Mushroom tyrosinase inhibitors from Aloe barbadensis Miller.
Two new chromones, 5-((S)-2'-oxo-4'-hydroxypentyl)-2-(β-glucopyranosyl-oxy-methyl)chromone (1) and 5-((S)-2'-oxo-4'-hydroxypentyl)-2-methoxychromone (2), together with four known analogues, 8-C-glucosyl-7-O-methyl-(S)-aloesol (3), isoaloeresin D (4), 8-C-glucosyl-(R)-aloesol (5), and aloesin (6) were isolated from the aqueous extract of Aloe barbadensis Miller. Their structures were determined on the basis of spectroscopic evidences (1-D and 2-D NMR, HRMS, UV, and IR data), chemical methods and the literature data. The Mosher's method was applied to establish the absolute configuration of compounds 1 and 2. The inhibitory effects of these chromones on the activity of mushroom tyrosinase were examined, and compound 6 was identified as a noncompetitive tyrosinase inhibitor with an IC(50) value of 108.62μg·mL(-1).
School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, 510006, PR China.
Xiaofang
X
Wu
Sheng
S
Yin
Jiasheng
J
Zhong
Wenjing
W
Ding
Jinzhi
J
Wan
Zhiyong
Z
Xie
D000363:Agaricales / Q000201:enzymology*; D000504:Aloe / Q000737:chemistry*; D002867:Chromones / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*
D002867:Chromones; D014442:Monophenol Monooxygenase