Brassicasterol

Brassicasterol
Names


IUPAC name 24-methyl cholest-5,22-dien-3β-ol
Other names brassicasterol (3β,22E)-ergosta-5,22-dien-3-ol 24β-methylcholesta-5,22-dien-3 beta-ol ergosta-5,22-dien-3β-ol
Identifiers
CAS Number	474-67-9^Y
3D model (JSmol)	Interactive image
ChemSpider	4444704^Y
ECHA InfoCard	100.006.807
PubChem CID	6432458
UNII	2B0KG2XFOF^Y
InChI InChI=1S/C28H46O/c1-18(2)19(3)7-8-20(4)24-11-12-25-23-10-9-21-17-22(29)13-15-27(21,5)26(23)14-16-28(24,25)6/h7-9,18-20,22-26,29H,10-17H2,1-6H3/b8-7+/t19-,20+,22-,23-,24+,25-,26-,27-,28+/m0/s1^Y Key: OILXMJHPFNGGTO-ZAUYPBDWSA-N^Y InChI=1/C28H46O/c1-18(2)19(3)7-8-20(4)24-11-12-25-23-10-9-21-17-22(29)13-15-27(21,5)26(23)14-16-28(24,25)6/h7-9,18-20,22-26,29H,10-17H2,1-6H3/b8-7+/t19-,20+,22-,23-,24+,25-,26-,27-,28+/m0/s1 Key: OILXMJHPFNGGTO-ZAUYPBDWBS
SMILES O[C@@H]4C/C3=C/C[C@@H]1[C@H](CC[C@@]2([C@H](CC[C@@H]12)[C@@H](/C=C/[C@H](C)C(C)C)C)C)[C@@]3(C)CC4
Properties
Chemical formula	C₂₈H₄₆O
Molar mass	398.68 g·mol⁻¹
Appearance	White solid
Melting point	150 to 151 °C (302 to 304 °F; 423 to 424 K)
Hazards
Flash point	Non-flammable
Related compounds
Related Sterols	cholesterol β-sitosterol campesterol stigmasterol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N (what is ^YN ?)
Infobox references

Brassicasterol (24-methyl cholest-5,22-dien-3β-ol) is a 28-carbon sterol synthesised by several unicellular algae (phytoplankton) and some terrestrial plants, e.g., oilseed rape. This compound has frequently been used as a biomarker for the presence of (marine) algal matter in the environment.

Brassicasterol has a low water solubility and, as a consequence, a high octanol – water partition coefficient. This means that, in most environmental systems, brassicasterol will be associated with the solid phase.

In anaerobic sediments and soils, brassicasterol is stable for many hundreds of years, enabling it to be used as an indicator of past algal production (see below).

Since the molecule has a hydroxyl (-OH) group, it is frequently bound to other lipids including glycerols; most analytical methods, therefore, utilise a strong alkali (KOH or NaOH) to saponify the ester linkages. Typical extraction solvents include 6% KOH in methanol. The free sterols are then separated from the polar lipids by partitioning into a less polar solvent (e.g, hexane). Prior to analysis, the hydroxyl group is frequently derivatised with BSTFA (bis-trimethyl silyl trifluoroacetamide) to replace the hydrogen with the less exchangeable trimethylsilyl (TMS) group. Instrumental analysis is frequently conducted on gas chromatograph (GC) with either a flame ionisation detector (FID) or mass spectrometer (MS). The mass spectrum for the TMS ether of brassicasterol can be seen in the figure.

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