Halocin SH10 production by an extreme haloarchaeon Natrinema sp. BTSH10 isolated from salt pans of South India

Halobacteria, members of the domain Archaea that live under extremely halophilic conditions, are often considered as dependable source for deriving novel enzymes, novel genes, bioactive compounds and other industrially important molecules. Protein antibiotics have potential for application as preserving agents in food industry, leather industry and in control of infectious bacteria. Halocins are proteinaceous antibiotics synthesized and released into the environment by extreme halophiles, a universal characteristic of halophilic bacteria. Herein, we report the production of halocin (SH10) by an extremely halophilic archeon Natrinema sp. BTSH10 isolated from salt pan of Kanyakumari, Tamilnadu, India and optimization of medium for enhanced production of halocin. It was found that the optimal conditions for maximal halocin production were 42 C, pH 8.0, and 104 h of incubation at 200 rpm with 2% (V/V) inoculum concentration in Zobell’s medium containing 3 M NaCl, Galactose, beef extract, and calcium chloride as additional supplements. Results indicated scope for fermentation production of halocin for probable applications using halophilic archeon Natrinema sp. BTSH10

Actinomycete Isolates from Arabian Sea and Bay of Bengal: Biochemical, Molecular and Functional Characterization

The thesis is comprised of seven chapters. Chapter 1 gives a general introduction to marine actinomycetes; Chapter 2 gives an account on the morphological, biochemical and physiological characterization of marine actinomycetes. Comprehensive description of molecular identification and phylogenetic analysis of actinomycetes is dealt with in Chapter 3. The antimicrobial property with special reference to antivibrio activity is described in Chapter 4. Chapter 5 explores the melanin production ability of marine actinomycetes, characterization of melanin and evaluation of its bioactivity. Chapter 6 illustrates the study on chitinolytic Streptomyces as antifungal and insecticidal agents. Summary and Conclusion of the study is presented in Chapter 7, followed by References and Appendices.The present study provides an insight into the various actinomycetes occurring in the sediments of Arabian Sea and Bay of Bengal. Streptomyces was found to be the dominant group followed by Nocardiopsis. Eventhough generic level identification is possible by traditional phenotypic methods, species level identification necessitate a polyphasic approach including both phenotypic and genotypic characterization. Antibiotic production coupled with biogranulation property helped in the effective utilization of the actinomycetes for the control of vibrios. Melanin from Streptomyces bikiniensis was proved to be a promising antioxidant and photoprotectant. Marine actinomycetes were found to be a good source of hydrolytic enzymes and the chitinolytic isolates could be explored as biocontrol agents in terms of antifungal and insecticidal property. The present study explored the potential of marine actinomycetes especially Streptomycetes as a promising source of bioactive molecules for application in aquaculture and pharmaceutical industry.

Amphiphile Verbindungen der 14. Gruppe - Synthese, Eigenschaften und Anwendungen von Organosilanolen

Im Rahmen dieser Dissertation wurde an der Darstellung stabiler, amphiphiler Silantriole gearbeitet. Es ist gelungen eine kontinuierliche Reihe sukzessive um CH2-Einheiten verlängerter Silantriole des Typs H3C(CH2)nC(CH3)2Si(OH)3 (n = 1-5) durch eine vierstufige Synthesesequenz ausgehend von n-Alkylbromiden herzustellen und zum Teil röntgenographisch zu untersuchen. Ihre oberflächenaktiven Eigenschaften in wässrigen Lösungen konnten erstmals mittels Oberflächenspannungsmessungen belegt werden. Durch gezielte Kondensationsreaktionen mit Trifluoressigsäure wurden ausgehend von den oben beschriebenen Silantriolen selektiv die entsprechenden Disiloxan-Tetrole erhalten und ebenfalls zum Teil durch Röntgenstrukturanalysen charakterisiert. Als weitere Kondensationsprodukte der Silantriole konnten die ersten Octasilsesquioxane mit tertiären Kohlenstoff-Substituenten durch Umsetzungen mit n-Bu4NF selektiv und in hohen Ausbeuten erhalten und ebenfalls röntgenographisch identifiziert werden. Es wurde an der Darstellung Aryl-substituierter Silantriole RSi(OH)3 (R = Mesityl-, Xylyl- und Tetramethyl-phenyl-) gearbeitet. Diese zeichnen sich jedoch durch ihre hohe Instabilität in Lösung und im Festkörper aus und konnten zum Teil nur zusammen mit ihren primären Kondensationsprodukten erhalten werden. Darüber hinaus wurden stabile Silandiole des Typs R(t-Bu)Si(OH)2 (R = n-Butyl und n-Pentyl) sowie das (o-CF3C6H4)2Si(OH)2 in hohen Ausbeuten und selektiv synthetisiert. Die Festkörpereigenschaften des (o-CF3C6H4)2Si(OH)2 sowie seiner Vorstufe (o-CF3C6H4)2SiCl2 konnten durch Kristallstrukturanalysen genauer untersucht werden. In der Arbeit wurden die ersten Anwendungen von Silanolen als Silan-Kupplungsreagenzien bei der Oberflächenmodifizierung von Glas beschrieben. Im Gegensatz zu gängigen säureassistierten Beschichtungen zeichnen sich diese Silanol-Beschichtungen durch eine deutlich höhere Hydrophobizität aus. Dies konnte durch Kontaktwinkel- und Zeta-Potential-Messungen bestätigt werden. Durch Röntgenreflektivitäts- und Sarfus-Messungen ist die Ausbildung von Monolagen im Falle von t-BuSi(OH)3-beschichteten Oberflächen plausibel. Die Oberflächenmorphologie der Silantriol-Beschichtungen wurde mittels AFM-Messungen untersucht. Die Si(OH)3-Funktion konnte in der vorliegenden Arbeit als ein neues Pharmakophor etabliert werden. Die Silantriole CySi(OH)3, TerSi(OH)3 und CH3CH2C(CH3)2Si(OH)3 (Cy = Cyclohexyl, Ter = Terphenyl) sind in der Lage das Enzym Acetylcholinesterase reversibel zu hemmen. Dabei zeigt das CySi(OH)3 mit 45 % relativ zur Kontrolle die höchste Inhibition.

Apatite-Polymer Composite Particles for Controlled Delivery of BMP-2: In Vitro Release and Cellular Response

Bone morphogenetic protein-2 (BMP-2) has the ability to induce osteoblast differentiation of undifferentiated cells, resulting in the healing of skeletal defects when delivered with a suitable carrier. We have applied a versatile delivery platform comprising a novel composite of two biomaterials with proven track records – apatite and poly(lactic-co-glycolic acid) (PLGA) – to the delivery of BMP-2. Sustained release of this growth factor was tuned with variables that affect polymer degradation and/or apatite dissolution, such as polymer molecular weight, polymer composition, apatite loading, and apatite particle size. The effect of released BMP-2 on C3H10T1/2 murine pluripotent mesenchymal cells was assessed by tracking the expression of osteoblastic makers, alkaline phosphatase (ALP) and osteocalcin. Release media collected over 100 days induced elevated ALP activity in C3H10T1/2 cells. The expression of osteocalcin was also upregulated significantly. These results demonstrated the potential of apatite-PLGA composite particles for releasing protein in bioactive form over extended periods of time.

Synthesis of unusual alpha-amino acids and study of the effect of their incorporation into antimicrobial peptides. Total synthesis of biactive marine natural products and analogues thereof

The principle theme of this thesis was the synthesis of bioactive compounds. To this end, this work was focus on two main projects. The first one, which was carried out in the Department of Chemistry of the University of Girona under the supervision of Dr Montserrat Heras, concerned the synthesis of new unnatural amino acids bearing a pyrimidine ring within their side chain for incorporation into the antimicrobial peptide BP100 following a rational design in order to improve its biological profile. On the other hand, the second chapter of this thesis was developed in collaboration with the Laboratoire de Chimie Organique (ESPCI-ParisTech, Paris, France) under the guidance of Pr Janine Cossy and Dr Arseniyadis. This chapter was centered on the total synthesis of three marine natural products with complex structures and interesting biological activities: acremolide B, (–) bitungolide F and lyngbouilloside.

Influência de substâncias bioativas na estabilidade fisico-química e funcional de emulsões fotoprotetoras

Autilização de filtros ultravioletas isolados em formulações fotoprotetoras, origina produtos com proteção limitada contra as radiações solares, o que evidencia a necessidade de associar compostos bioativos. Estudos anteriores demonstraram que a rutina, um composto bioativo, interage sinergicamente com filtros solares incorporados em preparações fotoprotetoras. Portanto, este trabalho teve como objetivo avaliar a influência da rutina sobre a estabilidade físico-química e funcional de emulsões fotoprotetoras. 16 formulações foram desenvolvidas, submetidas ao teste de estabilidade preliminar e caracterizadas de acordo com o pH, perfil reológico e eficácia fotoprotetora in vitro . A formulação com o melhor desempenho e a formulação correspondente, sem rutina, foram submetidos ao teste de estabilidade normal. Todas as formulações apresentaram valores de pH compatível com a pele e comportamento reológico semelhante. A formulação F16 e a mesma formulação, sem rutina, foram submetidas ao teste de estabilidade normal e apresentaram valores de pH semelhantes e perfis reológicos que foram mantidos ao longo dos dias de análise. Aatividade antirradicalar foi estável apenas para formulações armazenadas a 5,0 ± 0,5°C. A eficácia fotoprotetora demonstrou resultados semelhantes entre ambas as formulações, que também foi observado em todos os dias de análise. Em conclusão, rutina não influenciou a fotoestabilidade da formulação sob as condições adotadas.

Aplicação de sub-produtos da “ginginha” de Óbidos em formulações tópicas: um estudo preliminar

Nos últimos anos estudos efectuados com frutos vermelhos têm revelado a sua riqueza em compostos bioactivos,sobretudo devido a presença de compostos polifenólicos. Neste trabalho foram avaliados os sub-produtos da ginja (Prunus cerasus L.) resultantes da indústria do licor de Óbidos, através da determinação do seu conteúdo em compostos fenólicos totais e, em particular, em antocianinas. As amostras de folhagens (pedúnculos e folhas) e de bagaço (película e película+caroço) foram extraídas por maceração através de 2 métodos de extracção diferentes, utilizando o etanol e o metanol como solventes. Na generalidade observaram-se diferenças significativas entre os teores em fenóis totais e antocianinas, quer dos extractos obtidos a partir de diferentes fracções (folhagem ou bagaço), quer dos extractos obtidos a partir da mesma fracção mas utilizando diferentes solventes. Os extractos das folhagens apresentaram valores de fenóis totais mais elevados que os extractos de bagaço. O metanol foi o solvente mais eficaz na extracção dos fenóis totais e das antocianinas para todas as amostras em estudo. Para as amostras de bagaço as amostras sem caroço (amostras de película) foram as que apresentaram valores mais elevados de fenóis totais e de antocianinas. Os resultados obtidos apontam no sentido dos sub-produtos agro-industriais analisados poderem constituir uma promissora fonte de compostos polifenólicos de custo reduzido, com potencial para aplicação em formulações dermocosméticas. Estudos futuros serão efectuados para avaliar o potencial destes resíduos como ingrediente antioxidante.

Estabilidade e eficácia de fotoprotetores contendo filtros inorgânicos e quercetina

A exposição ao sol traz benefícios à saúde, no entanto, o excesso pode ocasionar danos cutâneos dentre os quais se destacam as neoplasias. A fotoproteção é um método para a prevenção dos efeitos danosos da radiação ultravioleta (UV) e a biodiversidade Brasileira é campo fértil para pesquisas nesta área. Dessa forma, os objetivos deste estudo envolveram o desenvolvimento de formulações fotoprotetoras contendo quercetina (composto bioativo) e filtros solares físicos (dióxido de titânio e óxido de zinco), com posterior caracterização das formulações e avaliação da sua estabilidade. As formulações contendo o composto bioativo, isolado ou em associação com os filtros físicos, possuíram valores de pH biocompatíveis com a pele,intervalo de viscosidade aparente entre 10550 e 23600 cP; fator de proteção solar (FPS) estimado entre 2.1 e 22.5; e amplo espectro de proteção, com comprimentos de onda crítico acima de 379 nm. Constatou-se que não foi adequado utilizar a quercetina associada aos filtros solares físicos devido às interações negativas que ocorreram entre o composto e os metais, somente identificadas ao longo do estudo de estabilidade. No entanto, em função da eficácia estimada in vitro apresentada pelo flavonoide, seu uso ainda pode ser explorado como substituto alternativo aos filtros solares clássicos.

Health Benefits of Organic Food: effects of the environment

Public concern over impacts of chemicals in plant and animal production on health and the environment has led to increased demand for organic produce, which is usually promoted and often perceived as containing fewer contaminants, more nutrients, and being positive for the environment. These benefits are difficult to quantify, and potential environmental impacts on such benefits have not been widely studied. This book addresses these key points, examining factors such as the role of certain nutrients in prevention and promotion of chronic disease, potential health benefits of bioactive compounds in plants, the prevalence of food-borne pesticides and pathogens and how both local and global environmental factors may affect any differences between organic and conventionally produced food. This book is an essential resource for researchers and students in human health and nutrition, environmental science, agriculture and organic farming. Main Contents 1. Organic farming and food systems: definitions and key characteristics. 2. The health benefits of n-3 fatty acids and their concentrations in organic and conventional animal-derived foods. 3. Environmental impacts on n-3 content of foods from ruminant animals. 4. Health benefits and selenium content of organic vs conventional foods. 5. Environmental impacts concerning the selenium content of foods. 6. Contaminants in organic and conventional food: the missing link between contaminant levels and health effects. 7. Mycotoxins in organic and conventional foods and effects of the environment. 8. Human pathogens in organic and conventional foods and effects of the environment. 9. What does consumer science tell us about organic foods? 10. The beneficial effects of dietary flavonoids: sources, bioavailability and biological functions. 11. Environmental regulation of flavonoid biosynthesis. 12. Nitrates in the human diet. 13. Impacts of environment and management on nitrate in vegetables and water. 14. Effects of the environment on the nutritional quality and safety of organically produced foods: Round-up and summary.

CD40 Triggering of Heterodimeric IL-12 p70 Production by Dendritic Cells In Vivo Requires a Microbial Priming Signal

CD40 ligation triggers IL-12 production by dendritic cells (DC) in vitro. Here, we demonstrate that CD40 cross-linking alone is not sufficient to induce IL-12 production by DC in vivo. Indeed, resting DC make neither the IL-12 p35 nor IL-12 p40 subunits and express only low levels of CD40. Nevertheless, after DC activation by microbial stimuli that primarily upregulate IL-12 p40 and augment CD40 expression, CD40 ligation induces a significant increase in IL-12 p35 and IL-12 p70 heterodimer production. Similarly, IL-12 p70 is produced during T cell activation in the presence but not in the absence of microbial stimuli. Thus, production of bioactive IL-12 by DC can be amplified by T cell–derived signals but must be initiated by innate signals.

Platelet 12-lipoxygenase activation via glycoprotein VI: involvement of multiple signaling pathways in agonist control of H(P)ETE synthesis

Lipoxygenases (LOX) contribute to vascular disease and inflammation through generation of bioactive lipids, including 12-hydro(pero xyeicosatetraenoic acid (12-H(P)ETE). The physiological mechanisms that acutely control LOX product generation in mammalian cells are uncharacterized. Human platelets that contain a 12-LOX isoform (p12-LOX) were used to define pathways that activate H(P)ETE synthesis in the vasculature. Collagen and collagen-related peptide (CRP) (1 to 10 g/mL) acutely induced platelet 12-H(P)ETE synthesis. This implicated the collagen receptor glycoprotein VI (GPVI), which signals via the immunoreceptor-based activatory motif (ITAM)- containing FcR chain. Conversely, thrombin only activated at high concentrations ( 0.2 U/mL), whereas U46619 and ADP alone were ineffective. Collagen or CRP-stimulated 12-H(P)ETE generation was inhibited by staurosporine, PP2, wortmannin, BAPTA/AM, EGTA, and L-655238, implicating src-tyrosine kinases, PI3-kinase, Ca2 mobilization, and p12-LOX translocation. In contrast, protein kinase C (PKC) inhibition potentiated 12-H(P)ETE generation. Finally, activation of the immunoreceptor tyrosine-based inhibitory motif (ITIM)– containing platelet endothelial cell adhesion molecule (PECAM-1) inhibited p12-LOX product generation. This study characterizes a receptor-dependent pathway for 12-H(P)ETE synthesis via the collagen receptor GPVI, which is negatively regulated by PECAM-1 and PKC, and demonstrates a novel link between immune receptor signaling and lipid mediator generation in the vasculature. (Circ Res. 2004;94:1598-1605.)

Functionalised amyloid fibrils for roles in cell adhesion

We describe experiments designed to explore the possibility of using amyloid fibrils as new nanoscale biomaterials for promoting and exploiting cell adhesion, migration and differentiation in vitro. We created peptides that add the biological cell adhesion sequence (RGD) or a control sequence (RAD) to the C-terminus of an 11-residue peptide corresponding to residues 105-115 of the amyloidogenic protein transthyretin. These peptides readily self-assemble in aqueous solution to form amyloid fibrils, and X-ray fibre diffraction shows that they possess the same strand and sheet spacing in the characteristic cross-beta structure as do fibrils formed by the parent peptide. We report that the fibrils containing the RGD sequence are bioactive and that these fibrils interact specifically with cells via the RGD group displayed on the fibril surface. As the design of such functionalized fibrils can be systematically altered, these findings suggest that it will be possible to generate nanomaterials based on amyloid fibrils that are tailored to promote interactions with a wide variety of cell types. (c) 2007 Elsevier Ltd. All rights reserved.

Cellular uptake and metabolism of flavonoids and their metabolites: implications for their bioactivity

Flavonoids have been proposed to act as beneficial agents in a multitude of disease states, including cancer, cardiovascular disease, and neurodegenerative disorders. The biological effect of these polyphenols and their in vivo circulating metabolites will ultimately depend on the extent to which they associate with cells, either by interactions at the membrane or more importantly their uptake. This review summarises the current knowledge on the cellular uptake of flavonoids and their metabolites with particular relevance to further intracellular metabolism and the generation of potential new bioactive forms. Uptake and metabolism of the circulating forms of flavanols, flavonols, and flavanones into cells of the skin, the brain, and cancer cells is reviewed and potential biological relevance to intracellular formed metabolites is discussed.

The use of colloidal gas aphrons as novel downstream processing for the recovery of astaxanthin from cells of Phaffia rhodozyma

BACKGROUND: There is an increasing interest in obtaining natural products with bioactive properties, using fermentation technology. However, the downstream processing consisting of multiple steps can be complicated, leading to increase in the final cost of the product. Therefore there is a need for integrated, cost-effective and scalable separation processes. RESULTS: The present study investigates the use of colloidal gas aphrons (CGA), which are surfactant-stabilized microbubbles, as a novel method for downstream processing. More particularly, their application for the recovery of astaxanthin from the cells of Phaffia rhodozyma is explored. Research carried out with standard solutions of astaxanthin and CGA generated from the cationic surfactant hexadecyl. trimethyl ammonium bromide (CTAB) showed that up to 90% recovery can be achieved under optimum conditions, i.e., pH 11 with NaOH 0.2 mol L-1. In the case of the cells' suspension from the fermentation broth, three different approaches were investigated: (a) the conventional integrated approach where CGA were applied directly; (b) CGA were applied to the clarified suspension of cells; and finally (c) the in situ approach, where CGA are generated within the clarified suspension of cells. Interestingly, in the case of the whole suspension (approach a) highest recoveries (78%) were achieved under the same conditions found to be optimal for the standard solutions. In addition, up to 97% recovery of total carotenoids could be achieved from the clarified suspension after pretreatment with NaOH. This pretreatment led to maximum cell disruption as well as optimum conditioning for subsequent CGA separation. CONCLUSIONS: These results demonstrate the potential of CGA for the recovery of bioactive components from complex feedstock. (c) 2008 Society of Chemical Industry.

Polymer-drug conjugates: current status and future trends

Polymer conjugates are nano-sized, multicomponent constructs already in the clinic as anticancer compounds, both as single agents or as elements of combinations. They have the potential to improve pharmacological therapy of a variety of solid tumors. Polymer-drug conjugation promotes passive tumor targeting by the enhanced permeability and retention (EPR) effect and allows for lysosomotropic drug delivery following endocytic capture. In the first part of this review, we analyze the promising results arising from clinical trials of polymer-bound chemotherapy. The experience gained on these studies provides the basis for the development of a more sophisticated second-generation of polymer conjugates. However, many challenges still lay ahead providing scope to develop and refine this field. The "technology platform'' of polymer therapeutics allows the development of both new and exciting polymeric materials, the incorporation of novel bioactive agents and combinations thereof to address recent advances in drug therapy. The rational design of polymer drug conjugates is expected to realize the true potential of these "nanomedicines".