Isolation of tyrosinase inhibitors from Artocarpus heterophyllus and use of its extract as antibrowning agent.
A new furanoflavone, 7-(2,4-dihydroxyphenyl)-4-hydroxy-2-(2-hydroxy propan-2-yl)-2, 3-dihydrofuro(3, 2-g)chromen-5-one (artocarpfuranol, 1), together with 14 known compounds, dihydromorin (2), steppogenin (3), norartocarpetin (4), artocarpanone (5), artocarpesin (6), artocarpin (7), cycloartocarpin (8), cycloartocarpesin (9), artocarpetin (10), brosimone I (11), cudraflavone B (12), carpachromene (13), isoartocarpesin (14), and cyanomaclurin (15) were isolated from the wood of Artocarpus heterophyllus. Their structures were identified by interpretation of MS,( 1)H-NMR,( 13)C-NMR, HMQC, and HMBC spectroscopic data. Among them, compounds 1-6 and 14 showed strong mushroom tyrosinase inhibitory activity with IC(50) values lower than 50 microM, more potent than kojic acid (IC(50) = 71.6 microM), a well-known tyrosinase inhibitor. In addition, extract of A. heterophyllus was evaluated for its antibrowning effect on fresh-cut apple slices. It was discovered that fresh-cut apple slices treated by dipping in solution of 0.03 or 0.05% of A. heterophyllus extract with 0.5% ascorbic acid did not undergo any substantial browning reaction after storage at room temperature for 24 h. The antibrowning effect was significantly better than samples treated with the extract (0.03 or 0.05%) or ascorbic acid (0.5%) alone. The results provide preliminary evidence supporting the potential of this natural extract as antibrowning agent in food systems.
Zheng
Zong-Ping
ZP
School of Biological Sciences, The University of Hong Kong, Hong Kong, PR China.
Cheng
Ka-Wing
KW
To
James Tsz-Kin
JT
Li
Haitao
H
Wang
Mingfu
M
D031622:Artocarpus / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D015416:Maillard Reaction / Q000187:drug effects*; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*
D047309:Flavones; D010455:Peptides; D010936:Plant Extracts