Young JD
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Steroids
Volume 54, Issue 3, September 1989, Pages 299-311
doi:10.1016/0039-128X(89)90004-4*|*How to Cite or Link Using DOI
Cited By in Scopus (8)
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3β-hydroxyandrost-4-en-6-one derivatives as aromatase inhibitors
Mitsuteru*Numazawa*, Ayako*Mutsumi, Masachika*Tsuji
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Tohoku College of Pharmacy, 4-1 Komatsushima-4-chome, Sendai 981, Japan
Received 29 September 1988; revised 27 January 1989; Available online 27 April 2004.
Abstract
The 3-formate (II), 3-acetate (III), 3-bromoacetate (IV), 3-propionate (V), 3-methyl ether (VI), and 3-deoxy-derivative (VII) of 3β-hydroxyandrost-4-ene-6,17-dione (I) were synthesized and tested in human placental microsomes for their ability to inhibit aromatase. II, III, and VII of this series were potent inhibitors of aromatase with the IC50's (1.7 and 3.3 μM) of the latter two comparable to that (1.2 μM) of 4-hydroxyandrostenedione. Kinetic studies showed that the three steroids are competitive inhibitors of the enzyme with Ki's of 16.0, 5.5, and 0.61 μM for II, III, and VII. Furthermore, II showed a time-dependent, pseudo-first order rate of inactivation of aromatase with Ki of 20.5 μM and kinact of 1.54 × 10−2 min−1, while III gave a time-dependent, biphasic loss of the enzyme activity. NADPH and oxygen were required for the time-dependent inactivation and the substrate, androstenedione, prevented it.
Corresponding author: Mitsuteru Numazawa
Purchase
Copyright © 1989 Published by Elsevier Inc.
Steroids
Volume 54, Issue 3, September 1989, Pages 299-311
Steroids
Volume 54, Issue 3, September 1989, Pages 299-311
doi:10.1016/0039-128X(89)90004-4*|*How to Cite or Link Using DOI
Cited By in Scopus (8)
**Permissions & Reprints
3β-hydroxyandrost-4-en-6-one derivatives as aromatase inhibitors
Mitsuteru*Numazawa*, Ayako*Mutsumi, Masachika*Tsuji
Purchase
Tohoku College of Pharmacy, 4-1 Komatsushima-4-chome, Sendai 981, Japan
Received 29 September 1988; revised 27 January 1989; Available online 27 April 2004.
Abstract
The 3-formate (II), 3-acetate (III), 3-bromoacetate (IV), 3-propionate (V), 3-methyl ether (VI), and 3-deoxy-derivative (VII) of 3β-hydroxyandrost-4-ene-6,17-dione (I) were synthesized and tested in human placental microsomes for their ability to inhibit aromatase. II, III, and VII of this series were potent inhibitors of aromatase with the IC50's (1.7 and 3.3 μM) of the latter two comparable to that (1.2 μM) of 4-hydroxyandrostenedione. Kinetic studies showed that the three steroids are competitive inhibitors of the enzyme with Ki's of 16.0, 5.5, and 0.61 μM for II, III, and VII. Furthermore, II showed a time-dependent, pseudo-first order rate of inactivation of aromatase with Ki of 20.5 μM and kinact of 1.54 × 10−2 min−1, while III gave a time-dependent, biphasic loss of the enzyme activity. NADPH and oxygen were required for the time-dependent inactivation and the substrate, androstenedione, prevented it.
Corresponding author: Mitsuteru Numazawa
Purchase
Copyright © 1989 Published by Elsevier Inc.
Steroids
Volume 54, Issue 3, September 1989, Pages 299-311