水蒸气蒸馏法提取大蒜挥发油的工艺研究

以挥发油提取率为指标,通过单因素和L9(34)正交试验设计确定了水蒸气蒸馏法提取大蒜挥发油的最佳提取工艺及条件。结果表明,各因素作用主次顺序为蒸馏时间(D)>料液比(C)>发酵温度(A)>浸泡时间(B),各因子的最优组合为A2B2C2D3,即以1∶3.5的料液比(m∶V),在35℃时浸泡3h后蒸馏2h为大蒜挥发油的最佳提取工艺,此时挥发油的提取率达到0.32%,证明此方法是大蒜挥发油提取的可靠、易行的科学方法。     

超声辅助提取华细辛挥发油中甲基丁香酚工艺优化

采用内标法测定甲基丁香酚的含量,在单因素试验基础上设计正交试验,研究浸泡时间、料液比、提取温度、提取时间对超声辅助提取(UAE)华细辛挥发油中甲基丁香酚提取率的影响.结果表明:最佳提取条件为:浸泡时间3h,料液比1∶40(g/mL),提取温度60℃,提取时间40 min,经3次平行实验验证,此条件下的甲基丁香酚平均得率为0.661％,比正交实验任意组得率高,该超声辅助提取工艺稳定可靠.     

正交试验法优选舒心胶囊原料药中挥发油的提取工艺

目的:探索舒心胶囊原料药中挥发油的提取工艺.方法:采用高效液相色谱法,用70%甲醇回流提取制样用作阿魏酸含量测定的方法学考察;用水蒸气蒸馏法提取挥发油,以挥发油提取率和阿魏酸含量为指标,采用L9(34)正交试验设计,筛选挥发油的最佳提取工艺.结果:舒心胶囊原料药中阿魏酸含量为0.070%.影响提取的主次因素为:浸泡时间>加水量>提取时间;优选得到的最佳提取条件为:药材不必浸泡,加10倍量水(v/w)后提取3h.结论:该工艺准确、稳定,重复性好.     

石甘散散剂挥发油的提取工艺研究

目的:探讨石甘散散剂挥发油提取工艺,优选石甘散散剂挥发油提取方法,确定提取的最佳工艺条件。方法:利用正交试验法,以水蒸气蒸馏法提取石甘散挥发油,计算挥发油得率;并用高效液相色谱法,以面积归一化法计算石甘散挥发油中β-细辛醚的含量为指标,研究石甘散挥发油提取工艺中的影响因素;对提取时间、浸泡时间和加水量三个影响因素的试验结果进行分析,计算不同因素影响下的石甘散散剂挥发油得率及β-细辛醚的含量,从而优选出石甘散挥发油最佳提取工艺。结果:影响石甘散挥发油得率及β-细辛醚含量的最主要因素为提取时间,其次为加水量,再者为浸泡时间。结论:通过这三个因素影响下的正交试验结果,筛选出的石甘散散剂挥发油最佳提取工艺为加水量10倍,浸泡时间1小时,提取时间8小时。该提取工艺简单易行、合理稳定,为石甘散散剂挥发油的最佳提取工艺条件。     

菊芋叶总黄酮提取工艺优化及含量动态变化

以菊芋叶为原料,研究了甲醇体积分数、提取温度、提取时间、固液比等因素对菊芋叶总黄酮含量的影响,在单因素试验的基础上,以L9(34)正交试验方法优化总黄酮提取工艺,然后在该工艺条件下研究不同采收时期对菊芋叶总黄酮含量的影响。结果表明:甲醇体积分数、提取温度、提取时间、固液比对菊芋叶总黄酮提取含量均有影响,最佳工艺组合为:用体积分数70%的甲醇,固液比1:30(g/mL),80℃条件下提取2 h,在此条件下,菊芋叶总黄酮含量为7.03%。采收时间对菊芋叶总黄酮含量影响较大,9月份总黄酮含量最高。     

千年健总黄酮的超声提取工艺

为了研究千年健黄酮的超声提取工艺,通过单因素实验,研究了超声功率、超声时间、乙醇浓度、液固比等因素对黄酮得率的影响,利用正交试验对提取工艺进行优化。结果表明,各因素的影响次序为:超声功率乙醇浓度液固比超声时间,其最佳提取工艺条件为:超声功率为300W、超声时间15min、乙醇浓度50%、液固比30:1,最佳工艺条件下黄酮提取率为0.5868%。     

响应曲面法优化马尾松中莽草酸的超声提取工艺

以马尾松松针为原料,采用超声波提取法从松针粉中提取莽草酸,通过考察料液比((VH2O∶m松针粉,mL:g)、提取时间、提取温度及超声波功率等因素对松针中总莽草酸含量的影响,并在单因素试验的基础上,选取料液比、提取时间、超声波功率3个变量,进行Box-Behnken中心组合设计优化,获得马尾松松针中莽草酸的最佳提取工艺参数为料液比1∶26,提取时间为46min,超声波功率为359 W,此条件下莽草酸的提取率为1.948%。     

大黄中大黄酸提取工艺研究

以大黄酸含量为参考指标,通过单因素实验分别考察硫酸浓度(A)、液料比(B)、提取加热时间(C)、提取加热温度(D)对大黄中大黄酸提取量的影响,并根据单因素试验结果设计正交试验。结果表明,影响大黄中大黄酸提取工艺的主次因素为:加热温度D>加热时间C>硫酸浓度A>液料比B,大黄中大黄酸的最佳提取工艺为:15%硫酸、5∶1液料比、55℃加热回流2.5 h。此法操作性强,优选出最佳提取工艺条件,为开发大黄中泻下有效部位提供了理论依据。     

超声法提取菝葜中总黄酮的正交实验研究

目的:对超声法提取菝葜中总黄酮的工艺进行优化.方法:利用超声法提取菝葜中的总黄酮,考察了超声时间、超声功率、乙醇浓度、固液比4个因素对总黄酮得率的影响,通过单因素试验和正交试验确定了提取的最佳工艺条件.结果:最佳提取工艺为超声功率250W、40KHz,超声时间30 min,乙醇浓度80%,液固比30.     

乌药超声提取工艺的研究

目的:用超声波法提取乌药有效成分,优化提取工艺条件.方法:以醚内醇为考察对象,通过研究超声波条件下影响浸提的几个因素,包括提取次数、超声后浸泡时间、超声时间、超声功率等,并通过单因素试验优化了工艺条件.结果:确定了超声前浸泡时间45 min、超声功率600 w、超声时间13.2 min、液固比10∶1、超声后浸泡时间1...     

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.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

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.