Direct Construction of the 9H‐Pyrrolo[1,2‐a]azepin‐9‐amine Skeleton via [4+3] Annulation of Alkyl 2‐Aroyl‐1‐chlorocyclo‐ propanecarboxylates

A direct diastereoselective synthesis approach of important 9H‐pyrrolo[1,2‐a]azepin‐9‐amines was established via base‐promoted [4+3] annulation between donor–acceptor reagents derived from 1H‐pyrrole‐2‐carbaldehydes and alkyl 2‐aroyl‐1‐chlorocyclopropanecarboxylates. This transition metal‐free domino reaction proceeded quickly under mild basic conditions, affording potentially bioactive azepine derivatives in moderate to high yields with high diastereoselectivities (up to >20:1).

     

A process for the complete fractionation of baker's yeast

A process for the preparation of yeast-derived food additives was developed. The four products obtained, yeast protein concentrate (YPC), cell-wall protein (CWP), semi-pure glucomannan (SPG) and yeast extract, compared well with similar products, present in the current market, with respect to functional properties. YPC and CWP exhibited improved water-holding and oil-binding properties over those of soy-protein isolate (SPI). The emulsifying capacity was very close to that observed in commercial samples. A one-step alkaline extraction enhanced the functional properties of primary yeast glycan to match traditional food hydrocolloid sources. SPG showed oil-binding properties significantly greater than commercial glucomannan.     

The Effect of Fullerenol C60(OH)36 on the Antioxidant Defense System in Erythrocytes

Background: Fullerenols (water-soluble derivatives of fullerenes), such as C₆₀(OH)₃₆, are biocompatible molecules with a high ability to scavenge reactive oxygen species (ROS), but the mechanism of their antioxidant action and cooperation with endogenous redox machinery remains unrecognized. Fullerenols rapidly distribute through blood cells; therefore, we investigated the effect of C₆₀(OH)₃₆ on the antioxidant defense system in erythrocytes during their prolonged incubation. Methods: Human erythrocytes were treated with fullerenol at concentrations of 50–150 µg/mL, incubated for 3 and 48 h at 37 °C, and then hemolyzed. The level of oxidative stress was determined by examining the level of thiol groups, the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase, and glutathione transferase), and by measuring erythrocyte microviscosity. Results: The level of thiol groups in stored erythrocytes decreased; however, in the presence of higher concentrations of C₆₀(OH)₃₆ (100 and 150 µg/mL), the level of -SH groups increased compared to the control. Extending the incubation to 48 h caused a decrease in antioxidant enzyme activity, but the addition of fullerenol, especially at higher concentrations (100–150 µg/mL), increased its activity. We observed that C₆₀(OH)₃₆ had no effect on the microviscosity of the interior of the erythrocytes. Conclusions: In conclusion, our results indicated that water-soluble C₆₀(OH)₃₆ has antioxidant potential and efficiently supports the enzymatic antioxidant system within the cell. These effects are probably related to the direct interaction of C₆₀(OH)₃₆ with the enzyme that causes its structural changes.     

4-(2-噻吩基)苯乙酸及其衍生物的合成

采用新方法设计并合成了4-(2-噻吩基)苯乙酸及其衍生物。通过对各步反应的研究,找到了最佳的反应条件和4-(2-噻吩基)苯乙酸及其衍生物的分离和纯化方法。并对这些化合物的结构用元素分析I、R1、H NMR进行了确证。并对其潜在的应用价值进行了探讨。     

N,N′,N″-三(异丙基)-1,4,7-三氮杂环壬烷的合成改进

在无水碳酸钾存在下,以1,4,7-三氮杂环壬烷和2-溴丙烷为原料合成了标题化合物,与文献方法相比,产物处理简单,产率高达99%。     

Friction and wear characteristics of organic thiophosphoro derivatives — a critical appraisal

The friction- and wear-reducing characteristics of a number of oil soluble sulphurised and phosphosulphurised derivatives for automotive and industrial applications have been reviewed. A critical appraisal of the suggested causes and mechanism of friction reduction and antiwear characteristics has been made. A review of the investigations carried out so far indicates that the creation of in situ films of simple inorganic salts, such as molybdenum disulphide, iron sulphide or phosphates of low shear strength and lamellar structures, does not appear to be the primary cause of low friction and wear. The authors have, therefore, undertaken a programme to synthesise and study the chemistry and tribochemical reactions in relation to friction and wear characteristics of hydrocarbon-soluble thiophosphoro derivatives of alkyl phenol, alcohols and fatty esters, in order to establish relationships between the reactivity, chemical nature and crystal structure of films formed on rubbing surfaces, and antifriction and antiwear characteristics. Molybdenum salts of various phosphorothio derivatives of pentadecylphenol and lauryl oleate of specific structures have been synthesised, and the friction and wear properties of their blends in mineral oil base stock have been studied. It can be clearly inferred from the results that type of bonding between sulphur, phosphorus and molybdenum, and reactivity of these derivatives with rubbing surfaces, determine their friction-reducing and antiwear characteristics. Their reactivity with iron and the nature of films formed are under investigation.     

5-甲基-1-芳基-1,2,3-三唑衍生物的合成研究

1,2,3-三唑衍生物具有良好的生物活性,鉴于这一性质,设计了由芳基胺合成1,2,3-三唑衍生物的路线,合成了6种5-甲基-1-芳基-1,2,3-三唑衍生物.目标产物结构经核磁共振谱、质谱确认,并测定了其中部分化合物的单晶结构.希望在此基础上,进一步研究1,2,3三唑衍生物的生物活性.     

几种新型吡啶腙类Schiff碱配体的合成

分别以6-溴吡啶-2-甲酸和3-腈基-4-甲基-2,6-二氯吡啶为原料,经过酰胺化、肼取代、缩合等反应合成4种新型吡啶腙类Schiff碱有机配体:N-苯基-2-甲酰胺-6-肼吡啶缩水杨醛;N-苯基-2-甲酰胺-6-肼吡啶缩香草醛;N-苯基-2-甲酰胺-6-肼吡啶缩对羟基苯甲醛;3-腈基-4-甲基-2,6-二肼吡啶二缩水杨醛。通过红外光谱、核磁共振谱对其结构进行了表征。     

高效液相色谱法同时测定紫草素及其衍生物

建立了高效液相色谱法同时测定紫草中的紫草素、去氧紫草素、异丁酰基紫草素、β,β-二甲基丙烯酰基紫草素、异戊酰基紫草素和2-甲基正丁酰基紫草素等萘醌类衍生物含量的方法。该方法简便、快速、线性范围宽、适应性好,可用于对紫草药材及紫草提取物中的萘醌类衍生物的含量测定和质量控制。     

壳聚糖及其衍生物在果蔬贮藏保鲜中的应用

壳聚糖是生物界中唯一大量存在的天然碱性多糖,无毒无味、可生物降解、生物相容性好、成本较低,具有优良的分散性、保湿性、成膜性、抗菌性等诸多优点。文中介绍了壳聚糖及其衍生物保鲜果蔬的机理,综述了壳聚糖及其衍生物在果蔬贮藏保鲜中的最新进展,分析了目前研究中存在的问题并对发展方向作出展望。