α-烷硫基-2-丁酮类化合物的合成

用硫醇与环氧丁烷发生开环反应得到β 烷硫基醇类化合物(Ⅰ),再经Swern氧化反应,合成了12种α 烷硫基 2 丁酮类化合物(Ⅱ),两步反应收率都大于70%。第一步反应先将0 1mol各种硫醇分别与0 2mol氢氧化钠在乙醇中反应0 5h,再滴加0 105mol环氧丁烷,回流反应2h,处理后得中间体Ⅰ;第二步反应在氮气保护下,温度为-49～-50℃,在二氯甲烷中,先将35mmol二甲基亚砜(DMSO)与25mmol草酰氯反应15min,再加入12 5mmolⅠ的二氯甲烷溶液,反应0 5h,然后加入三乙胺,反应1h,恢复到室温,处理后得产物Ⅱ。所合成的化合物Ⅱ的结构经IR、MS、1HNMR得到了确认。     

α,α-二苯基-4-哌啶甲醇催化氢化合成工艺研究

研究了催化氢化法合成α,α-二苯基-4-哌啶甲醇的工艺。以Pt/C为催化剂,考察了反应溶剂,压力,反应时间和催化剂添加比例对催化加氢反应的影响。在优惠的工艺条件下,α,α-二苯基-4-哌啶甲醇的收率可达92.4%,产品纯度为98.8%。     

气相色谱法测定α-蒎烯和马鞭草烯酮

建立气相色谱外标法同时检测α-蒎烯和马鞭草烯酮.采用Rtx@-Wax极性柱(30 m×0.25 mm×0.25 μm)程序升温,流速41.8 mL/min、进样量0.8μL,得α-蒎烯和马鞭草烯酮标准曲线:A1 =6.13×105ρ1-8.58 ×104,A2 =5.03×105ρ2-1.75×105,相关系数R2 ＞...     

Efficient Biocatalytic Synthesis of Highly Enantiopure α-Alkylated Arylglycines and Amides

A number of racemic α-alkylarylglycine amides including 1-amino-1-carbamoyl-1,2,3,4-tetrahydronaphthalene underwent efficient biocatalytic hydrolysis under very mild conditions to afford the corresponding (S)-α-alkylarylglycines and (R)-α-alkylarylglycine amides in excellent yields with enantiomeric excesses higher than 99.5%. Both the reaction rate and enantioselectivity of biocatalytic kinetic resolution were strongly dependent upon the nature of the substituent and the substitution pattern on the benzene ring of the substrate. In contrast, no effective biotransformation of the Strecker nitrile derived from acetophenone was observed under the catalysis of a nitrile hydratase/amidase-containing microbial Rhodococcus sp. AJ270 whole-cell catalyst. Coupled with the chemical hydrolysis of amide, this biotransformation process provided efficient syntheses of α-substituted arylglycines in both enantiomeric forms from readily available racemic amides.     

α-亚麻酸高效提取纯化工艺研究

介绍了α-亚麻酸乙酯的制备和纯化工艺等现状。通过对传统工艺和优化工艺的对比分析,优化工艺具有废水排放少、能耗少、产品得率及含量高等优点,在技术和经济上是合理可行稳定可靠的,可以为工业化生产提供依据。     

裂叶荨麻醇提物体外抗氧化及α-葡萄糖苷酶抑制作用的研究

以裂叶荨麻为原料,用70%乙醇对其进行提取,以醇提物为研究对象,测定其黄酮含量。以抗环血酸(VC)为阳性对照,通过测定1,1-二苯基-2-三硝基苯肼自由基(DPPH·)清除率、羟基自由基(·OH)清除率及总还原力来评价裂叶荨麻醇提物体外抗氧化能力;以对硝基苯-α-D葡萄糖吡喃苷(4-Nitrophenylα-D-glucopyranoside,PNPG)为底物,研究裂叶荨麻醇提物对α-葡萄糖苷酶的抑制作用。结果表明,裂叶荨麻醇提物中黄酮含量为12.09 mg/g;对DPPH自由基的最大清除率为92.76%,半抑制浓度(IC50)为9.960μg/mL,对羟基自由基的最大清除率为98.05%,IC50值为1.123 mg/mL,总还原力随醇提物浓度的增加而增强;对α-葡萄糖苷酶的最大抑制率为59.06%,IC50值为31.598 mg/mL。结果表明裂叶荨麻醇提物具有明确的体外抗氧化活性及α-葡萄糖苷酶抑制作用,有望开发成为抗氧化降糖功能性食品。     

酱香型白酒中非乙醇类物质抗炎活性研究

研究酱香型白酒中非乙醇物质(maotai-flavor liquor extract,MTE)的体外抗炎活性及其作用机制。采用氯仿萃取及真空冻干获得MTE,液相色谱-质谱联用技术(high performance liquid chromatography-mass spectrometry,HPLC-MS)分析其成分,脂多糖(lipopolysaccharide,LPS)诱导IEC-6细胞建立炎症模型;检测MTE及MTE中26种化合物对LPS诱导的IEC-6细胞凋亡的影响;酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)测定MTE及α-雪松醇处理细胞对NO及相关炎症因子IL-6、IL-8、TNF-α、IL-10及细胞迁移能力的影响。结果表明,MTE、α-雪松醇(0.22 mg/mL)可显著提高IL-10分泌、降低LPS诱导的细胞凋亡、提高细胞迁移能力,降低IL-6、IL-8、TNF-α等的分泌,上调细胞紧密连接蛋白Occludin和ZO-1 mRNA表达。酱香型白酒中含有的非乙醇物质具有一定的抗炎活性,其中α-雪松醇可显著降低LPS诱导引起的IEC-6细胞凋亡,可通过抑制炎症因子IL-6、IL-8和TNF-α的分泌及提高IL-10分泌发挥抗炎能力。     

α-淀粉酶降解玉米淀粉对淀粉胶性能的影响

介绍了制备高固含量的淀粉胶配方、工艺条件及过程。通过正交设计选择α－淀粉酶对玉米淀粉降解的最佳条件,使胶固含量高、流动性好;再交联、接枝,以提高胶的粘结性与稳定性,满足高速卷烟用胶的性能要求。     

Formation mechanism of β-Sialon with different morphologies based on DFT calculation and its effect on the performance of refractory composites

β-Sialon with whisker-like, columnar, and plate-shaped structures was successfully synthesized with Al₂O₃–C refractory compositions. In the presence of a catalyst, the preferential growth face of columnar β-Sialon was (100), whereas plate-like β-Sialon preferred (101) and (111). DFT calculations demonstrated that the SiO adsorption energy on the (100), (101), and (111) faces of β-Sialon crystal were –34.95, –52.88, and –45.08 eV, respectively. Therefore, the (101) and (111) faces were more stable in Al-rich β-Sialon. With the increase in catalyst content, the Si-rich Si–Al–O–N liquid phases, which contributed to the generation of columnar β-Sialon, were converted into the Al-rich Al–Si–O–N system that was conducive to the formation of plate-like β-Sialon. Compared to the sample without the catalyst, the CMOR and HMOR of the specimen were increased by 45.07% and 60.47%, respectively, with the addition of Fe₂O₃. This was attributed to the formation of β-Sialon with a one- or two- dimensional shape.     

顶空气相色谱法研究柠檬醛+α-紫罗兰酮+β-紫罗兰酮体系的汽液平衡

采用顶空气相色谱法测定了柠檬醛(1)+ α-紫罗兰酮(2)、柠檬醛(1)+ β-紫罗兰酮(2)和α-紫罗兰酮(1)+ β-紫罗兰酮(2)体系在333.15、368.15和403.15 K温度下的等温汽液相平衡数据;采用Redlich-Kister面积检验法和van Ness点检验法进行热力学一致性检验;采用Aspen plus V10.0软件、Britt-Luecke算法回归NRTL和 UNIQUAC活度系数模型参数;采用NRTL活度系数模型计算体系的超额自由焓(G^E)。结果表明,所测体系的p-T-x-y数据均符合热力学一致性;柠檬醛(1)+ α-紫罗兰酮(2)、柠檬醛(1)+ β-紫罗兰酮(2)和α-紫罗兰酮(1)+ β-紫罗兰酮(2)体系的气相组成(y₁)的计算值与实验值的最大平均绝对偏差(AAD)分别为0.0044、0.0060和0.0032;三组二元体系 G^E的正、负偏差最大值分别为0.4002、0.2315和 –0.7143 kJ·mol^-1。