Abstract:
The inhibitory effects on tyrosinase of the methanolic extracts from 10
Nostoc strains were investigated.The results show that the inhibitory action for the above 6 strains of
Nostoc enhanced with the increase of concentration of the methanolic extracts.The methanolic extracts of
Nostoc sp.FACHB892 has great inhibitory capacity on tyrosinase,of which the inhibitory rate is 60.54% at concentration of 33.3 μg/mL,while the methanolic extracts of other 5 strains(
Nostoc sp.FACHB95,
Nostoc sp.FACHB106,
N.punctiforme FACHB252,
N.calcicola FACHB389 and
N.parmiloides FACHB392) exhibitted weaker inhibitory effects.The inhibitory rates are 41.55%,37.58%,46.94%,52.12% and 47.95% respectively at the same concentration.The inhibitory mechanism of the methanolic extracts of
Nostoc sp.FACHB892 on tyrosinase is reversible and noncompetitive indicated by the enzymatic kinetic analysis.