灵芝多糖对糖尿病肾病小鼠肾小管上皮细胞间充质转化的抑制作用

本研究采用氯化胆碱/乳酸/愈创木酚三元共熔溶剂（DES）来提取灵芝多糖（GLPs）,优化DES溶剂提取灵芝多糖的工艺参数,采用傅里叶变换红外光谱（Fourier Transform Infrared Spectroscopy,FT-IR）和凝胶渗透色谱（Gel Permeation Chromatography,GPC）对GLPs结构进行了表征,并研究其体外抗氧化活性,最后,采用密度泛函理论初步研究了DES提取GLPs的分子机制。结果表明,在含水量为50%、提取温度为80 ℃、提取时间为1 h、料液质量体积比为1:30 g/mL的条件下,GLPs得率达9.20%±0.27%。FT-IR和GPC分析表明,4000～500 cm⁻¹区域GLPs具有典型的多糖结构,GLPs的数均分子量为8057 Da,多分散系数为1.6。体外抗氧化活性测试显示,当GLPs质量浓度为5 mg/mL时,其总还原力为0.67±0.04。此外,GLPs对DPPH、OH和ABTS⁺自由基的清除能力的IC₅₀值分别为2.366、6.179和2.440 mg/mL。密度泛函理论模拟分析表明,DES与葡萄糖之间的结合能为65.29 kcal/mol,远高于水与葡萄糖之间的结合能（20.38 kcal/mol）,DES提取多糖是通过三重氢键相互作用来实现的。研究成果从分子水平上阐明了DES提取GLPs效果优于传统热水提取方法的内在机制。

     

愈创木酚胺基多元醇的合成及表征

以木质素模型化合物愈创木酚、二乙醇胺及多聚甲醛为原料,通过Mannich反应合成了愈创木酚胺基多元醇,研究了物料滴加顺序、物料配比、反应温度及时间等因素对Mannich反应的影响。实验结果表明:反应物料按物质的量比n(愈创木酚):n(甲醛):n(二乙醇胺)1:1:1,甲醛与二乙醇胺60℃反应2 h生成1,3-氧氮杂环戊烷,再将其滴入愈创木酚中,80~90℃反应3~4 h,二乙醇胺的转化率最高可达到90.71%。并采用HPLC、LC-MS及FT-IR表征了愈创木酚胺基多元醇的化学结构。     

邻甲氧基苯胺重氮化反应的研究

从重氮化反应原理出发,分析重氮化反应在愈创木酚生产中的应用,以找出较好的生产工艺条件议。     

固体酸催化合成3-甲氧基-4-羟基苯乙醇酸

为了得到高质量和高收率的3-甲氧基-4-羟基苯乙醇酸,使愈创木酚和乙醛酸在碱性水溶液中在固体酸催化剂存在下进行缩合反应,反应温度15℃,反应时间18h。将生成的3-甲氧基-4-羟基苯乙醇酸以钠盐形式沉淀分离出来,产品纯度98%。以γ-氧化铝、4A分子筛、活性二氧化硅、轻质氧化镁和活性氧化锌等两性氧化物用做催化剂进行研究。以4A分子筛作催化剂时收率达88·6%,比无催化剂时收率提高8·8%。     

Aggregation pheromone system of adult gregarious desert locust schistocerca gregaria (forskal)

Six electrophysiologically active aromatic compounds, viz., anisole, benzaldehyde, veratrole, guaiacol, phenylacetonitrile, and phenol, were identified in the volatiles of older-adult male desert locust. Young adults and females of all age groups produced none or only trace quantities of these compounds. Comparison of the aggregation responses of young and older adults to the crude, older-adult, volatile extract and different synthetic blends of the six compounds showed that the aggregation pheromone system of the adult gregarious locust consists of phenylacetonitrile, guaiacol, phenol, and benzaldehyde. Like the crude volatile extract of older males, neither the synthetic blend of the six compounds nor the adult pheromone blend evoked any significant aggregation responses from nymphs. These results confirm our previous report of sexual differentiation in the production of adult aggregation pheromone in the desert locust and of the evidence of two distinct aggregation pheromone systems in the two stages of the insect.     

由邻苯二酚合成愈创木酚的反应过程和动力学研究

在连续固定床反应器中,以复合的固体酸为催化剂,以邻苯二酚和甲醇为原料,在270～300℃下进行了气固催化合成愈创木酚的反应过程研究,通过对实验结果进行分析,给出了适宜的反应条件并关联出了与实验吻合的宏观动力学方程。     

Refinement of the kinetic model for guaiacol hydrodeoxygenation over platinum catalysts

In our prior work (Ind Eng Chem Res, 2015, 54, 10638-10644), hydrodeoxygenation (HDO) kinetics of guaiacol, a well-known model compound of bio-oil, over Pt/AC (activated carbon) catalysts were investigated under integral operating conditions. It was found that the pseudo-homogeneous plug-flow model utilizing these kinetics describes the experimental observations well (with normalized RMS error = 7.6%). In the present work, under differential operating conditions instead, we refine the kinetic model for the same reaction network over the same catalyst. We show that among the five reaction steps in the network, the reaction order of one step differs from our prior work, while the orders remain unchanged for the other four steps. The activation energies of two steps differ from our prior values by 10–15 kJ/mol, and for the other three steps remain essentially consistent with our prior work. The kinetic parameters from the present work are used to predict fixed-bed reactor performance under integral operating conditions as well. The comparison between experimental and predicted values for both the prior and new sets of data is excellent and even better than our prior model (with reduced normalized RMS error = 4.2%). The kinetic analysis additionally proposed that the direct and indirect pathways of phenol formation from guaiacol HDO depend on guaiacol conversion values. The present work demonstrates that kinetic expressions and parameters obtained from a gradientless differential reactor are more reliable and can be used to successfully predict integral reactor performance data.     

CONTROL OF FERULIC ACID AND 4-VINYL GUAIACOL IN BREWING

Phenolic acids in beer are important because they can be decarboxylated to phenols, which usually impart off-flavours. An improved high performance liquid chromatographic system was used to monitor phenolic acids and phenols during the brewing process. Ferulic acid was the most significant phenolic acid found in beers prepared from malted barley. Extraction of ferulic acid from malt involved an enzymatic release mechanism with an optimum temperature about 45°C. Mashing-in at 65°C significantly decreased the release of free ferulic acid into the wort. Wort boiling produced 4-vinyl guaiacol by thermal decarboxylation, in amounts (0.3 mg/L) close to its taste threshold, from worts that contained high contents of free ferulic acid (> 6 mg/L). The capacity of yeasts to decarboxylate phenolic acids (Pof⁺ phenotype) was strong in wild strains of Saccharomyces and absent in all lager brewing yeast and most ale brewing yeasts. Some top-fermenting strains, especially those used in wheat beer production, possessed a weak decarboxylating activity (i.e. Pof^δ). During storage of beers there were appreciable temperature-dependent losses of 4-vinyl guaiacol. These results indicated that the production of 4-vinyl guaiacol is amenable to close technological control.     

基于漆酶的时间-温度指示剂研究

目的研制基于漆酶的时间-温度指示剂(time-temperatureintegrators,TTI),指示并预测相应食品的货架期。方法利用漆酶对愈创木氧化分解反应的催化作用,通过调节加酶量,使愈创木酚的氧化反应产生随时间和温度累积的颜色变化效应,从而获得4种不同效果的TTI。在4、10、25、35℃恒温条件下对4种不同TTI动力学参数进行了研究,计算其反应活化能值。结果 4种TTI的活化能指示范围分别为0～50、17～67、15～65、11～61kJ/mol。结论该方法操作简单,颜色变化所产生的指示效果明显。根据TTI反应的终点与食品货架寿命的终点相吻合的原则, 4种TTI可分别用于牛奶、肉类新鲜度的指示。     

涡旋辅助液液微萃取结合GC-MS法检测67 种白酒中四甲基吡嗪、4-甲基愈创木酚4-乙基愈创木酚

采用涡旋辅助液液微萃取结合气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）法对67?种白酒中四甲基吡嗪、4-甲基愈创木酚和4-乙基愈创木酚进行检测。酒样经二氯甲烷提取,涡旋辅助萃取1?min,6?000?r/min离心5?min,然后采用GC-MS进行分析。结果表明,四甲基吡嗪、4-甲基愈创木酚和4-乙基愈创木酚分别在质量浓度为0.5～2?500、1.0～2?500、1.0～2?500?μg/L的范围内具有较好的线性关系（R2＞0.99）;检出限分别为0.25、0.5、0.5?μg/L;不同添加水平的平均回收率为80.1%～88.0%。对67?种白酒含量分析表明,所有样本都含有四甲基吡嗪,含量范围为1.5～2?434.3?μg/L;51?种样本中含有4-甲基愈创木酚,含量范围为2.8～1?709.0?μg/L;53?种样本中含有4-乙基愈创木酚,含量范围为1.3～1?167.5?μg/L。白酒酿造原料、工艺的差异可能是造成其健康因子含量不同的潜在因素。