''Norsteroids'' (
nor-, L. ''norma'', from "normal" in chemistry, indicating carbon removal) are a structural class of steroids that have had an atom or atoms (typically carbon) removed,
biosynthetically or
synthetically, from positions of branching off of rings or side chains (e.g., removal of
methyl
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula (whereas normal methane has the formula ). In formulas, the group is often abbreviated as ...
groups), or from within rings of the steroid ring system.
For instance, 19-norsteroids (e.g.,
19-norprogesterone) constitute an important class of natural and synthetic steroids derived by removal of the methyl group of the
natural product
A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical s ...
progesterone
Progesterone (; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...
; the equivalent change between
testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...
and
19-nortestosterone (nandrolone) is illustrated below.
Examples
Norsteroid examples include:
19-norpregnane (from
pregnane),
desogestrel,
ethylestrenol,
etynodiol diacetate,
ethinylestradiol
Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. Ethinylestradiol was widely used for various indications such as the treatment of menopausal symptoms, gynecological ...
,
gestrinone,
levonorgestrel
Levonorgestrel is a hormonal medication used in a number of birth control methods. It is combined with an estrogen to make combination birth control pills. As an emergency birth control, sold under the brand names Plan B One-Step and Julie, ...
,
norethisterone
Norethisterone, also known as norethindrone and sold under the brand name Norlutin among others, is a progestin medication used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medicatio ...
(norethindrone),
norgestrel, norpregnatriene (from
pregnatriene),
quinestrol,
19-norprogesterone (from a
progesterone
Progesterone (; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...
),
Nomegestrol acetate,
(from a
testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...
), and
norethisterone acetate.
References
External links
*
Steroids
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