1,10-Phenanthrine is a metal chelator and inhibitor of metalloproteases.1,2,3 It inhibits zinc-dependent hydrolysis of Fa-Gly-Leu-NH2 by B. subtilis neutral protease and B. thermoproteolyticus thermolysin.1 1,10-Phenanthrine is fungistatic against P. verrucosa (MIC = 0.8 μg/ml) and inhibits zinc-induced P. verrucosa metallo-type peptidase activity in a concentration-dependent manner.2 It induces uncoupling of and inhibits egg production by adult S. mansoni worm pairs in vitro when used at concentrations ranging from 0.5 to 150 μM.3 1,10-Phenanthrine (20 mg/kg per day) reduces worm burden in a mouse model of S. mansoni infection.

|1. Feder, J., Garrett, L.R., and Kochavi, D. Studies on the inhibition of neutral proteases by 1,10-phenanthroline. Biochim. Biophys. Acta 235(2), 370-377 (1971).|2. Granato, M.Q., Massapust, P.d.A., Rozental, S., et al. 1,10-Phenanthroline inhibits the metallopeptidase secreted by Phialophora verrucosa and modulates its growth, morphology and differentiation. Mycopathologia 179(3-4), 231-242 (2014).|3. Day, T.A., and Chen, G.-Z. The metalloprotease inhibitor 1,10-phenanthroline affects Schistosoma mansoni motor activity, egg laying and viability. Parasitology 116(Pt. 4), 319-325 (1998).