39 resultados para secondary metabolite

em Deakin Research Online - Australia


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Lovastatin is a potent hypercholesterolemic drug used for lowering blood cholesterol. It acts by competitively inhibiting the enzyme, 3-hydroxy-3-methylglutaryl coenzyme A reductase involved in the biosynthesis of cholesterol. It is produced by a variety of filamentous fungi including Penicillium species, Monascus ruber and Aspergillus terreus as a secondary metabolite. Production of lovastatin by biotechnology decreases the production cost compared to costs of chemical synthesis. In recent years, lovastatin has also been reported as a potential therapeutic agent for the treatment of various types of tumors and also play a tremendous role in the regulation of the inflammatory and immune response, coagulation process, bone turnover, neovascularization, vascular tone, and arterial pressure. This review focus on the structure, biosynthesis, biotechnological production and biomedical applications of lovastatin.

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Arbuscular mycorrhiza is a symbiotic association formed between plant roots and soil borne fungi that alter and at times improve the production of secondary metabolites. Detailed information is available on mycorrhizal development and its influence on plants grown under various edapho-climatic conditions, however, very little is known about their influence on transformed roots that are rich reserves of secondary metabolites. This raises the question of how mycorrhizal colonization progresses in transformed roots grown in vitro and whether the mycorrhizal fungus presence influences the production of secondary metabolites. To fully understand mycorrhizal ontogenesis and its effect on root morphology, root biomass, total phenolics, rosmarinic acid, caffeic acid and antioxidant production under in vitro conditions, a co-culture was developed between three Agrobacterium rhizogenes-derived, elite-transformed root lines of Ocimum basilicum and Rhizophagus irregularis. We found that mycorrhizal ontogenesis in transformed roots was similar to mycorrhizal roots obtained from an in planta system. Mycorrhizal establishment was also found to be transformed root line-specific. Colonization of transformed roots increased the concentration of rosmarinic acid, caffeic acid and antioxidant production while no effect was observed on root morphological traits and biomass. Enhancement of total phenolics and rosmarinic acid in the three mycorrhizal transformed root lines was found to be transformed root line-specific and age dependent. We reveal the potential of R. irregularis as a biotic elicitor in vitro and propose its incorporation into commercial in vitro secondary metabolite production via transformed roots.

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In order to discover phytochemicals that are potentially bioactive against Phytophthora cinnamomi, (a soil-borne plant pathogen) a metabolite profiling protocol for investigation of metabolic changes in Lupinus angustifolius L. plant roots in response to pathogen challenge has been established. Analysis of the metabolic profiles from healthy and P. cinnamomi-inoculated root tissue with high resolution mass spectrometry and nuclear magnetic resonance spectroscopy confirmed that although susceptible, L. angustifolius upregulated a defence associated genistein and 2′-hydroxygenistein-based isoflavonoid and a soyasapogenol saponin at 12h post inoculation which increased in concentration at 72h post inoculation. In contrast to the typical susceptible interaction, the application of a phosphorous-based treatment to L. angustifolius foliage 48h before P. cinnamomi challenge negated the ability of the pathogen to colonise the root tissue and cause disease. Importantly, although the root profiles of water-treated and phosphite-treated plants post pathogen inoculation contained the same secondary metabolites, concentration variations were observed. Accumulation of secondary metabolites within the P. cinnamomi-inoculated plants confirms that pathogen ingress of the root interstitially occurs in phosphite-treated plants, confirming a direct mode of action against the pathogen upon breaching the root cells.

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The 1998 Report of the National Standards and Guidelines for Initial Teacher Education Project, 'Preparing a Profession' illustrates the emphasis being placed in Australia on the development of numeracy skills amongst not only primary but also secondary school pupils. This report demands that graduates of all initial teacher training courses should not only be numerate themselves, but should also understand the contribution of numeracy to education and daily life, and be able to identify and respond to pupils' numeracy learning needs. This report and its implementation in Victoria through the 'Guidelines for the Evaluation of Teacher Education Courses' led to the introduction in 1999 of a compulsory unit 'Numeracy across the curriculum' for all Deakin University students in the final year of their secondary teacher training course. This paper discusses the nature of the current emphasis on numeracy. It also describes the rationale, development and delivery of the first year of the 'Numeracy across the curriculum' unit, provides a brief evaluation from the perspective of staff and students, and discusses what impact such teacher education programs might have on secondary schools' approaches to numeracy.

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In secondary school biology in Victoria State, Australia, practical work including laboratory exercises, fieldwork and other research activities is carried out more frequently than in Japanese senior high school biology. The authors examined the contents of the practical work and how often such practical work is carried out in some urban and rural secondary schools in Victoria. The topics of biology practical work were based on the VCE Biology Study Design which was published by the Victorian Board of Studies. Some of the activities continued for some weeks. Sometimes students went out from their school for fieldwork for a few days. The average number of practical work per credit was about 4. This number is consider ably larger than the value (2.3 per credit) which was reported on senior high schools in Osaka Prefecture. Why so often can the practical work be carried out? The main reason is that as well as the scores of ordinary paper tests, the evaluation of each practical work is taken into consideration at the entrance examination of universities and other tertiary education institutes in Victoria State.

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In the first stage of a three-year study in which the effects of using computers for the teaching and learning of mathematics are being explored, a questionnaire was developed and administered to teachers of students in grades 7–10 in a representative sample of co-educational post-primary schools in Victoria, Australia. Using open and closed response formats, the information sought included data on the teachers' professional backgrounds, computer ownership and use, and their beliefs and practices in using computers for the teaching of mathematics. In this article, findings related to ownership, professional development, perceptions of technological skills, beliefs about the efficacy of computer use in mathematics, and data on how teachers are using computers for teaching secondary mathematics are presented and discussed.

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The solid-state structures of the previously known para-substituted diphenyltellurium dichlorides, (p-XC6H4)2TeCl2 (X=H (1), Me (2), MeO (3)) were investigated by 125Te MAS NMR spectroscopy and in case of 2 by single crystal X-ray diffraction. The 125Te-NMR shielding anisotropy (SA) was studied by tensor analyses based on relative intensities of the observed spinning sidebands. Solid-state NMR parameters, namely the isotropic chemical shift (δiso), anisotropy (ζ) and asymmetry (η), were discussed in relation to the molecular structures established by X-ray crystallography. The asymmetry (η) was found to be particularly sensitive to structural differences stemming mostly from the diverse secondary Te...Cl interactions, but no correlation with geometric parameters could be established.


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The School Innovation in Science intiative is operating in more than 300 schools in Victoria. It has achieved considerable success in transforming science teaching and learning in primary and secondary schools. This paper describes the core elements of SIS, and provides an overview of the different types of initiatives pursued by secondary schools arising out of an action planning process. case studies of initiatives illustrate the richness and range of innovation in schools. It is argued that the SIS model provides the conditions for deep seated change and innovation in schools' science programs.

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Two major predictors of subjective quality oflife (SQOL) in adults are known to beself-esteem and a sense of primary control.Moreover, secondary control is known to be animportant defence strategy when primary controlfails. This study aimed to determine whetherthese relationships also apply to children. Asample of 66 children aged from 5 to 12 yearswere compared on their use of primary andsecondary control and on their ratings of SQOLand self-esteem. SQOL was measured using theComprehensive Quality of Life Scale,self-esteem by using the CoopersmithSelf-Esteem Inventory, and primary andsecondary control were measured by codingchildren's responses to three short video clipsof children in stressful situations. It wasfound that younger children use more primarycontrol and less secondary control than olderchildren. However, five year olds were foundcapable of producing secondary controlstrategies. Contrary to expectation, primaryand secondary control did not predict eitherself-esteem or SQOL. However, self-esteempredicted SQOL as expected and no sexdifferences were found. These findingsemphasise important differences from the adultliterature and the reasons for this arediscussed.

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This article describes an exploration of a class of secondary school students perceptions of a constructivist informed teaching and learning environment for geometric optics. The students perceived the environment as one where they could freely express their ideas and be involved in activities. What was also apparent in this exploration was the students' preference for a classroom that involved small group discussions to whole class discussions that reflected a need for time to think about issues. They also have a preference for relevant, practical work that tests their ideas and a preference to have fewer notes that they construct themselves rather than notes dictated by the teacher.

NT: Refereed article. Includes bibliographical references.

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The aim of this research was to ascertain changes in sun-related knowledge, attitudes and self-care practices among Australian secondary school students between 1993 and 1996. Two cross-sectional surveys of sun-related attitudes, beliefs and behavior of young people aged 12–17 years of age, were conducted in 1993 and 1996. Over 80% of adolescents at both time periods knew about the issues related to skin cancer prevention, frequency of burning and burning on cloudy days. Adolescent attitudes had shifted positively in the areas of staying inside in 1996 [relative risk (RR): 1.13; 95% confidence interval (CI): 1.09–1.17] and staying under shade in 1996 (RR: 1.16; 95% CI: 1.13–1.18). Desire for a moderate or dark tan was lower in 1996 (45%) than in 1993 (50%). Respondents reported that they were less likely to wear brief clothing to get a suntan in 1996 (RR: 0.81; 95% CI: 0.78–0.84) and were significantly more likely to stay in the shade in 1996 (RR: 1.19; 95% CI: 1.16–1.23). We conclude that there has been a shift in attitudes towards use of shade and avoidance of unnecessary exposure, and away from use of sunscreens and sunglasses. The results suggest that adolescents may be more ready to accept structural changes that move desired activities out of the sun.