600 MHZ H-1-NMR SPECTROSCOPY OF HUMAN CEREBROSPINAL-FLUID - EFFECTS OF SAMPLE MANIPULATION AND ASSIGNMENT OF RESONANCES

Extensive assignments of resonances in the 600 MHz H-1-NMR spectra of cerebrospinal fluid are reported. These have been achieved by the meas urement of a combination of two-dimensional experiments comprising hom onuclear J-resolved, COSY45, and double-quantum filtered COSY (DQCOSY) spectra. By these means the previous total of 18 endogenous metabolit es, of which in general only selected resonances have been assigned, h as been augmented to 46 molecules including all of the resonances of b oth alpha- and beta-anomers of glucose. With only a few exceptions all resonances have been assigned for all of the metabolites. In addition , the effect of freeze-drying on the 600 MHz H-1-NMR spectrum of human cerebrospinal fluid (CSF) is presented using both lyophilization with reconstitution into either H2O or D2O. Freeze-drying and reconstituti on into H2O Causes a significant sharpening of many small molecule res onances, including notably those of glutamate and glutamine as well as other amino acids and in addition causes the loss of volatile compone nts, principally acetone. Further exchange of the H2O solvent by D2O c auses no additional changes in the spectra.