The directly selective hydrogenolysis of xylitol to ethylene glycol(EG) and 1,2-propylene glycol(1,2-PDO)was performed on Cu–Ni–ZrO_2 catalysts prepared by a co-precipitation method. Upon optimizing the reaction con...The directly selective hydrogenolysis of xylitol to ethylene glycol(EG) and 1,2-propylene glycol(1,2-PDO)was performed on Cu–Ni–ZrO_2 catalysts prepared by a co-precipitation method. Upon optimizing the reaction conditions(518 K, 4.0 MPaH_2 and 3 h), 97.0% conversion of xylitol and 63.1% yield of glycols were obtained in water without extra inorganic base. The catalyst still remained stable activity after six cycles and above 80% total selectivity of glycols was obtained when using 20.0% xylitol concentration. XRD, TEM and ICP results indicated that Cu–Ni–ZrO_2 catalysts possess favorable stability. Cu and Ni are beneficial to the cleavage of C–O and C–H bond, respectively. To reduce the hydrogen consumption, isopropanol was added as in-situ hydrogen source and 96.4% conversion of xylitol with 43.6% yield of glycols were realized.展开更多
Xylitol and erythritol have been reported in numerous previous and recent studies as potential antidiabetic sweeteners,however,it is not certain which one is most effective in this regard.In the present study,the effe...Xylitol and erythritol have been reported in numerous previous and recent studies as potential antidiabetic sweeteners,however,it is not certain which one is most effective in this regard.In the present study,the effects of xylitol and erythritol were comparatively investigated on blood glucose,insulin level,dyslipidemia,pancreatic islet morphology andβ-cell function,and redox imbalance in a type 2 diabetes(T2D)model of rats.Seven-week-old male Sprague-Dawley rats were randomly divided into 8 groups:Normal Control(NC),Diabetic Control(DC),Diabetic Xylitol 5%(DX5),Diabetic Xylitol 10%(DX10),Diabetic Xylitol 20%(DX20),Diabetic Erythritol 5%(DE5),Diabetic Erythritol 10%(DE10),and Diabetic Erythritol 20%(DE20).T2D was induced in the diabetic groups initially by feeding 10%fructose solution to induce insulin resistance followed by an intraperitoneal injection of streptozotocin(40 mg/kg body weight)dissolved in citrate buffer(pH 4.5)to induce partial pancreaticβ-cells dysfunctions.The animals in NC group were fed with normal drinking water and injected with citrate buffer only.After the confi rmation of diabetes,the xylitol and erythritol with above-mentioned concentrations were supplied to the respective animal groups when the animals in NC and DC groups were supplied with normal drinking water.After 8 weeks intervention period,the body weight,fl uid and water intake,blood glucose,serum alanine aminotransferase,aspartate aminotransferase,CK-MB and creatinine were signifi cantly decreased,while the serum insulin level,serum lipids,glucose tolerance ability,pancreatic islet morphology andβ-cell function,pancreatic and serum redox imbalance were improved in the most xylitol and erythritol fed groups compared to the DC group,when effects were better for xylitol compared to erythritol.The data of this study suggests that xylitol has better antioxidant and antidiabetic effects compared to erythritol.Therefore,xylitol can be used as a preferrable dietary anti-diabetic sweetener or supplement over erythritol for the management of diabetes and its associated complications.展开更多
基金financial supports provided by the National Natural Science Foundation of China (21406255)the Shanghai Science and Technology Committee (16dz1207200)the Youth Innovation Promotion Association CAS (2015231)
文摘The directly selective hydrogenolysis of xylitol to ethylene glycol(EG) and 1,2-propylene glycol(1,2-PDO)was performed on Cu–Ni–ZrO_2 catalysts prepared by a co-precipitation method. Upon optimizing the reaction conditions(518 K, 4.0 MPaH_2 and 3 h), 97.0% conversion of xylitol and 63.1% yield of glycols were obtained in water without extra inorganic base. The catalyst still remained stable activity after six cycles and above 80% total selectivity of glycols was obtained when using 20.0% xylitol concentration. XRD, TEM and ICP results indicated that Cu–Ni–ZrO_2 catalysts possess favorable stability. Cu and Ni are beneficial to the cleavage of C–O and C–H bond, respectively. To reduce the hydrogen consumption, isopropanol was added as in-situ hydrogen source and 96.4% conversion of xylitol with 43.6% yield of glycols were realized.
基金supported by funding from the Research office,University of KwaZulu-Natal,Durbanthe National Research Foundation,Pretoria,South Africa(112430)。
文摘Xylitol and erythritol have been reported in numerous previous and recent studies as potential antidiabetic sweeteners,however,it is not certain which one is most effective in this regard.In the present study,the effects of xylitol and erythritol were comparatively investigated on blood glucose,insulin level,dyslipidemia,pancreatic islet morphology andβ-cell function,and redox imbalance in a type 2 diabetes(T2D)model of rats.Seven-week-old male Sprague-Dawley rats were randomly divided into 8 groups:Normal Control(NC),Diabetic Control(DC),Diabetic Xylitol 5%(DX5),Diabetic Xylitol 10%(DX10),Diabetic Xylitol 20%(DX20),Diabetic Erythritol 5%(DE5),Diabetic Erythritol 10%(DE10),and Diabetic Erythritol 20%(DE20).T2D was induced in the diabetic groups initially by feeding 10%fructose solution to induce insulin resistance followed by an intraperitoneal injection of streptozotocin(40 mg/kg body weight)dissolved in citrate buffer(pH 4.5)to induce partial pancreaticβ-cells dysfunctions.The animals in NC group were fed with normal drinking water and injected with citrate buffer only.After the confi rmation of diabetes,the xylitol and erythritol with above-mentioned concentrations were supplied to the respective animal groups when the animals in NC and DC groups were supplied with normal drinking water.After 8 weeks intervention period,the body weight,fl uid and water intake,blood glucose,serum alanine aminotransferase,aspartate aminotransferase,CK-MB and creatinine were signifi cantly decreased,while the serum insulin level,serum lipids,glucose tolerance ability,pancreatic islet morphology andβ-cell function,pancreatic and serum redox imbalance were improved in the most xylitol and erythritol fed groups compared to the DC group,when effects were better for xylitol compared to erythritol.The data of this study suggests that xylitol has better antioxidant and antidiabetic effects compared to erythritol.Therefore,xylitol can be used as a preferrable dietary anti-diabetic sweetener or supplement over erythritol for the management of diabetes and its associated complications.
