D-chiro-inositol affects accumulation of raffinose family oligosaccharides in developing embryos of Pisum sativum

Developing garden pea embryos are able to take up exogenously applied cyclitols: myo-inositol, which naturally occurs in pea, and two cyclitols absent in pea plants: d-chiro-inositol and d-pinitol. The competition in the uptake of cyclitols by pea embryo, insensitivity to glucose and sucrose, and susceptibility to inhibitor(s) of H⁺-symporters (e.g. CCCP and antimycin A) suggest that a common cyclitol transporter is involved. Both d-chiro-inositol and d-pinitol can be translocated through the pea plant to developing embryos. During seed maturation drying, they are used for synthesis of mainly mono-galactosides, such as fagopyritol B1 and galactosyl pinitol A. Accumulation of d-chiro-inositol (and formation of fagopyritols), but not d-pinitol, strongly reduces accumulation of verbascose, the main raffinose oligosaccharide in pea seeds. The reasons for the observed changes are discussed.     

药用植物学立体化课程体系的构建与实践

药用植物学是医学院中药、药学等相关专业和高等农业院校中药资源开发与利用等专业的专业基础课,是培养相关专业学生掌握和运用药用植物形态解剖学及系统分类学的基本知识和技能,准确识别和鉴定药用植物种类,保证临床用药准确有效的重要课程。课题组通过整合药用植物学教学内容,建立多元化的教学方法,构建多层次实践教学体系,建立合理的综合性考核评价体系,培养学生双创能力。     

Photosynthetic marine organisms as a source of anticancer compounds

Since early human history, plants have served as the most important source of medicinal natural products, and even in the “synthetic age” the majority of lead compounds for pharmaceutical development remain of plant origin. In the marine realm, algae and seagrasses were amongst the first organisms investigated by marine natural products scientists on their quest for novel pharmaceutical compounds. Forty years after the pioneering work in the field of marine drug discovery began, the biodiversity of marine organisms investigated as potential sources of anticancer, anti-inflammatory, and antibiotic compounds has increased tremendously. Nonetheless, marine plants are still an important source of novel secondary metabolites with interesting biomedical properties. The present review focuses on the antitumour properties of compounds isolated from marine algae, phytoplankton, mangroves, seagrasses, or cordgrasses. Compounds produced by marine epi- or endophytic fungi are also discussed.     

Evaluation of genetic stability using FRAPD markers as novel method along with antioxidant and anti-diabetic properties of micropropagated <Emphasis Type="Italic">Salacia chinensis</Emphasis> L.

Salacia chinensis L., a perennial medicinal plant, is well-known for its well-documented anti-diabetic properties. The daily growing demand in pharmaceutical industry is stimulating the conservation and wide-ranging production of the plant using plant tissue culture techniques (micropropagation). In the present study, the plants generated by direct micropropagation from nodal explants were assessed using fluorescently labeled RAPD (FRAPD) primers. Although standard RAPD primer bands in agarose gel showed genetic stability, using FRAPD analysis in genetic DNA sequencer as a novel strategy showed more accurate and reliable method has indicated by the evidence in 5% genetic variation. Antioxidant and anti-diabetic activities of micropropagated plants versus mother plant were examined using DPPH, FRAP, α-amylase, and α-glucosidase assays. The results showed that the micropropagated plants, which are able to produce higher amount of secondary metabolites than the mother plant, possess higher in vitro antioxidant and anti-diabetic properties.     

Cyclitol utilization associated with the presence of Klebsielleae in botanical environments.

Bacteria of the tribe Klebsielleae are capable of metabolizing the cyclitols myoinositol, sequoyitol, and pinitol, which are present in aqueous extracts of redwood. Of the combined Klebsiella isolates from clinical and environmental origins, 100% (138/138), 97% (34/35), and 86% (119/138) fermented inositol, sequoyitol, and pinitol, respectively. These compounds were also used as a sole source of carbon and energy by Klebsiella. Similar results were obtained with Enterobacter isolates, but most other enteric bacteria tested could not metabolize cyclitols. Strains of Klebsiella multiplied to levels exceeding 10(5)/ml in aqueous extracts of nonsterile redwood within 6 days. Most other enteric bacteria did not grow in these extracts. Cyclitol metabolism was found to correlate well with the ability to multiply in redwood extract in the presence of cyclitol-negative indigenous bacteria. The capacity to use cyclitols, which are present in a variety of plant material, might afford Klebsielleae of both environmental and clinical origins an advantage in competing for nutrients and colonizing botanical environments.     

Improvement of hairy root cultures and plants by changing biosynthetic pathways leading to pharmaceutical metabolites: Strategies and applications

A plethora of bioactive plant metabolites has been explored for pharmaceutical, food chemistry and agricultural applications. The chemical synthesis of these structures is often difficult, so plants are favorably used as producers. While whole plants can serve as a source for secondary metabolites and can be also improved by metabolic engineering, more often cell or organ cultures of relevant plant species are of interest. It should be noted that only in few cases the production for commercial application in such cultures has been achieved. Their genetic manipulation is sometimes faster and the production of a specific metabolite is more reliable, because of less environmental influences. In addition, upscaling in bioreactors is nowadays possible for many of these cultures, so some are already used in industry. There are approaches to alter the profile of metabolites not only by using plant genes, but also by using bacterial genes encoding modifying enzymes. Also, strategies to cope with unwanted or even toxic compounds are available. The need for metabolic engineering of plant secondary metabolite pathways is increasing with the rising demand for (novel) compounds with new bioactive properties. Here, we give some examples of recent developments for the metabolic engineering of plants and organ cultures, which can be used in the production of metabolites with interesting properties.     

Cyclitol utilization associated with the presence of Klebsielleae in botanical environments.

Bacteria of the tribe Klebsielleae are capable of metabolizing the cyclitols myoinositol, sequoyitol, and pinitol, which are present in aqueous extracts of redwood. Of the combined Klebsiella isolates from clinical and environmental origins, 100% (138/138), 97% (34/35), and 86% (119/138) fermented inositol, sequoyitol, and pinitol, respectively. These compounds were also used as a sole source of carbon and energy by Klebsiella. Similar results were obtained with Enterobacter isolates, but most other enteric bacteria tested could not metabolize cyclitols. Strains of Klebsiella multiplied to levels exceeding 10(5)/ml in aqueous extracts of nonsterile redwood within 6 days. Most other enteric bacteria did not grow in these extracts. Cyclitol metabolism was found to correlate well with the ability to multiply in redwood extract in the presence of cyclitol-negative indigenous bacteria. The capacity to use cyclitols, which are present in a variety of plant material, might afford Klebsielleae of both environmental and clinical origins an advantage in competing for nutrients and colonizing botanical environments.     

南京地区药用植物资源调查

对南京地区的药用植物资源进行了初步调查,据植物分类学统计,南京地区有药用植物107科281属357种,其中蕨类植物12科12属12种,种子植物95科269属345种.对数种江苏特产和稀有的药用植物进行了介绍.     

Influence of environmental abiotic factors on the content of saponins in plants

Saponins are a large group of secondary metabolites occurring in significant amounts in many plant species. However, the saponin content of plants is variable and it can be influenced by the surrounding environment. The local geoclimate, seasonal changes, external conditions such as light, temperature, humidity and soil fertility, as well as cultivation techniques, affect both the quantitative amount and qualitative composition of saponins. Such variation substantially impacts on the quality and properties of wild and cultivated plants exploited for pharmaceutical, nutritional and industrial applications. This review summarizes the available data on the effects of abiotic environmental factors on saponin level in plants, especially those of considerable economic importance, highlighting current problems such as the reduction in natural plant resources, over-exploitation and destruction of wild habitats, climate shifts as well as the consequences of the growing demand for plant-derived medicinal and industrial products. The need for a theoretical basis for a reasonable harvest, attempts at the domestication of wild plant species and the development of new agricultural technologies allowing high production under optimized conditions are also discussed.     

Patterns of pinitol accumulation in soybean plants and relationships to drought tolerance

Previous studies indicate that methylated cyclitols are potentially important osmolytes in plants. In a search for genetic diversity for pinitol (D -3-O-methyl-chiro-inositol) accumulation in soybean (Glycine max (L.) Merr.), two- to three-fold differences in pinitol accumulation in leaf blades were found among Chinese plant introductions. Furthermore, it was found that genotypes that accumulated high concentrations of pinitol, when grown under well-watered conditions, had been selected for performance in regions of China having low rainfall. Among the carbohydrates analysed, pinitol accumulation was uniquely associated with adaptation to dry areas of China. A detailed study of pinitol accumulation in the soybean plant showed two- to three-fold gradients in pinitol concentration from the bottom to the top of the plant. The gradient shifted during plant development, with consistently higher concentrations of pinitol in the uppermost leaves. Pinitol accumulation was not correlated with activity of the key biosynthetic enzyme, inositol methyl transferase. This result and other lines of evidence indicated that shifting patterns of pinitol accumulation were due to translocation of the cyclitol from lower to upper nodes. Pinitol, proline, and sugars accumulated in leaf blades on soybean plants subjected to drought, but the molar concentration of pinitol in stressed plants was greater than the concentrations of proline or sugars. Although the mechanism by which pinitol participates in drought tolerance is not fully known, our results provide additional correlative evidence linking pinitol and drought tolerance in soybean.     

植物3-羟基-3-甲基戊二酰辅酶A还原酶基因研究进展

细胞分裂素、赤霉素、脱落酸、叶绿素、萜类等类异戊二烯物质,是植物中广泛存在的一类代谢产物,在植物生长发育过程中起着非常重要的作用。一些萜类化合物作为药物的合成前体或有效的药用成分在工农业及医药生产上具有重要的经济价值。类异戊二烯物质主要通过甲羟戊酸代谢途径中的一系列酶催化合成,其中,3-羟基-3-甲基戊二酰辅酶A还原酶(3-hydroxy-3-methylglutaryl coenzyme A reductase, HMGR)是该代谢途径中的第一个关键限速酶,能够将3-羟基-3-甲基戊二酰辅酶A转化成中间代谢产物甲羟戊酸。对植物HMGR基因的克隆、酶结构和功能分析、基因组织表达及调控等方面进行了综述,旨在为其在重要农作物的遗传改良、代谢产物工程植物创制以及植物亲缘关系分析中的应用等研究提供理论依据。     

Cyclitol production in transgenic tobacco

High levels of cyclic sugar alcohols (cyclitols) correlate with tolerance to osmotic stress in a number of plant species. A gene encoding a cyclitol biosynthesis enzyme from a halophyte, Mesembryanthemum crystallinum has been introduced into tobacco. The gene, lmt1 , encodes a myo -inositol O -methyl transferase that, in M. crystallinum , catalyzes the first step in the stress-induced accumulation of the cyclitol pinitol. Tobacco transformed with the lmt1 cDNA under the control of the CaMV 35S promoter appeared phenotypically normal and exhibited IMT1 enzyme activity. Transformants accumulated a carbohydrate product not detectable in non-transformed control plants. This product was identified by HPLC and NMR as ononitol (1- d -4- O -methyl myo -inositol). Ononitol was a major carbohydrate constituent in leaf tissue of plants expressing the lmt1 gene, accumulating to up to 25% the level of sucrose in transformant seedlings. The identification of ononitol as the IMT1 product and the specific accumulation of this compound in transformed tobacco support a role for ononitol as a stable intermediate in pinitol biosynthesis and indicate that an epimerization activity lacking in tobacco is responsible for the conversion of ononitol to pinitol in M. crystallinum . The production of ononitol in tobacco indicates that plant carbohydrate metabolism is flexible and can accommodate the synthesis and accumulation of non-endogenous metabolites. The transgenic system described here will serve as a useful model to test the ability of cyclitols such as ononitol to confer tolerance to environmental stress in a normally glycophytic plant.     

The Compatibility of d-Pinitol and 1d-1-O-Methyl-Muco-Inositol with Malate Dehydrogenase Activity

Pinitol (1d -3-O-methyl-chiro-inositol) and 1d -1-O-methyl-muco-inositol, two cyclitols wide-spread in the plant kingdom, were isolated from plant sources in order to test their compatibility with malate dehydrogenase activity. Both compounds had no inhibitory effect on malate dehydrogenase from Rhizophora mangle in a range of 100 to 1000 mol . m^?3. Their influence on malate dehydrogenase activity from different plant sources (Rh. mangle L., Mesembryanthemum crystallinum L., Cicer arietinum L. and Spinacia oleracea L.) was also small and similar to that observed for a number of well established compatible solutes (e.g. proline, glycine betaine). A possible role of cyclitols as cryoprotectants or radical scavengers is discussed.     

Microbial xyloglucanases: a comprehensive review

Xyloglucan is one of the major hemicellulose components of the plant cell wall in majority of dicots and many monocots. Xyloglucanases break down xyloglucan and their role is implicated in the process of plant growth and pathogenesis. They are ubiquitously found in plants as well as in a variety of bacteria, fungi, actinomycetes, etc. In microbes, they are majorly extracellular and are active at a wide range of pH and temperature. They are a diverse group, with varying physicochemical and/or functional properties as well as substrate specificities and thereby the products they give rise to. Their biotechnological potential is immense, with applications in paper and pulp, textile, pharmaceutical and food industries as well as in production of biomaterials and biofuels. This review attempts to give an overview about microbial xyloglucanases and includes important sources, biochemical properties, industrial applications and a brief look at their catalytic mechanisms and GH families.     

Molecular farming of pharmaceutical proteins

Molecular farming is the production of pharmaceutically important and commercially valuable proteins in plants. Its purpose is to provide a safe and inexpensive means for the mass production of recombinant pharmaceutical proteins. Complex mammalian proteins can be produced in transformed plants or transformed plant suspension cells. Plants are suitable for the production of pharmaceutical proteins on a field scale because the expressed proteins are functional and almost indistinguishable from their mammalian counterparts. The breadth of therapeutic proteins produced by plants range from interleukins to recombinant antibodies. Molecular farming in plants has the potential to provide virtually unlimited quantities of recombinant proteins for use as diagnostic and therapeutic tools in health care and the life sciences. Plants produce a large amount of biomass and protein production can be increased using plant suspension cell culture in fermenters, or by the propagation of stably transformed plant lines in the field. Transgenic plants can also produce organs rich in a recombinant protein for its long-term storage. This demonstrates the promise of using transgenic plants as bioreactors for the molecular farming of recombinant therapeutics, including vaccines, diagnostics, such as recombinant antibodies, plasma proteins, cytokines and growth factors. This revised version was published online in August 2006 with corrections to the Cover Date.     

转基因植物表达药用蛋白的研究进展

基因工程技术的进步使得转基因植物广泛应用于工业、农业各个领域,尤其在医药制造领域。研究成果表明,转基因植物作为生物反应器在制备药用蛋白,如重组疫苗、重组动物抗体、细胞因子等方面较其他表达系统,如微生物及动物表达系统具有成本低、应用安全等优势,但在工业化技术方面仍存在障碍。     

Betalains in the era of global agri-food science, technology and nutritional health

Natural pigments from plants are of growing interest as substitutes for synthetic dyes in the food and pharmaceutical industry and they increase their added value if they possess positive effects on health. These pigments can be added as such if they are in the legal authorized lists of additives or can be added as phytochemical-enriched plant extract achieving the original product, which has received it, the new nomenclature of functional food. In this way, we comprise on this review a wide point of view of a group of natural pigments known as betalains. From a chemical point of view, betalains are ammonium conjugates of betalamic acid with cyclo-DOPA (betacyanins, violet) and aminoacids or amines (betaxanthins, orange or yellow), which are compounds present in our diet. Besides and taking into account that one type of betalain, betanin is approved as food colorant (E-162) by the European Union and that enlarges the specific weight of these compounds in the diet, we have evolved an overview from the biosynthesis, technology and promoting production, industrial uses as pigments up to physiological and nutritional biovailability or biological and health-promoting properties of betalains for accessible information to industrials, researchers and consumers.     

植物黄酮类化合物的研究进展

植物黄酮类化合物作为一类具有较高药用价值的化合物,一直是国内外生物类和医药类研究的热门课题。随着研究的不断进展,黄酮类化合物的药用价值及其构效关系也不断被发掘,越来越多的黄酮类化合物药物制剂也相继投入临床应用。综述了近年来植物黄酮类化合物的研究进展,对其种类结构、理化性质、药理活性及分离提纯与鉴定作了较为系统的阐述。针对生产工艺中存在的主要问题,提出了相应的解决方法。展望了其在医药卫生方面的应用前景。     

药用植物分子农场研究进展

植物分子农场可以利用植物生产具有药物用途的重组蛋白或者次生代谢化合物,应用广泛。随着对动植物中具有药物用途的代谢途径的深入解析,代谢途径中关键限速酶或调控蛋白的功能不断被明确,如何选择植物分子农场的底盘植物和遗传改造途径等问题,特别是如何协同提高植物制药产量与品质一直是植物分子农场体系建立中面临的关键科学问题。综述了药用的植物分子农场的最新研究进展,着重介绍了底盘植物的选择与药用植物分子农场的构建策略,以期为提高分子农场应用效果提供有力的科技支撑。     

Plants actively control nitrogen cycling: uncorking the microbial bottleneck

Ecologists have tried to link plant species composition and ecosystem properties since the inception of the ecosystem concept in ecology. Many have observed that biological communities could feed back to, and not simply result from, soil properties. But which group of organisms, plants or microorganisms, drive those feedback systems? Recent research asserts that soil microorganisms preclude plant species feedback to soil nitrogen (N) transformations due to strong microbial control of soil N cycling. It has been well documented that litter properties influence soil N cycling. In this review, we stress that under many circumstances plant species exert a major influence over soil N cycling rates via unique N attainment strategies, thus influencing soil N availability and their own fitness. We offer two testable mechanisms by which plants impart active control on the N cycle and thereby allow for plant-litter-soil-plant feedback. Finally, we describe the characteristics of plants and ecosystems that are most likely to exhibit feedback.