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Biomimetic Assembly Of Reactive Units For The Total Synthesis Of Marine Natural Products From Dual Biosynthetic Origin
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Book Synopsis Biomimetic Assembly of Reactive Units for the Total Synthesis of Marine Natural Products from Dual Biosynthetic Origin by : Xinming Zhang
Download or read book Biomimetic Assembly of Reactive Units for the Total Synthesis of Marine Natural Products from Dual Biosynthetic Origin written by Xinming Zhang and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work described in this PhD dissertation is dedicated to the total synthesis of intriguing natural product structures. Two distinct families of natural substances of marine origin have been targeted in this work: the halichonadins and the araiosamines.- With the halichonadins, we plunge into the marine terpene chemistry. Isolated from sponges of the genus Halichondria, two structures have particularly drawn our attention: halichonadins K and L. Indeed, besides two subunits of terpene origin (namely halichonadin C, a natural isonitrile) with an eudesmane skeleton, a central core of peptidic origin is also original (especially a carboxylic acid disubstituted piperidine ring). A part of the work is dedicated to understanding how, in nature, isonitrile natural products may be formed and may react. The experimental part is organized according to the two following topics:1- Devise an efficient and straightforward total synthesis of halichonadin C. A strategy starting from santonin has been studied and developed. The presence of an isopropyl pending group has attracted many synthetic problems. Anyhow, an advanced intermediate comprising the whole skeleton and the crucial nitrogen atom of the target has been reached and provides good hopes for the access to halichonadin C.2- Conceiving a strategy of the stereocontroled access to the central piperidine ring of halichonadins K and L. Several strategies have been evaluated including the recourse to double Michael additions and reactions inspired by Robinson's tropinone synthesis. The peptidic central core is now accessible in a limited number of steps.Most of the pieces of the puzzle are in our hands at the end of this PhD to secure a rapid access to the complex targets that constitutes halichonadins K and L.- The chapter dedicated to araiosamines (A-D, isolated from sponges of the genus Clathria) is exploratory and allows to propose promising strategies for a bio-inspired synthesis that constitutes true challenges for the organic chemists. One of the challenges to take up is to prepare highly reactive indole aldehyde units that could be foreseen as chemical equivalents of postulated biosynthetic intermediates. A method to generate in situ such units is studied. The first applications have been directed to the synthesis of “Discodermia pyridiniums” and appear to be promising towards the total synthesis of these molecules.The work conducted during this PhD take place in the framework of the “art of total synthesis”. But, in our strategies, the chemical understanding of biosynthetic pathways is never far away.
Book Synopsis Synthesis of Marine Natural Products 2 by : K.F. Albizati
Download or read book Synthesis of Marine Natural Products 2 written by K.F. Albizati and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volumes five and six of Bioorganic Marine Chemistry differ from their predecessors in two respects - they deal exclusively with laboratory synthesis of marine natural products and they represent the effort of a single author and his associates. The rationale for these departures is readily perceived. For several decades organic synthesis has without doubt been the most spectacular branch of organic chemistry. While the late R.B. Woodward's dictum - organic compounds can undergo only four basic reactions: they can gain electrons; they can lose electrons; they can be transformed with acid or with base - is still true, the wealth and variety of available reagents which will accomplish chemical transformations has reached staggering proportions. Little wonder then, that synthetic methodology has achieved a high degree of predictability and total synthesis of natural products has been successfully directed toward ever more challenging targets. As for the second point, that of single authorship, multiple authorship would invariably have led to gaps and overlaps, thus making it difficult to assemble and assess recent research in a systematic and comprehens ive fashion.
Book Synopsis Studies in the Synthesis of Natural Products and Designed Molecules by : Ross Steven Harvey
Download or read book Studies in the Synthesis of Natural Products and Designed Molecules written by Ross Steven Harvey and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The desire to synthesise molecules in new and improved ways is arguably what motivates research across all of organic chemistry. This thesis will describe efforts in two areas that are consistent with this broad objective, concerning the synthesis of natural products, and the development of methods for the synthesis of designed molecules. Our desire to better utilise the Diels-Alder reaction - a powerful means for the formation of carbon-carbon bonds, sits as a guiding principle behind these investigations.Part 1 of this thesis concerns the synthesis of the ramonanin natural products: four dimeric structures formed biosynthetically through a Diels-Alder dimerisation reaction. Chapter 1 will review the prior art on natural products formed using a Diels-Alder dimerisation as a key step. The area has not been reviewed substantively thus far - something overdue given the rapid development in this area over the past 15 years. Biomimetic synthesis is a recurrent theme of the chapter, with the vast majority of syntheses covered to some extent inspired by an understanding of the target's biosynthetic origin.Chapter 2 will cover original research performed in the total synthesis of the ramonanin family of the natural products. The chapter begins with a discussion of the possible biosynthetic origins of the ramonanins, and the ways this might be applied in a biomimetic synthesis. After this, an account is given of the successful forward synthesis of the ramonanin natural products. This begins with an account of the synthesis of the ramonanin monomeric subunit, followed by a detailed discussion of the dimerisation event from which the natural products were formed. Part 2 concerns the use of tricarbonyliron-diene complexes as building blocks in the synthesis of reactive cross-conjugated hydrocarbons.Chapter 5 concerns a methods-driven investigation, aimed at establishing the basic means by which cross-conjugated hydrocarbons might be assembled from a tricarbonyliron-diene starting material. A range of 1-[3]dehydrodendralenes and 1-(Z)-[3]dendralenes were prepared using this general method - the first general method for the synthesis of either class of hydrocarbon.Chapter 6 concerns the repurposing of the methods of chapter 5 to greater ends. In the first part of the chapter, the synthesis of higher and greatly more reactive polyenes using these general methods is detailed. The second part of the chapter details the use of a 1-(Z)-[3]dendralenes in a Diels-Alder cascade - a model for future applications in target-driven synthesis that might follow.
Book Synopsis Synthesis of Marine Natural Products 1 by : K.F. Albizati
Download or read book Synthesis of Marine Natural Products 1 written by K.F. Albizati and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volumes five and six of Bioorganic Marine Chemistry differ from their predecessors in two respects - they deal exclusively with labor atory synthesis of marine natural products and they represent the effort of a single author and his associates. The rationale for these departures is readily perceived. For several decades organic synthesis has without doubt been the most spectacular branch of organic chemistry. While the late R.B. Woodward's dictum - organic compounds can undergo only four basic reactions: they can gain electrons; they can lose electrons; they can be transformed with acid or with base - is still true, the wealth and variety of available reagents which will accomplish chemical transformations has reached staggering proportions. Little wonder then, that synthetic methodology has achieved a high degree of predictability and total synthesis of natural products has been successfully directed toward ever more challenging targets. As for the second point, that of single authorship, multiple authorship would invariably have led to gaps and overlaps, thus making it difficult to assemble and assess recent research in a systematic and comprehens ive fashion.
Book Synopsis Total Synthesis of Marine Natural Products by : David Adam Skyler
Download or read book Total Synthesis of Marine Natural Products written by David Adam Skyler and published by . This book was released on 2002 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Inspirations from Nature by : Iman Mohammad Khalil
Download or read book Inspirations from Nature written by Iman Mohammad Khalil and published by . This book was released on 2015 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine natural products are becoming widely recognised as novel sources of drug leads. Their structural complexity has attracted synthetic chemists to explore new synthetic strategies and reagents. More recently, biosynthetic considerations of natural product has led to the proposal of biogenetic precursors that may lead to a biomimetic synthesis of a particular family of compounds. If successful, biomimetic syntheses may lead to the synthesis of multiple compounds in a family of natural products from simple precursors in a short, stepwise fashion. Thiaplidiaquinone A (2.1) and B (2.2) were synthesised in a 5-step biomimetic reaction sequence where the dimeric core was constructed by allowing a simple benzoquinone to dimerise and cyclise in the presence of base. The installation of the dioxothiazine ring system allowed for the synthesis of the two natural products alongside their corresponding dioxothiazine regioisomers 2.58 and 2.59. Cytotoxicity bioassays revealed that the position of the geranyl sidechains determined the mode of cell death (necrosis versus apoptosis) whereas the dioxothiazine ring regulated the potency of the compounds. The synthesised regioisomers were found to be more potent than their natural product counterparts with one, 2.58, exhibiting sub-panel selectivity towards melanoma cancer cell lines and was selected for acute toxicity testing by the NCI. A biomimetic synthesis of pyridoacridine alkaloids amphimedine (3.3), deoxyamphimedine (3.16) and demethyldeoxyamphimedine (3.11) from the structurally simpler styelsamine D (3.13) was developed. Addition of formaldehyde to the proposed biosynthetic precursor, styelsamine D, gave the two natural products 3.11 and 3.16 in a one pot synthesis where subsequent oxidation of 3.16 gave amphimedine. It was found that pre-functionalisation of the dopamine precursor to styelsamine D allowed for the synthesis of N-ethyl analogues of amphimedine and deoxyamphimedine as well as an N-benzyl analogue of deoxyamphimedine. Biomimetic considerations of the neoamphimedine, arnoamine and alpkinidine scaffold were also investigated and the results highlighted herein. Biological evaluation of the amphimedine, deoxyamphimedine and demethyldeoxyamphimedine at the NCI identified deoxyamphimedine as a strong cytotoxic agent, exhibiting sub-panel selectivity towards central nervous system cancer cell lines.
Book Synopsis Synthetic and Biosynthetic Approaches to Marine Natural Products by : Asunción Barbero
Download or read book Synthetic and Biosynthetic Approaches to Marine Natural Products written by Asunción Barbero and published by MDPI. This book was released on 2020-03-24 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine natural products containing a heterocyclic moiety in their structure are present in a wide variety of sponges, corals, algae, and fungi. Many of them show important biological activities such as cytotoxic properties against several cancer cell lines. Their challenging chemical structures have attracted the attention of many researchers who have developed various synthetic approaches. This Special Issue presents some examples of new synthetic or biosynthetic methodologies to access this type of marine natural drug.
Book Synopsis Towards the Total Synthesis of Mycaperoxide B by : Eduarda Marlene Peixoto da Silva
Download or read book Towards the Total Synthesis of Mycaperoxide B written by Eduarda Marlene Peixoto da Silva and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The main purpose of this work was to complete the total synthesis of the marine natural product Mycaperoxide B 2a via a proposed biomimetic pathway. The key aim of this project has been to investigate the viability of the second proposed biosynthetic pathway reported by Capon for the biosynthesis of norsesterterpene cyclic peroxides. According to this hypothesis, it was expected that generation of a tertiary hydroperoxide and subsequent intramolecular Michael cyclisation would allow preparation of the final target"--Page 11 of introduction.
Book Synopsis Natural Product Synthesis II by : U. Beifuss
Download or read book Natural Product Synthesis II written by U. Beifuss and published by Springer Science & Business Media. This book was released on 2005-02-11 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: T. Heckrodt and J. Mulzer: Marine Natural Products from Pseudopterogorgia Elisabethae: Structures, Biosynthesis, Pharmacology and Total Synthesis .-M. Kalesse: Recent Advances in Vinylogous Aldol Reactions and their Applications in Natural Product Synthesis .- U. Beifuss and M. Tietze: Methanophenazine and Other Biologically Active Phenazines .-H.-J. Knoelker: Occurrence, Biological Activity, and Convergent Organometallic Synthesis of Carbazole Alkaloids .-U. Nubbemeyer: Recent Advances in Charge Accelerated Aza-Claisen Rearrangements.- P. Metz: Synthetic Studies on the Pamamycin Macrodiolides
Book Synopsis Total Synthesis of Marine Natural Products by : Katharine Elaine McElhone
Download or read book Total Synthesis of Marine Natural Products written by Katharine Elaine McElhone and published by . This book was released on 1999 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis of Marine Natural Products and Molecules Inspired by Marine Substances by : Emiliano Manzo
Download or read book Synthesis of Marine Natural Products and Molecules Inspired by Marine Substances written by Emiliano Manzo and published by . This book was released on 2021-11-04 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine natural products are characterized by high chemical diversity, biochemical specificity, and other molecular properties that make them favorable as lead structures for drug discovery. In this field, one of the main problems is often the reduced natural availability of isolated substances, which can complicate both the structural characterization and possible future developments. For these reasons, the study of bioactive marine metabolites should rely on the development of chemical synthesis and synthetic strategies aimed at the preparation of pure compounds and analogs both for structural confirmation and/or for the large-scale preparation necessary for future applications. Moreover, natural products can be a crucial starting point for the preparation of molecules structurally inspired by the latter, opening the path to new classes of biologically active compounds with pharmacological potential. This book collects original research articles regarding synthetic strategies for secondary marine metabolites and/or analogs that favor applications of these molecules and/or solve structural challenges common in the field of natural substances.
Book Synopsis Progress Towards Total Synthesis of Marine Natural Product Ansalactam A by : Zhanhao Liang
Download or read book Progress Towards Total Synthesis of Marine Natural Product Ansalactam A written by Zhanhao Liang and published by . This book was released on 2022 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Total Synthesis of Bioactive Marine Natural Products Inspired by Enolate Chemistry & Developments of New Haloalkylations Via Soft Enolizations by : Aaron Thomas Herrmann
Download or read book Total Synthesis of Bioactive Marine Natural Products Inspired by Enolate Chemistry & Developments of New Haloalkylations Via Soft Enolizations written by Aaron Thomas Herrmann and published by . This book was released on 2015 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: The final part describes a new procedure for the generation of syn-1,3-diols, which addresses both stereo- and regiocontrol in the rhenium catalyzed transposition of allylic alcohols.
Book Synopsis Synthetic and Biocatalytic Strategies for Natural Product Synthesis Via Ortho-Quinone Methide Intermediates by : Trevor Nelson Purdy
Download or read book Synthetic and Biocatalytic Strategies for Natural Product Synthesis Via Ortho-Quinone Methide Intermediates written by Trevor Nelson Purdy and published by . This book was released on 2021 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organisms across all domains of life have developed elegant strategies to produce specialized metabolites, also referred to as natural products, for defense, structure, and communication. Natural products provide novel inspiration for pharmaceutical development given their potent biological activities and structural diversity. Recent advancements in DNA sequencing technology and the development of predictive bioinformatics tools have unveiled a vast collection of biosynthetic machinery responsible for generating this structural diversity that may be harnessed by synthetic chemists. Many of the enzymes encoded by biosynthetic genes catalyze chemical reactions that are difficult to replicate with the same selectivity by traditional synthetic methods. An example of this discrepancy is illustrated by the current enzymatic and chemical methods known to generate a highly reactive ortho-quinone methide (o-QM) intermediate. The utility of o-QMs in total synthesis has been hampered by complications that surround the preparation of their precursors, the harsh generation methods, and poor chemo-, regio-, and stereoselective control. In contrast, multiple enzymes have been reported to catalyze o-QM formation under mild conditions with remarkable selectivity. Chapter 1 of this dissertation examines several different enzymatic strategies developed to generate o-QMs. Chapter 2 describes progress towards the biomimetic total synthesis of (-)-chlorizidine A that aims to synthetically replicate the final biosynthetic intramolecular cyclization via an o-QM intermediate. Chapter 3 reports the discovery of tetrachlorizine, a novel tetrachlorinated marine natural product, and the identification of its associated biosynthetic gene cluster. Biochemical characterization of a pivotal flavin-dependent oxidase revealed a dehydrogenation reaction that proceeds via an unprecedented o-QM mechanism. This oxidase was then repurposed to generate an isolable o-QM, an extremely rare chemical motif. Chapter 4 investigates the structure-function relationships of two homologous flavin-dependent oxidases with divergent reaction selectivities and highlights their favorable biocatalytic properties. This chapter also discloses the first reported bacterial enzymes capable of performing oxidative cyclization reactions to produce cannabinoids.
Book Synopsis Synthesis of Marine Natural Products 2 by : Kim Albizati
Download or read book Synthesis of Marine Natural Products 2 written by Kim Albizati and published by Springer. This book was released on 1992-03-10 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volumes five and six of Bioorganic Marine Chemistry differ from their predecessors in two respects - they deal exclusively with laboratory synthesis of marine natural products and they represent the effort of a single author and his associates. The rationale for these departures is readily perceived. For several decades organic synthesis has without doubt been the most spectacular branch of organic chemistry. While the late R.B. Woodward's dictum - organic compounds can undergo only four basic reactions: they can gain electrons; they can lose electrons; they can be transformed with acid or with base - is still true, the wealth and variety of available reagents which will accomplish chemical transformations has reached staggering proportions. Little wonder then, that synthetic methodology has achieved a high degree of predictability and total synthesis of natural products has been successfully directed toward ever more challenging targets. As for the second point, that of single authorship, multiple authorship would invariably have led to gaps and overlaps, thus making it difficult to assemble and assess recent research in a systematic and comprehens ive fashion.
Book Synopsis Total Synthesis of the Marine Natural Products (+)- Rogioloxepane A and Bistramide A by : Amy C. DeBaillie
Download or read book Total Synthesis of the Marine Natural Products (+)- Rogioloxepane A and Bistramide A written by Amy C. DeBaillie and published by . This book was released on 2005 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Total Synthesis of Natural Products by :
Download or read book The Total Synthesis of Natural Products written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
