69 resultados para Bioactive


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Among marine bacteria isolated from the cytotoxic sponge Hymeniacidon perleve, one strain NJ6-3-1 classified as Pseudomonas sp. showed both cytotoxic and antimicrobial activities. Fatty acid analysis indicated that the bacterial strain consists mainly of C16:1, C16:0, C18:1, C18:0, C15:0, C14:0. One unusual 9,10-cyclopropane-C17:0 fatty acid and C26:0 also constitute major components, as well as the existence of squalene, the precursor of triterpenoids. The major metabolites in the culture broth were identified as alkaloids, including diketopiperazines and indole compounds, namely 3,6-diisopropylpiperazine-2,5-dione, 3-benzyl-3-isopropylpiperazine-2,5-dione, 3,6-bis-(2-methylpropyl)-piperazine-2,5-dione, indole-3-carboxaldehyde, indole-3-carboxylic acid methyl ester, indole-3-ethanol, and quinazoline-2,4-dione.

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Biofingerprinting chromatogram, analysis, which is defined as the comparison of fingerprinting chromatograms of the extract of traditional Chinese medicines (TCMs) before and after the interaction with biological systems (DNA, protein. cell. etc.), was proposed for screening and analysis of the multiple bioactive compounds in TCMs. A method of microdialysis sampling combined with high performance liquid chromatography (HPLC) was applied to the study of DNA-binding property for the extracts of TCMs. Seven compounds were found to bind to calf thymus DNA (ct-DNA) from the TCMs of Coptis chinensis Franch (Coptis), but only three ones from Phellodendron amurense Rupr. (Phellodendron) and none from Sophoraflavescens Ait. (Sophora) to bind to ct-DNA. respectively. Three of them were identified as berberine, palmatine and jatrorrhizine and their association constants (K) to ct-DNA were determined by microdialysis/HPLC. Competitive binding behaviors of them to ct-DNA were also investigated. © 2005 Elsevier B.V. All rights reserved.

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Protein-Chip as micro-assays for the determination of protein interaction, the analysis, the identification and the purification of proteins has large potential applications. The Optical Protein-Chip is able to detect the multi-interaction of proteins and multi-bio-activities of molecules directly and simultaneously with no labeling. The chip is a small matrix on solid substrate containing multi-micro-area prepared by microfabrication with photolithography or soft lithography for surface patterning, and processed with surface modification which includes the physical, chemical, and bio-chemical modifications, etc. The ligand immobilization, such as protein immobilization, especially the oriented immobilization with low steric hindrance and high bio-specific binding activity between ligand and receptor is used to form a sensing surface. Each area of the pattern is corresponding to only one bioactivity. The interval between the areas is non-bioactive and optically extinctive. The affinity between proteins is used to realize non-labeling microassays for the determination of protein identification and protein interaction. The sampling of the chip is non-disturbing, performed with imaging ellipsometry and image processing on a database of proteins.

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水母雪莲(Saussurea medusa Maxim.)和新疆雪莲(Saussurea involucrata Karel. et Kir.)是我国珍稀的药用植物资源,具有清热解毒、止痉镇痛、敛伤、消肿及治疗热病、风湿等多种功效。雪莲的主要药用成份为紫丁香甙(Syringin)、芦丁(Rutin)、高车前素(Hispidulin)和Jaceosidin等苯基丙酸类(phenylpropanoid)和黄酮类(flavonoids)物质。最新的药理研究表明,上述物质还具有抗菌消炎、保肝降压、延缓衰老和抑制癌细胞增殖等重要的研发价值。 雪莲生境恶劣,生长缓慢,人工引种困难,加上长期掠夺性采挖,已使雪莲处于灭绝的边缘。为了保存国家珍稀植物品种,保护生态环境,满足临床上对雪莲药物的需求,本研究在雪莲组织培养的基础上,应用诱导子添加技术和毛状根培养技术对雪莲中具有重要药用价值的次生代谢物质进行调控,并对雪莲MYB类转录因子的功能进行了初步探索,为保护珍稀植物资源、维护生态环境、开发野生雪莲替代产品、缩短雪莲药用成份的生产周期奠定了基础。另外,分析了野生雪莲和雪莲培养物中主要生物活性成份的种类及含量,为今后雪莲药理药效研究及品质评价奠定了基础。 为了提高雪莲黄酮的产量,满足工业化生产的需要,在细胞培养水平上,通过添加茉莉酸甲酯(MJ),对雪莲黄酮类物质的代谢进行调控。研究了诱导子的添加时间、添加浓度对水母雪莲红色系悬浮细胞的生物量和总黄酮产量的影响。发现在细胞培养的指数期(第9天)添加5.0 µmol/L的MJ,可以使总黄酮产量提高2.4倍(1134.5 ± 63.86 mg/L),而雪莲细胞干重(dw)仅比对照提高23.8 %(20.4 ±0.27 g/L)。另外,细胞中苯丙氨酸裂解酶(PAL)的活性分析表明,MJ添加后PAL活性的增加与雪莲总黄酮含量增长之间存在相关性。 在器官培养水平上,对雪莲毛状根的诱导频率及其培养条件进行了研究。结果表明,选择发根农杆菌R1601侵染预培养2天的新疆雪莲根段外植体,毛状根的诱导效率可达到83 %。毛状根的冠瘿碱检测、PCR和Southern分析表明,Ri质粒中的T-DNA已整合到植物基因组中并稳定表达。以新疆雪莲毛状根为外植体,能够容易地获得再生芽。在含有1.0 mg/L 6-BA的MS固体培养基上,其再生频率高达91 ± 5.9 %,是其正常根的2.4倍。而水母雪莲在该培养条件下,仅有少量的畸形芽出现。进而对毛状根的培养条件进行初步研究,结果表明在无激素附加的MS液体培养基中,新疆雪莲的HR1601根系在一个培养周期内(32 天),其生物量能够达到接种量的16倍,而紫丁香甙含量(43.5 ± 1.13 mg/g dw)能够达到野生雪莲的83倍。从而显示了雪莲毛状根培养体系的优良特性。 在基因水平上,对雪莲黄酮类物质代谢调控的研究已经展开。玉米P基因编码的Myb类转录因子能够调节黄酮类物质代谢途径关键酶基因的表达。根据P基因的保守序列设计引物,从雪莲细胞培养物中获得了SmP基因。核酸序列分析表明,SmP基因与烟草中涉及苯丙素类物质代谢途径的LBM 1、LBM 3和MybAS 1基因具有较高的一致性,分别为66 %、60 %和61 %。因此为了研究雪莲SmP基因的功能,构建了正义表达载体,并与先前构建好的反义表达载体分别导入烟草,分析了转基因植株的形态特征及黄酮类物质的含量变化。其中,约有30 %转反义SmP基因的株系表现叶片皱缩、叶脉紊乱、主侧脉角度缩小、叶片、花瓣失去对称性以及花粉败育等性状。 另外,通过正交试验设计优化了雪莲提取工艺的条件,并对雪莲细胞提取物进行了分离纯化。正交试验设计结果表明,温度对雪莲黄酮提取效率的影响极为显著,而分批多次提取比一次性浸提,能够收到较好的提取效果。考虑到工业生产中的实际问题,推荐在60 ℃水浴条件下,采用50 %乙醇对雪莲样品连续浸提2次的方案。对雪莲提取物的纯化研究表明,雪莲成份复杂,仅依靠单一的分离手段,往往难以奏效。另外,野生雪莲及雪莲培养物中生物活性成份的比色法、HPLC(High Performance Liquid Chromatography)、LC-ESI-MS(Liquid Chromotagraphy Electrospray Ionization Mass Spectrometry)分析表明,传统的NaNO2-AlCl3 法测定雪莲总黄酮的含量,结果偏高,不利于雪莲黄酮的实验室研究分析与今后工业化生产的质量监控。而AlCl3 法的显色反应较为特异,今后有望取代NaNO2-AlCl3 法,作为雪莲类药材品质评价的标准。而HPLC-DAD结合LC-ESI-MS可以对雪莲中的主要生物活性成份进行较为准确的定性分析,从而解决了由于缺乏相应的雪莲化合物标准品而难以对雪莲中的成份进行定性定量分析及比较的难题。最后综合利用上述分析方法,对雪莲细胞培养物中的花素类物质进行了分析。结果表明,雪莲细胞中至少含有7种花色素类物质,分别为矢车菊素-3-O-葡萄糖甙及其衍生物、天竺葵素糖甙衍生物和芍药色素糖甙衍生物。

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The hornet possesses highly toxic venom, which is rich in toxin, enzymes and biologically active peptides. Many bioactive substances were identified from wasp venom. Two families of antimicrobial peptides were purified and characterized from the venom of

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Amphibian skin is a rich resource of bioactive peptides like proline-rich bombesin from frog Bombina maxima. A novel cDNA clone encoding a precursor protein that comprises proline-rich bombesin and a novel peptide, designated as bombestatin, was isolated from a skin cDNA library of B. maxima. The predicted primary structure of the novel peptide is WEVLLNVALIRLELLSCRSSKDQDQKESCGMHSW, in which two cysteines form a disulfide bond. A BLAST search of databases did not detect sequences with significant similarity. Bombestatin possesses dose-dependent contractile activity on rat stomach strips. The differences between cDNAs encoding PR-bombesin plus bombestatin and PR-bombesin alone are due to fragment insertions located in 3'-coding region and 3'-untranslational region, respectively. (c) 2005 Elsevier B.V. All rights reserved.

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Amphibian skin secretions contain many bioactive compounds. In the present work, an irreversible serine protease inhibitor, termed baserpin, was purified for the first time from the skin secretions of toad Bufo andrewsi by Successive ion-exchange and gelfiltration chromatography. Baserpin is a single chain glycoprotein, with an apparent molecular weight of about 60 kDa in SDS-PAGE. Baserpin is an irreversible inhibitor and effectively inhibits the catalytic activity of trypsin, chymotrypsin and elastase. SDS-stable baserpin-trypsin complex could be seen in SDS-PAGE indicates that it possibly belongs to the serpin superfamily. According to the association rates determined, baserpin is a potent inhibitor of bovine trypsin (4.6 X 10(6) M-1 S-1), bovine chymotrypsin (8.9 X 10(6) M-1 s(-1)) and porcine elastase (6.8 X 10(6) M-1 s(-1)), whereas it shows no inhibitory effect on thrombin. The N-terminal sequence of baserpin is HTQYPDILIAKPXDK, which shows no similarity with other known serine protease inhibitors. (c) 2005 Elsevier Ltd. All rights reserved.

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Rubrifloradilactone C (4), a novel bioactive nortriterpenoid, along with four other nortriterpenoids (1-3, 5) were isolated from Schisandra rubriflora. The structure of 4 was determined by extensive NMR spectral analysis, computational evidence by using t

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A new nortriterpenoid, 20-hydroxymicrandilactone D (1) and a novel lignan glycoside, lancilignanside A (2) were isolated from leaves and stems of Schisandra lancifolia, together with three known nortriterpenoids (3-5) and nine known phenolics (6-14). The structures of new compounds 1 and 2 were determined by detailed analysis of their 1D and 2D NMR spectra, and chemical evidences. In addition, compounds 1-2, 6-7, and 9-11 showed anti-human immunodeficiency virus (HIV)-1 activities with 50% effective concentration (EC50) in the range of 3.0-99.0 mu g/ml. Compound 12 was not bioactive in this assay with EC50 more than 200 mu g/ml.

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Ovulation in the Bactrian camel depends upon ovulation-inducing factors in the seminal plasma. The present study was conducted to isolate and purify the bioactive fractions from the seminal plasma of these camels. The seminal plasma was fractionated by anion-exchange chromatography, and six fractions were obtained. The bioactive potential of each fraction was estimated from its effect on rat pituitary tissue cultured in vitro and by the effect of an intramuscular injection of the fraction into female camels in vivo. Both the third fraction (F3) and the fifth fraction (F5) stimulated the release of LH in vitro and in vivo. In addition, female camels ovulated within 48 h after intramuscular injection of F3. However, neither F3 nor F5 had any significant effect on the secretion of FSH, either in vitro or in vivo. When F3 was further fractionated into four subfractions, the third subfraction (F3-3) still stimulated the in vitro release of LH, but not of FSH. An attempt to further purify the ovulation-inducing factors in F3-3 failed owing to the similarity of the molecular characters.

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本文首次制备了纳米生物玻璃左旋聚乳酸复合材料,并针对两者之间界面不相容的现象,对生物玻璃表面进行了有针对性的改性;对其纳米颗粒的分散能力进行了表征,并对复合材料的力学性能和生物相容性进行了研究,以期能得到一种具有良好力学性能和生物活性的可降解骨组织修复材料。 (1) 以正硅酸乙酯为硅源,以磷酸氢二铵为磷源,硝酸钙为钙源制备了纳米生物玻璃的凝胶颗粒(BAG, SiO2: CaO: P2O5 =37/54/9, mol/mol) ;以其表面的硅羟基为引发点,采用丙交酯开环聚合原位改性的方法对其进行了表面改性得到了改性纳米生物玻璃的凝胶颗粒(m-BAG);通过改性,使其表面性质由亲水性变为亲油性,提高了其在聚乳酸基体内的分散能力;m-BAG/PLLA复合材料改变了改性以前BAG/PLLA力学性能随生物玻璃含量增加而不断下降的趋势,保持了聚乳酸的力学性能,在m-BAG含量为2%的时候其拉伸强度相对于纯聚乳酸提高16%左右,模量达到纯聚乳酸的1.4倍;而当m-BAG含量为10wt%,复合材料保持与纯聚乳酸相似的拉伸强度,而此时10wt%BAG/PLLA复合材料的力学性能只有纯聚乳酸的80%; 生物玻璃凝胶/聚乳酸复合材料在模拟体液中表现了较高的钙沉积能力,最后在其表面都形成了羟基磷灰石的晶体,但是表面改性使其钙沉积的速度降低,在一定程度上减小了其活性;细胞试验表明,不论生物玻璃凝胶/聚乳酸复合材料还是改性后的复合材料都表现出了很高的细胞黏附性能和增殖性能。 (2) 通过煅烧将生物玻璃的凝胶颗粒制备了生物玻璃纳米颗粒,通过XRD和TGA确定该组成类型的生物玻璃的结晶温度在826ºC,我们选择其经过600ºC煅烧的非晶态的材料作为我们进一步研究的对象。通过六次甲基异氰酸酯作为偶联剂,我们将低分子量的Mn=9,700Da的聚乳酸偶连到生物玻璃纳米颗粒的表面;通过改性提高了生物玻璃/聚乳酸的拉伸强度和拉伸模量,并提高了其分散能力;模拟体液试验表明,其复合材料具有很强的钙沉积能力,细胞培养证明了优异的生物相容性;而且通过试验可以看出,生物玻璃相对于其原始的纳米凝胶颗粒具有更优异的钙沉积能力和细胞相容性。 (3) 通过将三臂聚乳酸添加到线性聚乳酸的内部,大幅度的提高了其冲击强度,当三臂聚乳酸含量达到2wt%-8wt%时,冲击强度达到线性聚乳酸的2倍左右;通过偏光显微镜观察,可以看到三臂聚乳酸提高了线性聚乳酸的结晶成核速度,使其最后晶体数量增多,形态变小;而通过等温结晶试验表明其结晶速度提高,结晶是以异相成核的三维生长方式进行的;流变学试验表明加入三臂聚乳酸有力的降低了体系的复数粘度,当三臂聚乳酸含量达到8%时候,在频率为1-10rad/s其数值仅为线性聚乳酸的60%左右,这种变化将提高其加工成型能力。 (4) 通过十六烷基三甲基溴化铵作为模板剂,制备了具有多孔结构的生物玻璃纳米颗粒,其孔径在2nm左右,比表面积为264m2/g; 通过模拟体液试验表明,其具有很强的生物活性,规整结构在浸泡的前8小时被破坏,体系中P和Ca的含量大幅度上升,在24小时以后形成了羟基磷灰石的晶体。该类型的材料有望应用于制备药物缓释材料,用于骨修复初期的感染和炎症治疗。

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随着软电离技术的发展,特别是基质辅助激光解析(MALDI)和电喷雾(ESI)两种软电离技术的出现,使质谱分析生物大分子成为可能,将质谱的应用范围迅速扩展到生命科学的诸多研究领域,特别是成为了蛋白质组分析,医学诊断,药物分析等领域不可替代的新工具。首先,采用凝胶电泳与傅立叶变换离子回旋共振质谱(FT-ICR MS)的高分辨率和高质量精确度性能相结合的新方法,对不同肺病患者的支气管肺泡灌洗液进行了快速直接的蛋白质组分析,为肺疾病诊断学、肺病相关机理的研究以及高分辨质谱在蛋白质组分析中的应用奠定了基础。一维(1-D)和二维(2-D)凝胶电泳与高分辨FT-ICR MS相结合,对慢性支气管炎(cblonic broncnitis,CB)和囊泡纤维化(cystic fibrosis,CF)患者的支气管肺泡灌洗液(BALF)中表面蛋白A和D进行了鉴定;并对表面蛋白的翻译后修饰(hydroxy-prollne)进行了直接的确定;对来自于不同肺泡蛋白沉积症(PAP)患者的BALF中的特异性蛋白进行了鉴定,鉴定出表面蛋白A的两个降解片段,为研究与肺病相关的SP-A降解产物的可能降解途径提供了初步的信息。证实了FT-ICR MS的高分辨率和高质量精确度在蛋白质的鉴定过程中的突出作用:(i)利用单个多肤的精确质量,可以避免依赖离子的串联质谱数据进行蛋白质鉴定,即无需对谱图中的离子进行串联质谱分析,就可实现蛋白质或蛋白质混合物的快速、确切的鉴定;(ii)在数据库检索中应用很小的误差范围可以大大提高蛋白质鉴定时的选择性;(iii)通过来自于微量蛋白质的少量肤峰就可以进行蛋白质的准确鉴定。通过MALDI/EST FT-ICR MS、园二色谱(CD)和H/D交换实验(hydrogedeuteriuln exchange)对一系列人SP-C及其类似物进行了表征。证实了溶液相中FFI-SP-C和rh-SP-C的非共价二聚体的存在;研究了人SP-C在有机溶剂中的构象变化和聚集行为,为探讨肺病相关机理奠定了基础。其次,以电喷雾多级串联质谱为研究手段,对部分生物类黄酮及其络合物进行系统的质谱研究,发现二氢黄酮及二氢黄酮醇类化合物在电喷雾条件负离子模式下具有不同的特征质谱行为,为质谱区分这两类化合物提供了重要的依据;黄酮金属络合物的研究中,四种二价过渡金属(Cu(II),Zn,Mn(II)和Fe(II))与芸香普均可以形成络合物,探讨了芸香普一铜络合物软电离条件下的碎裂机理,并利用多级串联质谱数据探讨了络合物C和D的结构,为质谱方法探讨金属清除疾病相关自由基的机理以及提高金属的生物利用度奠定了基础。

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近年来,我们致力于蟾蛛(Bufo andrewski)皮肤活性组份的研究,构建了缥蛛皮肤cDNA文库,检测了蟾蛛皮肤分泌液中多种生物活性,进一步纯化得到了四个新的生物活性蛋白:溶菌酶、抗爱滋病毒蛋白以及两个丝氨酸蛋粼酶抑制剂,并,简述如下;I、第三章报导了我们从蟾蛛皮肤分泌液中分离得到的一个谊薇酚犷杰女呱BA一娜"zym")·BA一lvs"Zym"经5DS一PAGE检测为一条带,其分子量约为巧k珍。·它是一个高效的溶菌酶,每毫克蛋白的溶菌活性为2.7xl护俪ts,还能抑制革兰氏阳性菌(金黄色葡萄球菌Slaj,匆褚ococcusaureus)和革兰氏阴性菌(大肠杆菌Esch邵ichiacoli)生长,其最小抑菌浓度(MIC)分别为1.36拼M和84并M。使用PCR筛选法,我们从蟾蛛皮肤c溯A文库中克隆得到编码BA一lyso即me的cDNA序列。BA一lysozymeN末端测序和肤质量图谱确认了蛋白和基因的网一性。它的蛋白全序列与鸡溶菌酶的相似性为5氏5%。系统发育分析显示,与其最相似的是来源于海龟的溶菌酶。11、第四章介绍了我们从蟋蛛皮肤分泌液中分离得到的一个新的抗lllV蛋白,命名为BAS一AH。BAS一AH是一个分子量为63kD。的单链蛋白,每摩尔蛋白质含有0.89摩尔血红素辅基。BAS一AH对人T淋巴细胞系CS166细胞的毒性(CCS。)为9.5尽M。BAs一AH具有较强的抗HIV活性,它对HIV感染和复制具有剂量依赖抑制效应,其选择指数(CCso/Ecs。)分别为14.4和11.4·BAS一麟J也能抑制HIV的逆转录酶,其1C5()为L32冬以。BAs一AH的N末端氨基酸为NA以KADvIGKIsILLGQDI』slvAAM,与己知的抗Hlv蛋白没有同源性·表明它可能是一个新的抗川v蛋自。BAs一AH没有检测到抗菌活性、蛋自酶水解活性、胰蛋自酶抑制剂活性、L一氨基酸氧化酶活性和过氧化氢酶活性。班、第五伞报导了我们通过离子交换、分子筛和反向层析,从蟾赊皮肤中分离得到的一个新的胰蛋白酶抑制剂,命名为BATI。BATI是一个单链糖蛋自·其分子量为22kD。。它是吵~个热稳定的竞争性的抑制剂,能有效抑制胰蛋自酶·其抑制常数凡为14nM。B灯I对凝血酶、弹性蛋白酶以及糜蛋白酶都没有抑制作用。BATI的N末端序列为El犯ITD,不同于其它物种来源的蛋白酶抑制剂。W、第六章介绍了蟾蛛皮肤分泌液中纯化得到的另外一个蛋白酶抑制剂(命名为baserpin)。与上述BATI不同的是,basel咖n不可逆地抑制多种蛋白酶。它是一个分子量约为60kDa的单链糖蛋白,除了能抑制胰蛋白酶,还能有效抑制糜蛋白酶和弹性蛋白酶。它抑制上述三种酶的二级反应常数(编)分别为4.6x1护M一,s一l、8.9》1护M一15一I以及6.8xl护M一ls一l。BaserPin是第一个来源于两栖类皮肤的不可逆抑制剂,其N末端氨基酸序列为HTQYPDILIAKPxDK,与其它物种来源的蛋白酶抑制剂不同。本论文综述了蟾蛛皮肤中的活性组份,报导了我们近年来研究蟾蛛皮肤活性蛋白与多肤的进展,分四章详细介绍了蟾蛛皮肤中纯化得到的四个活性蛋白。BA一lysozyme是两栖类动物中第一个得到蛋白质全序列的溶菌酶,能有效抑制革兰氏阳性菌和革兰氏阴性菌生长;BA象AH是一个含血红素辅基的抗HIV蛋白,其独特的理化性质和功能证明它是一个新的抗病毒蛋白。根据所鉴定的性质判断,BATI和bos仰in分别属于竞争性抑制剂和不可逆抑制剂。其中,base印in是第一个从两栖类皮肤中分离得到的不可逆抑制剂。

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A new nortriterpenoid, 20-hydroxymicrandilactone D (1) and a novel lignan glycoside, lancilignanside A (2) were isolated from leaves and stems of Schisandra lancifolia, together with three known nortriterpenoids (3—5) and nine known phenolics (6—14). The structures of new compounds 1 and 2 were determined by detailed analysis of their 1D and 2D NMR spectra, and chemical evidences. In addition, compounds 1—2, 6—7, and 9—11 showed anti-human immunodeficiency virus (HIV)-1 activities with 50% effective concentration (EC50) in the range of 3.0—99.0m g/ml. Compound 12 was not bioactive in this assay with EC50 more than 200m g/ml.