枯草芽孢杆菌防治柑桔青绿霉病初报

室内平皿抑菌测定和果实处理试验初步结果表明,枯草芽孢杆菌对柑桔青绿霉具有较强的抑菌作用,能减少果实贮藏过程中病害的发生。     

明胶/纳米SiO2复合膜的体外抑菌试验

本实验测定了明胶、纳米SiO2、明胶/纳米SiO2复合膜对6种供试菌的抑菌效果,结果表明,明胶不具有抑菌作用;纳米SiO2对供试菌具有较好的抑茵效果;20种明胶/纳米SiO2复合膜材料中,有11种复合膜对供试菌具有较强的抑菌效果.用琼脂平板稀释法测定了具有较强抑菌作用复合膜的最低抑菌浓度(MIC),结果表明,最低抑菌浓度因膜的配比和菌种类型的不同而有所差异,为16.0 mg/mL～256.0 mg/mL.复合膜对蜡样芽孢杆菌的最低抑菌浓度(MIC)最大(256.0 mg/mL),而对其他供试菌相对较低,为64.0 mg/mL～128.0 mg/mL.     

苦豆籽中抑菌活性物质的跟踪筛选研究

目的:对苦豆籽中抑菌活性物质进行跟踪筛选。方法:采用溶剂萃取法获得苦豆籽不同极性溶剂萃取的浸膏,对其浸膏及实验室自制单体类化合物通过纸片扩散法(K-B)法进行抑菌试验研究。结果:苦豆籽粗提物对实验所用菌种都有不同程度的抑制作用,尤其是氯仿浸膏中可能含大量生物碱,因此表现出强的抑菌效果;苦豆籽单体类化合物对实验所用菌种都具有较强的抑制作用,苦参碱的抑菌效果最好。结论:苦豆籽中主要抑菌成分为生物碱类化合物,其中苦参碱的抑菌效果优于氧化苦参碱。     

亳芍总生物碱提取及抑菌活性的研究

为了探讨亳芍总生物碱提取条件及其抑菌活性,在前期研究基础上,通过单因素和正交实验对亳芍总生物碱的提取条件进行了研究。采用滤纸片法对亳芍总生物碱提取物对大肠杆菌、金色葡萄球菌酵母菌及黑曲霉菌的体外抑菌活性进行初步测定。结果表明,亳芍总生物碱最佳提取条件为:乙醇浓度为60%,提取时间为3 h,提取温度为60℃,料液比为1∶20。此条件下,测得亳芍总生物碱的含量为0.58‰,提取的总生物碱对大肠杆菌、金色葡萄球菌及酵母菌、黑曲霉菌均有抑制作用,但抑菌效果不同,抑菌作用顺序为:金色葡萄球酵母菌黑曲霉菌菌大肠杆菌。     

亳芍总生物碱提取及抑菌活性的研究北大核心CSCD

为了探讨亳芍总生物碱提取条件及其抑菌活性,在前期研究基础上,通过单因素和正交实验对亳芍总生物碱的提取条件进行了研究。采用滤纸片法对亳芍总生物碱提取物对大肠杆菌、金色葡萄球菌酵母菌及黑曲霉菌的体外抑菌活性进行初步测定。结果表明,亳芍总生物碱最佳提取条件为:乙醇浓度为60%,提取时间为3 h,提取温度为60℃,料液比为1∶20。此条件下,测得亳芍总生物碱的含量为0.58‰,提取的总生物碱对大肠杆菌、金色葡萄球菌及酵母菌、黑曲霉菌均有抑制作用,但抑菌效果不同,抑菌作用顺序为:金色葡萄球>酵母菌>黑曲霉菌菌>大肠杆菌。     

杭黄菊提取物的体外抗菌活性研究

本文研究杭黄菊花水提物和醇提物对常见的人体肠道致病菌的抑菌活性。采用超声波提取法获得杭黄菊提取物,用琼脂扩散法测试该粗提物对受试菌的抑菌作用,并用倍比稀释法确定最小抑菌浓度。实验结果表明杭黄菊花水提物和醇提物对常见的7种肠道致病菌具有较强的抑制作用,尤其对变形杆菌、痢疾杆菌和伤寒杆菌的抑制作用较强。采用相同提取方法的高浓度提取物比低浓度提取物具有更显著(P0.01)的抑菌作用,而相同浓度的水提物比醇提物抑菌效果更为明显(P0.01),水提物对相同细菌的最低抑菌浓度(MIC)低于醇提物。杭黄菊提取物对肠道致病菌有明显的抑制作用,可被开发用于抗菌新药研制。     

青天葵体外抑菌活性研究

目的:研究青天葵水提取液、醇提取液和水醇提取液对金黄色葡萄球菌、大肠杆菌、白色念珠菌、伤寒沙门菌、绿脓杆菌、黑曲霉菌6种菌株的抑菌效果。方法:制备青天葵3种提取液,采用试管两倍稀释法测定3种提取液对金黄色葡萄球菌等6种菌株的最低抑菌浓度(MIC)。结果:青天葵水提取液对伤寒沙门菌的抑菌作用较强(MIC为12.5%),对金黄色葡萄球菌、大肠杆菌、绿脓杆菌和黑曲霉菌的抑菌作用较弱(MIC为50%);醇提取液对伤寒沙门菌和绿脓杆菌都有很强的抑菌作用(MIC为6.25%),对金黄色葡萄球菌也有较强的抑菌活性(MIC为12.5%),对大肠杆菌的抑菌作用较弱(MIC为50%);水醇提取液的抑菌活性与醇提取液相当。结论:青天葵对金黄色葡萄球菌等6种菌株表现出不同程度的抑制活性。     

响应面法优化豫西山茱萸叶黄酮的提取及其抑菌和抗氧化活性

通过响应面法对山茱萸叶黄酮的提取工艺进行优化,并对其体外抑菌和抗氧化活性进行研究。经优化后,山茱萸叶黄酮在超声功率290 W、液料比31∶1(mL/g)、乙醇体积分数61%、提取时间23 min的工艺条件下提取得率最高,达到6.31%,与模型预测值相符。抑菌实验结果表明山茱萸叶黄酮对沙门氏菌有较强的抑菌作用,对绿脓杆菌、金黄色葡萄球菌和中华根霉有较弱的抑菌作用,说明山茱萸叶黄酮对细菌有较强的抑菌作用,对真菌有较弱的抑菌作用。山茱萸叶黄酮浓度为1.2 mg/mL时其对DPPH自由基的清除率为77.24%,对羟基自由基的清除率达到83.54%;山茱萸叶黄酮清除DPPH自由基和羟基自由基的IC_(50)分别为0.699和0.631 mg/L,表明山茱萸叶黄酮具有较强的抗氧化活性。     

芦荟抑菌成份的筛选提取及其活性的比较分析

目的：对传统上用于治疗作用的6个不同品种芦荟的蒽甙（蒽衍生物）进行了提取,并进行了抑菌作用的比较研究。方法：琼脂扩散法。结果：从叶皮中提取的有效成分表现出不同程度的抑菌活性,而叶肉提取物几乎没有抑菌效果。其中,龙山芦荟,皂质芦荟和木立芦荟的叶皮提取物对革兰阴性菌和革兰阳性菌均具有较强的抑菌能力,而且这种抑菌活性与蒽醌成分呈正相关性。     

硼类化合物在滴眼剂中抑菌效力的探讨

探讨硼类化合物(硼酸、硼砂)在滴眼剂中的抑菌效力。通过实验设计不同浓度的硼酸、硼砂供试品组,测定其抑菌效力。结果表明,在牛磺酸滴眼剂品种中,3组供试品组对真菌组达到抑菌效力的判断标准。但在细菌组中,3组供试品组未达到抑菌效力判断标准。在氯霉素滴眼剂中,白色念珠菌98001、金黄色葡萄球菌26003、铜绿假单胞菌10104组均满足抑菌效力的判断标准,但对大肠埃希菌44102未体现出明显抑菌作用。硼类化合物(硼酸、硼砂)在1 mg/m L剂量下即具有一定的抑菌效力。因此在滴眼剂处方设计时,硼类化合物抑菌效力需被正视,同时需结合配伍注意控制使用剂量。     

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.     

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。     

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.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

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.