[H]C12OC=CC1([H])c1c(cc(OC)c3c4c(c(=O)oc13)C(=O)CC4)O2
DRUGMATRIX assay inhibits PDE5 enzyme (substrate: [3H]cGMP + cGMP) and targets a single protein. It uses human platelet cells and is an in vitro binding assay. Does the molecule work for this assay?