3,4-Dihydroxymandelic acid

3,4‑Dihydroxymandelic acid is a metabolite of Norepinephrine (HY-13715) with free radical scavenging and antioxidant activities. 3,4-Dihydroxymandelic acid acts as a chemoattractant for enterohaemorrhagic Escherichia coli (EHEC), regulates virulence gene expression and bacterial adhesion to intestinal epithelial cells in a QseC-dependent manner, and targets EHEC to preferred infection sites. 3,4‑Dihydroxymandelic acid can be used in studies related to oxidative stress and enterohaemorrhagic Escherichia coli infection^[1][2]. In Vitro:3,4-Dihydroxymandelic acid (DHMA) acts as a chemoattractant for the EHEC O157:H7 strain 86-24, which is evidenced by the cell aggregation observed at the edge of agarose plugs containing 500 μM DHMA after 30 min of incubation; the MMC value increases at concentrations ranging from 50 to 5000 μM^[1].
3,4-Dihydroxymandelic acid (50 μM) induces QseC-dependent upregulation of virulence genes in EHEC O157:H7 strain 86-24; it also increases the adhesion of the strain to HeLa S3 cells in a QseC-dependent manner^[1].
3,4-Dihydroxymandelic acid (DHMA) potently scavenges DPPH free radicals in cell-free assays, with an EC₅₀ of 0.062 mol/mol and an ARP of 16; it also efficiently scavenges superoxide anion radicals in cell-free chemiluminescence assays, with an IC₅₀ of 130 nM^[2].
3,4-Dihydroxymandelic acid (0.0001-0.001%; 48-hour incubation) enhances the antioxidant capacity of human skin fibroblasts in a dose-dependent manner^[2].
3,4-Dihydroxymandelic acid (0.005-0.05%) potently inhibits accelerated lipid autoxidation in degummed soybean oil (AOI 9.5), degummed squalene (AOI 34) and evening primrose oil (AOI 6.7), and exhibits synergistic activity with α-tocopherol in soybean oil and squalene^[2].
3,4-Dihydroxymandelic acid (0.0001-0.01%; 24-72 h incubations) exhibits acute cytotoxicity only at the concentration of 0.01% after 24 h of incubation^[2]. In Vivo:3,4-Dihydroxymandelic acid (DHMA) content in fecal contents of C57BL/6 mice is approximately 2 μM, and its production depends on the presence of the symbiotic microbiota^[1].
3,4-Dihydroxymandelic acid (DHMA) accumulates at high levels in the myocardium of aged rats compared with other tested tissues^[2].