Specific interaction of some non-steroidal compounds with the progesterone binding site of uteroglobin

Uteroglobin binds progesterone with high affinity. A few substituted diphenyl ketones were observed to inhibit uteroglobin-progesterone binding in a dose-dependent manner. 4,4'-Dimethoxy-2-hydroxy benzophenone had relatively higher affinity for uteroglobin. The structure-activity relationship amongst the substituted diphenyl ketones indicated considerable sensitivity towards minor structural modifications. These observations offer a tool to investigate nonsteroidal compounds in relation to progesterone related functions of uteroglobin in pregnancy.