Kinetic analysis for the degradation of glycyl-L-leucine and L-leucyl-glycine in subcritical water.
Two dipeptides, glycyl-L-leucine (G-L) and L-leucyl-glycine (L-G), the concentrations of which were 10 mmol/L, were degraded in subcritical water in order to understand fully the phenomena occurring during treatment. Treatment was administered in a stainless steel tubular reactor, which was connected to an HPLC pump and immersed in an oil bath at 200-240 °C, with residence times of 10-180 s. When G-L and L-G were treated, L-G and G-L significantly formed, respectively, and then they gradually decreased at every temperature. Irrespective of the kind of substrate, ring formation occurred, and cyclo-(glycyl-L-leucine) was one of the final products. The reaction rate constants related to degradation were estimated under the assumption that all the reactions obeyed first-order kinetics, and the simulated results corresponded well with the experimental ones in every case.
Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan.
Takashi
T
Kobayashi
Ryo
R
Fujita
Incharoensakdi
I
Chaiyapat
Hajime
H
Mori
Asao
A
Hosoda
Hisaji
H
Taniguchi
Shuji
S
Adachi
D004151:Dipeptides / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008956:Models, Chemical; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
D004151:Dipeptides; D014867:Water; C015905:glycylleucine