für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The book entitled Triterpenoids: an important bioactive class of natural products is based on the general view about triterpenoids. This book contains background, introduction, nomenclature, chemical tests, classification, biological importance, biosynthesis, extraction, isolation, characterization of triterpenoids and bibliography. This book deals mainly with the biosynthesis, bioactivity and characterization of triterpenoids. The chemical structure of various triterpenoids including recently discovered are being given in the book. The preparation of this book has been done with great care of previous research on triterpenoids. A brief discussion from several researches has been given in the book and the bibliography has given for further reading about the topic. This book is important for students as well as phytochemists working in the field of isolation and bioactivity of triterpenoids. We hope this book would give the idea about triterpenoids and their application in medicine. We certified that the matter of this book is not original or from our own work but this is based on previously published work and the sources of the same have been cited in the text. ····· 1036192339
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The present work entails the synthesis of different cross-conjugated (CC) heterodiene systems, and their transformations in various heterocyclic compounds using the hetero Diels-Alder (HDA) methodology. One of the main highlights of present work includes the development of simple and convenient procedure for the synthesis of stable CC azatrienes, and their tandem [2+2] cycloadditions and highly facile [3,3] sigmatropic Cope rearrangements with conjugated ketenes, leading to facile synthesis of various functionalized azocinone derivatives. A generalized and relevant study regarding the reactivity of thiazolic diazadienes with different ketenes was also conducted, and a remarkable increase in reactivity was observed with the introduction of electron donating group across the carbonyl group. Considering the biological and medicinal importance of C-5 or C-6 substituted pyrimidinones, the dienyl moiety of thiazolopyrimidinones was utilized further in Diels-Alder cycloadditions with both symmetrical and unsymmetrical dienophiles. Additionally, the synthesis of various pyrans, thiopyrans, thiophenes, thiazoles, 1,3-thiazines etc. is also described. ····· 1036192135
für 35.91€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Anticancer properties of naturally occurring (2R, 3R)-(-)-1-methoxyspirobrassinol methyl ether and their synthetic amino analogs inspired us to study the synthesis of new target compounds with a C-C bond in the 2-position of indole rather than a C-N or C-O bond. The goal was efficiently achieved by electrophilic - nucleophilic 3,2-difunctionalisation of 1-methoxybrassinin in the presence of bromine and Grignard reagent leading to the formation of cis-(±)- and trans-(±)-C-C analogs of 1-methoxyspirobrassinol methyl ether. The formation of magnesium bromide, during the bromine initiated spirocyclization followed by addition of Grignard reagent, played the crucial role in the formation of acyclic products rather then spirocyclized brassinins. Finally, the anticancer activities of new prepared compounds were measured in order to show the importance of a heteroatom in the 2-substituted indole on the anticancer activity of spirobrassinols and acyclic brassinins. ····· 1036192046
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The work of the book is devoted to a study of a series of organic reactions from readily available and less costly starting materials such as coumarins, pyrazoles, and chromones. These heterocyclic compounds were readily converted to polyketomethylene compounds by treatment with active methylene compounds such as triacetic acid lactone, dimedone, 3-methyl-1-phenyl-5-pyrazolone and nitrogenous bases such as hydrazine hydrate, phenyl-hydrazine, hydroxylamine respectively under different reaction conditions and the structures of all new compounds were identified on the basis of IR, NMR, and mass spectroscopy. Some of these synthesized compounds have been investigated for anti-inflammatory, analgesic, antipyretic and antibacterial activities. Most of the compounds have been found to possess significant activities and their effect was compared with the standard drugs. ····· 1036191817
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Petroleum is an extremely complex mixture of hydrocarbon compounds with minor amounts of nitrogen-, oxygen-, and sulfur-containing compounds as well as trace amounts of metal-containing compounds. Four Egyptian crude oils were collected from four oil fields namely Shokeir-22, West Ashrafi, Hana-3 and Arta-4 from the province of Gulf of Suez were characterized through petroleum measurements and chromatographic analysis. The physicochemical properties of the studied crude oils were achieved using standard test methods (ASTM, UOP and/or IP). The poly aromatic fractions of the four oil samples were analyzed via high performance liquid chromatography (HPLC). The paraffinic fraction of West Ashrafi crude oil is subjected to Gas chromatography-Flame ionization detector (GC-FID) to determine the carbon distribution of normal and branched paraffinic hydrocarbons and physicochemical properties to study the source and composition of crude oil then it subjected to Gas chromatography-Mass spectrometry (GC-MS) to determine the biological marker compounds (steranes and hopanes) to characterize the type of organo-facies, oil classes, depositional environments and the degree of thermal maturity. ····· 1036191816
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The electronic and optical behavior of conjugated small molecules constitutes one of the most extensively studied properties of this class of organic compounds. In particular, electron donor-acceptor compounds separated by -conjugation have attracted much research interest because of their applications as electroactive and photoactive materials in molecular electronic areas such as fluorescent technology, chemoluminescence, and photovoltaics. This work aims to demonstrate the synthesis and some of the interesting properties of new carbazole, indole, and diphenylamine donor-based donor-acceptor compounds. Basically, we have divided our compounds into two groups: (a) aromatic fumaronitrile core-based compounds and (b) 2,7-carbazole linker-based compounds. We designed and synthesized these compounds for possible applications in electroluminescent devices (such as OLEDs), organic sensors, organic nanoparticles, sensitizers in organic dye-sensitized solar cells (DSSCs), and other optoelectronic devices. We have shown their possible application in above mentioned fields by doing relevant experiments as discussed in the body of the book. ····· 1036191486
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Considerando que muchas benzofenonas naturales y sintéticas poseen reconocida actividad antimicrobiana, se realizó la síntesis de nuevos derivados bencilestannilados funcionalizados a través de la reacción de Barbier y su posterior uso como sustratos en la rección de acoplamiento Stille, a través de la generación de enlaces Csp3-Csp2, bajo diferentes condiciones de reacción para la síntesis de estructuras bencilarílicas que forman parte de estructuras de importancia farmacológica. También se realizó la reacción en condiciones sonoquímicas y por microondas, probando en última instancia la reacción de acoplamiento libre de catalizador de paladio a fin de establecer los alcances de la inducción sonoquímica y de microondas. Finalmente la oxidación del centro bencílico de los diarilmetanos obtenidos, permite obtener las benzofenonas sustituidas de interés, las cuales representan una aproximación sintética corta y flexible a nuevos antibióticos, o a la producción de análogos, los cuales podrían ser luego testeados para determinar en qué grado afecta la variación estructural su actividad antimicrobiana. ····· 1036191198
für 26.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La quiralidad es una característica fundamental presente en la naturaleza incluso en el medio ambiente abundan las características asimétricas. Además, la quiralidad es una propiedad intrínsecamente relacionada con el desarrollo de los seres vivos y tanto los metabolitos primarios (aminoácidos, azúcares) como los metabolitos secundarios producidos por plantas y microorganismos son compuestos quirales que se presentan enantioméricamente puros. Muchos de estos metabolitos secundarios actúan como fármacos en mamíferos superiores, ya que interaccionan de manera específica con los receptores biológicos quirales, los cuales están constituidos por complejas organizaciones estructurales como las hélices y las láminas. ····· 1036191100
für 35.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray En esta Tesis iniciamos una línea completamente nueva basada en la búsqueda de antimetabolitos del pirofosfato de farnesilo. Éste es el sustrato de numerosos enzimas importantes en rutas biosintéticas claves para el metabolismo de las celulas y de los organismos. Así, es transformado por la escualeno sintetasa en escualeno, precursor de todos los esteroides. Inhibir la escualeno sintetasa podría ayudar a controlar el nivel de colesterol en los organismos superiores o podría interferir en el crecimiento bacteriano en el caso de las escualenos sintetasas procariotas. Por otra parte, el pirofosfato de farnesilo es sustrato de la farnesiltransferasa, responsable de la farnesilación, y por tanto, activación, de proteínas, como la RAS, que juegan un papel clave en la transducción de señales. Esta transducción de señales está descontrolada en las células cancerosas. La inhibición de la farnesilación, al no activar a RAS, detiene el proceso de transducción y lleva a la célula cancerosa a la muerte... ····· 1036190988
für 80.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray El objetivo del presente trabajo es estudiar la síntesis y reactividad de hidantoínas 5-sustituidas. Este tipo de hidantoínas son importantes intermedios en la producción industrial de aminoácidos. El trabajo se divide en dos partes. Por un lado en la síntesis de 5-aril-hidantoínas y por otro en la síntesis y reactividad de 5-metilenhidantoínas. La primera estrategia se ha realizado mediante una alquilación de Friedel-Crafts. Este tipo de reacciones se pueden llevar a cabo a partir de urea, ácido glioxílico y el compuesto aromático one-pot. Otra posibilidad es el uso de un derivado de hidantoína como es el caso de 5-clorohidantoína o 5-bromohidantoína. En la segunda estrategia se ha introducido un grupo metileno en posición 5 de la hidantoína. Este grupo sirve de intermedio sintético para obtener un gran número de moléculas mediante reacciones tipo Michael, cicloadiciones, reacciones de Heck, etc. ····· 1036190730
für 62.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Desde los orígenes de la humanidad el hombre se ha relacionado con las plantas, primero como fuente de alimentos y posteriormente, a medida que fue conociendo sus propiedades, las empleó como medicamentos entre otros propósitos. Actualmente, existe un gran interés en utilizar para este fin productos naturales de origen vegetal en lugar de sustancias sintéticas. La búsqueda de estos compuestos se realiza mediante investigaciones fitoquímicas que se basan en la determinación cuantitativa y el aislamiento de metabolitos que son evaluados para su posterior aplicación como fármacos u otras aplicaciones. En este libro se aborda el estudio del Agave brittoniana Trel.,especie endémica cubana conocida por la población como Maguey , vocablo que proviene de la cultura taína. Estas plantas crecen en la región central de la isla y pertenecen al género Agave (fam. Agavaceae) son ricas en azúcares, compuestos lipídicos, sapogeninas y saponinas esteroidales, metabolitos que se caracterizan por poseer una amplia gama de actividades biológicas. ····· 1036189996
für 26.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray La síntesis de compuestos orgánicos enantioméricamente puros que permitan descartar actividades biológicas no deseadas por parte de uno de los enantiómeros, es uno de los objetivos principales de la industria farmacéutica actual. El uso en esta industria de compuestos ampliamente distribuidos en la naturaleza, ha llevado a la autora a centrarse en la síntesis de compuestos enantiopuros como las alilaminas, habitualmente empleadas como fungicidas, y los beta-aminoalcoholes, utilizados en la preparación de un amplio número de compuestos biológicamente activos. En el presente trabajo se ha logrado desarrollar, partiendo de sustratos de fácil acceso y bajo coste como son los alfa-aminoácidos, una preparación de alilaminas y beta-aminoalcoholes, sencilla general y eficaz, permitiendo que los datos y técnicas aportados puedan ser aplicados en posteriores estudios y en el desarrollo de futuros productos farmacológicos. ····· 1036189691
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Advances in the chemistry of chlorosulphonyl isocyanate (CSI) contributed by the author`s research group at Indian Institute of Technology, Kanpur (1976-94) are highlighted and reviewed in this work. The applications of chlorosulphonyl isocyanate are covered by a large number of patents form several countries around the world viz Belgium, Britain, Canada, China, Europe, France, Germany, India, Italy, Netherlands, Spain, Switzerland, and USA. Chlorosulphonyl Isocyanate has been employed for the synthesis of a large variety of compounds, which are associated with a broad range of useful properties including in therapeutics. ····· 1036189018
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Gas Chromatography-Mass Spectrometry (GC-MS)is a sophisticated, quick and reliable analytical technique for the separation, identification and quantitative determination of complex mixtures of compounds in general and essential oils in particular. The volatility and polarity of essential oil components make capillary GC-MS the technique of election for their analysis. Compound identification by GC-MS is mainly based on mass spectra or by chromatographic data (Kovats indices, linear retention indices, relative retention time) measurable with FID (flame ionization detector) or TCD (thermal conductivity detector) or better by both. Enantioselective or chiral recognition (ES-GC-MS)of essential oil components is one of the most important achievements reached in essential oil analysis during recent times enabling to determine the enantiomeric excess (EE) in an essential oil sample. The present work reports the essential oil composition of some unexplored aromatic plants like Rhododendron lepidotum, Nepeta laevigata and Artemisia pallens growing in Jammu and Kashmir. ····· 1036189012
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Malaria statistics have become familiar. It is estimated that 300 to 500 million malaria infections occur annually, 90% of these in sub-Sahara Africa. A third of those visiting rural dispensaries are seeking treatment for malaria. Malaria accounts for between 20 and 50% of all admissions in African health services, with the poorest countries bearing the greatest burden of morbidity and mortality. Studies in a number of African countries have shown that the emergence of the chloroquine-resistant malaria parasites is associated with a two-fold increase in malaria deaths, but in one study in Mlomp Senegal, it was shown that malaria mortality in children under the age of four increased 11-fold within six years of the emergence of the chloroquine-resistance. The emergence of drug-resistant strains of Plasmodium falciparum has resulted in an urgent need to develop new antimalarial chemotherapeutic agents. Hence, the research for new drugs against this disease has become a pressing, global demand. ····· 1036188319
für 35.91€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book describes the synthesis of amidines and imidate esters from 2-oxy/amino-4`-benzonitrile, thiosemicarbazone from 2-oxy-4`-benzaldehyde, dimethylaminomethylene ketone and chalcone from 2-oxy-4`-acetylphenyl derivatives of 1,4-benzodiazepine (2.094-2.100). The structures of all compounds have been established by elemental analysis (Carbon, Hydrogen, Nitrogen and Sulfur), IR, 1H NMR, and Mass spectral data. ····· 1036188259
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book is a result of an investigation of organic chemistry instructional techniques used in Kenya to determine their effectiveness in enhancing understanding of organic chemistry concepts. The author addresses the problem of students poor performance in organic chemistry. The book is based on a study conducted in the Rift Valley and Western provinces of Kenya in which quantitative data generation and analysis was largely employed. The major finding was that teachers instructional practices do not conform to the expectations of good teaching. Dr. Waswa argues that stakeholders such as: chemistry teachers, heads of department, heads of schools and quality assurance officers should encourage adherence to lesson plans by every organic chemistry teacher. This book is a must-read for chemistry teachers, chemistry teacher trainees, chemistry teacher trainers, Heads of Science departments, and Quality assurance Officers in Kenya and beyond. ····· 1036187711
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray 1. All the 1,2,4-triazole derivatives prepared are pro-drugs since all have -N-C=O or -N-C=S links, which are enzymatically degradable, thus releasing both i.e. 1,2,4-triazole and the ligand at the target site. 2. The conjugate of curcumin with triazole has been found to be a more potent antifungal and antibacterial reagent. Further in vitro and in vivo experiments can be carried out. 3. 1,2,4-triazole dervative of isoproturon has been found to be most effective herbicide which could be used as a substitute of isoproturon. Further field trials are required. 4. The observed enhanced activity of all these synthetic compounds may be due to their combined effect at the receptor, producing synergism. 5. However, the validation of this synergistic effect needs further work. 6. The results have opened a new approach for designing novel and more effective pro-drugs. ····· 1036187592
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This monograph is a condensed form of the fundamental knowledge on the named reaction Prins cyclization in organic synthesis. This monograph consists of three distinct chapters: chapter 1 provides detailed description of the Prins cyclization, contemporary approaches to the synthesis of chiral 1,3-diol units and application to the total synthesis of biologically active natural products chapter 2 describes the historical and biological background of the naturally occurring, cytotoxic 14-membered macrolide (+)-Neopeltolide, including their isolations, structural elucidation and previous synthetic approaches and my synthetic route to the total synthesis of (+)-Neopeltolide macrolactone, while chapter 3 provides information on the use of Prins cyclization for the synthesis of 4-iodo, 4-amido, 4-azidotetrahydropyran derivatives. This monograph is an indispensable reference for any chemist working with tetrahydropyran, dihydropyran and piperidine containing natural products. ····· 1036187432
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The present investigation comprises a survey covering the antioxidant activities of compounds containing the oxadiazole, thiadiazole and triazole ring system, with particular reference to benzimidazole and indole derivatives. In this work, 34 intermediates and 128 new compounds derived from indole and benzimidazole were synthesized. The structures of new compounds were confirmed by both analytical and spectral data (IR, NMR and MS). The antioxidant activities were tested in vitro using DPPH radical scavenging assay. ····· 1036186950
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The present investigation comprises a survey covering the biological activities of compounds containing the indole ring system, with particular reference to indole-2-carboxylate and pyridazinoindole derivatives. The Microwave assistance of selected reactions has profouned effect on the speed of reactions. The structures of new compounds were confirmed by both analytical and spectral data. substituted indolylthiazolidinones were evaluated for their anticonvulsant as well as tranquilizing activities. The results show that, all tested compounds protected significantly against the strychnine induced convulsion and one compound has anticonvulsant activity similar to diazepam. Furthermore, substituted indolylthiazolidinones exhibited muscular incoordination (tranquilizing activity) this was indicated by significantly decrease falling time from vehicle treated group. The activities of synthesized compounds against representative Gram positive, negative bacteria and fungi were tested by by the disk diffusion method. ····· 1036186796
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book emphasizes mainly on polyurethanes, raw materials to synthesize it, its applications and synthesis of polyurethane-based block copolymers. Polyurethanes are arguably the most multifaceted family of polymers. Polyurethanes can be prepared range from soft elastomeric polymers to hard elastoplastics. Polyurethanes are used as structural materials, coatings, adhesives, hydrogels and sealants. This book presents the details of polyurethane synthesis and its chemistry, preparation of different kinds of polyurethane ionomers and block copolymers. ····· 1036186604
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Number of methods are known for the the synthesis of the natural product 7-Methoxy-2-[4-(methoxy)phenyl)-l-benzofuran-5-carboxaldehyde are known. It is conveniently synthesized by using Intramolecular Wittig reaction of ester. Reductive amination is one of the versatile method for the synthesis of secondary or tertiary amines from aldehydes or ketones by using suitable reducing agent in one-pot fashion. This reaction has been carried out at room temperature and in acidic medium (by using acetic acid). 7-Methoxy-2-[4-(methoxy)phenyl)-l-benzofuran-5-carboxaldehyde was reacted with 3-fluoroaniline in ethylene dichloride in presence of catalytic amount of acetic acid forming 3-fluoro-N-{[7-methoxy-2-(4-methoxyphenyl)-1-benzofuran-5-yl]methyl}aniline. It is novel benzofuran amine. It`s HPLC method validation has been carried out and apply to series of compounds. ····· 1036186583· 1 ·· 2 ·· 3 ·· 4 ·· 5 ·· 6 ·· 7 ·· 8 ·· 9 ·
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