Steppogenin

Mol Nutr Food Res. 2008 Dec;52(12):1530-8.

Isolation of tyrosinase inhibitors from Artocarpus heterophyllus and use of its extract as antibrowning agent.[Pubmed: 18683821]

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.
METHODS AND RESULTS:
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.
CONCLUSIONS:
The results provide preliminary evidence supporting the potential of this natural extract as antibrowning agent in food systems.

Fitoterapia. 2013 Jan;84:242-7.

Characterization of tyrosinase inhibitors in the twigs of Cudrania tricuspidata and their structure-activity relationship study.[Pubmed: 23262271]

METHODS AND RESULTS:
The twigs of Cudrania tricuspidata were found to show strong tyrosinase inhibitory activity, and further detailed component analysis resulted in the isolation of a new flavanol glucoside, (2S,3S)-2,3-trans-dihydromorin-7-O-β-d-glucoside (1), plus twenty-seven known compounds (2-28). Their structures were elucidated on the basis of ESI-MS and NMR spectral data.
CONCLUSIONS:
Among the isolated compounds, trans-dihydromorin (8), oxyresveratrol (9), and Steppogenin (12) were found to exhibit significant tyrosinase inhibition activities. Moreover, the structure-activity relationship of these isolated compounds was also discussed.