beta-Hydroxypropiovanillone

Nat Prod Commun. 2012 Feb;7(2):185-6.

Phenolic constituents from the heartwood of Artocapus altilis and their tyrosinase inhibitory activity.[Pubmed: 22474950]

METHODS AND RESULTS:
From the MeOH extract of the heartwood of Artocapus altilis, thirteen phenolic compounds have been isolated, namely curcumin (1), desmethoxycurcumin (2), retrodihydrochalcone (3), apigenin (4), tangeretin (5), nobiletin (6), O-methyldehydrodieugenol (7), dehydrodieugenol (8), beta-Hydroxypropiovanillone (9), p-coumaric acid (10), p-hydroxybenzaldehyde (11), vanillin (12), and vanillic acid (13). This is the first report on the presence of these compounds in the heartwood of A. altilis.
CONCLUSIONS:
Compounds 1, 2, and 10 showed more potent tyrosinase inhibitory activities, with IC50 values ranging from 2.3 to 42.0 microM, than the positive control kojic acid (IC50, 44.6 microM). The most active compound, p-coumaric acid (10) (IC50, 2.3 microM), was 22 times more active in tyrosinase inhibitory activity than kojic acid.

J Bacteriol. 2003 Mar;185(6):1768-75.

Roles of the enantioselective glutathione S-transferases in cleavage of beta-aryl ether.[Pubmed: 12618439 ]

Cleavage of the beta-aryl ether linkage is the most important process in lignin degradation.
METHODS AND RESULTS:
Here we characterize the three tandemly located glutathione S-transferase (GST) genes, ligF, ligE, and ligG, from low-molecular-weight lignin-degrading Sphingomonas paucimobilis SYK-6, and we describe the actual roles of these genes in the beta-aryl ether cleavage. Based on the identification of the reaction product by electrospray ionization-mass spectrometry, a model compound of beta-aryl ether, alpha-(2-methoxyphenoxy)-beta-Hydroxypropiovanillone (MPHPV), was transformed by LigF or LigE to guaiacol and alpha-glutathionyl-beta-Hydroxypropiovanillone (GS-HPV). This result suggested that LigF and LigE catalyze the nucleophilic attack of glutathione on the carbon atom at the beta position of MPHPV. High-pressure liquid chromatography-circular dichroism analysis indicated that LigF and LigE each attacked a different enantiomer of the racemic MPHPV preparation. The ligG gene product specifically catalyzed the elimination of glutathione from GS-HPV generated by the action of LigF. This reaction then produces an achiral compound, beta-Hydroxypropiovanillone, which is further degraded by this strain.
CONCLUSIONS:
Disruption of the ligF, ligE, and ligG genes in SYK-6 showed that ligF is essential to the degradation of one of the MPHPV enantiomers, and the alternative activities which metabolize the substrates of LigE and LigG are present in this strain.