Пропионат холестерина

Description

Cholesterol propionate (cholesteryl propionate, cholesterol n-propionate) is an ester of cholesterol and propionic acid, CAS 633-31-8, gross formula C30H50O2. Like other cholesterol esters, the compound belongs to the class of thermotropic cholesteric liquid crystals: when heated, it forms a characteristic helical (cholesteric) mesophase with optical properties that depend on temperature. Obtained by esterification of cholesterol with propionic acid or its derivatives; the short acyl chain (three carbon atoms) distinguishes it from the longer chain esters of the same family - caproate, caprylate, nonanoate, decanoate and cholesterol oleate, which differ in melting points and the width of the mesophase temperature window.

Basic Attributes

• CAS No.: 633-31-8
• Chemical formula: C30H50O2
• Molecular weight: 442.72
• Exact weight: 442.72
• EU number: 211-191-7
• PSA specifications: 26.30000
• XLogP3: 8.3496

Physico-chemical characteristics

• Appearance: white to pale yellow waxy liquid
• Density: 0.99 g/cm3
• Melting point: 113.0 °C
• Boiling point: 505.7 °C at 760 mm Hg. Art.
• Flash point: 256.6 °C
• Specific rotation: -40° (C=2, CHCl3)
• Stability: Stable at normal temperatures and pressures

Cholesteric mesophase

The molecules of cholesteryl ether in the liquid crystalline state are arranged in layers in which the direction of preferential orientation smoothly rotates from layer to layer, forming a helical supramolecular structure - hence the name “cholesterol” phase, which was first studied in detail specifically on cholesteryl ethers. The pitch of the spiral determines the wavelength of selectively reflected light and, accordingly, the visible color of the film; Since the spiral pitch is sensitive to temperature, when heated or cooled within the operating range, the color changes smoothly across the entire visible spectrum. It was this property that made cholesteryl acetate, cholesteryl propionate and related esters the first materials on which thermochromic liquid crystal indicators were demonstrated.

Scope of application

Cholesterol esters, including propionate, form cholesteric liquid crystals - their layers are spirally twisted relative to each other, and the pitch of the spiral depends on temperature, which makes such mixtures convenient indicators of thermal fields (liquid crystal thermometers and temperature-sensitive coatings). The effect is based on the selective reflection of light of a certain wavelength corresponding to the pitch of the spiral: when the temperature changes by a fraction of a degree, the visible color of the film changes noticeably, which is used in medical skin thermography, in overheating indicators of electronic components and in decorative thermochromic coatings. In cosmetics, cholesteryl esters are used as a component of hair products and decorative cosmetics, giving the composition a pearlescent, iridescent shine when mixed with other cholesteryl esters (cholesteryl chloride, cholesteryl oleyl carbonate), and in a mixture of several esters with different lengths of the acyl chain, the desired temperature range for the operation of the liquid crystalline composition is selected.

Safety Information

• Safety instructions: 24/25 (protect skin and eyes upon contact)

Storage and transportation conditions

Store in a tightly closed container in a cool, dry, well-ventilated area, away from incompatible substances. The substance is stable at normal temperatures and pressures; the passport does not indicate special cooling conditions (unlike some other esters of this series). The high melting point (113 °C) and boiling point (505.7 °C) reflect the large size and low volatility of the steroid molecule; the container must prevent prolonged contact with air and moisture, which can gradually oxidize the oxygen-sensitive cholesterol core.