Reaction rate, activation energy, and detection limit for the reaction of 5-furoylquinoline-3-carboxaldehyde with neurotransmitters in artificial cerebrospinal fluid.
The fluorogenic reagent 5-furoylquinoline-3-carboxaldehyde (FQ) has proven valuable in the analysis of proteins and small neurotransmitters. We monitored the reaction rate between this reagent and five neurotransmitters at 40 degrees and 65 degrees C in artificial cerebrospinal fluid. The reactions followed pseudo-first order kinetics. The activation energy for the reaction of FQ was 10.6, 10.7, 22.0, 31.4, and 34.4 kJ mol(-1) for alanine, taurine, gamma-aminobutyric acid (GABA), glutamine, and glutamic acid, respectively. At 65 degrees C, the reaction rate was quite similar for alanine, taurine, glutamine, and glutamic acid (1.8 x 10(-3) s(-1)) but was twice as fast for GABA. A reaction time of nearly 1 h was required to quantitatively convert these neurotransmitters to their fluorescent products at 65 degrees C. Detection limits for the labeled neurotransmitters were 10(-9)-10(-8) M, which corresponded to 0.3-7 amol injected onto the capillary.
Wu
J
J
Department of Chemistry, University of Alberta, Edmonton, Canada.
Chen
Z
Z
Dovichi
N J
NJ
D000818:Animals; D001921:Brain / Q000196:embryology; D019075:Electrophoresis, Capillary; D005456:Fluorescent Dyes; D005663:Furans / Q000737:chemistry*; D007700:Kinetics; D008954:Models, Biological; D018377:Neurotransmitter Agents / Q000134:cerebrospinal fluid* / Q000737:chemistry / Q000378:metabolism; D011804:Quinolines / Q000737:chemistry*; D051381:Rats; D012680:Sensitivity and Specificity
C413243:5-furoylquinoline-3-carboxaldehyde; D005456:Fluorescent Dyes; D005663:Furans; D018377:Neurotransmitter Agents; D011804:Quinolines