Thiosemicarbazones of formyl benzoic acids as novel potent inhibitors of estrone sulfatase.
Thiosemicarbazones of the microbial metabolite madurahydroxylactone, a polysubstituted benzo[a]naphthacenequinone, have been previously reported by us as potent nonsteroidal inhibitors of the enzyme estrone sulfatase (cyclohexylthiosemicarbazone 1, IC50 0.46 microM). The active pharmacophore of 1 has now been identified to be 2-formyl-6-hydroxybenzoic acid cyclohexylthiosemicarbazone (25, IC50 4.2 microM). The active partial structure was derivatized in the search for novel agents against hormone-dependent breast cancer. Further substantial increases in activity were achieved by reversal of functional groups leading to the cyclohexylthiosemicarbazones of 5-formylsalicylic acid (35, IC50 0.05 microM) and 3-formylsalicylic acid (34, IC50 0.15 microM) as the most potent analogues identified to date. Both compounds were shown to be noncompetitive inhibitors of estrone sulfatase with Ki values of 0.13 microM and 0.12 microM, respectively. The compounds showed low acute toxicity in the hen's fertile egg screening test.
Jütten
Peter
P
Leibniz Institute for Natural Products Research and Infection Biology, HKI, Beutenbergstrasse 11a, 07745 Jena, Germany.
Schumann
Winfried
W
Härtl
Albert
A
Dahse
Hans-Martin
HM
Gräfe
Udo
U
D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy; D002645:Chickens; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy; D010920:Placenta / Q000201:enzymology; D012459:Salicylates / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013429:Sulfatases / Q000037:antagonists & inhibitors*; D013882:Thiosemicarbazones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D023382:Toxicity Tests, Acute
C523418:2-(4-cyclohexylthiosemicarbazono)methyl-6-hydroxybenzoic acid; C523419:3-(4-cyclohexylthiosemicarbazono)methyl-2-hydroxybenzoic acid; C523420:5-(4-cyclohexylthiosemicarbazono)methyl-2-hydroxybenzoic acid; D000970:Antineoplastic Agents; D012459:Salicylates; D013882:Thiosemicarbazones; D013429:Sulfatases; C020121:estrone sulfatase