Antimutagenic activity of gigantol from Dendrobium nobile.

摘要

A methanol extract of rhizomes of D. nobile (collected from Japan) suppressed umu gene expression of Salmonella typhimurium TA1535/pSK1002 induced by the mutagen 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide). The extract was re-extractedwith n-hexane, dichloromethane, 1-butanol and water, respectively. An active compound in the n-hexane fraction was isolated by SiO2 column chromatography and chemical fractionation. It was identified as gigantol. Gigantol suppressed the SOS-inducing activity of furylfuramide in the umu test. Gigantol (<0.73μmol/ml) suppressed gene expression by 90% (ID50 value of 0.35μmol/ml). Gigantol also suppressed gene expression induced by 3-amino-1,4-dimethyl-5H-pyridol[4,3b]indole in the umu test; gene expression was suppressed by 91% at gigantol concentrations of <0.73μmol/ml (ID50 value of 0.32μmol/ml). Gigantol was assayed for suppressive effects against UV irradiation in the umu test. Gigantol (<0.36μmol/ml) suppressed gene expression caused by UV irradiation by 84% (ID50 value of 0.17μmol/ml).