In the urine of a Niemann-Pick disease type C (NPC) patient, we have identi ed three characteristic intense peaks that have not been observed in the urine of a 3β-hydroxysteroid-Δ 5 -C 27 -steroid dehydrogenase de ciency patient or a healthy infant and adult. Based on accurate masses of the protonated molecules, we focused on two of them as candidate NPC diagnostic markers. Two synthesized authentic preparations agreed with the two compounds found in NPC patient urine in regard to both chromatographic behavior and accurate masses of the deprotonated molecules. Moreover, the isotopic patterns of the deprotonated molecules, twin peaks unique to the sulfur-containing compounds appearing in their second isotope positions, and accurate masses of product ions observed at m/z 97 also agreed between the target compounds and authentic preparations. We identi ed the two compounds as the sulfated cholesterol metabolites as 3β-sulfooxy-7β-hydroxy-5-cholen-24-oic acid and 3β-sulfooxy-7-oxo-5-cholen-24-oic acid.ese two compounds represent more promising candidate diagnostic markers for NPC diagnosis than three other candidates that are multiple conjugates of cholesterol metabolites, 3β-sulfooxy-7β-N-acetylglucosaminyl-5-cholen-24-oic acid and its glycine and taurine conjugates, although we have reported an analytical method for determining the urinary levels of these compounds using liquid chromatography/electrospray ionization tandem mass spectrometry, because of their lack of N-acetylglucosamine conjugation.
A method for the synthesis of two (23R)- and (23S)-epimeric pairs of 23-fluoro-3α,7α,12α-trihydroxy-5β-cholan-24-oic acid and 23-fluoro-3α,7α-dihydroxy-5β-cholan-24-oic acid is described. The key intermediates, 23,24-dinor-22-aldehyde peracetates were prepared from cholic and chenodeoxycholic acids via the 24-nor-22-ene, 24-nor-22ξ,23-epoxy, and 23,24-dinor-22-aldehyde derivatives. The Horner-Wadsworth-Emmons reaction of the 23,24-dinor-22-aldehydes using triethyl 2-fluoro-2-phosphonoacetate in the presence of LiCl and 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU), and subsequent hydrogenation of the resulting 23ξ-fluoro-22-ene ethyl esters, followed by hydrolysis, gave a mixture of the epimeric (23R)- and (23S)-fluorinated bile acids which were resolved efficiently by preparative RP-HPLC. The stereochemical configuration of the fluorine atom at C-23 in the newly synthesized compounds was confirmed directly by the X-ray crystallographic data. The (1)H and (13)C NMR spectral differences between the (23R)- and (23S)-epimers were also discussed.
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