C82 is an inhibitor of M. tuberculosis (Mtb) cyclic dinucleotide phosphodiesterase (CdnP; IC50 = 17.5 µM), the enzyme that catalyzes the hydrolysis of cyclic di-AMP to adenosine 5’-monophosphate . It is selective for Mtb CdnP over the additional bacterial CDN phosphodiesterases (PDEs) Yybt, RocR, and group B streptococcus (GBS) CdnP, the mammalian CDN PDE ENPP1, and the viral CDN PDE poxin at 200 µM.