Article ID Journal Published Year Pages File Type
10544601 Food Chemistry 2005 5 Pages PDF
Abstract
This study was aimed to evaluate the kinetic properties and capacities of 95% ethanolic (GE95), 50% ethanolic (GE50) and water (GWE) extracts from Graptopetalum paraguayense for their potential to inhibit mushroom tyrosinase activity. The results showed that GE95, GE50 and GWE showed potent inhibitory effects on l-3,4-dihydroxyphenylalanine (l-Dopa) oxidation catalyzed by tyrosinase. It was found that the tyrosinase inhibitory activities of all the extracts increased with the increase of their concentrations. The inhibition kinetics, analyzed by Lineweaver-Burk plots, revealed that G. paraguayense extracts showed a mixed-type inhibition for mushroom tyrosinase when l-Dopa was used as substrate. A comparison of the IC50 and Ki values showed that GE95 exhibited the most effective inhibition of tyrosinase among the extracts.
Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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