番石榴叶中总黄酮最佳提取条件的探讨及其抑菌作用的研究

设计正交实验,采用超声波法从番石榴叶中提取总黄酮,综合各因素确定最佳提取条件为乙醇浓度40％,固料比（番石榴干叶：浸提剂）=1g：60mL,浸泡25h超声波处理时间50min,获得提取液总黄酮含量为9．9167％。采用牛津杯法做抑菌实验,结果表明番石榴叶和果实的水提、醇提粗提液对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、阴沟肠杆菌、溶血葡萄球菌等均有很好的抑菌效果。叶和果实的总黄酮提取液的抑菌作用也很明显。番石榴有望作为药食同源产品和天然食品防腐剂进行开发利用。     

淫羊藿总黄酮的超声辅助提取及其抗氧化活性

利用超声波辅助乙醇提取淫羊藿中的总黄酮,通过单因素和正交试验法获得最佳工艺条件后,考察黄酮提取物对油脂的抗氧化性能及对·OH的清除效果.结果表明:体积分数70％的乙醇、料液比(g/mL) 1:30、超声提取时间30 min、超声温度50℃时为最佳条件,得到淫羊藿提取物中总黄酮质量分数为2.246％.淫羊藿总黄酮对·OH清除效果随浓度的增大而升高,对油脂氧化亦有较强的抑制作用.     

莲子心总黄酮的超声波萃取工艺研究

研究了超声波萃取法从莲子心中提取总黄酮的最佳工艺。通过单因素控制法和正交试验,以乙醇为溶剂,总黄酮提取率为考察指标,在超声波辅助下研究了乙醇浓度、提取时间、料液比和提取温度对总黄酮提取率的影响。结果表明影响莲子心中总黄酮提取率的主要因素是乙醇的浓度,其次依次为提取温度、料液比、超声波萃取时间;提取的最佳条件是:乙醇的浓度为60%,提取温度是70℃,料液比为1:24,超声波萃取时间为30 min,此条件下得到的总黄酮的提取率是10.86 mg/g。     

青牛胆总黄酮的对比提取研究

采用分光光度法对青牛胆块根中总黄酮进行超声波法、浸提法和微波法比较提取研究.以总黄酮提取率为考察对象,研究提取温度、乙醇体积分数、料液比及提取时间等因素对青牛胆块根中总黄酮提取率的影响.结果表明:最佳提取方法为浸提法,最佳提取条件:乙醇体积分数60％,提取温度90℃,料液比1∶30,提取时间4h,总黄酮提取率6.294 mg/g.     

不同黄秋葵花中总黄酮的提取和含量测定

通过对超声波法、水浴法、水浴超声波法、水浴微波法四种不同方式辅助提取黄秋葵花中总黄酮的方法进行比较,确定以水浴超声波法辅助提取测定黄秋葵花中总黄酮效果较好.采用紫外可见分光光度法,以芦丁为标准品,样品总黄酮在0.00 ～0.067 mg/mL范围内线性良好,其回归方程为y=12.046x-0.0015,R2 =0.9993.采用水浴超声波法辅助提取、硝酸铝显色法测定11个湘葵品系的样品花中总黄酮含量,结果表明：在11种黄秋葵花样品中,湘葵3号的花中总黄酮含量最高,为5.29％,湘葵8号的花中总黄酮含量最低,为1.70％.上述研究结果为黄秋葵的质量评价及今后的产业化研究提供新思路.     

银杏叶总黄酮的超声波提取法

本文通过单因素实验和正交实验,确定了超声波法提取银杏叶中黄酮类化合物的最佳提取工艺,并与常规乙醇浸提法,微波提取法作了比较研究。实验表明：超声波提取法优于常规乙醇浸提法和微波提取法。超声波法的最佳操作条件为：320W超声波功率,温度30℃,70％乙醇,在液固比15：1条件下提取10min,连续提取2次,总黄酮提取率可达94．1％。     

八角叶总黄酮的提取及其捕获自由基作用研究

目的:为八角叶资源的合理开发和利用提供科学依据。方法:分别以乙醇、石油醚、水等作提取溶剂,用超声波与非超声波对比提取八角叶总黄酮,考察在不同温度、溶剂浓度、超声波功率、提取时间等不同条件下用超声波/乙醇浸提法提取八角叶总黄酮,对所提取的黄酮类物质进行验证,并用分光光度法测定含量,用八角叶总黄酮对羟自由基清除作用进行试验。结果:超声波乙醇浸提法提取八角叶总黄酮的最佳工艺条件为:溶剂90%乙醇,温度80℃,超声波功率60 W,提取时间3.0 h。百色、南宁、贺州、河池、钦州所产八角叶总黄酮的含量分别为0.1649mg/mL、0.1022 mg/mL、0.1122 mg/mL、0.1850 mg/mL、0.1693 mg/mL,八角叶总黄酮提取液对Fenton体系产生的.OH自由基有很好的清除作用。结论:超声波乙醇浸提法提取八角叶总黄酮的效果最佳,产总黄酮含量最高,提示八角叶具有较高的开发利用价值。     

扁蓄总黄酮提取方法的比较研究

目的:筛选扁蓄总黄酮的最佳提取方法和提取工艺.方法:以扁蓄总黄酮的提取率为指标,分别采用乙醇回流法、超声波法和微波法提取扁蓄总黄酮,通过正交试验对提取工艺中的温度、固液比、提取功率及时间等技术参数进行考察,使用分光光度法测定扁蓄总黄酮含量.结果:回流提取扁蓄总黄酮提取率为1.09%,超声波提取扁蓄总黄酮的最佳条件为温度80℃,固液比1:10,功率700 W,提取2次,每次20 min,提取率为1.67%,微波法提取扁蓄总黄酮的最佳条件为温度100℃,功率700 W,固液比1:20,提取2次,每次10min,提取率为1.98%.结论:微波提取法提取扁蓄总黄酮具有高效、省时、节能等优点,在中药提取中有良好的应用前景.     

节节草黄酮类化合物的提取及抑菌活性研究

目的：研究节节草地上部位黄酮类化合物的提取方法,并对提取物进行了抑菌试验。方法：比较各种提取方法,通过显色反应、沉淀反应和抑菌实验作用于该提取物。结果：索氏提取法总黄酮得率为0．749％,超声波辅助提取法居次。显色反应呈阳性,沉淀反应生成明显的沉淀;在抑菌实验中产生明显的抑菌圈。结论：超声波辅助提取法是提取节节草总黄酮的比较理想的方法,该植物含有较为丰富的黄酮类化合物,节节草黄酮类化合物对大肠杆菌、八叠球菌等具有明显的抑菌作用。     

吉林长白山刺五加总皂苷超声提取工艺研究

以吉林长白山野生刺五加果实为原料,采用正交试验设计通过香草醛—高氯酸显色法对不同超声处理条件下刺五加果实粗提物中总皂甙得率进行测定,优化野生刺五加果实总皂甙超声提取工艺.结果表明:超声提取吉林长白山野生刺五加果实总皂甙的最佳工艺条件为料液比1∶20、乙醇体积分数70％、超声波功率450W、超声提取时间50 min,测得刺五加粗提物中总皂甙含量为3.57 mg/g,该提取方法简便、快捷,可用于长白山野生刺五加果实总皂甙提取和测定.     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。