Purpurogallin is a phenol that has been found in D. divisa and a derivative of pyrogallol that has diverse biological activities, including antimicrobial, antioxidant, and enzyme inhibitory properties.1,2,3,4,5,6 It is active against the Gram-positive bacteria S. aureus, methicillin-resistant S. aureus (MRSA), S. epidermidis, and B. subtilis (MICs = 11-110 ?g/ml), the Gram-negative bacteria S. marcescens, P. vulgaris, K. pneumoniae, E. coli, S. typhi, and E. cloacae (MIC = 110 ?g/ml for all), as well as P. falciparum strain FCB1 clone NC-1 (IC50 = 55 ?M).1,3 Purpurogallin (2, 5, and 10 ?M) scavenges 2,2-diphenyl-1-picrylhydrazyl radicals in a cell-free assay and reduces hydrogen peroxide- and radiation-induced production of reactive oxygen species (ROS) in HaCaT keratinocytes.2 It inhibits the activity of EGFR, glutathione-S-transferase (GST), prolyl endopeptidase, and glyoxalase I (IC50s = 27.5, 8, 16, and 50 ?M, respectively), as well as catechol O-methyltransferase (COMT; Ki = 0.074 ?M), in cell-free assays.1,3,4,5,6
1.Inamori, Y., Muro, C., Sajima, E., et al.Biological activity of purpurogallinBiosci. Biotechnol. Biochem.61(5)890-892(1997) 2.Zhen, A.X., Piao, M.J., Hyun, Y.J., et al.Purpurogallin protects keratinocytes from damage and apoptosis induced by ultraviolet B radiation and particulate matter 2.5Biomol. Ther. (Seoul)27(4)395-403(2019) 3.Barnard, J.F., Vander Jagt, D.L., and Honek, J.F.Small molecule probes of glyoxalase I and glyoxalase IIBiochim. Biophys. Acta1208(1)127-135(1994) 4.Abou-Karam, M., and Shier, W.T.Inhibition of oncogene product enzyme activity as an approach to cancer chemoprevention. Tyrosine-specific protein kinase inhibition by purpurogallin from Quercus sp. nutgallPhytother. Res.13(4)337-340(1999) 5.Das, M., Bickers, D.R., and Mukhtar, H.Plant phenols as in vitro inhibitors of glutathione S-transferase(s)Biochem. Biophys. Res. Commun.120(2)427-433(1984) 6.Veser, J.Kinetics and inhibition studies of catechol O-methyltransferase from the yeast Candida tropicalisJ. Bacteriol.169(8)3696-3700(1987)