Departamento de Farmácia, Faculdade Assis Gurgacz, 85806-090 Cascavel, PR, Brazil.
Maria Izabel
MI
Pereira
Andrea Caroline
AC
Ruthes
Elaine R
ER
Carbonero
Rodrigo
R
Marcon
Cristiane H
CH
Baggio
Cristina S
CS
Freitas
Adair Roberto S
AR
Santos
Sionara
S
Eliasaro
Guilherme L
GL
Sassaki
Philip Albert J
PA
Gorin
Marcello
M
Iacomini
D019342:Acetic Acid / Q000494:pharmacology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000302:isolation & purification* / Q000627:therapeutic use*; D001203:Ascomycota; D001938:Brazil; D004195:Disease Models, Animal; D008351:Mannans / Q000737:chemistry / Q000302:isolation & purification / Q000627:therapeutic use; D051379:Mice; D019906:Nuclear Magnetic Resonance, Biomolecular; D010146:Pain / Q000188:drug therapy; D013237:Stereoisomerism
D000894:Anti-Inflammatory Agents, Non-Steroidal; D008351:Mannans; C022901:(1-6)-alpha-glucomannan; D019342:Acetic Acid