c16 (drug) c16 (drug) c16 (pkri, gw 506033x) is a drug which acts as a selective inhibitor of the enzyme double-stranded rna-dependent protein kinase (pkr). it has been shown to effectively inhibit pkr function in vivo and has neuroprotective and nootropic effects in animal studies. c16identifiers iupac name 6,8-dihydro-8-(1h-imidazol-5-ylmethylene)-7h-pyrrolobenzothiazol-7-one cas number608512-97-6pubchem cid6490494chemspider4990932uniic9q75qzk84echa infocard100.211.648 chemical and physical dataformulac13h8n4osmolar mass268.29 g·mol−13d model (jsmol)interactive image smiles o=c3c2ccc1ncsc1c2c3=cc4ccn4 inchi inchi=1s/c13h8n4os/c18-13-8(3-7-4-14-5-15-7)11-9(17-13)1-2-10-12(11)19-6-16-10/h1-6h,(h,14,15)(h,17,18)/b8-3-key:vfbgxtugodtspk-baqgirsfsa-n