Formation of deoxyfructosazine and its 6-isomer by the browning reaction between fructose and ammonium formate.

Conversions of Cellobiose and Inulin to Deoxyfructosazine in Aqueous Solutions

“…Figure S4 shows the UV–Vis spectrum of the product obtained from the conversion of cellobiose, and that synthesized from inulin was similar. The strong absorption at 275 nm was due to the conjugated aromatic ring of 2,6‐DOF or 2,5‐DOF 30. The IR spectra of the products obtained from the conversion of cellobiose and inulin were also similar.…”

“…It is known that the reactions of sugars with amino‐compounds are very complex, and providing a convinced mechanism is a great challenge at the present state. Some researchers have made contribution on this 30, 31. More work should be done on this interesting topic.…”

“…The yield increased with temperature in the range of 100 to 150°C, and then decreased with further increasing temperature. From the mechanism of the formation of 2,6‐DOF 30, 31, we know that the reaction of NH 3 released from the ammonium formate with CO group in the glucose is crucial for the formation of 2,6‐DOF. The ammonium formate was relatively stable at lower temperature.…”

“…2,6‐Deoxyfructosazine (2,6‐DOF) and 2,5‐deoxyfructosazine (2,5‐DOF) are very useful chemicals and have different applications, such as flavors in tobacco industry 22–24, treatment and prevention of diabetes (type II) 25, resistance of cancers 26, treatment of immunological and inflammatory disease 27, reagents for DNA strand cleavage 28. 2,6‐DOF and 2,5‐DOF have been prepared by reactions of glucose and fructose with ammonium salts 29, 30. The 2,5‐DOF and 2,6‐DOF were obtained in approximately equal ratio from the reaction of glucose with ammonium in weak acidic medium (pH 5.3∼6.0) 29, while the yield of 2,5‐DOF was much higher than that 2,6‐DOF in the reaction of fructose with ammonium formate 30.…”

“…2,6‐DOF and 2,5‐DOF have been prepared by reactions of glucose and fructose with ammonium salts 29, 30. The 2,5‐DOF and 2,6‐DOF were obtained in approximately equal ratio from the reaction of glucose with ammonium in weak acidic medium (pH 5.3∼6.0) 29, while the yield of 2,5‐DOF was much higher than that 2,6‐DOF in the reaction of fructose with ammonium formate 30. It has been also reported that 2,6‐DOF was a dominant product from the reaction of glucose with each of the following ammonium salts: monohydrogenphosphate, sulfite, sulfide, citrate, acetate, carbonate, chloride sulfate, and bicarbonate 31.…”