MFH290 is a novel cysteine (Cys)-directed covalent inhibitor of CDK12 13. MFH290 forms a covalent bond with Cys-1039 of CDK12, exhibits excellent kinome selectivity, inhibits the phosphorylation of serine-2 in the C-terminal domain (CTD) of RNA-polymerase II (Pol II), and reduces the expression of key DNA damage repair genes. Importantly, these effects were demonstrated to be CDK12-dependent as mutation of Cys-1039 rendered the kinase refractory to MFH290 and restored Pol II CTD phosphorylation and DNA damage repair gene expression. Consistent with its effect on DNA damage repair gene expression, MFH290 augments the antiproliferative effect of the PARP inhibitor olaparib.
4’-hydroxy Trazodone is a metabolite of the antidepressant and sedative trazodone.1It is an inhibitor of organic anion transporter 3 (OAT3; Ki= 16.9 μM) and is selective for OAT3 over OAT1 (Ki= >200 μM).2 1.Yamato, C., Takahashi, T., Fujita, T., et al.Studies on metabolism of trazodone, II. Metabolic fate after intravenous administration and effects on liver microsomal drug-metabolizing enzymes in ratsXenobiotica4(12)765-777(1974) 2.Zou, L., Matsson, P., Stecula, A., et al.Drug metabolites potently inhibit renal organic anion transporters, OAT1 and OAT3J. Pharm. Sci.110(1)347-353(2021)
Indoxyl sulfate-d5 is intended for use as an internal standard for the quantification of indoxyl sulfate by GC- or LC-MS. Indoxyl sulfate is a uremic toxin and a metabolite of tryptophan. It is formed via sulfation of indole, an intermediate generated from tryptophan by intestinal bacteria, by the sulfotransferase (SULT) isoform 1A1 variant 2 (SULT1A1*2) in the liver. Indoxyl sulfate activates the aryl hydrocarbon receptor (AhR) in HepG2 40 6 hepatoma cells (EC50 = 12.1 nM in a reporter assay). It also inhibits the organic anion transporter (OAT) isoforms OAT1 and OAT3 (Kis = 34.2 and 74.4 µM, respectively for the rat transporters) in S2 proximal tubule cells. Indoxyl sulfate (0.2 and 1 mM) increases superoxide anion and nitric oxide levels in isolated human mononuclear blood cells. It increases serum creatinine and blood urea nitrogen (BUN) levels in the 5 6 nephrectomized rat model of chronic renal failure when administered at a dose of 50 mg kg.