内生真菌紫杉醇生物合成的研究现状与展望

紫杉醇是重要的抗癌药物之一,已经证明其对多种癌症具有显著疗效。目前,人们主要是从红豆杉的树皮中提取、分离和纯化紫杉醇,但由于红豆杉为生长缓慢、散生、濒危的珍稀植物,且随着紫杉醇临床用途的不断拓宽,市场需求的稳定增长,单纯依靠从红豆杉树皮中提取紫杉醇已经无法满足日益增长的市场需求。为了解决紫杉醇的药源不足,科学家已把目光从红豆杉树分离提取紫杉醇转向了其他替代方法,如化学全合成、半合成、组织培养与细胞培养、微生物发酵法生产紫杉醇等。因此,了解内生真菌紫杉醇生物合成的分子基础和遗传调控机制,对解析内生真菌紫杉醇生物合成机制、构建高产紫杉醇基因工程菌株和早日实现内生真菌紫杉醇工业化生产具有重要的科学意义和现实意义。结合本课题组多年来的科研工作,概述了红豆杉细胞紫杉醇生物合成途径、内生真菌发酵生产紫杉醇的优势、产紫杉醇内生菌的分离研究现状和生物多样性及紫杉醇生物合成相关基因的研究现状。内生真菌生物发酵合成紫杉醇是可以无限生产、大量获取紫杉醇、解决紫杉醇药源短缺问题的很有前景的方法之一。     

微生物发酵生产紫杉醇研究进展

概述了微生物发酵法生产紫杉醇的研究进展,包括产紫杉醇内生真菌的多样性和真菌产紫杉醇的优势,内生真菌分离、紫杉醇纯化和含量测定方法,同时对如何提高内生真菌紫杉醇产量进行了比较全面的综述。     

内生真菌产紫杉醇研究的回顾与展望

紫杉醇是一种高效、低毒、广谱的天然抗癌药物,是人类未来20年间最有效的抗癌药物之一。近年来的研究发现,从植物内生真菌中发酵生产紫杉醇被证明是解决药源问题的有效途径。本文概述了微生物发酵生产紫杉醇的研究进展,包括产紫杉醇内生真菌的分离、多样性和真菌产紫杉醇的优势,紫杉醇的提取和检测技术,同时对如何提高内生真菌紫杉醇产量进行了比较全面的综述。随着现代分子生物学技术和微生物发酵工程的发展,工业上大规模发酵生产紫杉醇将有望实现。     

内生真菌紫杉醇生物合成的研究现状与展望（英文）

紫杉醇是重要的抗癌药物之一,已经证明其对多种癌症具有显著疗效。目前,人们主要是从红豆杉的树皮中提取、分离和纯化紫杉醇,但由于红豆杉为生长缓慢、散生、濒危的珍稀植物,且随着紫杉醇临床用途的不断拓宽,市场需求的稳定增长,单纯依靠从红豆杉树皮中提取紫杉醇已经无法满足日益增长的市场需求。为了解决紫杉醇的药源不足,科学家已把目光从红豆杉树分离提取紫杉醇转向了其他替代方法,如化学全合成、半合成、组织培养与细胞培养、微生物发酵法生产紫杉醇等。因此,了解内生真菌紫杉醇生物合成的分子基础和遗传调控机制,对解析内生真菌紫杉醇生物合成机制、构建高产紫杉醇基因工程菌株和早日实现内生真菌紫杉醇工业化生产具有重要的科学意义和现实意义。结合本课题组多年来的科研工作,概述了红豆杉细胞紫杉醇生物合成途径、内生真菌发酵生产紫杉醇的优势、产紫杉醇内生菌的分离研究现状和生物多样性及紫杉醇生物合成相关基因的研究现状。内生真菌生物发酵合成紫杉醇是可以无限生产、大量获取紫杉醇、解决紫杉醇药源短缺问题的很有前景的方法之一。     

真菌紫杉醇/烷研究近况

紫杉醇（Taxol?）是天然抗癌药物,已在临床上广泛使用,市场需求量大,由于生产原料的制约,供需之间存在巨大缺口,价格仍然昂贵。利用真菌发酵生产紫杉醇是解决药源的一条新途径。对产紫杉醇内生真菌的多样性,紫杉醇真菌的采集鉴定、真菌紫杉醇提取和测定的一些经验,紫杉醇真菌分子生物及生物合成代谢研究进展等进行了综述。     

紫杉醇免疫检测方法的研究进展

紫杉醇是一种有效的抗肿瘤药物,广泛应用于治疗卵巢癌、乳腺癌和肺癌等癌症。紫杉醇在紫杉树皮中的含量极低（仅为0．01％）,而且紫杉醇是一种对蛋白质有着高亲和力的小分子,在体液中约有98％的分子与蛋白质结合,因此需要一种高灵敏度、高通量的检测方法对紫杉醇进行鉴定。在分析紫杉醇检测方法的基础之上,综述了紫杉醇免疫学检测方法的研究进展,包括紫杉醇半抗原的分子修饰、蛋白偶联物的构建和鉴定以及免疫学检测方法在植物组织和病人血浆中紫杉醇定性和定量中的应用。     

植物内生真菌生产紫杉醇大有希望

索取紫杉醇(taxol)的传统方法需要砍伐大量紫杉树木,取其树皮以提取紫杉醇,其代价很高。采用细胞-组织培养索取紫杉醇的方法正在积极实验研究之中。我国第四军医大学曾采用非生物方法即手性催化技术合成紫杉醇及多烯紫杉醇取得成功。目前,国内外采用微生物方法生产紫杉醇已经取     

紫杉醇生物合成研究历史、现状及展望北大核心CSCD

紫杉醇是从红豆杉中分离出来的一种二萜类化合物,是目前临床上使用最广泛的抗癌药物之一。回顾了紫杉醇生物合成的研究历史,主要包括参与红豆杉紫杉醇生物合成的结构基因、调控基因、红豆杉代谢组、内生真菌紫杉醇生物合成研究历史以及国际上紫杉醇生物合成专利情况等。介绍了近年来红豆杉和内生真菌紫杉醇生物合成研究的现状。最后探讨了本领域未来的研究方向并对其前景进行展望。     

多组学助力紫杉醇合成生物学研究

紫杉醇是高效的天然抗癌产物,广泛用于多种癌症的临床治疗。目前紫杉醇的生产主要是从红豆杉属(Taxus)植物中提取天然前体(如巴卡亭Ⅲ)然后再化学合成。受制于红豆杉植物资源,导致制药成本高。合成生物学的兴起为紫杉醇原料药的获取提供了新途径,但紫杉醇合成生物学的研究还有待推进。近年来,多组学被逐步应用到紫杉醇的合成生物学研究中。本文综述了多组学助力紫杉醇合成通路基因、调控基因和异源合成研究的最新进展,为紫杉醇的合成生物学研究提供了新的见解。     

红豆杉植株紫杉醇含量研究进展(综述)

影响红豆杉中紫杉醇含量的因素较多。为了提高红豆杉紫杉醇及其衍生物的含量,国内外已开展大量研究,其中多数是以天然红豆杉为研究对象。研究表明,不同种类、树龄、器官、物候期、生长环境等因子对天然红豆杉中紫杉醇含量均有影响。本文综述了影响红豆杉紫杉醇含量的各种因子,并对紫杉醇测定方法、天然红豆杉与人工红豆杉中紫杉醇含量以及红豆杉中其它紫杉烷类化合物含量等进行了比较。     

Taxol inhibits stimulation of cell DNA synthesis by human cytomegalovirus

The microtubule (MT)-stabilizing drug, taxol, inhibited human cytomegalovirus (CMV)-initiated cell DNA synthesis by up to 100% in serum-arrested mouse embryo (ME) fibroblasts that were abortively infected by CMV. Taxol concentrations known to increase MT polymerization and to stabilize existing MTs (10 to 20 micrograms/ml) blocked CMV-stimulated cell DNA synthesis, while taxol concentrations of 2.5 micrograms/ml, or less, did not. Taxol maximally inhibited CMV initiation of cell DNA synthesis when added 3 h after virus infection and inhibited this initiation by greater than 50% when added up to 12 h after CMV infection. Control experiments suggest that taxol specifically inhibited CMV-stimulated cell DNA synthesis. Pretreatment of CMV stock with taxol did not reduce the stimulatory effect of CMV on cell DNA synthesis and taxol had no detectable effect on CMV-specific early protein synthesis. Moreover, taxol did not appear to alter thymidine pool sizes, affect cell viability, or compromise the DNA synthetic machinery in CMV-infected cells. Since taxol increases tubulin polymerization and inhibits MT disassembly, these results suggest that dynamic changes in MTs or in the pool of free tubulin subunits are necessary for CMV to stimulate cell entry into a proliferative cycle.     

天然药物紫杉醇的研究与开发综述

本文对近年来紫杉醇(Taxol)的研究与开发进行了综述,其中包括:1.对紫杉醇研究的历史回顾;2.独特的药理作用机制;3.在植物界的分布;4.前药设计;5.半合成;6.全合成;7.组织培养;8.真菌发酵;9.构效关系等。     

Will fungi be the new source of the blockbuster drug taxol?

Taxol (paclitaxel) is widely used for the treatment of various kinds of cancers. Originally, the major source of taxol was bark of the Pacific yew tree (Taxus brevifolia). However, this proved devastating to natural populations of the trees. To protect the Pacific yew, alternatives to the use of trees are sought. One solution is the use of taxol or its precursors derived from fungi. A large number of endophytic fungi that reside within healthy plants have been reported to be taxol producers. However, fungal epiphytes, pathogens and saprophytes have also been found to produce taxol. Several strains of fungi belonging to species Metarhizium anisopliae and Cladosporium cladosporioides MD2 are very promising, producing taxol at levels up to 800 μg/L. This review examines the potential for production of taxol from fungi. The biology of taxol synthesis in fungi and measures which may improve taxol yield are also discussed.     

紫杉醇生物合成的研究

抗癌新药紫杉醇是具有萜类环状结构的天然次生代谢产物。研究紫杉醇的生物合成对于人为定向地提高合成效率以及克隆重组合成中的关键酶基因,进而提高紫杉醇的合成量,都是十分有意义的基础工作。本文以植物和微生物的次生代谢及其主要代谢途径为知识背景,介绍了紫杉烷类物质的基本结构及其结构骨架的分类情况,综述了近年来围绕紫杉醇二萜骨架和侧链基团的生物合成途径的研究进展,对合成中的影响因素进行了初步的讨论。     

紫杉醇生物合成的研究

抗癌新药紫杉醇是具有萜类环状结构的天然次生代谢产物。研究紫杉醇的生物合成对于人为定向地提高合成效率以及克隆重组合成中的关键酶基因,进而提高紫杉醇的合成量,都是十分有意义的基础工作。本文以植物和微生物的次生代谢及其主要代谢途径为知识背景,介绍了紫杉烷类物质的基本结构及其结构骨架的分类情况,综述了近年来围绕紫杉醇二萜骨架和侧链基团的生物合成途径的研究进展,对合成中的影响因素进行了初步的讨论。     

基于定量PCR技术探讨紫杉醇生物合成的限速步骤

次生代谢产物牛物合成受到发育和诱导的调控,本实验研究了组织分化和诱导处理对紫杉醇生物合成的影响,并采用定量PCR技术分析了紫杉醇生物合成不同阶段关键酶基因的动态表达特征。结果表明。紫杉醇主要分布在中国红豆杉（Taxus chinensis）树皮和根皮组织中,针叶内含量很少,催化紫杉醇功能官能团连接的关键酶摹因也主要定位在树皮和根皮组织巾;茉莉酸甲酯（MJ）和真菌诱导子F5分别提高了中国红豆杉悬浮培养细胞HG-1紫杉醇得率8倍和10倍,同时有效诱导紫杉醇生物合成基因的表达。发现催化紫杉醇侧链连接的基因与紫杉醇生物合成早正相关。结果表明。紫杉醇生物合成的限速步骤是催化功能官能团连接的步骤。     

Inhibitory effect of taxol, a microtubule stabilizing agent, on induction of DNA synthesis is dependent upon cell lines and growth factors.

Growth-arrested rat fibroblasts, 3Y1, and human diploid fibroblasts, TIG-1, were induced to synthesize DNA by stimulation with various agents such as fetal bovine serum (FBS), epidermal growth factor (EGF), colcemid, or colchicine. Taxol, a microtubule-stabilizing agent, blocked the induction of DNA synthesis after stimulation with colcemid or colchicine in both cell lines. Taxol inhibited the induction of DNA synthesis after stimulation with FBS or EGF in TIG-1, but did not in 3Y1. 12-O-tetradecanoylphorbol-13-acetate (TPA) induced DNA synthesis in TIG-1, which was reduced only partly by taxol. Taxol stabilized or polymerized microtubules in both cell lines. These results indicate that the inhibitory effect of taxol on the induction of DNA synthesis varied among cell lines and among growth factors, and suggest that signal transduction processes may be differentiated by taxol sensitivity. In TIG-1 cells, when taxol was added within 6 h, about halfway into the initiation of DNA synthesis after the addition of FBS or EGF, the inhibition of DNA synthesis still occurred. Taxol did not inhibit the induction of c-fos and c-myc genes by FBS or EGF stimulation. Colchicine itself did not induce these genes in TIG-1. Thus, taxol appeared to inhibit the induction of DNA synthesis not by blockage in the early transduction process of the growth signal from the cell surface to nuclei but by blockage in processes operating in the mid- or late-prereplicative phase.     

Independence of centriole formation and initiation of DNA synthesis in Chinese hamster ovary cells

The relationship between centriole formation and DNA synthesis was investigated by examining the effect of taxol on the centriole cycle and the initiation of DNA synthesis in synchronized cells. The centriole cycle was monitored by electron microscopy of whole-mount preparations [Kuriyama and Borisy, J. Cell Biol., 1981, 91:814-821]. A short daughter centriole appeared in perpendicular orientation to each parent during late G1 or early S and elongated slowly during S to G2. Addition of 5-20 micrograms/ml taxol to a synchronous population of cells in S phase did not inhibit centriole elongation; rather, elongation was accelerated. In contrast, when taxol was added to M phase or early G1 cells, centriole duplication was completely inhibited. The taxol block was reversible since nucleation and elongation of centrioles resumed as soon as the drug was removed. Cells exposed to taxol progressed through the cell cycle and became blocked in mitosis, as indicated by an increase in the mitotic index, but eventually the mitotic arrest was overcome, resulting in formation of multinucleated cells. A peak in mitotic index was seen in the following generation, indicating that chromosomes duplicated in the presence of taxol. Incorporation of 3H-thymidine followed by autoradiography confirmed that DNA synthesis was initiated in the presence of taxol even though formation of daughter centrioles was inhibited. It seems, therefore, that centriole duplication is not a prerequisite for entry into S phase. Since DNA synthesis has already been demonstrated not to be necessary for centriole duplication, these two events, normally coordinated in time, appear to be independent of each other.     

Microtubules and lymphocyte responses: effect of colchicine and taxol on mitogen-induced human lymphocyte activation and proliferation

The role of microtubules in mitogen-induced human lymphocyte activation and proliferation was examined. The effect of colchicine, a microtubule-disrupting agent, was compared with taxol, a microtubule-stabilizing drug, and with isaxonine (N-isopropyl-amino-2-pyrimidine orthophosphate), a proposed microtubular-active drug. Lymphocyte proliferation, assessed by measuring the increase in the number of cells in mitogen-stimulated cultures, was completely suppressed by both colchicine and taxol (100 nM) whereas significant inhibition by isaxonine required much higher concentrations (5 mM). In order to characterize the inhibition, initial lymphocyte blast transformation and subsequent DNA synthesis were investigated. Neither colchicine nor taxol inhibited lymphocyte blast transformation assessed by quantitating the change in volume of the stimulated cells after a 24-hour incubation. In contrast, isaxonine (2-5 mM) suppressed blast transformation. Initial DNA synthesis, evaluated by measuring the cumulative incorporation of [3H]thymidine between 30 and 48 hours of culture, was inhibited in a concentration-dependent manner by both isaxonine and colchicine but not by taxol. Electron microscopic studies confirmed that both taxol and colchicine (10 nM) arrested the responding lymphocytes in mitosis, and that isaxonine inhibited initial activation. These results suggest that normal microtubule function is only necessary for cell division and that drug effects on blast transformation and initial DNA synthesis are unrelated to microtubules.