Прегненолон

Description

Pregnenolone is a pregnane steroid, (3β)-3-hydroxypregn-5-en-20-one. It occupies the starting position in the biosynthesis of all steroid hormones: cholesterol, under the action of the side chain cleavage enzyme CYP11A1, is converted into pregnenolone, from which progestogens, mineralocorticoids, glucocorticoids, androgens and estrogens are further formed. Synthesis occurs in the mitochondria of the adrenal cortex, gonads, placenta and nervous tissue; Pregnenolone, produced in the nervous system, is classified as a neurosteroid. The practical application of the substance is a raw material for the semisynthesis of steroid hormones, a reference standard in endocrinological analysis, a component of biochemical studies of steroidogenesis. Synonymous series: Δ5-pregnenolone, 5-pregnenolone, pregn-5-en-3β-ol-20-one, 3β-hydroxy-Δ5-pregnen-20-one, Arthenolone, Enelone, Natolone, Prenolon, Skinostelon, Pregnetan, Pregneton, Pregnolon, Regnosone, Bina-Skin, Pregnelone.

Basic Attributes

• CAS No.: 145-13-1
• Chemical formula: C21H32O2
• Molecular Weight: 316.478
• Exact weight: 316.48
• EU number: 205-647-4
• NSC Number: 18158 and 1616
• DSSTox ID: DTXSID00872921
• HS code: 2937290090
• PSA specifications: 37.30
• XLogP3: 4.5153

Physico-chemical characteristics

• Appearance: White to pale powder
• Density: 1.09 g/cm³
• Melting point: 192 °C
• Boiling point: 443.3 °C at 760 mmHg. Art.
• Flash point: 188.9 °C
• Refractive index: 1.549
• Solubility: soluble in ethanol up to 10 mg/ml, clear solution, colorless to slightly yellow
• Vapor pressure: 1.02 × 10⁻⁹ mm Hg. Art. at 25 °C

Structure

The molecule contains a hydroxyl group at C-3 in the β configuration, a double bond between C-5 and C-6, and an acetyl moiety at C-17. Hence the alternative structure notation is 17β-[1-ketoethyl]-Δ5-androsten-3β-ol. It is the Δ5 double bond and the 3β-hydroxyl group that distinguishes pregnenolone from progesterone, into which it is converted by the enzyme 3β-hydroxysteroid dehydrogenase.

Position in steroidogenesis

• cholesterol → pregnenolone (CYP11A1, side chain cleavage) - common starting reaction
• pregnenolone → progesterone → corticosteroids
• pregnenolone → 17α-hydroxypregnenolone → dehydroepiandrosterone → androgens and estrogens

Solubility in practice

XLogP3 4.5153 with a polar surface of 37.30 Ų describes a lipophilic steroid: solubility in water is insignificant, working solutions are prepared in ethanol (up to 10 mg/ml) or in dimethyl sulfoxide. Vapor pressure is about 10⁻⁹ mmHg. Art. means virtually no volatility at room temperature, so inhalation is possible only with dust.

Transportation

• Transport code: UN 1648

Hazard classification

The GHS classification, hazard statements and precautions are not listed on the original product data sheet, so the H and P phrases are not included here. The data is taken from the safety data sheet for a specific batch.

Storage and handling

Tightly closed container, dry place, protected from light. As the hormonally active substance is stored and accounted for separately from technical chemistry, personnel access is regulated. Weighing and pouring the powder is carried out with respiratory protection, gloves and goggles, since the main route of entry is dust.