源于微生物的海鞘天然产物

海洋动物是具有生物活性海洋天然产物的重要来源。海鞘中含有丰富的微生物类群,如细菌、放线菌、真菌和蓝细菌。越来越多的直接或间接证据表明,一些从海鞘中分离的天然产物并不是海鞘本身产生的,而是由其共生微生物产生的。本文对近些年来的海鞘天然产物的微生物来源的研究方法进行综述,包括可培养细菌的分离、不可培养细菌的粗提物检测、宏基因组学、全基因组测序等直接方法,以及化合物结构比对的间接方法。通过对海鞘-微生物共生体中天然产物生物合成来源的研究,不仅可以从根本上解决动物药源的问题,而且可为研究海鞘与微生物共生关系提供有力证据。     

海洋药物的抗病毒研究

海洋由于其特殊的生态环境,包含着极其丰富的生物来源的天然产物。自本世纪七十年代以来,已经从海藻类、海绵类、海鞘类、海星类、腹足动物、棘皮动物、腔肠动物、软体动物、珊瑚及海洋微生物等海洋生物中分离出一系列有抗病毒作用的天然化合物,其中有些结构类型已成为抗病毒药物研究的导向化合物。基于现代分离和分析技术的发展、新的实验模型的建立和在病毒学方面分子生物学研究的进展,从海洋生物中寻找新的抗病毒药物已步入一个新的时代。     

海洋药物的抗病毒研究

海洋由于其特殊的生态环境,包含着极丰富的生物来源的天然产物。自本世纪七十年代以来,已经从海藻类、海绵类、海鞘类、海星类、腹足动物、棘皮动物、腔肠动物、软体动物、珊瑚及海洋微生物等海洋生物中分离出一系列有抗病毒作用的天然化合物,其中有些结构类型已成为抗病毒药物研究的导向化合物。基本现代分离和分析技术的发展、新的实验模型的建立和在病毒学方面分子生物学研究的进展,从海洋生物中寻找新的抗病毒药物已步入一个     

中国沿海海鞘的物种多样性

至今,中国海已经记录了66种海鞘。其中,渤海有5种,黄海21种,东海24种,南海53种。种类分布从北往南逐渐递增,柄瘤海鞘在黄海、渤海数量很大(8100个/m²),但往南分布,未发现超过罗源湾。皱瘤海鞘在南海数量很大(2225个/m²),往北也未发现超过罗源湾。玻璃海鞘和乳突皮海鞘在全国沿海都有分布。     

海鞘与蓝藻的共生关系

互利共生是指两种不同生物之间所形成的紧密互利关系。文章以海鞘与蓝藻共生关系的典型实例为代表,介绍了蓝藻与海鞘共生关系的发现过程;蓝藻在海鞘间世代传递的机制;两者在共生关系中可能存在的生理功能,如蓝藻共生体通过碳固定、参与氮循环和产生代谢物等方式为海鞘提供营养并参与海鞘的防御活动,海鞘可供给共生体生长所需的一部分氮素营养和提供抗紫外线的保护等。对海鞘与蓝藻共生关系的研究将有助于理解生物进化过程,以及为进一步开发利用海洋生物之间的共生关系提供研究基础。     

中国沿海污损性海鞘生态特点及研究展望

海鞘是海洋污损生物群落的重要组成部分, 其附着会给水产养殖业带来严重危害。在中国沿海, 引发生物污损的海鞘共8 科20 属40 种, 其中渤海海域7 种, 黄海17 种, 东海23 种和南海27 种。北方海域以柄瘤海鞘(Styela clava)、乳突皮海鞘(Molgula manhattensis)和米氏小叶鞘(Diplosoma listerianum)为优势种, 南方则以冠瘤海鞘(Styela canopus)、皱瘤海鞘(S.plicata)和大洋纵列海鞘(Symplegma oceania)为优势种。海鞘污损特点与设施所处地理位置、浸海时间、环境状况等因子密切有关。今后除了继续对沿岸代表性海域开展深入研究外, 还需结合海洋经济发展和科学研究的需要, 加强离岸设施(尤其深海环境)污损生物群落的研究, 以期更好地掌握污损性海鞘的组成分布、种群特点及发展趋势。     

脊索动物海鞘的类副肌球蛋白

脊索动物门尾索亚门的海鞘(Ciona intestinalis)肌肉中可抽提出副肌球蛋白,该蛋白对有机溶剂稳定并能在低离子强度环境形成纤维状晶体。海鞘副肌球蛋白纤维状晶体长度可达200微米,用电子显微镜观察其负染后的样品,具有横纹结构,横纹的总周期在150～160毫微米,其中包含有93与60毫微米的亚周期,另有若干细节在8.1与8.6毫微米左右。我们尚未见到海鞘和文昌鱼的副肌球蛋白之间有何免疫交叉反应。     

中国玻璃海鞘属一新纪录种——萨氏海鞘Ciona savignyi

海鞘(尾索动物亚门Urochordata,海鞘纲Ascidiacea)是与脊椎动物亲缘关系最近的分支1,是研究动物进化和发育的重要材料。其中玻璃海鞘(Ciona intestinalis)在世       

脊索动物海鞘的类副肌球蛋白

脊索动物门尾索亚门的海鞘(Ciona intestinalis)肌肉中可抽提出副肌球蛋白,该蛋白对有机溶剂稳定并能在低离子强度环境形成纤维状晶体。海鞘副肌球蛋白纤维状晶体长度可达200微米,用电子显微镜观察其负染后的样品,具有横纹结构,横纹的总周期在150～160毫微米,其中包含有93与60毫微米的亚周期,另有若干细节在8.1与8.6毫微米左右.我们尚未见到海鞘和文昌鱼的副肌球蛋白之间有何免疫交叉反应。     

海洋共附生微生物天然产物生物合成基因研究进展

对海洋无脊椎动物天然产物的研究表明,很多种活性物质的真正生产者是与其共生或附生的未培养微生物.克隆这些未培养微生物中特定活性物质的生物合成基因,不仅为活性物质的来源提供遗传学证据,也使通过异源表达相关生物合成基因来大量获取目标化合物成为可能.本文综述了来源于海绵、海鞘、苔藓虫、深海管状蠕虫和深海沉积物中共附生微生物天然产物生物合成基因簇的研究进展.     

Antitumor potential of natural products from Mediterranean ascidians

Ascidians, invertebrates belonging to the subphylum Urochordata (Tunicata), are renowned for their great chemical diversity, and during the last 25 years, they have been shown to produce an array of cytotoxic molecules. Among the first six marine-derived compounds that have reached clinical trials as antitumor agents, three are derived from ascidians, as evidence of the high potential of these organisms as a new source of antitumor compounds. Reported in this communication are some recent results on the chemistry of Mediterranean ascidians; a number of new molecules with different structural features but all endowed with antiproliferative or cytotoxic activity are discussed. These results strongly evidence the highly significant role that Mediterranean ascidians natural products could play in anticancer drug discovery and development process.     

Bioactive Peptides from Marine Ascidians and Future Drug Development–A Review

Marine ascidians are considered as one of the richest sources of bioactive compounds. The extraction and utilization of marine peptides have been attracted much attention owing to their potential health benefits. Most of the bioactive compounds from marine ascidians are already in different phases of the clinical and preclinical pipeline. They can be used in different functional and nutraceutical values due to their antineoplastic, antihypertensive, antioxidant, and antimicrobial properties. The screening in vivo and in vitro bioassays are coupled to the purification process for the exploration of its biological interest which is of great value. The growing significance to study marine natural products results from the discovery of novel pharmacological tools including potent anticancer drugs and other drugs are in clinical/pre-clinical trials. The present review highlights the recent research progress in marine ascidians’ peptides and its prospects for the future pharmaceutical development.     

源于海洋真菌的抗肿瘤天然产物

海洋真菌因其特殊的生存环境和代谢机制而具有产生新型生物活性物质的潜力。近年来随着对海洋微生物研究的深入,从海洋真菌中发现了越来越多的具有抗肿瘤活性且结构新颖的天然产物。这些海洋真菌有的分离自海水、海泥或海洋沉积物,有的来自于海洋生物体。本文综述了近几年来从海洋真菌中分离得到的抗肿瘤天然产物的研究状况。     

戊二酰亚胺类天然产物生物合成研究进展

微生物天然产物是天然药物的重要组成部分,而天然产物的良好生物活性很大程度上取决于发挥药效的结构基团。这些特殊药效基团的生物合成,通常是利用小分子羧酸、氨基酸等结构简单的初级代谢产物,经过复杂的生物化学过程,最终合成结构复杂活性多样的天然产物。戊二酰亚胺类天然产物是一类重要的细菌来源天然产物,它们具有良好的生物活性,是潜在的先导化合物,部分化合物已被开发成分子探针。本文综述了近年来微生物来源的戊二酰亚胺类天然产物及其生物合成研究,包括Iso-Migrastatin、Lactimidomyin、Cycloheximide、Streptimidone、Gladiostatin、Sesbanimide等,对戊二酰亚胺类天然产物的生物合成研究,将有效促进通过基因组挖掘策略寻找新型戊二酰亚胺类天然产物。     

海洋动物来源微生物的共培养研究进展

近年来,由于一些新疾病的发生和细菌耐药性的出现,微生物来源次级代谢产物的筛选重复率越来越高,微生物一些代谢基因在现有实验室条件下无法表达,所以需要发现新的微生物资源,同时找到激活微生物代谢产物基因的方法.海洋动物体内蕴含着大量的共附生微生物资源,可以产生很多具有生物活性的化合物,是潜在的药用资源.本文综述了近年来海洋动...     

Natural diversity and adaptive responses of Lactococcus lactis

Lactococcus lactis is the primary model organism for lactic acid bacteria (LAB) and is widely used in the production of fermented dairy products. In recent years there has been increasing interest in strains isolated from non-dairy environments, as these exhibit a high metabolic diversity and have unique flavour-forming activities. Recent progress has been made in understanding the natural diversity and adaptive responses of L. lactis from dairy and non-dairy origins. Genome sequencing and comparative genomics have also had an impact on understanding natural diversity within the species, and have provided new opportunities for industrial strain development.     

被囊动物中生物活性物质研究的一些进展

本文对近年从海鞘中提取分离的环肽类及生物碱类化合物作了综述,对一些典型化合物如Didemnins、Patellamides、Merdine、Eudistomins及Ecteinascidins等作了较详细的介绍。     

Highlights of marine invertebrate-derived biosynthetic products: their biomedical potential and possible production by microbial associants

Coral reefs are among the most productive marine ecosystems and are the source of a large group of structurally unique biosynthetic products. Annual reviews of marine natural products continue to illustrate that the most prolific source of bioactive compounds consist of coral reef invertebrates-sponges, ascidians, mollusks, and bryozoans. This account examines recent milestone developments pertaining to compounds from invertebrates designated as therapeutic leads for biomedical discovery. The focus is on the secondary metabolites, their inspirational structural scaffolds and the possible role of micro-organism associants in their biosynthesis. Also important are the increasing concerns regarding the collection of reef invertebrates for the discovery process. The case examples considered here will be useful to insure that future research to unearth bioactive invertebrate-derived compounds will be carried out in a sustainable and environmentally conscious fashion. Our account begins with some observations pertaining to the natural history of these organisms. Many still believe that a serious obstacle to the ultimate development of a marine natural product isolated from coral reef invertebrates is the problem of compound supply. Recent achievements through total synthesis can now be drawn on to forcefully cast this myth aside. The tools of semisynthesis of complex natural products or insights from SAR efforts to simplify an active pharmacophore are at hand and demand discussion. Equally exciting is the prospect that invertebrate-associated micro-organisms may represent the next frontier to accelerate the development of high priority therapeutic candidates. Currently in the United States there are two FDA approved marine-derived therapeutic drugs and two others that are often cited as being marine-inspired. This record will be examined first followed by an analysis of a dozen of our favorite examples of coral reef invertebrate natural products having therapeutic potential. The record of using complex scaffolds of marine invertebrate products as the starting point for development will be reviewed by considering eight case examples. The potential promise of developing invertebrate-derived micro-organisms as the starting point for further exploration of therapeutically relevant structures is considered. Also significant is the circumstance that there are some 14 sponge-derived compounds that are available to facilitate fundamental biological investigations.     

Chemistry and biological activity of azoprenylated secondary metabolites

N-Prenyl secondary metabolites (isopentenylazo-, geranylazo-, farnesylazo- and their biosynthetic derivatives) represent a family of extremely rare natural products. Only in recent years have these alkaloids been recognized as interesting and valuable biologically active secondary metabolites. To date about 35 alkaloids have been isolated from plants mainly belonging to the Rutaceae family, and from fungi, bacteria, and/or obtained by chemical synthesis. These metabolites comprise anthranilic acid derivatives, diazepinones, and indole, and xanthine alkaloids. Many of the isolated prenylazo secondary metabolites and their semisynthetic derivatives are shown to exert valuable in vitro and in vivo anti-cancer, anti-inflammatory, anti-bacterial, anti-viral, and anti-fungal effects. The aim of this comprehensive review is to examine the different types of prenylazo natural products from a chemical, phytochemical and biological perspective.