细菌素产生菌的筛选及其细菌素的分离纯化

从香肠中分离得到一株产细菌素的乳酸片球菌，其发酵液经硫酸铵沉淀，CM—Sephadex C50阳离子交换柱层析后，得到的细菌素样品通过SDS—PAGE证明是一条带，分子量约20．83ku，该细菌素对热及酸碱稳定，易被酶降解而失去活性，对许多革兰氏阳性茵有较强的抑制作用，而对革兰氏阴性茵、酵母和霉没有作用。     

Mersacidin, a new antibiotic from Bacillus. Fermentation, isolation, purification and chemical characterization.

Mersacidin (1) is a new peptide antibiotic containing beta-methyllanthionine. It is classified as a member of the proposed lantibiotic group of antibiotics, and is produced by a species of Bacillus. Mersacidin has a molecular weight of 1,824 (C80H120N20O21S4). The antibiotic is active against Gram-positive organisms including methicillin-resistant Staphylococcus aureus, but has no activity against Gram-negative bacteria or fungi.     

湿法磷酸化学净化制磷酸盐技术的现状和改进

介绍对湿法磷酸传统化学除杂净化技术进行革新改造后的新工艺:不仅可替代热法磷酸制高品质磷酸盐产品;更有除杂净化成本和原材料消耗低的优势。     

抗生素新药研发中分析分离的3种方法

从发酵液中分离纯化抗生素,是抗生素新药研发的难点.目前已发展毛细管电泳法、高速逆流色谱法和反相高效液相色谱法这3种较有优势的分离技术,它们都可以简单、快速、高效的分离出结构上相似的不同抗生素,从而广泛应用于抗生素新药开发中的药理研究和血药浓度测定.现对这3种方法在抗生素分离分析中的应用进行综述.     

决明子中橙黄决明素的提取、分离及纯化方法的研究

目的研究决明子中橙黄决明素的提取、分离、纯化工艺,为橙黄决明素的开发及生产提供参考数据。方法以橙黄决明素含量为指标,采用正交试验法考察提取时间、提取次数、乙醇浓度及用量对橙黄决明素提取率的影响,再采用硅胶柱层析方法,选择适当洗脱系统分离决明子中橙黄决明素,丙酮反复多次重结晶以获得纯度较高橙黄决明素。结果最佳提取工艺为:决明子用6倍量90%乙醇回流提取2次,1 h.次-1;柱层析法[石油醚(60~90℃)-丙酮=(9∶1)]及丙酮重结晶后得到的橙黄决明素纯度可>99%。结论乙醇浓度对决明子中橙黄决明素提取率有显著影响,分离纯化方法操作简单、实用性强、成本低、可推广应用。     

Pumilacidin, a complex of new antiviral antibiotics. Production, isolation, chemical properties, structure and biological activity

New antibiotic pumilacidins A, B, C, D, E, F and G were isolated from the culture broth of a strain of Bacillus pumilus. They are cyclic acylheptapeptide composed of a beta-hydroxy fatty acid, two L-leucine, two D-leucine, L-glutamic acid, L-aspartic acid and L-isoleucine (or L-valine). Pumilacidin components were inhibitory to herpes simplex virus type 1 and H+, K(+)-ATPase and demonstrated antiulcer activity in rat.     

Research advances in the development of peptide antibiotics

Bacterial resistance to antibiotics is a growing concern in both nosocomial and community acquired infections. Resistance began to emerge as early as the 1950s. Much research has been dedicated to the improvement of existing classes of antibiotics. Antimicrobial peptides (AMPs) are part of the innate immune system, and an important component of immune defense. They are produced by plants, animals, insects, and single celled organisms, and possess anti-microbial properties. As such, they are an ideal target for future antibiotic production. Bacteriocins are a subgroup of AMPs, produced by various bacteria. It has been shown that the production of chimeric peptides consisting of bacteriocins and pheromones can be targeted toward the killing of specific bacterial species. In contrast to the clonal, acquired adaptive immunity, endogenous peptide antibiotics provide a fast and energy-effective mechanism as front line defense. This review will provide an overview of AMPs and their potential for target-specific anti-infective therapy.     

Relationship between chemical structure of antibiotics and pharmacokinetics

Modifications to the chemical structure of antibiotics can modify nearly all pharmacokinetic parameters: digestive absorption, half-life, protein binding, tissue distribution, metabolic biotransformation, biliary and renal elimination. Examples of increased oral bioavailability are given for beta-lactams, macrolides, tetracyclines, fosfomycin, quinolones and acyclovir. The structural modifications responsible for prolonged or shortened half-life, increased or decreased biliary excretion, increased or decreased renal clearance for the different families of antibiotics are reviewed.     

糖肽类抗生素N-甲基无糖万古霉素的分离、纯化和结构鉴定

目的 利用含N-甲基转移酶的粗酶液对无糖万古霉素进行催化,从得到的反应液中分离、纯化N-甲基无糖万古霉素,并进行结构鉴定。方法 利用大孔树脂吸附、中压反相制备色谱等方法进行分离纯化。利用光谱分析,进行结构解析。结果 分离到一个糖肽类化合物N-甲基无糖万古霉素。结论     

B群链球菌荚膜多糖抗原的分离纯化工艺研究

目的为提高荚膜多糖抗原得率,降低荚膜多糖中残余蛋白质含量和核酸含量,提高荚膜多糖抗原纯度,优化B群链球菌荚膜多糖的提取纯化工艺条件。方法研究pH值,沉淀核酸和荚膜多糖的乙醇浓度,乙醇沉淀多糖所需的温度和时间;比较蛋白酶K法、Sevag法和冷酚抽提法去除荚膜多糖中杂蛋白质的效果。结果建立起25%乙醇沉淀去核酸,冷酚抽提法去蛋白质分离纯化荚膜多糖,55%乙醇沉淀多糖的方法。3批GBSⅢ发酵液中获得的荚膜多糖的唾液酸含量为12.4%~14.8%;分配系数(Kav)≤0.5的多糖回收率达90%以上;荚膜多糖得率为0.021~0.027 g/L,抗原纯度较高。结论从发酵液中提取纯化荚膜多糖抗原的工艺是可行有效的。     

高效液相色谱法在合成多肽分离与纯化中的应用

近年来，多肽药物化学形成并迅速发展成为药物化学的重要分支。而随着分离纯化技术的进展，又大大加快了新活性多肽的发现和合成速度。在多肽合成中．许多杂质显示与产物类似的性质，随着肽链的增长，分离的难度也增大，因此纯化的方法和工艺显得异常重要。本文综述了凝胶过滤色谱、离子交换色谱和反相色谱等高效液相色谱技术在合成多肽分离与纯化中的设计和应用。     

草木樨药材中香豆素类化合物提取分离纯化研究

目的：建立草木樨药材中主要活性成分香豆素类化合物工业化提取分离纯化方法与条件。方法：通过比较不同的提取条件；有机溶剂萃取法与大孔树脂分离纯化，采用HPLC法测定香豆素。结果：药材最佳提取工艺：取草木樨药材粗粉，加50％乙醇回流提取3次，每次提取1．0h，溶媒用量依次为20，15，12倍。纯化最佳工艺：选用YWD07D1型大孔吸附树脂，为200g药材／L溶液，上样树脂柱径高比为1：7，药材和树脂用量比为7：1。上样后先用3倍柱体积去离子水洗脱，再用3倍柱体积80％乙醇洗脱。收集80％乙醇洗脱液，50℃减压浓缩。结论：总有效部位以香豆素计含量达到50％以上。