刺桐属植物的生物碱类成分及药理作用的研究进展

刺桐属(Erythrina)植物的主要化学成分有生物碱和黄酮。其中生物碱类成分的结构类型主要是6-5-6-6环系刺桐烷类生物碱,药理作用主要有抗焦虑,促进睡眠,抗痉挛,杀虫和抗乙酰胆碱酯酶作用。本文对此属中分离得到的刺桐生物碱及其药理作用的研究现状进行综述,为今后对此属植物的进一步研究提供参考依据。     

琴叶榕根和叶的化学成分初步研究

通过化学反应鉴别法对琴叶榕根和叶的化学成分类型进行初步分析,发现琴叶榕根和叶中均含有酚类、蒽醌类、强心苷类,根可能含有生物碱,叶中不含有生物碱;叶含有黄酮,根可能含有黄酮,实验结果表明同种植物不同部位所含的化学成分是不同的。这些结果将为后续琴叶榕的化学成分研究提供一定的参考依据以及完善桑科榕属属植物化学分类学具有重要意义。     

木榄属植物的化学成分研究进展

从木榄属植物海莲、尖瓣海莲、柱果木榄中分离获得的化学成分主要有二萜、三萜、酚类、含硫化合物、生物碱类化合物等。其中一些化学成分显示了抗肿瘤等药理活性。本研究就近几十年来这几种木榄属植物的化学成分研究进行综述。     

南药大果榕抗骨质疏松研究

目的:对南药大果榕的化学成分及抗骨质疏松研究进行探讨。方法:查阅近年来的有关文献。结果:榕属植物种类较多,资源丰富,目前国内外对榕属植物大果榕化学成分的报道较多。结构类型主要包括三萜类、黄酮类、生物碱类等。生物活性研究显示,大果榕具有抗骨质疏松和抗氧化等作用。结论:南药大果榕对抗骨质疏松有显著作用,对其进一步研究和开发将具有重要意义。     

茉莉花叶化学成分的预实验

对广西茉莉花叶的化学成分进行预实验研究。采用化学成分鉴别法分别对广西产茉莉花叶乙醇提取液、水提取液和石油醚提取液进行化学成分预实验。通过预实验,提示广西产茉莉花叶中可能含有黄酮类、酚类、香豆素类、挥发油、植物甾醇、糖类、苷类、鞣质、有机酸、生物碱等化学成分。此试验为进一步进行该植物的生物活性成分研究提供了实验基础。     

风吹楠属植物化学成分及活性研究进展

为了全面了解和综合利用风吹楠属植物,本文对风吹楠属植物的化学成分和药理活性研究进展进行了综述。目前风吹楠属植物研究所涉及的种类仅5种,从中共分离到40个化学成分,包括黄酮、色原酮、木脂素、生物碱、芳基酮等结构类型。活性研究表明,一些化学成分具有明显的细胞毒活性和抗疟疾活性。开展风吹楠属植物的研究,对发现新的药用活性成分及资源保护具有重要的意义。     

鸡骨草茎化学成分的预试验

通过预实验,初步探索鸡骨草茎的化学成分。采用化学反应鉴别法分别对鸡骨草茎水提取液、乙醇提取液和石油醚提取液进行化学成分预试验。预试验项目中的多肽、蛋白质、氨基酸、糖类、苷类、有机酸、黄酮类、酚类、香豆素类、强心苷、植物甾醇、生物碱、挥发油项目均出现正反应现象,其他项目出现负反应现象。通过实验,可发现鸡骨草茎中可能含有多肽、蛋白质、氨基酸、糖类、苷类、有机酸、黄酮类、酚类、香豆素类、强心苷、植物甾醇、生物碱、挥发油这些化学成分。通过试验为进一步进行该植物的生物活性成分研究提供了基础。     

水杨梅化学成分和生物活性的研究现状

从茜草科水团花属植物水杨梅中分离得到的化合物达到50种以上,主要为三萜以及三萜皂苷类、色酮类、生物碱类化合物等。艾纳香属植物主要有抑菌活性,抗病毒、抗肿瘤的活性。文章主要介绍瑶药水杨梅在化学成分和生物活性的研究现状。     

药用植物中乙酰胆碱酯酶抑制剂研究进展

众多学者对植物中治疗老年性痴呆的化学成分进行了大量研究,发现了一些具有乙酰胆碱酯酶抑制的活性成分,主要为生物碱、萜、黄酮和香豆素等结构类型的化合物。其中生物碱类乙酰胆碱酯酶抑制剂如石杉碱甲、加兰他敏等因活性高、选择性强而受到广泛的关注。进一步开展药用植物中乙酰胆碱酯酶抑制活性成分研究,寻找新作用机制的化合物对发现新的治疗老年性痴呆的药用成分有重要意义。     

蜡梅属生物碱成分及生物活性研究进展

蜡梅属生物碱是从蜡梅属植物中分离得到,因其结构新颖、种类丰富、生物活性较高而成为化学家关注的焦点。综述了蜡梅属生物碱的主要化学成分及生物活性研究进展,拟为蜡梅属生物碱的合理开发与利用提供参考。     

微波消解—原子吸收光谱法测定蓬莱葛中的金属元素

采用微波消解对中草药蓬莱葛进行消解,并在火焰原子吸收光谱仪器最佳工作条件下,用标准曲线法测定其所含锌、铁、铜、钙、铅5种金属元素的含量。结果表明,方法检出限均小于0.0022μg/mL,加标回收率92.2%~110.0%,相对标准偏差RSD≤6.47%。     

氮化物对柴油加氢脱硫影响的研究进展

分别从催化剂,工艺条件等方面介绍了氮化物对柴油加氢脱硫反应(HDS)影响的机理。介绍了氮化物对柴油HDS反应影响的动力学研究。结果表明:氮化物对柴油HDS反应具有抑制作用;在不同催化剂活性中心上和不同的工艺条件下氮化物对柴油HDS反应的影响存在差异且符合于拟一级反应动力学。氮化物对柴油HDS的影响研究,可以指导高活性催化剂的开发,寻求最优柴油HDS反应工艺。     

Differences in Effects of Pyrrolizidine Alkaloids on Five Generalist Insect Herbivore Species

The evolution of the diversity in plant secondary compounds is often thought to be driven by insect herbivores, although there is little empirical evidence for this assumption. To investigate whether generalist insect herbivores could play a role in the evolution of the diversity of related compounds, we examined if (1) related compounds differ in their effects on generalists, (2) there is a synergistic effect among compounds, and (3) effects of related compounds differed among insect species. The effects of pyrrolizidine alkaloids (PAs) were tested on five generalist insect herbivore species of several genera using artificial diets or neutral substrates to which PAs were added. We found evidence that structurally related PAs differed in their effects to the thrips Frankliniella occidentalis, the aphid Myzus persicae, and the locust Locusta migratoria. The individual PAs had no effect on Spodoptera exigua and Mamestra brassicae caterpillars. For S. exigua, we found indications for synergistic deterrent effects of PAs in PA mixtures. The relative effects of PAs differed between insect species. The PA senkirkine had the strongest effect on the thrips, but had no effect at all on the aphids. Our results show that generalist herbivores could potentially play a role in the evolution and maintenance of the diversity of PAs.     

Effects of thermally oxidized triglycerides on the oxidative stability of soybean oil

Soybean oil purified by silicic acid column chromatography did not contain peroxides, free fatty acids, phospholipids or oxidized polar compounds. The purified soybean oil was thermally oxidized at 180°C for 96 hr in the presence of air. The thermally oxidized compounds (31.3%) were separated from the purified soybean oil by gradient elution silicic acid chromatography. Thermally oxidized compounds contained hydroxyl groups, carbonyl groups andtrans double bonds according to the infrared spectrum. Thermally oxidized compounds were added to soybean oil and purified soybean oil at 0, 0.5, 1.0, 1.5 and 2.0% to study the effects of these compounds on the oxidative stability of oil. The oxidative stabilities of oils were determined by gas chromatographic analysis of volatile compound formation and molecular oxygen disappearance in the headspace of oil bottles. The thermally oxidized compounds showed prooxidant effects on the oxidative stabilities of both refined, bleached and deodorized soybean oil and purified soybean oil. Duncan’s Multiple Range Test showed that thermally oxidized compounds had a significant effect on the volatile compound formatiion and oxygen disappearance in the headspace of oil at α=0.05.     

稀土氧化物和硫酸盐对聚氯乙烯热稳定作用的研究

本文着重研究了不同稀土无机化合物对聚氯乙稀热稳定性的影响,并对其作用机理进行了初步探讨。     

工程用聚合物基复合材料摩擦行为研究进展

综述了复合改性聚合物材料摩擦磨损性能研究发展 ,主要分析了纤维、金属及其化合物、无机非金属化合物及聚合物填料对材料摩擦性能的影响和作用机理 ,以及工况条件及摩擦磨损形式对材料摩擦行为的影响 ,简述了复合材料摩擦行为模拟及预测的研究现状及研究中存在的问题 ,进一步探讨了材料摩擦行为模拟和预测的可能性。     

Effects of organic nitrogen compounds on hydrotreating and hydrocracking reactions

A major issue encountered in hydrotreating and hydrocracking reactions, as in many others fixed bed catalytic processes, is the decrease of catalytic activity with time on stream. The organic nitrogen compounds act as temporary poisons in hydroprocessing catalysts besides being coke precursors. The inhibiting effects of nitrogen compounds present in crude oil have been studied on SRGO hydrotreating reactions and VGO hydrocracking reactions. The results show that selective removal of nitrogen by adsorption using silica and alumina in varying proportions, would not only increase the HDS catalyst activity by more than 60%, but would also reduce hydrogen consumption. This step of nitrogen removal can be installed additionally in the upstream of an existing SRGO HDS reactor to achieve higher desulphurization or can be designed with the grass roots units.

The inhibition effects of nitrogen on VGO hydrocracking have been studied at different temperatures and the reaction has been found to be highly non-linear in nature and the conversion rapidly drops and the slope becomes less steep as the nitrogen level increases. At higher reaction temperature, the drop in activity or conversion with feed nitrogen is less than that in lower temperatures due to the higher rate of desorption of nitrogen compounds at elevated temperatures. The drop in conversion with nitrogen compounds present in VGO indicates the presence of organo nitrogen compounds having higher basicity compared to the nitrogen compounds by pyridine doping. The hysteresis exists in adsorption/desorption of nitrogen compounds and it indicates that desorption is a very slow process. With the increase of nitrogen compounds in the feed, the conversion drops rapidly and it takes long time to reach an equilibrium value. Similarly, with the step increase in reactor temperature, nitrogen desorption takes place at a slow rate and the conversion level comes to an equilibrium value after 8 days.

The observed effects of nitrogen inhibition on SRGO hydrotreating and VGO hydrocracking conversion are explained reasonably well by kinetic models.     

吲哚类衍生物理论研究进展综述

简要介绍了吲哚类衍生物密度泛函理论研究进展,重点评述理论化学方法在吲哚类衍生物的理化性质、计算方法以及化合物结构和性质的主要影响,并介绍了目前这类化合物最常出现的部分理论化学方法。     

渣油中硫化物的测定方法研究进展

渣油中硫化物的存在对石油加工和石油生产带来很多不利条件,渣油中的主要硫化物为硫醚硫和噻吩硫,总硫与硫醚硫的差值即为噻吩硫。对硫化物定量研究,可以为渣油加工提供理论依据和数据基础。本文概述了渣油中硫醚硫的测定方法,并对各种方法的优缺点进行了讨论,在实际应用中应结合实际条件选择合适的方法对硫化物进行研究。     

高级脂肪酰胺基烷基咪唑啉合成工艺条件的研究

本文合成了三种高级脂肪酰胺基烷基咪唑啉中间体,利用正交试验,优化出最佳工艺条件,通过红外光谱与熔点测定确定咪唑啉中间体的结构,讨论了反应条件对高级脂肪酰胺基烷基咪唑啉中间体收率的影响。