copper usnate copper usnate copper usnate is the copper salt of usnic acid. it has been used as an antimicrobial. copper usnateclinical dataatc codeg01ax15 (who) identifiers iupac name copper 4,8-diacetyl-2,9a-dimethyl-7,9-dioxodibenzofuran-1,3-diolate pubchem cid46222573drugbankdb13830 ychemspider30647422unii2ev5p25e2schemical and physical dataformulac18h14cuo7molar mass405.849 g·mol−13d model (jsmol)interactive image smiles cc1c(c(c2c(c1)c3(c(=cc(=o)c(c3=o)c(=o)c)o2)c)c(=o)c). inchi inchi=1s/c18h16o7.cu/c1-6-14(22)12(8(3)20)16-13(15(6)23)18(4)10(25-16)5-9(21)11(7(2)19)17(18)24;/h5,11,22-23h,1-4h3;/q;+2/p-2key:bjkwdvrcnoatjs-uhfffaoysa-l (verify)