Kishimoto Y, Williams M, Moser H W, Hignite C, Biermann K
J Lipid Res. 1973 Jan;14(1):69-77.
A mixture of isomers of methylhexadecanoic acid was isolated from glycerolipids of brain, spinal cord, and sciatic nerve of a patient who died from methylmalonic aciduria, a disease in which vitamin B(12) is not converted to deoxyadenosyl B(12). The isomers were identified by gas-liquid chromatographic-mass spectrometric analyses, and the data indicated that the points of methyl branching are located predominantly on the even-numbered carbon atoms. The concentration of these branched-chain acids among the glycerolipid fatty acids in the patient's nervous system was at least 0.3-0.9%, while the control tissues contained no more than a trace amount, if any, of these acids. In the spinal cord, these branched acids were distributed among all phosphatides and were in highest concentration on the beta position of phosphatidylcholine. On the other hand, most extraneural tissues contained these acids in much lower concentrations; there were only trace amounts in liver, kidney, muscle, and skin, and 0.2, 0.2, and 0.5% in total ester-linked fatty acids in spleen, duodenum, and lung, respectively. A second abnormality was the 6-13-fold increase in 15:0 and 17:0 fatty acids in all of the glycerolipids in the nervous system of the patient. This abnormality was also observed to a somewhat smaller extent in every extraneural tissue examined. The C(17) aldehydes of phosphatidylethanolamine plasmalogens from the spinal cord of the patient were identified by converting them to the corresponding dimethylacetals. 17:0 dimethylacetal accounted for nearly 10% of total dimethylacetals. There were no abnormalities in total lipids, cholesterol, cerebrosides, and sphingomyelins.
从一名死于甲基丙二酸尿症的患者的脑、脊髓和坐骨神经的甘油脂质中分离出了甲基十六烷酸异构体混合物。甲基丙二酸尿症是一种维生素B(12)不能转化为脱氧腺苷钴胺素的疾病。通过气液色谱-质谱分析鉴定了这些异构体，数据表明甲基分支点主要位于偶数碳原子上。患者神经系统甘油脂质脂肪酸中这些支链酸的浓度至少为0.3 - 0.9%，而对照组织中这些酸的含量即使有也不超过痕量。在脊髓中，这些支链酸分布于所有磷脂中，在磷脂酰胆碱的β位浓度最高。另一方面，大多数神经外组织中这些酸的浓度要低得多；肝脏、肾脏、肌肉和皮肤中只有痕量，脾脏、十二指肠和肺中总酯连接脂肪酸中的含量分别为0.2%、0.2%和0.5%。第二个异常是患者神经系统中所有甘油脂质中15:0和17:0脂肪酸增加了6 - 13倍。在每个检查的神经外组织中也观察到了程度稍小的这种异常情况。通过将患者脊髓中磷脂酰乙醇胺缩醛磷脂的C(17)醛转化为相应的二甲基缩醛来进行鉴定。17:0二甲基缩醛占总二甲基缩醛的近10%。总脂质、胆固醇、脑苷脂和鞘磷脂没有异常。
