title: Structure-activity relationship studies of the amide functionality in (p-O-sulfamoyl)-N-alkanoyl tyramines as estrone sulfatase inhibitors.
abstract: Recently, we reported the synthesis and biomedical studies of a series of (p-O-sulfamoyl)-N-alkanoyl tyramines as nonsteroidal estrone sulfatase inhibitors. One of the most potent inhibitors in this series is (p-O-sulfamoyl)-N-tridecanoyl tyramine 1 with an 1C50 value of 61.3 nM. In this study, we synthesized four analogs of 1 (compounds 2-5) to investigate the structure-activity relationships of the amide functionality in (p-O-sulfamoyl)-N-tridecanoyl tyramine. Replacement of the amide functionality in 1 with an ethylene moiety to form the alkyl analog 5 resulted in complete loss of sulfatase inhibitory activity (IC50 of 61.3 nM vs. > 20 microM). The keto, hydroxy, and ester analogs (inhibitors 2-4) are 8-15 times less in affinity to the sulfatase than inhibitor 1. However, their inhibitory activities are significantly higher than the alkyl analog 5. The results suggest that the amide functionality is favorable for sulfatase inhibitory activity and that there may be a hydrogen bonding component to the enzyme interaction in this region.
authors.affiliation: Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA.
authors.forename: G H
authors.initials: GH
authors.lastname: Chu
authors.forename: S
authors.initials: S
authors.lastname: Milano
authors.forename: L
authors.initials: L
authors.lastname: Kluth
authors.forename: M
authors.initials: M
authors.lastname: Rhodes
authors.forename: R
authors.initials: R
authors.lastname: Boni
authors.forename: D A
authors.initials: DA
authors.lastname: Johnson
authors.forename: P K
authors.initials: PK
authors.lastname: Li
mesh_terms: D000577:Amides / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013429:Sulfatases / Q000037:antagonists & inhibitors*; D013449:Sulfonamides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D014439:Tyramine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000577:Amides; D004791:Enzyme Inhibitors; D013449:Sulfonamides; C108251:(4-O-sulfamoyl)-N-tridecanoyl tyramine; D013429:Sulfatases; C020121:estrone sulfatase; D014439:Tyramine