Brassicasterol

Brassicasterol
	Brassicasterol source ↗
	source ↗
Names
	IUPAC name Ergosta-5,22-dien-3β-ol
	Systematic IUPAC name (1R,3aS,3bS,7S,9aR,9bS,11aR)-1-[(2R,3E,4R)-5,6-Dimethylhept-3-en-2-yl]-9a,11a-dimethyl-2,3,3a,3b,4,6,7,8,9,9a,9b,10,11,11a-tetradecahydro-1H-cyclopenta[a]phenanthren-7-ol
	Other names brassicasterol; (3β,22E)-ergosta-5,22-dien-3-ol; 24β-methylcholesta-5,22-dien-3 beta-ol; 24-methyl cholest-5,22-dien-3β-ol
Identifiers
CAS Number	474-67-9 Y;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:3168;
ChemSpider	4444704 Y;
ECHA InfoCard	100.006.807
PubChem CID	6432458;
UNII	2B0KG2XFOF Y;
CompTox Dashboard (EPA)	DTXSID80197124 ;
	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	398.675 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 verify (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, like rape. This compound has frequently been used as a biomarker for the presence of (marine) algal matter in the environment, and is one of the ingredients in stigmasterol-rich plant sterols (Number E499 in the European numbering system).

There is some evidence to suggest that it may also be a relevant additional biomarker in Alzheimer's disease. More specifically, AD patients have lower levels of this sterol in their cerebrospinal fluid.¹

Chemical properties

Solubility

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.

Degradation

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).

Formation and occurrences

It can be found in Mirabilis jalapa.²

Algal sources

Brassicasterol is formed in plants from the isoprenoid squalene through campesterol as an intermediate. A list of the algae in which brassicasterol has been identified is shown below together with approximate composition.³⁴

Sterol content of selected dinoflagellates (as percentage). Data from Volkman, 1986
Species	A	B	C	D	E	F	G	H	others
Gonyaulax spp	100	0	0	0	0	0	0	0	0
Peridinium foliaceum	100	0	0	0	0	0	0	0	0
Peridinium foliaceum	80	20	0	0	0	0	0	0	0
Gonyaulax diegensis	39	0	0	0	0	0	0	29	32
Pyrocystis lunula	76	6	0	2	1	0	0	0	15
Gonyaulax polygramma	36	1	0	9	7	0	0	0	47
Gymnodinium wilczeki	26	39	0	35	1	0	0	0	0
Glenodinium hallii	8	50	0	0	0	42	0	0	0
Noctiluca milaris	0	1	1	5	73	0	6	0	14
Gymnodinium simplex	0	0	0	0	53	0	0	0	47
Prorocentrum cordatum	7	0	0	0	5	0	63	0	25

A = cholesterol

B = campesterol

C = sitosterol

D = 22-dehydrocholesterol ((22E)-cholesta-5,22-dien-3β-ol)

E = brassicasterol

F = stigmasterol

G = 24-methylene cholesterol

H = fucosterol

Use as a tracer for marine algae

The principal source of brassicasterol in the environment is from marine algae. Its relatively high concentration and stability allows it to be used in the assessment of the origin of organic matter in samples, especially sediments.

References

Vanmierlo, T.; Popp, J.; Kölsch, H.; Friedrichs, S.; Jessen, F.; Stoffel-Wagner, B.; Bertsch, T.; Hartmann, T.; Maier, W.; von Bergmann, K.; Steinbusch, H.; Mulder, M.; Lütjohann, D. (September 2011). "The plant sterol brassicasterol as additional CSF biomarker in Alzheimer's disease: Plant sterols as biomarker in AD". Acta Psychiatrica Scandinavica. 124 (3): 184–192. doi:10.1111/j.1600-0447.2011.01713.x. PMID 21585343.
Siddiqui, S.; Siddiqui, B. S.; Adil, Q.; Begum, S. (1990). "Constituents of Mirabilis jalapa". Fitoterapia. 61 (5): 471 ref. 1.
Data from a review by Volkman, 1986
Volkman, John K. (January 1986). "A review of sterol markers for marine and terrigenous organic matter". Organic Geochemistry. 9 (2): 83–99. doi:10.1016/0146-6380(86)90089-6.

[1] Vanmierlo, T.; Popp, J.; Kölsch, H.; Friedrichs, S.; Jessen, F.; Stoffel-Wagner, B.; Bertsch, T.; Hartmann, T.; Maier, W.; von Bergmann, K.; Steinbusch, H.; Mulder, M.; Lütjohann, D. (September 2011). "The plant sterol brassicasterol as additional CSF biomarker in Alzheimer's disease: Plant sterols as biomarker in AD". Acta Psychiatrica Scandinavica. 124 (3): 184–192. doi:10.1111/j.1600-0447.2011.01713.x. PMID 21585343.

[2] Siddiqui, S.; Siddiqui, B. S.; Adil, Q.; Begum, S. (1990). "Constituents of Mirabilis jalapa". Fitoterapia. 61 (5): 471 ref. 1.

[3] Data from a review by Volkman, 1986

[4] Volkman, John K. (January 1986). "A review of sterol markers for marine and terrigenous organic matter". Organic Geochemistry. 9 (2): 83–99. doi:10.1016/0146-6380(86)90089-6.

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