Chemical synthesis and tyrosinase-inhibitory activity of isotachioside and its related glycosides.
Carbohydr Res 2018;
465:22-28. [PMID:
29920401 DOI:
10.1016/j.carres.2018.06.004]
[Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/07/2018] [Accepted: 06/07/2018] [Indexed: 11/21/2022]
Abstract
Isotachioside (1) and its related natural product 2 are isolated from Isotachis japonica and Protea neriifolia, respectively, and are categorized as analogs of arbutin (3), a tyrosinase inhibitor for practical use. Both of the natural products and several derivatives such as glucoside 4, xyloside 5, cellobioside 6, and maltoside 7 were synthesized via Schmidt glycosylation as a key step, and their tyrosinase inhibitory activity was evaluated. The half maximal inhibitory concentration (IC50) of 1-3 could not be determined even when the concentration was increased to 1000 μM. Contrastingly, glycosides 4-7, missing methyl and benzoyl groups, acted as tyrosinase inhibitors with IC50s of 417 μM, 852 μM, 623 μM, and 657 μM, respectively. Among these novel inhibitors, derivative 4 was the most potent, indicating that the structural combination of resorcinol and glucose was significant for inducing the inhibitory effect.
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