Identification and quantification of gamma-glutamyl conjugates of biogenic amines in the nervous system of the snail, Helix aspersa, by gas chromatography-negative-ion chemical ionisation mass spectrometry.
The gamma-glutamyl conjugates of p-octopamine and dopamine were identified unambiguously for the first time and quantified in a single cerebral ganglion or pleural plus pedal ganglia of the snail, Helix aspersa, by gas chromatography-negative-ion chemical ionisation mass spectrometry. A new method was used for synthesis of gamma-glutamylamine standards. The concentration of gamma-glutamyltyramine was found to be low in the tissues, therefore it was used as an internal standard. The gamma-glutamylamines were extracted with water and derivatised with pentafluoropropionic anhydride and trifluoroethanol. Under negative-ion chemical ionisation conditions, the trifluoroethyl and pentafluoropropionyl derivatives produced significant ions which were sufficiently abundant to be suitable for selective ion monitoring. The method had a limit of detection of ca. 80 pg of gamma-glutamyl conjugate per tissue and calibration curves were linear over the range examined.
Department of Pharmaceutical Science, University of Strathclyde, Glasgow, UK.
P
P
Zhou
D G
DG
Watson
J M
JM
Midgley
D000818:Animals; D001679:Biogenic Amines / Q000032:analysis* / Q000737:chemistry; D004298:Dopamine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D005724:Ganglia / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006372:Helix, Snails; D007477:Ions; D015394:Molecular Structure; D009655:Octopamine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D014439:Tyramine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry
D001679:Biogenic Amines; D007477:Ions; D009655:Octopamine; C034720:gamma-glutamyl dopamine; C057116:gamma-glutamyl tyramine; C057117:gamma-glutamyl octopamine; D004298:Dopamine; D014439:Tyramine