17a-Hydroxypregnenolone

From NuGOwiki

(Redirected from HMDB00363)

The NuGOwiki Metabolite Database is a joint initiative of NuGO and HMDB

Taxonomy Navigation Box; search by

17a-Hydroxypregnenolone
2D structure for 17a-Hydroxypregnenolone
Chemical Name	1-[(3S,8R,9S,10R,13S,17R)-3,17-dihydroxy-10,13-dimethyl-1,2,3,4,7,8,9,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-17-yl]ethanone
Chemical Formula	C₂₁H₃₂O₃
CAS Number	387-79-1
Chemical Information	HMDB00363
Biochemical Taxonomy	Steroids and Steroid Derivatives
Functional Taxonomy	Not Available
Nutritional Taxonomy	Not Available
Metabolic Pathways	C21-Steroid Hormone Metabolism
Biofluid Location	Blood
Tissue Location	Testes Adrenal Cortex
Normal Biofluid Concentrations	Blood: 0.0008 - 0.0062 uM Blood: 0.0008 - 0.012 uM Blood: 0.001 - 0.012 uM Blood: 0.001 - 0.012 uM
Normal Tissue Concentrations	Not Available
Diseases / Conditions Related to Nutrition	ACTH-stimulated patients with premature pubarche Patients with premature pubarche
Other (Monogenic Disorders)	Not Available
Abnormal Biofluid Concentrations	Blood (ACTH-stimulated patients with premature pubarche): 0.05 - 0.11 uM Blood (Patients with premature pubarche): 0.004 - 0.153 uM
Abnormal Tissue Concentrations	Not Available
Physiological Processes	Not Available

Authors:
Affiliations:

Introduction

guidelines
17a-Hydroxypregnenolone is a 21-carbon steroid that is converted from pregnenolone by cytochrome P450 17alpha hydroxylase/C17,20 lyase (CYP17, EC 1.14.99.9). 17a-Hydroxypregnenolone is an intermediate in the delta-5 pathway of biosynthesis of gonadal steroid hormones and the adrenal corticosteroids. The first, rate-limiting and hormonally regulated step in the biosynthesis of all steroid hormones is the conversion of cholesterol to pregnenolone. The conversion of cholesterol to pregnenolone is accomplished by the cleavage of the cholesterol side chain, catalyzed by a mitochondrial cytochrome P450 enzyme termed P450scc where scc designates Side Chain Cleavage. All steroid hormones are made from the pregnenolone produced by P450scc; thus, the presence or absence of each of the activities of CYP17 directs this pregnenolone towards its final metabolic pathway. While all cytochrome P450 enzymes can catalyze multiple reactions on a single active site, CYP17 is the only one described to date in which these multiple activities are differentially regulated by a physiologic process. 17a-Hydroxypregnenolone is converted to dehydroepiandrosterone by the 17,20 lyase activity of CYP17. The ratio of the 17,20 lyase to 17 alpha-hydroxylase activity of CYP17 determines the ratio of C21 to C19 steroids produced. This ratio is regulated post-translationally by at least three factors: the abundance of the electron-donating protein P450 oxidoreductase, the presence of cytochrome b5, and the serine phosphorylation of CYP17. (PMID: 12573809)