Oestrogens synthetic

In a similar fashion to the oestrogens, synthetic proges-togens were investigated and a large number were synthesised. One of the first to be used was ethisterone. 

Dixon LA. 1998. Potency of combined estrogenic pesticides Synergy between synthetic oestrogens. Chemtracts Org Chem 11 306-308. 

Photocyclization in synthetic oestrogens Clomiphene Stilboestrol Dienoestrol Tamoxifen Vitamin D group Vitamin K group Dithranol... 

Since the development of the oral contraceptive steroids in the 1960s, various steroids and procedures have been used. Synthetic steroids are now used since their half-hves in the body are longer than the natural steroids. Combined oestrogen-progesterone contraception involves taking one piU each day which contains a synthetic progestogen plus an oestrogen. The pill is taken for 21 dyas, with a break for... 

A study showed the collapse of a population of fish in an isolated lake spiked with relatively high levels of the synthetic oestrogen 17a-ethinylestradiol [116]. Other studies on aquatic populations in a waste-impacted stream in Boulder, Colorado, showed reproductive effects from estrogenic wastewater effluent [117]. 

Natural oestrogens generally only retain a significant proportion of their activity if administered intravenously. Several synthetic analogues have been developed which can be administered orally. Most of these substances also display more potent activity than native oestrogen. The most important synthetic oestrogen analogues include ethinyloestradiol and diethylstilboestrol (often simply termed stilboestrol). These are orally active and are approximately 10 and 5 times (respectively) more potent than oestrone. 

Ethinyloestradiol Synthetic oestrogen Used for oestrogen replacement therapy in deficient states, both pre- and postmenopausal. Treatment of prostate cancer (male), breast cancer (post-menopausal women). Component of many oral contraceptives... 

Mestranol Synthetic oestrogen Treatment of menopausal, post-menopausal or menstrual disorders. Component of many oral contraceptives... 

Quinestrol Synthetic oestrogen, with prolonged duration of action Oestrogen deficiency... 

Stilboestrol Synthetic oestrogen (non-steroidal) Treatment of breast/prostate cancer. Management of menopausal/ post-menopausal disorders... 

Figure 1.3. Chemical structure of the major synthetic and native oestrogens used clinically...

Figure 1.4. Structure of clomiphene and tamoxifen, two non-steroidal synthetic anti-oestrogens that have found medical application...

Fosfestrol is indicated in the treatment of carcinoma of the prostate. It is a synthetic non-steroidal estrogen which is dephosphorylated to stilboestrol. Polyestradiol phosphate is an oestrogen with sustained activity that is exclusively used for prostate cancer. It is stored in tissues and slowly dephosphorylated to estrogen. 

V.a.1.1. Oral HRT preparations. For oral therapy, there is a choice between conjugated equine oestrogens purified from urine, synthetic oestro-gens such as ethinyloestradiol and tibolone, and oestradiol itself. In women with an intact uterus, the oestrogen should normally be given in conjunction with a progestagen in order to protect the endometrium from unopposed oestrogenic stimulation. 

It is a synthetic steroid which combines oestrogenic and progestogenic activity with... 

A. Collier, J. Wang, D. Diamond and E. Dempsey, Microchip micellar electrokinetic chromatography coupled with electrochemical detection for analysis of synthetic oestrogen mimicking compounds, Anal. Chim. Acta, 550 (2005) 107-115. 

Community. The administration of hormone growth promoters was prohibited because of fears about health effects from residues, although there is a need to standardise conditions of trade in animal products from countries outside the EU where these compounds are still licensed for use. The use of one particular group of synthetic anabolic agents with oestrogenic activity, the stilbene compounds,... 

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