Structural elucidation of mulberry leaf oligosaccharide and its selective promotion of gut microbiota to alleviate type 2 diabetes mellitus

Two oligosaccharide fractions(MLO 2-1 and 2-2)were purified from enzymatic hydrolysate of mulberry leaf polysaccharide.The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide,which could be degraded by human digestive juice;while MLO 2-1 possessed the non-digestible property in the upper gastrointestinal tract and performed the function by regulating the gut microbiota.Hence,MLO 2-1 was selected for the further analysis.The structure of MLO 2-1 was elucidated as follow:α-T-Glcp-(1→3)-β-Glcp-(1→5)-α-Araf-(1→5)-α-Araf-1→5)-α-Araf-(1→3)-α-(2-OAc)-Glcp-1.The in vitro fecal fermentation results showed that MLO 2-1 could modulate the composition of gut microbiota.Meanwhile,MLO 2-1 was effectively metabolized by fecal bacteria to produce lactate and short chain fatty acids,especially acetate and butyrate.The specific metabolic pathways of MLO 2-1 by gut microbiota were further illuminated.Gut microbiota analysis revealed that MLO 2-1 selectively promoted the growth of Ligilactobacillus murinus,a commensal bacterium presented a reduced level in T2DM mice.Animal experiments indicated that MLO 2-1 and L.murinus exhibited hypoglycemic activities.These results demonstrated that MLO 2-1 might alleviate T2DM by selectively accelerating the proliferation of L.murinus.

Linear Regression Relationship between Lychee Juice Content and Buffering Capacity

Juice drinks are an important commercialization alternative for lychee, a tropical and subtropical fruit. Although the lychee juice content is important when assessing the quality of a drink, there are no published methods to determine it, particularly simple ones for the routine inspection of juice drinks. Lychee juice drinks contain ingredients with buffering capacity including proteins and ions such as phosphate, citrate, lactate, carbonate, acetate and propionate. The relationship between their buffering capacity and lychee juice content was studied. Citric acid was added to pure lychee dilutions in distilled water containing 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20% and 10% lychee juice. The pH of the dilutions was measured to obtain a linear model for the molar H+ concentration as a function of the added citric acid (g/L) amount LC = (BC-494.2)/12,031, where LC was the lychee juice content and BC was defined as the juice buffering coefficient.

Study on experiment and mechanism of thermal dissolved sulfuration of low grade lead-zinc oxide ore in lanpin

The thermal dissolved sulfuration technology is brought forward and performed based on the characteristic of low grade lead-zinc oxide ore in lanpin. Using sulfur as the sulphidizing agent in the experiment, the oxides in the sandstone and ignimbrite are changed into sulfides. The disproportionation reaction of sulfur in a solution is confirmed as 4S＋3H2O=2S^2-＋S2O3^2--＋6H^＋. The dynamics process is studied and the first-order reaction rate equation -1n（1-a）=ktt is obtained. The effects of the reactive products, stirring speed, dosage of sulfuration agent, value of pH and sulphidizing temperature on the sulfuration of oxide ore are investigated. The results indicate that the reactive apparent activation energy is 100.8 kJ/mol and the sulfuration ratio of lead-zinc oxide ore reaches 60% under the conditions of pH 5.9-7.5, the sulfuration temperature of 130 ℃, sulfuration time of 180 min and the stirring speed of 800 r/min.

基于神经网络预测的锌挥发率影响机制分析

浸出渣回转窑煅烧回收锌、铟等有价金属是湿法炼锌行业资源绿色循环的关键环节,呈现多因素耦合、大时滞等特点,能耗高、锌挥发率不稳定,快速优化调控困难。以国内30万吨/年锌浸出渣回转窑煅烧工程为研究对象,在工况参数灰色关联度定量分析的基础上,引入粒子群算法优化建立BP神经网络锌挥发率预测模型,结合反应机理和单因子情景分析法,重点考察了焦粉投入强度、温度和浸出渣关键组分对锌挥发率的影响规律。结果表明,焦粉投入强度对锌挥发率影响显著,关联系数达0.842;同时,锌挥发率预测模型R2达0.987,整体误差≤±0.6%;焦粉投入强度、窑尾温度和浸出渣含Fe率最优模拟调控值分别为0.60 t/t,680℃和23wt%。本研究可为湿法炼锌行业锌浸出渣绿色高质循环利用的优化控制提供理论指导和技术支撑。

Structural identification and antioxidant potency evaluation of pomelo vinegar polyphenols

Polyphenols are the main antioxidant ingredient of honey pomelo vinegar.However,the antioxidant contributions of various individual phenolics to total polyphenols and antioxidant mechanism are unclear.In this study,phenolic compounds were identified,and the antioxidant potency and antioxidant contribution of individual phenolics were analyzed.The antioxidant mechanism was also studied in HepG2 cells.A total of seven phenolics were identified,including naringin,narirutin,rhoifolin,vanillic acid,methyl hesperidin,vicenin-2,and ferulic acid;among which,ferulic acid had the highest extracellular antioxidant potency,while methyl hesperidin had the lowest.Without considering the synergistic effect of the phenolics,naringin,ferulic acid,and vicenin-2 were major contributors to the antioxidant potency of pomelo vinegar polyphenols(PVP)using four antioxidant assays.PVP at the concentrations of 20μg/mL and 100μg/mL had a protective effect against H_(2)O_(2)-induced oxidative damage to HepG2 cells.PVP also reduced lactic dehydrogenase(LDH)release and reactive oxygen species(ROS)accumulation in cells.The western blotting results revealed that PVP promoted translocation of NFE2-related factor 2(Nrf2)from the cytoplasm to the nucleus and up-regulated the expression of its governed antioxidant enzymes such as NAD(P)H:quinone oxidoreductase 1(NQO1),heme oxygenase-1(HO-1),glutathione S-transferase A2(GSTA2),and glutamate-cysteine ligase catalytic subunit(GCLC).In summary,PVP could serve as a potential therapeutic agent for oxidative stress-related disorders.