title: cis-3,4-Methylene-heptanoylcarnitine: characterization and verification of the C8:1 acylcarnitine in human urine.
abstract: Acylcarnitine profiles have been used to diagnose specific inherited metabolic diseases. For some acylcarnitines, however, the detailed structure of their acyl group remains a question. One such incompletely characterized acylcarnitine is cis-3,4-methylene-heptanoylcarnitine. To investigate this problem, we isolated the "C8:1" acylcarnitine from human urine, transesterified it to form its acyl picolinyl ester, and characterized it by GC/EI-MS. These results were compared to GC/EI-MS results from authentic standards we synthesized (cis-3,4-methylene-heptanoylcarnitine, trans-2-octenoylcarnitine, 3-octenoylcarnitine, cis-4-octenoylcarnitine, and trans-4-octenoylcarnitine). Only cis-3,4-methylene-heptanoylcarnitine matched the urinary "C8:1" acylcarnitine. The standards were then spiked in human urine, converted to pentafluorophenacyl esters, and detected by HPLC/MS. cis-3,4-Methylene-heptanoylcarnitine exactly matched the "C8:1" acylcarnitine in urine, whereas none of the other C8:1 acylcarnitine standards matched. Based on the data from GC/EI-MS and HPLC/MS, the "C8:1" acylcarnitine in human urine is shown to be cis-3,4-methylene-heptanoylcarnitine.
authors: Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
authors: Shuming
authors: S
authors: Yang
authors: Paul
authors: P
authors: Minkler
authors: Charles
authors: C
authors: Hoppel
mesh_terms: D002331:Carnitine / Q000031:analogs & derivatives* / Q000097:blood / Q000138:chemical synthesis / Q000737:chemistry / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D004952:Esters / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D004952:Esters; C116917:acylcarnitine; C524571:cis-3,4-methylene-heptanoylcarnitine; D002331:Carnitine