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 JLC31681 by the paper disk method.
Results: We totally got three peptide toxins: alpha-amanitin (alpha-AMA), beta-amanitin (beta-AMA) and phalloidin (PHD). The contents of alpha-AMA, beta-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 alpha-AMA and PHD were 11.7 mg/g and 7.98 mg/g in the mixture of stipe and volva , but the beta-AMA was not detected in this part. The inhibition ratio of the crude toxin and alpha-AMA, beta-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 beta-AMA to B. albicans JLC31681 was 10.16% and 11.10% (P < 0.01), while that of alpha-AMA's was 6.89% (P < 0.05).
Conclusions: A. pallidorasea is a new resource of peptide toxins with antifungal activity.