5-亚苄基绕丹宁乙酸衍生物的微波合成

利用微波辐射催化芳香醛与绕丹宁乙酸的缩合反应,合成了10个5-亚苄基绕丹宁乙酸衍生物,反应时间8~20min,产率良好,操作简便。     

Effects of ready to drink teas on AhR- and PXR-mediated expression of cytochromes P450 CYP1A1 and CYP3A4 in human cancer cell lines and primary human hepatocytes

A variety of xenobiotics are taken in the diet and they can interfere with regulatory pathways of drug metabolizing enzymes in humans. This can result in food-drug interactions, which is undesirable clinical situation where drug pharmacokinetics are influenced by dietary compounds. Xenobiotics-mediated food-drug interactions include the induction of drug metabolizing cytochromes P450. The expression of the most important inducible cytochromes CYP1A and CYP3A4 are regulated by xenoreceptors PXR and AhR.We examined extracts from 17 different flavoured ready to drink teas (RDTs) for their capabilities to activate PXR and AhR receptors and to induce CYP3A4 and CYP1A genes. Primary cultures of human hepatocytes and cancer cell lines HepG2 and LS174T were used as in vitro models. Gene reporter assays, RT-PCR and Western blots were performed.We identified three RDTs that induced CYP3A4 mRNA and protein, implying a potential for food-drug interactions. Several RDTs slightly elevated CYP1A1 expression or activated AhR.     

紫苏醛合成紫苏葶的工艺研究

在酸碱缓冲溶液中由紫苏醛与盐酸羟胺缩合合成紫苏葶,经红外光谱、气相色谱-质谱联机、氢核磁共振谱图确定了产物紫苏葶的结构。研究了反应体系的pH、反应温度以及紫苏醛和盐酸羟胺的投料比对紫苏葶收率的影响,确定优化工艺条件为:反应体系的pH为6.5,紫苏醛与盐酸羟胺的摩尔投料比为1∶7,40℃下反应6h,紫苏葶的产率和纯度可分别达到91.1%和98.20%。优化后的实验条件有效地抑制了紫苏葶的酸性分解,与文献方法相比,明显提高了紫苏葶的收率和纯度。     

酸奶保存期内风味物质与风味变化研究

研究成品酸奶在4℃冷藏条件下主要风味物质的变化,包括羰基化合物乙醛、双乙酰以及挥发酸和酸性物质,同时考察酸奶的感官品评分数。结果显示,酸奶的主要风味化合物含量均呈增加趋势,且增长速度先快后慢。当乙醛与双乙酰含量的比例在0.56～0.80之间时,酸奶的风味比较协调。风味物质和风味评分分数的相关分析证明,酸奶中的各风味化合物相关性显著,且对酸奶的风味强度和风味协调性均有不同程度的影响。     

添加助剂的非木浆二氧化氯漂白

研究了添加醛类助剂对非木浆二氧化氯漂白的活化效果。在ClO2脱木素（D）段添加1.0%～1.5%的甲醛助剂,可以有效地促进和改善ClO2脱木素的速率和效率。与对照样相比,ClO2脱木素（D）后和碱抽提（DE或DEP）后纸浆的卡伯值均有所降低,ClO2的实际消耗量增大,表明甲醛对ClO2脱木素有较好的活化作用。除了甲醛以外,乙醛、乙二醛、葡萄糖等醛类或醛糖也可以起到一定的活化效果。甲醛的活化效果与未漂浆初始卡伯值的高低有关。未漂浆初始卡伯值越高,甲醛对ClO2脱木素段的活化效果越好。对原浆卡伯值为21.7的烧碱-蒽醌法麦草浆,在D段添加1.5%的甲醛助剂,采用DEPP漂序,可使漂白终点白度达到81.8%,比对照样提高了2.5个点,部分强度指标有所下降。     

Investigation of the Aroma Profile of Green Tea Leaves Using Organic Synthesis and Conventional Analytical Techniques

Although many aroma components have been identified in green tea leaves, the aroma compounds contributing to green tea＇s characteristic odor have not yet been reported. The authors recently reported that aroma components with a matcha-like odor are present in both green tea and black tea prepared from the Sayamakaori tea cuttivar. This matcha-like odor is similar to the odor of commercial available matcha （high-quality powdered green tea）, and is a specific odor feature of green tea leaves. At present, the green-tea odor is thought to arise from the combination of a large number of constituents. Recent reports indicate that a complex interaction between olfactory receptors and odorants is important for the evaluation of the odors. Taking into consideration these findings, the authors investigated the aroma profile of green tea, focusing on the characteristic molecular structures of the constituents that give matcha-like odor. Using a combination of organic synthesis and gas chromatography-mass spectrometry plus gas chromatography-olfactometry, the authors identified aroma components with matcha-like odors in five other tea cultivars. This investigation also revealed that several compounds with a formyl group were important constituents of the aroma of green tea leaves, although the odor of each constituent was not individually similar to the tea＇s overall aroma. The authors found for the first time a group of key components that have the matcha-like odor.     

芳基烷醇-β-D-葡萄糖苷的化学合成与应用

采用改进的Helferich法立体选择合成了芳基烷醇-β-D-葡萄糖苷,合成路线比传统的Koenigs-Knorr法减少了一步,产物收率分别为53%(3a)和49%(3b),通过LC/MS、~1H-NMR、~(13)C-NMR等检测条件对产物结构进行了表征;添加芳基烷醇-β-D-葡萄糖苷对低焦油卷烟的香味具有一定的补偿作用,但转化率很低,仅为7.3%(3a)和5.03%(3b);芳基烷醇-β-D-葡萄耱苷对植物病原菌具有明显的抑制作用。     

Aggregation pheromone for the pepper weevil,Anthonomus eugenii cano (Coleoptera: Curculionidae): Identification and field activity

This study describes the identification of an aggregation pheromone for the pepper weevil,Anthonomus eugenii and field trials of a synthetic pheromone blend. Volatile collections and gas chromatography revealed the presence of six male-specific compounds. These compounds were identified using chromatographic and spectral techniques as: (Z)-2-(3,3-dimethylcyclohexylidene)ethanol, (E)-2-(3,3-dimethylcyclohexylidene)ethanol, (Z)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-3,7-dimethyl-2,6-octadienoic acid (geranic acid), and (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol). The emission rates of these compounds from feeding males were determined to be about: 7.2, 4.8, 0.45, 0.30, 2.0, and 0.30µg/male/day, respectively. Sticky traps baited with a synthetic blend of these compounds captured more pepper weevils (both sexes) than did unbaited control traps or pheromone-baited boll weevil traps. Commercial and laboratory formulations of the synthetic pheromone were both attractive. However, the commercial formulation did not release geranic acid properly, and geranic acid is necessary for full activity. The pheromones of the pepper weevil and the boll weevil are compared. Improvements for increasing trap efficiency and possible uses for the pepper weevil pheromone are discussed. A convenient method for purifying geranic acid is also described.The mention of firm names or trade products does not imply endorsement or recommendation by the U.S. Department of Agriculture over other firms or similar products not mentioned. All programs and services of the U.S. Department of Agriculture are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, age, marital status or handicap.     

无配体碘化亚铜催化碘代芳烃与氨基醇的胺化反应研究

在40%的nBu4N+OH-水溶液中,采用碘化亚铜催化碘代芳烃与醇胺类物质进行胺化反应,合成了一系列含氮芳烃,并且效果很理想。该方法无需任何配体,同时具有经济、高效、环保等特点。产物的结构经1 H NMR、13C NMR、MS和元素分析证实。     

HPAM/酚醛/脲醛复合交联聚合物凝胶暂堵剂的室内实验研究

研制了一种部分水解聚丙烯酰胺（HPAM）为主要成分的复合交联聚合物暂堵剂,考察了HPA、稳定剂、温度等因素对暂堵剂性能的影响。实验结果表明,最佳配方体系可在75℃下成胶,可配制出黏弹性高、强度高、黏度保持率高的复合交联聚合物凝胶暂堵剂。该暂堵剂可用于120℃以下高温油藏的暂堵作业。