Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur GraphSearch.
Concept
Progestogen ester
Résumé
A progestogen ester is an ester of a progestogen or progestin (a synthetic progestogen). The prototypical progestogen is progesterone, an endogenous sex hormone. Esterification is frequently employed to improve the pharmacokinetics of steroids, including oral bioavailability, lipophilicity, and elimination half-life. In addition, with intramuscular injection, steroid esters are often absorbed more slowly into the body, allowing for less frequent administration. Many (though not all) steroid esters function as prodrugs.
Esterification is particularly salient in the case of progesterone because progesterone itself shows very poor oral pharmacokinetics and is thus ineffective when taken orally. Unmodified, it has an elimination half-life of only 5 minutes, and is almost completely inactivated by the liver during first-pass metabolism. Micronization, however, has allowed for progesterone to be effective orally, although oral micronized progesterone was not developed until recent years.
Examples of important progestogen esters include the 17α-hydroxyprogesterone derivatives medroxyprogesterone acetate, megestrol acetate, cyproterone acetate, and hydroxyprogesterone caproate, the 19-norprogesterone derivative nomegestrol acetate, and the 19-nortestosterone derivatives norethisterone acetate and norethisterone enanthate.
Estrogens were discovered in 1929, and beginning in 1936, a variety of estradiol esters, such as estradiol benzoate and estradiol dipropionate, were introduced for clinical use. Testosterone esters, such as testosterone propionate and testosterone phenylacetate, were also introduced around this time. In contrast to estradiol and testosterone, progesterone proved more difficult to esterify. In fact, esterification involves the replacement of a hydroxyl group with an alkoxy group, and unlike estradiol and testosterone, progesterone does not possess any hydroxyl groups, so it is actually not chemically possible to esterify progesterone itself.
Source officielle
À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.