at-076 at-076 at-076 is a so-called opioid "pan" antagonist and is the first reasonably balanced antagonist known of all four opioid receptor types. it acts as a silent antagonist of all four of the opioid receptors, behaving as a competitive antagonist of the μ-opioid receptor (ki = 1.67 nm) and δ-opioid receptor (ki = 19.6 nm) and as a noncompetitive antagonist of the κ-opioid receptor (ki = 1.14 nm) and nociceptin receptor (ki = 1.75 nm). at-076 was derived from the selective κ-opioid receptor antagonist jdtic via removal of the 3,4-dimethyl group of the trans-(3r,4r)-dimethyl-4-(3-hydroxyphenyl)piperidine antagonist scaffold which increased affinity for the nociceptin receptor by 10-fold and for the μ- and δ-opioid receptors by 3-6-fold. at-076identifiers iupac name (3r)-7-hydroxy-n--3-methylbutan-2-yl]-1,2,3,4-tetrahydroisoquinoline-3-carboxamide cas number1657028-64-2pubchem cid91938095chemspider58145111uniint43s9bkj2chemical and physical dataformulac26h35n3o3molar mass437.584 g·mol−13d model (jsmol)interactive image smiles cc(c)(cn1ccc(cc1)c2=cc(=cc=c2)o)nc(=o)3cc4=c(cn3)c=c(c=c4)o inchi inchi=1s/c26h35n3o3/c1-17(2)25(16-29-10-8-18(9-11-29)19-4-3-5-22(30)12-19)28-26(32)24-14-20-6-7-23(31)13-21(20)15-27-24/h3-7,12-13,17-18,24-25,27,30-31h,8-11,14-16h2,1-2h3,(h,28,32)/t24-,25-/m1/s1key:lgydwjjzdcxeov-jwqcquifsa-n