5-(3',4'-Dihydroxyphenyl)-γ-valerolactone is an active metabolite of various polyphenols, including (-)-epicatechin and procyanidin .1,2 It is formed from these polyphenols by gut microbiota. 5-(3',4'-Dihydroxyphenyl)-γ-valerolactone is an inhibitor of matrix metalloproteinase-1 (MMP-1) and MMP-2 collagen degradation activity (IC50s = 108 and 106 nM, respectively), MMP-1 and MMP-9 gelatin degradation activity (IC50s = 45.2 and 17.7 nM, respectively), and MMP-2 and MMP-9 elastin degradation activity (IC50s = 61.8 and 89 nM, respectively).3 It also scavenges free radicals in a Trolox equivalent antioxidant capacity (TEAC) assay.1
1.Unno, T., Tamemoto, K., Yayabe, F., et al.Urinary excretion of 5-(3',4'-dihydroxyphenyl)-γ-valerolactone, a ring-fission metabolite of (?)-epicatechin, in rats and its in vitro antioxidant activityJ. Agric. Food Chem.51(23)6893-6898(2003) 2.Appeldoorn, M.M., Vincken, J.-P., Aura, A.-M., et al.Procyanidin dimers are metabolized by human microbiota with 2-(3,4-dihydroxyphenyl)acetic acid and 5-(3,4-dihydroxyphenyl)-γ-valerolactone as the major metabolitesJ. Agric. Food Chem.57(3)1084-1092(2009) 3.Grimm, T., SchÄfer, A., and HÖgger, P.Antioxidant activity and inhibition of matrix metalloproteinases by metabolites of maritime pine bark extract (pycnogenol)Free Radic. Biol. Med.36(6)811-822(2004)