Determination of main peptide toxins from Amanita pallidorosea with HPLC and their antifungal action on Blastomyces albicans

Abstract:

Abstract: ［Objective］ To detect peptide toxins in Amanita pallidorasea and to study the antifungal activities of peptide toxins against Blastomyces albicans． ［Methods］We separated and identified peptide toxins and determined its contents in the fruiting body，pileus and the mixture of stipe and volva from A． pallidorasea by HPLC and ESI-MS methods．Meanwhile，we detected antifungal activities of the crude toxin and the separated peptide toxins against Blastomyces albicans JLC31680 and JLC31681by the paper disk method．［Results］We totally got three peptide toxins: α-amanitin (α-AMA)，β-amanitin (β-AMA) and phalloidin (PHD)．The contents of α-AMA，β-AMA and PHD were 30.3 mg/g，6.99 mg/g and 9.95 mg/g in fruiting body，and 45.0 mg/g，11.1 mg/g and 11.3 mg/g in pileus．The contents of α-AMA and PHD were 11.7 mg/g and 7.98 mg/g in the mixture of stipe and volva，but the β-AMA was not detected in this part． The inhibition ratio of the crude toxin and a-AMA，β-AMA and PHD to B．albicans JLC31680 were 11.96%，32.52%，23.29%(P＜0.01) and 15.46%(P＜0.05)．The inhibition ratio of the crude toxin and β-AMA to B．albicans JLC31681 was 10.16% and 11.10%(P＜0.01)，while that of α-AMA s was 6.89%(P＜0.05)．[Conclusions] A．pallidorasea is a new resource of peptide toxins with antifungal activity．

Key words:Keywords: Amanita，peptide toxin，antifungal action