English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The time-dependent inactivation of aromatase by epoxy analogs of the good aromatase inhibitors, androst-4-ene-6,17-dione (3) and androst-5-ene-4,17-dione (7), 4beta,5beta-epoxy and 5beta,6beta-epoxy compounds 10 and 13 and their 19-oxo derivatives 11 and 14, was examined in either the presence or absence of NADPH. The 4beta,5beta-epoxy-19-oxo steroid 11 along with the 19-methyl-5beta,6beta-epoxide 13 inactivated human placental aromatase in a mechanism-based manner, in the presence of NADPH, with rate constants for inactivation (k(inact)) of 0.133 min(-1) for steroid 11 and 0.100 min(-1) for steroid 13, whereas the two other steroids, 10 and 14, did not. On the other hand, none of four epoxides studied caused time-dependent inactivation of aromatase in an affinity-labeling manner in the absence of NADPH. These results are the first report showing that inhibitors 11 and 13 are suicide substrates having an epoxyketone structural feature.

biological and pharmaceutical bulletin

Studies of the Time-Dependent Inactivation of Aromatase by 4.BETA.,5.BETA.-Epoxy-6-one and 5.BETA.,6.BETA.-Epoxy-4-one Steroids under Various Conditions.