scholarly journals Investigations of Azulene Derivatives as Self-Indicating Chromophores for Applications in Protecting Group Strategies and Solid-Phase Purification

2021 ◽  
Author(s):  
◽  
Thomas Bevan
Keyword(s):  
Electronic Properties ◽  
Solid Phase ◽  
Protecting Groups ◽  
Protecting Group ◽  
Blue Colour ◽  
Derivatives Of ◽  
Potential Use

<p>Azulene is a hydrocarbon that exhibits an intense blue colour. Derivatives of azulene exhibit different colours depending on the position and electronic properties of the substituents. The chemical and chromophoric properties of azulene and guaiazulene derivatives are investigated for the potential use in applications such as chromophoric protecting groups and self-indicating scavenger resins. Investigations were carried out on the scope of known reactions on the 3- position of guaiazulene for this purpose...</p>

scholarly journals Investigations of Azulene Derivatives as Self-Indicating Chromophores for Applications in Protecting Group Strategies and Solid-Phase Purification

2021 ◽  
Author(s):  
◽  
Thomas Bevan
Keyword(s):  
Electronic Properties ◽  
Solid Phase ◽  
Protecting Groups ◽  
Protecting Group ◽  
Blue Colour ◽  
Derivatives Of ◽  
Potential Use

<p>Azulene is a hydrocarbon that exhibits an intense blue colour. Derivatives of azulene exhibit different colours depending on the position and electronic properties of the substituents. The chemical and chromophoric properties of azulene and guaiazulene derivatives are investigated for the potential use in applications such as chromophoric protecting groups and self-indicating scavenger resins. Investigations were carried out on the scope of known reactions on the 3- position of guaiazulene for this purpose...</p>

scholarly journals Revisiting NO2 as Protecting Group of Arginine in Solid-Phase Peptide Synthesis

2020 ◽  
Vol 21 (12) ◽  
pp. 4464
Author(s):  
Mahama Alhassan ◽  
Ashish Kumar ◽  
John Lopez ◽  
Fernando Albericio ◽  
Beatriz G. de la Torre
Keyword(s):  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Side Reaction ◽  
Reducing Agent ◽  
Protecting Groups ◽  
Side Chain ◽  
Protecting Group ◽  
Mild Acid

The protection of side-chain arginine in solid-phase peptide synthesis requires attention since current protecting groups have several drawbacks. Herein, the NO2 group, which is scarcely used, has been revisited. This work shows that it prevents the formation of δ-lactam, the most severe side-reaction during the incorporation of Arg. Moreover, it is stable in solution for long periods and can be removed in an easy-to-understand manner. Thus, this protecting group can be removed while the protected peptide is still anchored to the resin, with SnCl2 as reducing agent in mild acid conditions using 2-MeTHF as solvent at 55 °C. Furthermore, we demonstrate that sonochemistry can facilitate the removal of NO2 from multiple Arg-containing peptides.

The synthesis of oligoribonucleotides. III. The use of silyl protecting groups in nucleoside and nucleotide chemistry. VIII

1979 ◽  
Vol 57 (17) ◽  
pp. 2230-2238 ◽  
Author(s):  
Kelvin K. Ogilvie ◽  
Aria L. Schifman ◽  
Christopher L. Penney
Keyword(s):  
Protecting Groups ◽  
Protecting Group ◽  
Cautionary Note ◽  
Derivatives Of ◽  
Isomeric Mono

The synthesis of all isomeric mono- and disilyl derivatives of cytidine, guanosine, and their N-benzoyl analogues using the tert-butyldimethylsilyl protecting group is described. These compounds and those containing a 5′-monomethoxytrityl group have been condensed via the phosphodichloridite procedure to produce nucleotides rapidly and in good yields. The synthesis of 2′–5′-linked nucleotides is described. A cautionary note is introduced in regard to the preparation of 5′-monomethoxytritylguanosine and a novel methanolysis of certain N-benzoylcytidines is mentioned.

scholarly journals Amino acid motifs in natural products: synthesis of O-acylated derivatives of (2S,3S)-3-hydroxyleucine

2014 ◽  
Vol 10 ◽  
pp. 1135-1142 ◽  
Author(s):  
Oliver Ries ◽  
Martin Büschleb ◽  
Markus Granitzka ◽  
Dietmar Stalke ◽  
Christian Ducho
Keyword(s):  
Natural Products ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Building Blocks ◽  
Synthetic Approach ◽  
Protecting Group ◽  
Nucleoside Antibiotics ◽  
Bioactive Natural Products ◽  
Sar Studies ◽  
Derivatives Of

(2S,3S)-3-Hydroxyleucine can be found in an increasing number of bioactive natural products. Within the context of our work regarding the total synthesis of muraymycin nucleoside antibiotics, we have developed a synthetic approach towards (2S,3S)-3-hydroxyleucine building blocks. Application of different protecting group patterns led to building blocks suitable for C- or N-terminal derivatization as well as for solid-phase peptide synthesis. With respect to according motifs occurring in natural products, we have converted these building blocks into 3-O-acylated structures. Utilizing an esterification and cross-metathesis protocol, (2S,3S)-3-hydroxyleucine derivatives were synthesized, thus opening up an excellent approach for the synthesis of bioactive natural products and derivatives thereof for structure activity relationship (SAR) studies.

Development of Strategies for Glycopeptide Synthesis: An Overview on the Glycosidic Linkage

2020 ◽  
Vol 24 (21) ◽  
pp. 2475-2497
Author(s):  
Andrea Verónica Rodríguez-Mayor ◽  
German Jesid Peralta-Camacho ◽  
Karen Johanna Cárdenas-Martínez ◽  
Javier Eduardo García-Castañeda
Keyword(s):  
Chemical Synthesis ◽  
Solid Phase ◽  
Building Blocks ◽  
Heterogeneous Environments ◽  
Phase Synthesis ◽  
Low Concentrations ◽  
Biological Sources ◽  
Synthetic Routes ◽  
The Impact ◽  
Potential Use

Glycoproteins and glycopeptides are an interesting focus of research, because of their potential use as therapeutic agents, since they are related to carbohydrate-carbohydrate, carbohydrate-protein, and carbohydrate-lipid interactions, which are commonly involved in biological processes. It has been established that natural glycoconjugates could be an important source of templates for the design and development of molecules with therapeutic applications. However, isolating large quantities of glycoconjugates from biological sources with the required purity is extremely complex, because these molecules are found in heterogeneous environments and in very low concentrations. As an alternative to solving this problem, the chemical synthesis of glycoconjugates has been developed. In this context, several methods for the synthesis of glycopeptides in solution and/or solid-phase have been reported. In most of these methods, glycosylated amino acid derivatives are used as building blocks for both solution and solid-phase synthesis. The synthetic viability of glycoconjugates is a critical parameter for allowing their use as drugs to mitigate the impact of microbial resistance and/or cancer. However, the chemical synthesis of glycoconjugates is a challenge, because these molecules possess multiple reaction sites and have a very specific stereochemistry. Therefore, it is necessary to design and implement synthetic routes, which may involve various protection schemes but can be stereoselective, environmentally friendly, and high-yielding. This review focuses on glycopeptide synthesis by recapitulating the progress made over the last 15 years.

Vasopressin and oxytocin analogs with interchanged sequence of amino acids in positions 7 and 8. synthesis and biological effects

1981 ◽  
Vol 46 (9) ◽  
pp. 2136-2139 ◽  
Author(s):  
Ivo Bláha ◽  
Viktor Krchňák ◽  
Milan Zaoral
Keyword(s):  
Amino Acids ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Biological Effects ◽  
Free Flow ◽  
Protecting Groups ◽  
Pressor Effect ◽  
Phase Synthesis ◽  
Antidiuretic Effect

p-Toluenesulfonyl-S-benzylcysteinyl-tyrosyl-phenylalanyl-glutaminyl-asparaginyl-S-benzylcysteinyl-NG-p-toluenesulfanylarginyl-prolyl-glycineamide (I) and S-benzylcysteinyl-tyrosyl-isoleucyl-glutaminyl-asparaginyl-S-benzylcysteinyl-leucyl-prolyl-glycine amide (III) were prepared by solid phase synthesis. After removal of the protecting groups, closure of the disulfide ring, and purification by continuous free-flow electrophoresis [arginine7, proline8]vasopressin (II) and [leucine7, proline8]oxytocin (IV) were obtained. The antidiuretic effect of II is markedly higher than its pressor effect; IV possesses c. 6% of the uterotonic and c. 10% of the galactogogous effect of oxytocin.

Cleavage of the Epimines of 1,6-Anhydrohexoses with Fluoride Anion

2005 ◽  
Vol 70 (12) ◽  
pp. 2075-2085 ◽  
Author(s):  
Jiří Kroutil ◽  
Klára Jeništová
Keyword(s):  
Fluoride Anion ◽  
Ring Cleavage ◽  
Protecting Group ◽  
Reaction Conditions ◽  
Aziridine Ring ◽  
Cleavage Reactions ◽  
Derivatives Of ◽  
Fluoro Derivatives

Aziridine ring cleavage reactions of five N-nosylepimines (2-6) having D-talo, D-galacto, D-manno, and D-allo configurations with potassium hydrogendifluoride under various reaction conditions have been performed. The cleavage regioselectively afforded diaxial isomers of vicinal amino-fluoro derivatives of 1,6-anhydro-β-D-gluco- and mannopyranose 7-11 in 51-94% yields. Removal of 2-nitrobenzenesulfonyl protecting group with benzenethiol has been attempted in the case of compound 10.

scholarly journals Biguanide-Based Synthesis of 1,3,5-Triazine Derivatives with Anticancer Activity and 1,3,5-Triazine Incorporated Calcium Citrate Nanoparticles

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1028
Author(s):  
Monnaya Chalermnon ◽  
Sarocha Cherdchom ◽  
Amornpun Sereemaspun ◽  
Rojrit Rojanathanes ◽  
Tanatorn Khotavivattana
Keyword(s):  
Anticancer Activity ◽  
Cell Lines ◽  
Anticancer Agent ◽  
Drug Loading ◽  
Calcium Citrate ◽  
Colorectal Cancer Cell Lines ◽  
Triazine Derivatives ◽  
Further Development ◽  
Derivatives Of ◽  
Potential Use

Twelve derivatives of biguanide-derived 1,3,5-triazines, a promising class of anticancer agent, were synthesised and evaluated for their anticancer activity against two colorectal cancer cell lines—HCT116 and SW620. 2c and 3c which are the derivatives containing o-hydroxyphenyl substituents exhibited the highest activity with IC50 against both cell lines in the range of 20–27 µM, which is comparable to the IC50 of cisplatin reference. Moreover, the potential use of the calcium citrate nanoparticles (CaCit NPs) as a platform for drug delivery system was studied on a selected 1,3,5-triazine derivative 2a. Condition optimisation revealed that the source of citrate ions and reaction time significantly influence the morphology, size and %drug loading of the particles. With the optimised conditions, “CaCit-2a NPs” were successfully synthesised with the size of 148 ± 23 nm and %drug loading of up to 16.3%. Furthermore, it was found that the release of 2a from the synthesised CaCit-2a NPs is pH-responsive, and 2a could be control released under the acidic cancer environment. The knowledge from this study is perceptive for further development of the 1,3,5-triazine-based anticancer drugs and provide the platform for the incorporation of other drugs in the CaCit NPs in the future.

scholarly journals Self-Supporting Hydrogels Based on Fmoc-Derivatized Cationic Hexapeptides for Potential Biomedical Applications

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 678
Author(s):  
Carlo Diaferia ◽  
Elisabetta Rosa ◽  
Enrico Gallo ◽  
Giovanni Smaldone ◽  
Mariano Stornaiuolo ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Supporting Cell ◽  
Diagnostic Tools ◽  
Cationic Peptides ◽  
Protecting Group ◽  
Synthetic Hydrogel ◽  
Acetyl Group ◽  
Biophysical Techniques ◽  
Fmoc Protecting Group ◽  
Derivatives Of

Peptide-based hydrogels (PHGs) are biocompatible materials suitable for biological, biomedical, and biotechnological applications, such as drug delivery and diagnostic tools for imaging. Recently, a novel class of synthetic hydrogel-forming amphiphilic cationic peptides (referred to as series K), containing an aliphatic region and a Lys residue, was proposed as a scaffold for bioprinting applications. Here, we report the synthesis of six analogues of the series K, in which the acetyl group at the N-terminus is replaced by aromatic portions, such as the Fmoc protecting group or the Fmoc-FF hydrogelator. The tendency of all peptides to self-assemble and to gel in aqueous solution was investigated using a set of biophysical techniques. The structural characterization pointed out that only the Fmoc-derivatives of series K keep their capability to gel. Among them, Fmoc-K3 hydrogel, which is the more rigid one (G’ = 2526 Pa), acts as potential material for tissue engineering, fully supporting cell adhesion, survival, and duplication. These results describe a gelification process, allowed only by the correct balancing among aggregation forces within the peptide sequences (e.g., van der Waals, hydrogen bonding, and π–π stacking).

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