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Showing 1 to 20 of 23 for “"Diketopiperazine"”.
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Total synthesis of cyclotryptamine and diketopiperazine alkaloids and biosynthetic pathway investigation of unsymmetrical diketopiperazine dimers
… Pathway The biogenesis of unsymmetrical dimeric diketopiperazines is investigated, in collaboration with the Sherman group at the University of Michigan. Sequencing and mining the genome of Streptomyces sp. CB MQ-030, known to produce unsymmetrical diketopiperazine dimers, allowed the …
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Total synthesis of cyclotryptamine and diketopiperazine alkaloids
… complex, and intricate dimeric epidithiodiketopiperazine natural products. Although the dimeric epidithiodiketopiperazines have been known for nearly four decades, none has succumbed to total synthesis. We report a concise enantioselective total synthesis of (+)- 12,12'-dideoxyverticillin …
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Development of Epipolythiodiketopiperazine syntheses and the total synthesis of diketopiperazine alkaloids
I. The Development of Epipolythiodiketopiperazine (ETP) Syntheses Epipolythiodiketopiperazine (ETP) alkaloids represent a structurally complex and biologically potent class of secondary fungal metabolites and these molecules have been known since the 1930s. The biological activity of these …
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Development and application of new strategies for synthesis of complex diketopiperazine alkaloids
… permanganate promoted hydroxylation of diketopiperazines has served as a pivotal transformation in the synthesis of complex epipolythiodiketopiperazine alkaloids. This late-stage C-H oxidation chemistry is strategically critical to access N-acyl iminium ion intermediates necessary for …
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Studies on stereospecific diketopiperazine oxidation and applications to the synthesis of complex epidithiodiketopiperazines
I. Introduction and Background on Epidithiodiketopiperazines A brief history and summary of methods for synthesis of epidithiodiketopiperazines (ETPs) are discussed. Three hypotheses for the mechanism of action of these biologically active natural products are reviewed, and the unified biosynthetic …
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Enantioselective synthesis of 2,2,5-Tri- and 2,2,5,5-tetrasubstituted tetrahydrofurans and synthesis of diketopiperazine containing natural products
… A partial synthesis of the bioactive diketopiperazine containing natural product gliocladin C was achieved in nine steps, and 13.4% overall yield. The synthesis featured several novel transformations including the construction of the core structure by an elimination and nucleophilic …
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Design, synthesis, and biological evaluation of diketopiperazine based ionizable lipids for the in vivo delivery of messenger RNA
Thousands of human diseases could be treated by selectively increasing the intracellular concentration of specific proteins. The successful delivery of messenger RNA (mRNA) to target cells in the body could accomplish this goal, but serious limitations with its systemic delivery must still be …
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DESIGN, SYNTHESIS, AND CHARACTERIZATION OF INDANE 2,5-DIKETOPIPERAZINES FOR LIQUID CRYSTAL APPLICATIONS
… interactions, we have designed an indane 2,5-diketopiperazine (DKP) scaffold. Crystal engineering studies with this scaffold show that the molecules assemble into one dimensional tapes via reciprocal amide hydrogen bonds, tapes assemble into two dimensional sheets via arene-arene interactions, …
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Total Synthesis of Lasionectrin and Synthetic Studies Towards Pestaloxazine A
… which contains a unique spiro[1,2-oxazinane-diketopiperazine] moiety. We sought to access the 1,2-oxazinane ring system by the application of oxidative radical cyclisation conditions to a N-hydroxylamine precursor. Our initial synthetic strategy hinged on the preparation of the …
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Total syntheses of (±)-dracephalone A and (±)-dracocequinones A and B, progress towards a total synthesis of cassiabudanols A and B, and synthetic studies towards total synthesis of N-oxy-diketopiperazine containing natural products.
… of the route, especially Mukaiyama hydration and diketopiperazine (DKP) formation steps, are discussed to achieve overall 13% yield. An asymmetric synthesis of the tricyclic core of [2.2.3]-Epidithiodiketopiperazines is described. The key step features a diastereoselective intramolecular NDA …
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Total Synthesis of Verticillin A and Application of Diazene-Directed Fragment Assembly to the Synthesis of Heterodimeric Epidithiodiketopiperazine Derivatives
… coupling to the synthesis of dimeric diketopiperazine alkaloids Our group’s initial route to heterodimeric ETP derivatives relied upon reductive cobalt dimerization, which produces a nearly statistical mixture of homo- and heterodimeric products. In contrast to the initial route, the …
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Mass spectrometric characterization of remotely charged amino acids and peptides
… with authentic samples confirmed the lack of diketopiperazine or oxazolone on b2 ion and electronic structure calculation suggested that the b2 ion is oxazolone-enol.</p>
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Total synthetic efforts and structure elucidation in route to brocazine and cahuitamycin natural products
… of key steps (i.e., spirolactonization, diketopiperazine (DKP) formation, and sulfenylation) and the access of the brocazine E and F carbon framework in a reproducible manner. Cahuitamycin C was isolated from the marine microbe Streptomyces gandocaensis, which possesses Acinetobacter …
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Studies on organic electron donors and their applications in chemistry
… process.;Chapter Two highlights the ability of diketopiperazines 1-4 to promote the cross-coupling reactions of aryl halides 5-16 with benzene in the presence of potassium tert-butoxide 17 to form biaryls 18-24 via electron transfer [graphic of electron transfer process].;It also investigates …
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Novel Poly(N-substituted glycine)s : synthesis, post-modification, and physical properties
… a thermally induced side-product, diallyl diketopiperazine (DKP), afforded the opportunity to explore photo-induced thiol-ene and acyclic diene metathesis (ADMET) polymerizations. Thiol-ene polymerization readily led to low molecular weight polymers (<2.5 kDa), that were insoluble in most …
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CONSTRUCTING NANOSTRUCTURES WITH ATOMIC PRECISION: THE SYNTHESIS OF SPIROLIGOMER-BASED MACROCYCLES
… connected through pairs of amide bonds to form a diketopiperazine consequently eliminating single bond rotation and, therefore, avoids the complicated folding process common to the field of peptidomimetics. Spiroligomers are shape-programmable since the three-dimensional structure is controlled by …
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Chemical Synthesis of Novel Calcium-Dependent Lipopeptide Antibiotics
… analogue enabled the side-reactions of diketopiperazine-driven depsipeptide bond cleavage and epimerization upon installation of the dipeptide building block to be addressed. Application of this synthetic strategy towards the native sequence of cadaside B generated the desired peptide …
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Vibrational spectroscopic studies of the structure and conformation of cyclic di-amino acid peptides
… the change in structure and conformation of the diketopiperazine (DKP) ring and the cis amide geometry of the peptide bond, in relation to the vibrational spectra of a series of cyclic di-amino acid peptides (CDAPs). Experimental Raman and infra-red spectra have been recorded for the following …
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Exploring the molecular diversity and biomedicinal potential of marine invertebrates and South African actinomycetes for tuberculosis drug discovery
… B, desoxy-nocardamine and nocardamine, and a diketopiperazine (DKP). The isolated compounds were characterized by the analysis of HRESIMS and 1D and 2D NMR data, as well as by comparison with the relevant literature. Three new dehydroxy desferrioxamine derivatives were tentatively identified …
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