Efficient Formation
of N‑(1-Deoxy‑d‑ribulos-1-yl)-Glutathione via Limited
Oxidation and Degradation of Glutathione during the Atmospheric–Vacuum
Thermal Reaction
posted on 2023-11-08, 23:29authored byLinhui Feng, Heping Cui, Pusen Chen, Khizar Hayat, Xiaoming Zhang, Chi-Tang Ho
The efficient preparation of the ribose-glutathione (Rib-GSH)
Amadori
rearrangement product (RG-ARP) as a potent precursor of meaty flavor
was studied through the atmospheric–vacuum thermal reaction.
Liquid chromatography–mass spectrometry (LC–MS) analysis
revealed that the oxidation and degradation of GSH occurred during
the preparation of RG-ARP via the atmospheric thermal reaction, especially
at a low molar ratio of Rib to GSH and high reaction temperature.
The RG-ARP and the ARPs derived from the products of GSH oxidation
and degradation with the participation of Rib were identified by MS/MS
as N-(1-deoxy-d-ribulos-1-yl)-glutathione, N-(1-deoxy-d-ribulos-1-yl)-cysteinylglycine, and N-(1-deoxy-d-ribulos-1-yl)-glutathione disulfide.
The selective formation of RG-ARP was disrupted due to the multiple
consumption pathways of GSH and Rib. The removal of water and the
reduction of oxygen content during vacuum dehydration exhibited an
obvious inhibitory effect on the oxidation of cysteinyl and the cleavage
of glutamyl, limiting the oxidation and degradation of GSH. Meanwhile,
the rapid evaporation of water promoted the molecular collision between
the reactants, which allowed the glycation reaction of GSH to be advanced
and fragmentation of RG-ARP to be inhibited at a mild dehydration
temperature. Accordingly, the atmospheric–vacuum thermal reaction
was proposed to limit the generation of secondary byproducts and enhance
the yield of RG-ARP, enabling the RG-ARP yield to reach 49.23% at
80 °C and a molar ratio of 2:1 (Rib/GSH) for 20 min.