Mushroom tyrosinase inhibitory activity of esculetin isolated from seeds of Euphorbia lathyris L.
A tyrosinase inhibitor was isolated from the seeds of Euphorbia lathyris L. by bioassay-guided fractionation and purification, using silica gel column chromatography. It was identified as esculetin by comparing its physical properties and spectral data with those of an authentic sample. The IC50 value of esculetin in the mushroom tyrosinase activity test was 43 microM. The kinetic study indicates that esculetin exhibited competitive inhibition against the oxidation of 3-(3,4-dihydroxyphenyl)-alanine by mushroom tyrosinase. The structure-activity relationships among five esculetin analogs suggest that hydroxyl groups at the C6 and C7 positions of the coumarin skeleton played an important role in the expression of tyrosinase inhibitory activity.
Graduate School of Natural Science and Technology, Okayama University, 1-1 Naka 3-chome, Tsushima, Okayama 700-8530, Japan.
Yukimitsu
Y
Masamoto
Hideya
H
Ando
Yoshiyuki
Y
Murata
Yasuaki
Y
Shimoishi
Mikiro
M
Tada
Kyoya
K
Takahata
D000363:Agaricales / Q000201:enzymology; D001667:Binding, Competitive; D003374:Coumarins / Q000737:chemistry; D019665:Euphorbiaceae / Q000737:chemistry*; D020128:Inhibitory Concentration 50; D007700:Kinetics; D007980:Levodopa / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011753:Pyrones / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry; D013329:Structure-Activity Relationship; D014468:Umbelliferones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
D003374:Coumarins; D010455:Peptides; D011753:Pyrones; D014468:Umbelliferones; D007980:Levodopa; C011890:kojic acid; C007628:esculetin