Lathosterol

Lathosterol
Names
	IUPAC name 5α-Cholest-7-en-3β-ol
	Systematic IUPAC name (1R,3aR,5aS,7S,9aS,9bR,11aR)-9a,11a-Dimethyl-1-[(2R)-6-methylheptan-2-yl]-2,3,3a,5,5a,6,7,8,9,9a,9b,10,11,11a-tetradecahydro-1H-cyclopenta[a]phenanthren-7-ol
Identifiers
CAS Number	80-99-9 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:17168 ;
ChemSpider	59151 ;
PubChem CID	65728;
	InChI InChI=1S/C27H46O/c1-18(2)7-6-8-19(3)23-11-12-24-22-10-9-20-17-21(28)13-15-26(20,4)25(22)14-16-27(23,24)5/h10,18-21,23-25,28H,6-9,11-17H2,1-5H3/t19-,20+,21+,23-,24+,25+,26+,27-/m1/s1 Key: IZVFFXVYBHFIHY-SKCNUYALSA-N ; InChI=1/C27H46O/c1-18(2)7-6-8-19(3)23-11-12-24-22-10-9-20-17-21(28)13-15-26(20,4)25(22)14-16-27(23,24)5/h10,18-21,23-25,28H,6-9,11-17H2,1-5H3/t19-,20+,21+,23-,24+,25+,26+,27-/m1/s1 Key: IZVFFXVYBHFIHY-SKCNUYALBG;
	SMILES O[C@H]1CC[C@@]2([C@@H]3\C(=C/C[C@H]2C1)[C@@H]4CC[C@H]([C@H](C)CCCC(C)C)[C@]4(CC3)C)C;
Properties
Chemical formula	C27H46O
Molar mass	386.65 g/mol
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Lathosterol is a cholesterol-like molecule found in small amounts in humans.^[1] The enzyme Δ7-sterol 5(6)-desaturase converts it to 7-dehydrocholesterol. It is accumulated in lathosterolosis.^[2]

Biosynthesis

The final step in the biosynthesis of lathosterol is by reduction of the double bond in the sidechain of the sterol 5α-cholesta-7,24-dien-3β-ol when acted on by the enzyme Δ²⁴-sterol reductase, which uses nicotinamide adenine dinucleotide phosphate (NADPH) as its cofactor.^[3]^[4]

H⁺

H⁺

In vertebrates, lathosterol is an intermediate in the pathway to cholesterol via 7-dehydrocholesterol.^[5]^[6]^[7] The enzyme Δ7-sterol 5(6)-desaturase catalyses the oxidation reaction:

+ 2 Fe²⁺ + 2 H⁺

O₂

2 H₂O

O₂

2 H₂O

+ 2 Fe³⁺

It uses two molecules of the cofactor ferrocytochrome b₅ with two protons and one oxygen for each molecule of lathosterol converted.^[5]

↑ Myant N.M. (1981). "The Distribution of Sterols and Related Steroids in Nature". The Biology of Cholesterol and Related Steroids: 123–159. doi:10.1016/B978-0-433-22880-6.50010-2. ISBN 9780433228806.
↑ Ho, A. C. C.; Fung, C. W.; Siu, T. S.; Ma, O. C. K.; Lam, C. W.; Tam, S.; Wong, V. C. N. (2013). "Lathosterolosis: A Disorder of Cholesterol Biosynthesis Resembling Smith-Lemli-Opitz Syndrome". JIMD Reports - Volume 12. Vol. 12. pp. 129–134. doi:10.1007/8904_2013_255. ISBN 978-3-319-03460-7. PMC 3897790. PMID 24142275.
↑ Enzyme 1.3.1.72 at KEGG Pathway Database.
↑ Bae SH, Paik YK (1997). "Cholesterol biosynthesis from lanosterol: development of a novel assay method and characterization of rat liver microsomal lanosterol delta 24-reductase". Biochem. J. 326 (2): 609–16. doi:10.1042/bj3260609. PMC 1218712. PMID 9291139.
1 2 Enzyme 1.14.19.20 at KEGG Pathway Database.
↑ Dempsey ME, Seaton JD, Schroepfer GJ, Trockman RW (1964). "The Intermediary Role of Δ^5,7-cholestadien-3-β-ol in Cholesterol Biosynthesis". J. Biol. Chem. 239: 1381–7. doi:10.1016/S0021-9258(18)91325-6. PMID 14189869.
↑ Nishino H, Nakaya J, Nishi S, Kurosawa T, Ishibashi T (1997). "Temperature-induced differential kinetic properties between an initial burst and the following steady state in membrane-bound enzymes: studies on lathosterol 5-desaturase". Arch. Biochem. Biophys. 339 (2): 298–304. doi:10.1006/abbi.1996.9871. PMID 9056262.