采用高温下稀硫酸催化葡萄糖的方法制备乙酰丙酸。考察了反应温度、硫酸浓度和搅拌转速对葡萄糖转化率和乙酰丙酸收率的影响，并优化确定了最优反应条件。进一步，分析了最优反应条件下不同葡萄糖初始浓度对乙酰丙酸收率的影响。为了提高高浓度葡萄糖底物反应时乙酰丙酸的收率，采用两种不同的补料方法进行实验：分3次，依次加入7%、6%与5%的葡萄糖；每次均添加3%的葡萄糖，共6次。结果表明：①提高硫酸浓度、反应温度和搅拌速度有利于加快葡萄糖转化和乙酰丙酸生成；②高浓度葡萄糖底物不利于乙酰丙酸的生成，且浓度越高，乙酰丙酸收率越低；③通过补料操作，可使乙酰丙酸收率由44.3%提高至65.9%。

Levulinic acid (LA) was prepared from glucose at high temperature and with dilute sulfuric acid. The effects of reaction temperature,sulfuric acid concentration and stirring speed on glucose conversion and LA yield were investigated and optimized. Furthermore,the influence of initial glucose concentration on LA yield under the optimized reaction conditions was analyzed. For the purpose of increasing LA yield under high glucose concentration,two kinds of fed-batch experiments were performed (7%,6%and 5%glucose concentration for three additions;every 3%glucose concentration for six additions). High sulfuric acid concentration,high reaction temperature and high stirring speed were favorable to increasing glucose conversion and levulinic acid generation. High glucose concentration was not conducive to generation of levulinic acid,and the higher the concentration of glucose,the lower the yield of levulinic acid. Yield of levulinic acid increased from 44.3%to 65.9%via fed-batch exp

以花生壳为原料,采用超声波预处理协同SO2-4/ TiO2-Al2 O3固体酸水解制备乙酰丙酸.在单因素试验基础上,以水解温度、水解时间和固体酸用量为因素,乙酰丙酸得率为响应面值,设计了三因素三水平的响应面分析实验,确定了花生壳制备乙酰丙酸的最优工艺参数为:水解温度235℃、水解时间31 min、固体酸用量4.5%和液固比为14∶1(mL/ g),此时乙酰丙酸得率为27.54%.与相同工艺下未采用超声波预处理相比,得率提高了7.18%.

@@@@Levulinic acid (LA)was prepared from peanut shells through synergistic hydrolysis using ultrasonic pretreatment cooperated with SO2 -4 / TiO2-Al2 O3 solid acid. Based on single factor test,the effects of hydrolysis temperature,hydrolysis time and the amount of solid acid on LA yield were studied,and the response surface method (RSM)with 3 factors and 3 levels was designed. The results showed that the optimum conditions were as followed:hydrolysis temperature is 235℃,hydrolysis time is 31 min,solid acid amount is 4. 5%,and liquid-solid ratio is 14∶1 (mL/ g). Then the LA yield gained 27. 54% . Comparing with that obtained by non-ultrasonic pretreatment at the same condition,the LA yield increased by 7. 18% .

利用二次浸渍焙烧法制备固体超强酸催化剂SO42?/高岭土,对其催化水解乳糖制备乙酰丙酸的反应机理作了推理,并通过单变量法考察了催化剂的焙烧温度、乳糖浓度、反应温度、反应时间、催化剂用量等对乙酰丙酸相对收率的影响,采用正交实验来确定最佳工艺条件,研究结果表明:当催化剂的焙烧温度为650℃、乳糖浓度5 g/L、反应温度200℃、反应时间120 min、催化剂用量为乳糖加入量的15%时,乙酰丙酸的相对收率最大,达到79.13%.

Solid superacid catalyst SO42?/Kaolin was prepared by twice impregnation-roasting,and the synthesis mechanism of conversion of lactose to levulinic acid was studied. The effects of technological condition , such as catalyst calcination temperature , catalyst dosage , lactose concentration,reaction temperature,reaction time on the relative yield of levulinic acid were investigated and orthogonal experiment was used to determine the optimum conditions. The result showed that the highest relative yield of levulinic acid was 79.13% under the optimal conditions of catalyst calcination temperature 650 ℃,lactose concentration 5 g/L,reaction temperature 200 ℃, reaction time 120 min,catalyst dosage 15%of lactose.

以色泽、气味、粘度、有无沉淀物作为感官指标,以氨基酸态氮、香气成分、氯丙醇和乙酰丙酸作为化学指标,对有关酿造酱油和配制酱油的区别进行了总结。

Use color,odor,viscosity,precipitates as sensory indexes,and use amino acid nitrogen, aroma components,chloropropanol and levulinic acid as chemical indexes,summarize the differences between natural fermented soy sauce and blended soy sauce.

目的：丙戊酸（valproic acid ，VPA ）可导致组蛋白乙酰化/去乙酰化失衡，一过性干扰孕鼠子宫内胚胎发育，诱导胎鼠心脏发育畸形，造成小鼠先天性心脏畸形。本实验探讨组蛋白乙酰化/去乙酰化一过性失衡的“开关机制”在先天性心脏畸形中的作用。方法 VPA作用后，应用RT-PCR和Western blot检测全胚胎HDAC1与HDAC2基因和蛋白的相对表达量。结果：VPA作用后全胚胎的HDAC1与HDAC2基因和蛋白的相对表达量均明显下调。结论：组蛋白乙酰化/去乙酰化失衡与先天心脏发育畸形密切相关。

Objective :To explore the role of histone acetylation/deacetylation imbalance in the pathogenesis of congenital heart disease .Methods Using VPA to interfere with the development of murine intrauterine embryos at specific time points and develop an embryonic murine cardiac abnormalities model .The mRNA and protein expressions of HDAC1 and HDAC2 were assessed by RT -PCR and Westernblot .Results The expression of HDAC1 and HDAC2 gene/protein both decreased significantly in the whole murine embryo after VPA treatment by RT -PCR and Western blot detection .Conclusion The histone acetylation/deacetylation imbalance may be involved in the pathogenesis of congenital heart diseases .