Leoidin is a metabolite of the lichen, Lecanora gangleoides, first published in 1986 and recently reported as an inhibitor of protein synthesis in Pseudomonas aeruginosa. Leoidin is bacteriostatic, targeting PheRS. Leoidin is identified in PubChem as a weak inhibitor of human HPGC (15-hydroxyprostaglandin dehydrogenase) and of sodium fluorescein uptake in OATP1B1- or OATP1B3-transfected CHO cells.