牛膝多糖的理化性质研究及结构确证

目的研究牛膝多糖的理化性质与结构。方法从中药牛膝中分离得到一小分子量的果聚糖，经凝胶柱色谱分离纯化后，用ESI-MS测定其分子量分布。根据甲基化、还原裂解乙酰化及GC-MS和NMR分析，确证其结构。结果单糖组成分析表明牛膝多糖由果糖-葡萄糖(8∶1)组成，其数均分子量为1 400 u，含有4至21糖；糖链中既含有1,2-连接的果糖残基，又含有2,6-连接的果糖残基。结论牛膝多糖为禾本科型果聚糖。     

多糖化学结构修饰方法的研究进展

多糖是一类重要的生物大分子物质,具有抗肿瘤、抗病毒、抗氧化、免疫活性调节等生物活性。多糖的生物活性与其结构有直接关系,因而对多糖结构通过适当的方法进行修饰是目前多糖领域研究的重要方向之一。简要地阐述多糖的化学修饰方法（包括硫酸化、羧甲基化、乙酰化和磷酸化等）研究进展,以及修饰后对生物活性的影响,以期为新药发现提供依据。     

香菇多糖结构修饰研究进展

目的　对香菇多糖化学结构的修饰方法及其生物活性进行系统总结。方法　通过查阅近年来中英文相关文献,对香菇多糖已经报道的化学结构修饰方法及修饰后的生物活性进行了系统分析,总结阶段性进展。结果　香菇多糖结构修饰方法有化学修饰,包括硫酸化、羧甲基化、磷酸化及与金属离子螯合法等,物理修饰和生物修饰法等。不同的修饰方法对香菇多糖的生物活性有较大的影响。结论　结构修饰及其药理活性的深入研究仍是香菇多糖一个重要的研究方向。     

羧甲基茯苓多糖的制备及抗肿瘤活性研究

目的 提取茯苓药材中的多糖,测定其总糖含量,并进行羧甲基化改性,考察茯苓多糖与修饰后的羧甲基茯苓多糖的抗肿瘤活性。方法 采用稀碱浸提法提取茯苓多糖,苯酚-硫酸显色法测定茯苓多糖中总糖含量,通过羧甲基化反应得到羧甲基茯苓多糖。并采用MTT法检测茯苓多糖与羧甲基茯苓多糖对人肝癌细胞HepG-2的毒性反应。结果 苯酚-硫酸法测得茯苓多糖中总糖含量为95.96%,羧甲基茯苓多糖与茯苓多糖对HepG-2细胞的增殖均具有一定的抑制作用,其中羧甲基茯苓多糖活性更强。结论 经过修饰后的羧甲基茯苓多糖具有更好的抗肿瘤活性。     

天麻多糖提取分离方法和药理作用研究进展

目的：对天麻多糖的提取分离方法及药理作用的相关研究进行汇总分析，以期为天麻多糖的开发研究提供参考。方法：以“天麻多糖”“提取分离”“药理作用”“Rhizoma Gastrodiae polysaccharide” 及“Gastrodia elata polysaccharide”等为关键词查阅相关文献，对天麻多糖的提取纯化工艺、结构特征、 结构修饰及主要药理作用等进行综述。结果与结论：天麻多糖是天麻中主要的一类活性成分，不仅含量高，且毒副作用较低，是目前药物开发和研究的热点之一。天麻多糖的提取方法有多种，常见的主要有热水浸提法、超声波辅助提取法、微波辅助提取法和酶提法。基于这些方法得到的多为天麻粗多糖，需进一步分离纯化，而常用的分离纯化方法有Sevage法、大孔树脂吸附层析法和凝胶层析法。提取纯化方法的多样性会导致天麻多糖结构产生差异，进而导致其药理活性的多样性。天麻多糖具有抗氧化、抗肿瘤、免疫调节、抗衰老、改善脑缺血、改善记忆力、降血压、降血脂和抑菌等多种药理活性。结构修饰天麻多糖具有抗氧化和抗肿瘤等药理作用。因此，天麻多糖可广泛应用于医药、食品及保健品等领域， 具有重要的研究和开发价值，但其高级结构与药理作用之间的内在联系及作用机制有待进一步深入研究。     

硫酸化香菇分级多糖抗肿瘤活性的研究

目的：研究硫酸化香菇分级多糖抗肿瘤活性。方法：提取香菇子实体多糖,用浓硫酸法进行结构修饰,经不同分子量超滤膜超滤进行分级,再对分级组分进行抗肝癌细胞HepG2活性检测。结果：得到6个香菇硫酸化分级多糖,其中两个组分有显著抗肿瘤活性。结论：在一定浓度范围内硫酸化分级多糖抗肝癌细胞的活性呈量效关系,且低分子量组分活性强于高分子量组分。     

牛膝多糖硫酸酯的合成及其抗病毒活性

从中药牛膝中提取得到的一种新多糖化合物一牛膝多糖,用不同的硫酸化试剂合成牛膝多糖硫酸酯。研究了最佳反应条件,其产物水溶性好,呈中性,最高产率达82.11%,取代度(Ds)···达到三以上,硫含量达21%以上。根据牛膝多糖的分子结构,多糖分子中的羟基已最大限度地被酯化。体外抗病毒试验初步表明牛膝多糖硫酸酯有很强的抑制乙型肝炎病毒HBsAg和HBeAg的活性,对I型单纯性疱疹病毒也有明显的抑制力。     

多糖结构修饰研究进展

多糖结构修饰能提高或赋予多糖活性，降低某些多糖的毒副作用。本文对多糖结构修饰的方法，包括化学，生物和物理等方法进行了阐述，并指出对多糖结构修饰进行系统深入地研究将推动糖药物学和糖生物学的发展。     

多糖的研究进展

本文简要概述近年来人们对多糖的研究成果，包括多糖的分离提取、结构测定、结构修饰的方式方法，以及多糖及其衍生物的各种药理活性。随着科学技术的发展，多糖的提取和研究出现越来越多的新方法，但是传统经典的方法仍沿用至今。在传统方法与现代仪器共同研究下多糖越来越多的性质及作用被人们发现，多糖的应用领域也越来越广泛了。     

呫吨酮类化合物及其药理活性

近年来从天然产物中分离得到大量呫吨酮类化合物，多数有异戊烯及其衍生物取代基，具有抗肿瘤、抗氧化、抗疟等多种活性，进行结构修饰后可得到活性显著的化合物。对近5年来分离的呫吨酮类化合物及其药理活性研究作一回顾。     

牛膝多糖硫酸酯和磷酸酯衍生物对人肺癌A549细胞的影响

目的探讨牛膝多糖硫酸酯(S-AbPS)和磷酸酯(P-AbPS)衍生物对人肺癌A549细胞的影响及其作用机制。方法用四甲基偶氮唑盐(MTT)法检测牛膝多糖、S-AbPS和P-AbPS对A549细胞增殖的抑制作用;流式细胞仪观察S-AbPS和P-AbPS处理A549细胞后细胞凋亡的改变。结果S-AbPS和P-AbPS对A549细胞的增殖有抑制作用,且存在时间和剂量相关性。S-AbPS和P-AbPS的48 h抑瘤活性均较同浓度的牛膝多糖强。流式细胞仪分析显示,S-AbPS和P-AbPS均可不同程度地诱导细胞凋亡。结论S-AbPS和P-AbPS较牛膝多糖能更有效地抑制人肺癌A549细胞的增殖,其机制可能是通过诱导A549细胞凋亡而实现。     

Biological activities of retro and diastereo analogs of a 13‐residue peptide with antimicrobial and hemolytic activities

Abstract: The biological activities of synthetic retro and diastereo analogs of PKLLKTFLSKWIG (SPFK), a 13‐residue peptide with antimicrobial and hemolytic activities, have been investigated. Retro peptides with C‐terminal acid and amide exhibited antibacterial activities comparable with those of SPFK. Their hemolytic activities were, however, only marginally lower. The diastereo analog with C‐terminal acid was not antibacterial and was weakly hemolytic. Amidation of this analog could restore antibacterial activity. Both retro analogs were unordered in aqueous medium but had a propensity for a helical structure in trifluoroethanol. However, diastereo analogs were unordered in both aqueous medium and trifluoroethanol. Thus, reversing the sequence in a short amphiphilic peptide may not always result in the selective loss of biological activity such as hemolytic activity. Also, introduction of enantiomeric amino acids in a short peptide to generate a diastereomer may result in loss of structure as well as antimicrobial and hemolytic activities, unless compensated by an increase in positive charges.     

雌酚酮3-醚衍生物的合成与生理活性初探

目的：合成雌激素3－醚化合物以观察雌激素活性，方法：以雌酚酮为原料，在3位与碱性侧相连，合成4个化合物，其中2个未见文献报道，并进行亲子宫和抗子宫和抗子宫活性测定，结果：经初步生理活性测定其雌激素活性明显小于母体化合物，结论：雌激素3－接上碱性侧链上对生理活性有影响。     

阿司匹林衍生物药理活性研究概述

阿司匹林具有多种药理活性,是老药新用的典型药物之一。近年来,人们为开发阿司匹林,对其结构进行修饰及改造,以期得到副作用更小、活性更好的衍生物。本文总结了30种阿司匹林衍生物的合成路线及药理活性。其药理活性主要集中在解热镇痛、抗炎、抗骨质疏松、防治心脑血管疾病及抗肿瘤活性等方面,可为相关研究和应用提供参考。     

槲寄生抗肿瘤有效成分研究进展

槲寄生类植物具有较好的抗肿瘤活性,其主要抗肿瘤活性成分为凝集素类和生物碱类.对这2类活性成分的分离纯化、结构与活性以及槲寄生制剂的临床试验的研究进展作了综述.     

Plant defensins and defensin-like peptides - biological activities and biotechnological applications

Plant defensins are cationic peptides that are ubiquitous within the plant kingdom and belong to a large superfamily of antimicrobial peptides found in several organisms collectively called defensins. The primary structure of these peptides includes 45 to 54 amino acid residues with considerable sequence variation. At the level of three-dimensional structure, they are small and globular, composed of three anti-parallel β-sheets and one α-helix, which is highly conserved among these peptides. The three-dimensional structure is stabilized by four disulfide bridges formed by eight strictly conserved Cys residues. Two of these bridges compose the Cys-stabilized α-helix β-strand motif, which is found in other peptides with biological activities. Plant defensins present numerous biological activities, such as inhibiting protein synthesis, ion channel function and α-amylase and trypsin activity; impairing microbial, root hair and parasitic plant growth; mediating abiotic stress and Zn tolerance; altering ascorbic acid redox state; stimulating sweet taste sensation; serving as epigenetic factors; affecting self-incompatibility; and promoting male reproductive development. Some of these biological activities, such as microbial growth inhibition and sweet taste induction, coupled with a scaffold that provides these peptides with incredible physicochemical resistance to harsh environments and the potential for simple amino acid substitution, raise the opportunity to improve the function of defensins or introduce new activities, endowing these peptides with great biotechnological and medical significance. This review will cover the biological activities and roles of plant defensins and will focus on their application in the field of biotechnology.     

Antinociceptive activities of alpha-truxillic acid and beta-truxinic acid derivatives

Our recent study demonstrated that the dimeric structure of alpha-truxillic acid derivatives played an important role in the expression of their anti-inflammatory activities. In the present report, to investigate the correlation between the structure and anti-inflammatory activity, alpha-truxillic acid (1) and its derivatives (2-6), beta-truxinic acid (7) and its derivatives (8-10) were prepared, and their activities were evaluated in the formalin test. All compounds showed only weak or no activities against the neurogenic pain response, but demonstrated significant activities against the inflammatory pain response induced by formalin. The highest anti-inflammatory activities were observed for alpha-truxillic acid (1) and its derivative 4,4'-dihydroxy-alpha-truxillic acid (2). In addition, alpha-truxillic acid (1) and its derivative, alpha-truxillic acid bis(p-nitrophenyl)ester (5), showed higher anti-inflammatory activities than beta-truxinic acid (7) and the corresponding derivative (10). Furthermore, free carboxylic acids (1, 2) showed higher activities than their dimethyl esters (3, 4) and bis(p-nitrophenyl)ester (5). These results confirmed that the alpha-formation of dimeric structure and the free carboxylic acid were also important for the expression of anti-inflammatory activities. Otherwise, 4,4'-dichloro-beta-truxinic acid (8) had higher activity than its parent compound 7; furthermore, 1,3-dibenzoyl-2,4-di(4-chlorophenyl)cyclobutane (6) also showed strong anti-inflammatory activity. These results suggested that substituents in the phenyl groups were also important for the expression of anti-inflammatory activity. In order to gain information about their activity intensity, the anti-inflammatory activities of 2 and 4,4'-dichlorolated derivatives (6, 8) were compared with that of indomethacin (a nonsteroidal anti-inflammatory drug) in the formalin test. As a result, compounds 2, 6 and 8 showed stronger anti-inflammatory activities than indomethacin. These results suggested that alpha-truxillic acid and beta-truxinic acid derivatives might be developed into a new type of anti-inflammatory drug.     

新型噁唑烷酮类抗菌药物的研究进展

目的阐述唑烷酮类抗菌药物的最新研究进展。方法根据近期关于新的唑烷酮类抗菌药物研究开发现状的29篇相关文献,对唑烷酮的3位芳基和5位侧链的结构改造特点进行整理和归纳。结果与结论大多数化合物具有提高的抗G+菌活性,部分化合物显示出抗G-菌的活性。另外,还介绍了一类具有扩大的抗菌谱的唑烷酮与其他类型抗菌药物形成的拼合化合物。     

马齿苋生物碱的研究进展

马齿苋是一种药食同源的植物,其主要含有生物碱、黄酮、萜类、多糖等成分,因其生物碱结构类型多样,且具有较好的药理活性,近年来引起了广泛关注。主要针对马齿苋中生物碱类化合物的结构类型、药理活性、质量评价及体内代谢研究进展进行归纳总结,为马齿苋的开发利用及进一步研究提供参考。