Cholecalciferol, an example of a 9,10-secosteroid. IUPAC-approved carbon numbering and ring labeling is shown in the picture. Since secosteroids are derived from steroids, they retain the same labeling system as steroids. [1]: §3S-8 The parent steroid skeleton. The B-ring of the parent steroid is broken between C9 and C10 to yield D vitamins.
A secosteroid (/ˈsɛkoʊˌstɛrɔɪd/) is a type of steroid with a "broken" ring. The word secosteroid derives from the Latin verb secare meaning "to cut",[2]: 241 and 'steroid'. Secosteroids are described as a subclass of steroids under the IUPAC nomenclature.[1]: §3S-1 [3] Some sources instead describe them as compounds derived from steroids.[4]
Types or subclasses of secosteroids are defined by the carbon atoms of the parent steroid skeleton where the ring cleavage has taken place. For example, 9,10-secosteroids are derived from cleavage of the bond between carbon atoms C9 and C10 of the steroid B-ring (similarly 5,6-secosteroids, 13,14-secosteroids, etc.).[1]: §3S-8
The prototypical secosteroid is cholecalciferol (vitamin D3).[5] Its IUPAC systematic is "(5Z,7E)-(3S)-9,10-secocholestra-5,7,10(19)-trien-3-ol".[1]: §3S-8
Some nonsteroidal estrogens, like doisynolic acid (cleaved on the D ring)[6] and allenolic acid,[citation needed] are also secosteroids or secosteroid-like compounds.
^ abcdeMoss GP and the Working Party of the IUPAC-IUB Joint Commission on Biochemical Nomenclature. "The Nomenclature of Steroids". Queen Mary University of London. also available as Moss GP (1989). "Nomenclature of Steroids (Recommendations 1989)". Pure Appl. Chem.61 (10): 1786f. doi:10.1351/pac198961101783.
a b c Chapters 3S-8 "Ring fission" and 3S-9 "Vitamin D group"
^ (esp. 3S-1.4, incl. note 4) "Steroids are compounds possessing the skeleton of cyclopenta[a]phenanthrene or a skeleton derived therefrom by one or more bond scissions or ring expansions or contractions."
^Ayers D (1972). Bioscientific Terminology. Tucson: University of Arizona Press. ISBN 978-0-8165-0305-6.
^Hill RA; Makin HL; Kirk DN; Murphy GM (1991). Dictionary of Steroids (1st ed.). London: Chapman & Hall. ISBN 978-0-412-27060-4.
^"Definition of secosteroid". Farlex Partner Medical Dictionary. TheFreeDictionary.com. A compound derived from a steroid in which there has been a ring cleavage.
^Hanson JR (2010). "Steroids: partial synthesis in medicinal chemistry". Nat Prod Rep. 27 (6): 887–99. doi:10.1039/c001262a. PMID 20424788.
^Meyers, CY; Kolb, VM; Gass, GH; Rao, BR; Roos, CF; Dandliker, WB (October 1988). "Doisynolic-type acids--uterotropically potent estrogens which compete poorly with estradiol for cytosolic estradiol receptors". Journal of Steroid Biochemistry. 31 (4A): 393–404. doi:10.1016/0022-4731(88)90307-x. PMID 3172773.
A secosteroid (/ˈsɛkoʊˌstɛrɔɪd/) is a type of steroid with a "broken" ring. The word secosteroid derives from the Latin verb secare meaning "to cut",: 241 ...
A deficiency may lead to sub-optimal plasma testosterone levels. The secosteroid vitamin D in levels of 400–1000 IU/d (10–25 μg/d) raises testosterone...
The B ring of the steroid nucleus structure is broken open, making a secosteroid. This then undergoes spontaneous isomerization into cholecalciferol,...
blood, although it stated more research is needed. Ergocalciferol is a secosteroid formed by a photochemical bond breaking of a steroid, specifically, by...
Cholecalciferol is one of the five forms of vitamin D. Cholecalciferol is a secosteroid, that is, a steroid molecule with one ring open. By itself cholecalciferol...
accepted standard coding system. Vitamin D – is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium...
progestogens as well as the glucocorticoids and mineralocorticoids.: 749 The secosteroids, comprising various forms of vitamin D, are characterized by cleavage...
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and for many other...
Prevent endometrial cancer by regulating effects of estrogen Calcitriol secosteroid (1,25-dihydroxyvitamin D3) skin/proximal tubule of kidneys VDR Active...
Calcifediol, also known as calcidiol, 25-hydroxycholecalciferol, or 25-hydroxyvitamin D3 (abbreviated 25(OH)D3), is a form of vitamin D produced in the...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
Calcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
biology – Use of Sodium by organisms Vitamin D – Group of fat-soluble secosteroids Kléber, André G.; Rudy, Yoram (2004-04-01). "Basic Mechanisms of Cardiac...
Alfacalcidol (or 1-hydroxycholecalciferol) is an analogue of vitamin D used for supplementation in humans and as a poultry feed additive. Alfacalcidol...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
Calcipotriol, also known as calcipotriene, is a synthetic derivative of calcitriol, a form of vitamin D. It is used in the treatment of psoriasis. It is...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
calcium homeostasis and metabolism. Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
C27 Cholestane Functional group 17-Ketosteroid Hydroxysteroid Halogenated steroid Elements removed Norsteroid Secosteroid Elements replaced Azasteroid...
Eldecalcitol is an analog of calcitriol, the active form of vitamin D. Commonly used in Japan for the treatment of osteoporosis. Osteoporosis is a common...