抄録
Gas chromatographic determination of C27-bile acids was investigated for the study of bile acid biosynthesis and related congenital disorders. The intermediate C27-bile acids in the β-oxidation step and related compounds were conveniently synthesized from the corresponding C24-bile acids as standard samples. The separation of methyl ester-trimethylsilyl ether (Me-TMS) and methyl ester-dimethylethylsilyl ether (Me-DMES) derivatives of the C27-bile acids was carried out by capillary gas chromatography. Then methylene units of the above derivatives were measured. The Me-DMES derivatives were more efficient for the separation of C27-bile acids than the Me-TMS derivatives. The calibration curves for the Me-DMES derivatives of C27-bile acids showed good linearities over the range of 5-200ng; the detection limits were ca. 0.5ng (S/N=5). The relative recoveries from biological samples were 93-105% for all C27-bile acids using 24- nor-chenodeoxycholic acid as an internal standard. An application to the diagnosis of Zellweger syndrome is also discussed.