tyropanoic acid tyropanoic acid tyropanoic acid and its salt sodium tyropanoate are radiocontrast agents used in cholecystography (x-ray diagnosis of gallstones). trade names include bilopaque, lumopaque, tyropaque, and bilopac. this molecule contains three heavy iodine atoms which obstruct x-rays in the same way as the calcium in bones to produce a visible image. after injection it is rapidly excreted into the bile. tyropanoic acid names preferred iupac name 2-butanoic acid other names 2-(3-butyramido-2,4,6-triiodobenzyl)butanoic acid2-methyl]butanoic acid identifiers cas number 27293-82-9 y 3d model (jsmol) interactive image chembl chembl1201261 n chemspider 5409 n echa infocard 100.043.976 ec number 248-389-8 kegg d01884 n mesh d014441 pubchem cid 5611 unii 4f05v145yr n comptox dashboard (epa) dtxsid5048269 inchi inchi=1s/c15h18i3no3/c1-3-5-12(20)19-14-11(17)7-10(16)9(13(14)18)6-8(4-2)15(21)22/h7-8h,3-6h2,1-2h3,(h,19,20)(h,21,22) nkey: ymoxvlqzfauuki-uhfffaoysa-n n smiles cccc(=o)nc1=c(c=c(c(=c1i)cc(cc)c(=o)o)i)i properties chemical formula c15h18i3no3 molar mass 641.02 g/mol pharmacology atc code v08ac09 (who) except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references