Husni, Amir Jeon, Je-Seung Um, Byung-Hun Han, Nam Soo Chung, Donghwa 2024-01-20T16:34:57Z 2024-01-20T16:34:57Z 2021-09-05 2011-07 0022-5142 https://pubs.kist.re.kr/handle/201004/130213 BACKGROUND: Tyrosinase plays a key role in hyperpigmentaion and enzymatic browning. The present study was aimed at investigating the inhibitory effects of water and 70% aqueous ethanol extracts of Stichopus japonicus, a sea cucumber long consumed as a tonic food and traditional medicine, on the diphenolase activity of tyrosinase. RESULTS: In the tyrosinase inhibition study, high-performance liquid chromatography completely separated L-3,4-dihydroxyphenylalanine and dopachrome from other compounds present in the extracts, and provided more reliable results than the commonly used spectrophotometry. The ethanol extract (IC(50) = 0.49-0.61 mg mL(-1)) showed higher inhibitory activity than the water extract (IC(50) = 1.80-1.99 mg mL(-1)). Enzyme inhibition by the extracts was reversible and of mixed type. For both extracts, the dissociation constants for binding to free enzyme were significantly smaller than those for binding to enzyme-substrate complex. Ethyl-a-D-glucopyranoside (IC(50) = 0.19 mg mL(-1)), isolated for the first time from sea cucumber, and adenosine (IC(50) = 0.13 mg mL(-1)), were identified as key tyrosinase inhibitors. CONCLUSION: The sea cucumber extracts were demonstrated to possess considerable inhibitory potency against the diphenolase activity of tyrosinase, suggesting that the sea cucumber may be a good source of safe and effective tyrosinase inhibitors. (C) 2011 Society of Chemical Industry English WILEY-BLACKWELL MUSHROOM TYROSINASE ANTIOXIDANT PROPERTIES CUCUMARIA-FRONDOSA SAPONIN CONSTITUENTS GLYCOSIDES ACID L. Tyrosinase inhibition by water and ethanol extracts of a Far Eastern sea cucumber, Stichopus japonicus Article 10.1002/jsfa.4335 1 JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, v.91, no.9, pp.1541 - 1547 JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 91 9 1541 1547 scie scopus 000291874000004 2-s2.0-79958738938 Agriculture, Multidisciplinary Chemistry, Applied Food Science & Technology Agriculture Chemistry Food Science & Technology Article MUSHROOM TYROSINASE ANTIOXIDANT PROPERTIES CUCUMARIA-FRONDOSA SAPONIN CONSTITUENTS GLYCOSIDES ACID L. tyrosinase inhibitor sea cucumber Stichopus japonicus mixed type ethyl-alpha-D-glucopyranoside