Alpha-methylacyl-CoA-racemase is an enzyme that transforms branched chain fatty acids and bile acid through beta oxidation to dihydroxy cholestanol
and trihydroxy cholestanol
thus transforming a-methyl branched chain fatty acids to CoA and S stereoisomers, and it is produced in the prostate in large amounts (5).
Precursor sterols and plant sterols (beta-sitosterol and campesterol), BAs and an intermediate product, cholestanol
, occur in trace quantities in plasma.
TC: total carbon; TN: total nitrogen; TP: total phosphorus; OM: organic matter; C[O.sub.3]=: carbonates; CO: coprostanol; EP: epicoprostanol; CH: cholesterol; CHL: cholestanol
; CA: campesterol; CAL: campestanol; ST: stigmasterol; STL: stigmastanol; DI: dinosterol; SI: sitosterol; SIL: sitostanol.
Beyond cholesterol and [beta][beta]-sitosterol, cholestanol
, brassicasterol, campesterol, stigmasterol, and stigmastanol were also identified based on exact m/z of such fragment ions and elution order.
Thirteen sterols (cholesterol, brassicasterol, 24-methylene-cholesterol, campesterol, campestanol, stigmasterol, [[DELTA].sup.7]-campesterol, [[DELTA].sup.5,23]-stigmastadienol, clerosterol, [beta]-sitosterol, sitostanol, [[DELTA].sup.5]-avenasterol, and [[DELTA].sup.5,24]-stigmastadienol) were identified in oil based on their relative retention times with respect to the internal standard, cholestanol
, according to the standardized reference method (EEC, 1991, Annexes V and VI).
Miettinen, "Liver transplantation modifies serum cholestanol
, cholesterol precursor and plant sterol levels," Clinica Chimica Acta, vol.
Sugihara, "A monolayer study on three binary mixed systems of dipalmitoyl phosphatidyl choline with cholesterol, cholestanol
and stigmasterol," Colloids and Surfaces B: Biointerfaces, vol.
(2) It is caused by mutations in the CYP27A1 gene, which lead to deficiency of the mitochondrial enzyme, sterol 27-hydroxylase, resulting in the accumulation of cholestanol
in the serum and many affected tissues (3) CTX manifests as tendon xanthomas, juvenile cataracts and seizures multiple progressive neurological symptoms.
Cholesterol has been shown to biologically hydrogenate into coprostanol and cholestanol
(dihydrocholesterol) in anoxic sediments, and the conversion to coprostanol has been shown to be negligible.
However, her cholestanol
level at 4 mg/dL was elevated to about 30 times normal.
It shows an abnormally high concentration of the diagnostic metabolite cholestanol
(C-18 [H.sub.3] resonance at 0.645 ppm, close to the C-18 [H.sub.3] of cholesterol).