Selective induction of secondary metabolism in Phaseolus lunatus by 6-substituted indanoyl isoleucine conjugates

A novel and highly efficient route to new indanoyl isoleucine conjugates is described, which allows a wide range of substituents to be attached to the 6-position of the indanoyl moiety. We report the synthesis of conjugates with methyl, methoxy, propoxy, allyloxy, pentoxy, and 2-(2-methoxy-ethoxy)-ethoxy 6-position substituents. Preliminary biological activities of the novel compounds with significantly enhanced water solubility were determined using the Lima bean (Phaseolus lunatus) volatile bioassay. The compounds induce variable volatile patterns, and structure-activity relationships show an ability to differentially induce separate pathways leading to secondary metabolites.     

Biosynthesis and Metabolism of Jasmonates

Jasmonates are derived from oxygenated fatty acids via the octadecanoid pathway and characterized by a pentacyclic ring structure. They have regulatory function as signaling molecules in plant development and adaptation to environmental stress. Until recently, it was the cyclopentanone jasmonic acid (JA) that attracted most attention as a plant growth regulator. It becomes increasingly clear, however, that biological activity is not limited to JA but extends to, and may even differ between its many metabolities and conjugates as well as its cyclopentenone precursors. The enzymes of jasmonate biosynthesis and metabolism may thus have a regulatory function in controlling the activity and relative levels of different signaling molecules. Such a function is supprted by both the characteration of loss of function mutants inArabidopsis, and the biochemical characterization of the enzymes themselves. Online publication: 27 January 2005     

Diversity and Complexity of Ceramide Signalling in Apoptosis

Sphingolipid ceramide has emerged as a lipid messenger of cell functions including differentiation and apoptosis. Diverse kinds of stresses (ultraviolet, irradiation, heat shock and hypoxia) and biological factors (TNF-, IFN-γ and Fas antibody) require ceramide generation to execute apoptosis. The review summarises the diversity and complexity of up- and downstream of ceramide signalling in apoptosis and clinical implications of ceramide-induced apoptosis.     

Microorganisms, Australia and the Convention on Biological Diversity

The Convention on Biological Diversity arose as an international agreement for the conservation and continued exploitation of Earth's biological diversity (biodiversity). It directly affects those involved in conservation, exploitation and investigation of biodiversity in all its forms, as well as affecting the viability of all life. Australia is one of more than 170 countries that have ratified the Convention. Its involvement in this Convention will be considered in terms of the National Strategy for the Conservation of Biological Diversity with a focus on the coverage of microorganisms within this strategy. Microorganisms represent a major part of the biodiversity on Earth but, as yet, remain relatively unknown. Among those microorganisms that have been described, many, originating from a range of countries, have been deposited in culture collections worldwide. The Convention contains articles that impact on ex situ collections, although precise protocols are not set out therein. An international code of conduct is now being formulated to ensure ongoing access to and exchange of microorganisms in the interests of sustainable development in industrialised and developing nations.     

NMR Structural Determinants of Eosinophil Cationic Protein Binding to Membrane and Heparin Mimetics

Eosinophil cationic protein (ECP) is a highly stable, cytotoxic ribonuclease with the ability to enter and disrupt membranes that participates in innate immune defense against parasites but also kills human cells. We have used NMR spectroscopy to characterize the binding of ECP to membrane and heparin mimetics at a residue level. We believe we have identified three Arg-rich surface loops and Trp³⁵ as crucial for membrane binding. Importantly, we have provided evidence that the interaction surface of ECP with heparin mimetics is extended with respect to that previously described (fragment 34-38). We believe we have identified new sites involved in the interaction for the first time, and shown that the N-terminal α-helix, the third loop, and the first and last β-strands are key for heparin binding. We have also shown that a biologically active ECP N-terminal fragment comprising the first 45 residues (ECP1-45) retains the capacity to bind membrane and heparin mimetics, thus neither the ECP tertiary structure nor its high conformational stability are required for cytotoxicity.     

Structural and Functional Diversity of Desmosomes

Abstract

Desmosomes anchor intermediate filaments at sites of cell contact established by the interaction of cadherins extending from opposing cells. The incorporation of cadherins, catenin adaptors, and cytoskeletal elements resembles the closely related adherens junction. However, the recruitment of intermediate filaments distinguishes desmosomes and imparts a unique function. By linking the load-bearing intermediate filaments of neighboring cells, desmosomes create mechanically contiguous cell sheets and, in so doing, confer structural integrity to the tissues they populate. This trait and a well-established role in human disease have long captured the attention of cell biologists, as evidenced by a publication record dating back to the mid-1860s. Likewise, emerging data implicating the desmosome in signaling events pertinent to organismal development, carcinogenesis, and genetic disorders will secure a prominent role for desmosomes in future biological and biomedical investigations.     

Biological Diversity, Dietary Diversity, and Eye Health in Developing Country Populations: Establishing the Evidence-base

Human and ecosystem health converge around biological diversity issues. Cultivated and wild plants as food and medicine make essential contributions to human health, which in turn provides rationales for conservation. While wild and cultivated plant diversity reasonably facilitates dietary diversity and positive health outcomes, the challenges of demonstrating this relationship limit its impact in concept, policy, and practice. We present a rationale for testing the dietary contribution of biological diversity to improved eye health as a case study based on existing phytochemical, pharmacological, and clinical knowledge. We consider the empirical evidence needed to substantiate, interpret, and apply this relationship at a population and ecosystem level within a unified research framework. Epidemiological data strongly support the prevention of childhood vitamin A deficiency blindness, cataract, and age-related macular degeneration by fruit and vegetable consumption. Phytonutrients, including the carotenoids lutein and zeaxanthin, protect the eye from oxidative stress and harmful light exposure. Laboratory, community, and population level research should prioritize food composition of dietary plants from both agriculture and the wild. Intervention studies, focus groups, and transmission of knowledge of local species and varieties within communities will further interpretation of epidemiological data. Population-based studies combining clinical data and measures of access and consumption of biological diversity are key to demonstrating the important relationships among biodiversity, dietary diversity, and health outcomes.     

非编码小RNA的多样性

RNA是一类广泛存在的极其重要的生物大分子,它不仅种类繁多,而且不同种类的RNA在结构方面有着显著的差异。RNA种类和结构的多样性决定了RNA具有很多重要的生物学功能。随着对非编码RNA(non-coding RNA,ncRNA)研究的不断深入,ncRNAs同样呈现出前所未有的复杂性和多样性。主要介绍了tRNA、snRNA、scRNA、rRNA、siRNA、miRNA、pi RNA和nat-si RNA等两大类持家ncRNA和调控ncRNA的结构和功能,为便于了解生物体内小的非编码RNA的多样性,进一步挖掘和利用ncRNAs提供一定的参考,促使人们对RNA的认识和地位作出新的思考。     

Shifting Cultivation and Conservation of Biological Diversity in Tripura, Northeast India

Shifting cultivation (jhooming) has been identified as one of the main human impacts influencing biodiversity in Tripura, Northeast India. Over the last few years a new class of shifting cultivators has emerged that has adopted non-traditional forms of jhooming, which have been responsible for the loss of biological diversity in the state. This paper describes the successes achieved by the state government in providing the jhumias (tribes practicing jhooming) with various non-jhooming options. Recommendations include the need for short and long term control measures, improvement of existing jhooming methods, and integration of traditional knowledge with new practices.     

AFLP技术在微生物分类鉴定、基因标定及遗传多样性方面的应用

简述了AFLP技术的原理,比较了AFLP方法与其他分子标记的不同及其优缺点。着重论述了该技术在微生物分类、鉴定、基因标定及遗传多样性方面的应用。     

Studies on Biological Activity of Cyclic Imide Compounds

The structure-activity relationships of l-phenylpyrrolidine-2,5-dione derivatives were investigated on Sclerotinia sclerotiorum by the agar dilution method. In addition, several representative compounds were tested for antimicrobial spectra in vitro with 15 pathogenic microbes and for foliage protection activity in green house tests with rice blast, rice brown spot, rice sheath blight and kidney bean stem rot. It was found that 3,5-dihalo-substituents on the benzene moiety are essential to high antifungal activity against Sclerotinia sclerotiorum. Generally, l-(3′,5′-dihalophenyl)pyrrolidine-2,5-diones are active against Corticiaceae, Dematiaceae, Pleosporaceae and Sclerotiniaceae, especially active against Sclerotinia sclerotiorum and Botrytis cinerea (the conidia form of Sclerotinia fuckeliana). N-(3,5-Dichlorophenyl)itaconimide showed a peculiarly broad antimicrobial spectrum. In green house tests, these compounds showed high activity against rice brown spot, rice sheath blight and kidney bean stem rot. Results of green house tests on the above-mentioned diseases correlate fairly well with those of in vitro tests.     

Synthesis,estrogen receptor binding affinity and molecular docking of pyrimidine-piperazine-chromene and -quinoline conjugates

Substituted 2-amino-7-((6-(4-(2-hydroxyethyl) piperazin-1-yl)-2-methylpyrimidin-4-yl)oxy)-4-phenyl-4H-chromene-3-carbonitriles and 2-amino-7-((6-(4-(2-hydroxyethyl)piperazin-1-yl)-2-methylpyrimidin-4-yl)oxy)-4-phenyl-1,4-dihydroquinoline-3-carbonitriles were synthesized via an efficient multi-component one pot synthesis under mild conditions. These compounds 1–20 were evaluated against human breast cancer cell lines (MCF-7) and human embryonic kidney cells (HEK293) for cytotoxic activities. Among them, compounds 6, 7, 15, 17 and 19 showed better anti-proliferative activities as (IC₅₀ value 48 ± 1.70, 65 ± 1.13, 92 ± 1.18, 30 ± 1.17 and 16 ± 1.10 µM) than curcumin drug (48 ± 1.11 µM). Molecular docking was also performed with active compounds 6, 7 and 15 against Bcl-2 protein which gave good binding affinity (ΔG = ?9.08, ?8.29 and ?7.70 kcal/mol) respectively. Furthermore, the structure-activity relationship (SAR) analysis revealed that the chromene and quinoline moieties, when attached with pyrimide and piperazine moieties, enhanced anti-proliferative activities.     

Synthesis and Biological Action of a New Cyclic AMP Analogue

Abstract

A new cyclic AMP analogue, adenosine- 3′, 5′-cyclic methyl phosphonate (cAMP-Me) was chemically synthesized. This compound was not a substrate for phosphodiesterase, and it did not activate cAMP-dependent protein kinases (type I or type II). However, it inhibited cAMP phosphodiesterase and protein kinase at milimolar concentration levels. It also inhibited malignant cell proliferation in vitro.     

1H, 13C and 15N resonance assignments for Binder of Arl2, BART

We report ¹H, ¹³C and ¹⁵N resonance assignments for Binder of Arl Two (BART), an effector of the small G protein Arl2. The BMRB accession code is 15914.     

Entomopathogenic Nematodes: Biodiversity, Geographical Distribution and the Convention on Biological Diversity

This paper addresses three major issues. Firstly, molecular taxonomy and its application to elucidate the biodiversity and biogeography of entomopathogenic nematodes is considered. Accurate identification is fundamental for understanding biodiversity, and because these nematodes are morphologically conservative, molecular techniques will provide the insights necessary to develop a robust, morphologically based taxonomy. Secondly, a review of the knowledge on their biogeography and habitat specificity, including a consideration of the limitations to the available data is given. Much of the information is presented in two tables which summarize the distributions of recognized species at continental and national levels. Thirdly, this paper provides a brief consideration of the Convention on Biological Diversity and its implications for future work with entomopathogenic nematodes and biological control.     

《生物多样性公约》传统知识议题的背景、进展与趋势

传统知识之所以成为《生物多样性公约》等国际公约的热点议题,主要源于其重要的研究价值、经济潜力以及特定的社会历史背景.《生物多样性公约》签署至今,在传统知识议题方面取得了许多进展,如:设立专门的传统知识工作组,为履行公约相关条款制定了工作方案和行动计划,推动特殊制度的谈判,达成一系列道德行为准则,以及通过了《生物多样性公约关于获取遗传资源和公正公平分享其利用所产生惠益的名古屋议定书》.根据公约第十次和第十一次缔约方大会达成的相关决议,习惯性可持续利用(customary sustainable use)、特殊制度(sui generis systems)、传统知识归还(repatriation)等将成为今后传统知识谈判的重点.我国需要加强生物多样性保护和知识产权等主管部门之间的协作,协调我国在不同国际法框架中传统知识议题的谈判立场;还需要开展习惯性可持续利用、特殊制度体系、传统知识就地或者活态保护(living protection)的研究.     

Synthesis and Biological Evaluation of some Acyclic Nucleoside Cyclic Phosphoramidate Derivatives

Abstract

The acyclic nucleosides 2 were treated with 2-chloro-3-methyl-1-oxa-3-aza-2-phosphacyclopentane (3) in the presence of diisopropylethylamine to give the corresponding phosphoramidite derivatives (4). The phosphoramidite intermediates (4) were oxidized with m-chloroperbenzoic acid to the phosphoramidate derivatives (5). Treatment of 5a,b with ZnBr₂ in CH₃NO₂ gave the corresponding acyclic nucleoside cyclic phosphoramidates (6a,b). Attempts to desilylation of 5c by tetrabutylammonium fluoride (TBAF) resulted in opening of the phosphoramidate ring. The newly synthesized compounds were evaluated for antiviral and antitumor cell activity.