scholarly journals An innovative approach for the synthesis of dual modality peptide imaging probes based on the native chemical ligation approach

2020 ◽  
Vol 56 (24) ◽  
pp. 3500-3503
Author(s):  
Ivan Hawala ◽  
Lucia De Rosa ◽  
Silvio Aime ◽  
Luca Domenico D’Andrea
Keyword(s):  
Aqueous Solution ◽  
Innovative Approach ◽  
Native Chemical Ligation ◽  
Chemical Ligation ◽  
Dual Modality ◽  
Imaging Probe ◽  
Mild Conditions ◽  
Imaging Probes ◽  
Peptide Imaging

The synthesis of a dual peptide-based imaging probe consists of two steps performed in aqueous solution under mild conditions.

scholarly journals A Cysteine Selenosulfide Redox Switch for Protein Chemical Synthesis

2020 ◽  
Author(s):  
Vincent Diemer ◽  
Nathalie Ollivier ◽  
Bérénice Leclercq ◽  
Hervé Drobecq ◽  
Jérôme Vicogne ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Growth Factor ◽  
Chemical Synthesis ◽  
Biologically Active ◽  
Native Chemical Ligation ◽  
Chemical Ligation ◽  
Mild Conditions ◽  
Redox Switch ◽  
Nitrogen Bonds ◽  
Hepatocyte Growth

The control of cysteine reactivity is of paramount importance for the synthesis of proteins using the native chemical ligation (NCL) reaction. We discovered that this goal can be achieved in a traceless manner during ligation by appending a simple N-selenoethyl group to cysteine. While in synthetic organic chemistry the cleavage of carbon-nitrogen bonds is notoriously difficult, we found that N-selenoethyl cysteine (SetCys) loses its selenoethyl arm in water under mild conditions upon reduction of its selenosulfide bond. Detailed mechanistic investigations uncover a novel mode of reactivity for Cys. Its implementation in a process enabling the modular and straightforward assembly of linear or backbone cyclized polypeptides is illustrated by the synthesis of biologically active cyclic hepatocyte growth factor variants.<br>

scholarly journals A Cysteine Selenosulfide Redox Switch for Protein Chemical Synthesis

2020 ◽  
Author(s):  
Vincent Diemer ◽  
Nathalie Ollivier ◽  
Bérénice Leclercq ◽  
Hervé Drobecq ◽  
Jérôme Vicogne ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Growth Factor ◽  
Chemical Synthesis ◽  
Biologically Active ◽  
Native Chemical Ligation ◽  
Chemical Ligation ◽  
Mild Conditions ◽  
Redox Switch ◽  
Nitrogen Bonds ◽  
Hepatocyte Growth

The control of cysteine reactivity is of paramount importance for the synthesis of proteins using the native chemical ligation (NCL) reaction. We discovered that this goal can be achieved in a traceless manner during ligation by appending a simple N-selenoethyl group to cysteine. While in synthetic organic chemistry the cleavage of carbon-nitrogen bonds is notoriously difficult, we found that N-selenoethyl cysteine (SetCys) loses its selenoethyl arm in water under mild conditions upon reduction of its selenosulfide bond. Detailed mechanistic investigations uncover a novel mode of reactivity for Cys. Its implementation in a process enabling the modular and straightforward assembly of linear or backbone cyclized polypeptides is illustrated by the synthesis of biologically active cyclic hepatocyte growth factor variants.<br>

scholarly journals Dual-Modality Imaging Probes with High Magnetic Relaxivity and Near-Infrared Fluorescence Based Highly Aminated Mesoporous Silica Nanoparticles

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Zhu Fei-Peng ◽  
Chen Guo-Tao ◽  
Wang Shou-Ju ◽  
Liu Ying ◽  
Tang Yu-Xia ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Near Infrared ◽  
Mesoporous Silica Nanoparticles ◽  
Near Infrared Fluorescence ◽  
Dual Modality ◽  
Imaging Probe ◽  
Nir Fluorescence ◽  
Imaging Probes ◽  
Dual Modality Imaging

Dual-modal imaging by combining magnetic resonance (MR) and near-infrared (NIR) fluorescence can integrate the advantages of high-resolution anatomical imaging with high sensitivity in vivo fluorescent imaging, which is expected to play a significant role in biomedical researches. Here we report a dual-modality imaging probe (NIR/MR-MSNs) fabricated by conjugating NIR fluorescent heptamethine dyes (IR-808) and MR contrast agents (Gd-DTPA) within highly aminated mesoporous silica nanoparticles (MSNs-NH2). The dual-modality imaging probes NIR/MR-MSNs possess a size of ca. 120 nm. The NIR/MR-MSNs show not only near-infrared fluorescence imaging property with an emission peak at 794 nm, but also highly MRT1relaxivity of 14.54 mM−1 s−1, which is three times more than Gd-DTPA. In vitro experiment reveals high uptake and retention abilities of the nanoprobes, while cell viability assay demonstrates excellent cytocompatibility of the dual-modality imaging probe. After intratumor injection with the NIR/MR-MSNs, MR imaging shows clear anatomical border of the enhanced tumor region while NIR fluorescence exhibits high sensitive tumor detection ability. These intriguing features suggest that this newly developed dual-modality imaging probes have great potential in biomedical imaging.

scholarly journals Practical Synthesis of 2-Iodosobenzoic Acid (IBA) without Contamination by Hazardous 2-Iodoxybenzoic Acid (IBX) under Mild Conditions

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1897
Author(s):  
Hideyasu China ◽  
Nami Kageyama ◽  
Hotaka Yatabe ◽  
Naoko Takenaga ◽  
Toshifumi Dohi
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Practical Method ◽  
Hypervalent Iodine ◽  
Mild Conditions ◽  
Sequential Procedures ◽  
Iodine Compounds ◽  
Practical Synthesis ◽  
Iodosobenzoic Acid ◽  
Lower Temperature

We report a convenient and practical method for the preparation of nonexplosive cyclic hypervalent iodine(III) oxidants as efficient organocatalysts and reagents for various reactions using Oxone® in aqueous solution under mild conditions at room temperature. The thus obtained 2-iodosobenzoic acids (IBAs) could be used as precursors of other cyclic organoiodine(III) derivatives by the solvolytic derivatization of the hydroxy group under mild conditions of 80 °C or lower temperature. These sequential procedures are highly reliable to selectively afford cyclic hypervalent iodine compounds in excellent yields without contamination by hazardous pentavalent iodine(III) compound.

scholarly journals Autocatalytic and oscillatory reaction networks that form guanidines and products of their cyclization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexander I. Novichkov ◽  
Anton I. Hanopolskyi ◽  
Xiaoming Miao ◽  
Linda J. W. Shimon ◽  
Yael Diskin-Posner ◽  
...  
Keyword(s):  
Chemical Cues ◽  
Native Chemical Ligation ◽  
Reaction Networks ◽  
Oscillatory Reaction ◽  
Experimental Conditions ◽  
Chemical Ligation ◽  
Chemical Systems ◽  
Life On Earth ◽  
Emergence Of Life ◽  
Equilibrium Chemical

AbstractAutocatalytic and oscillatory networks of organic reactions are important for designing life-inspired materials and for better understanding the emergence of life on Earth; however, the diversity of the chemistries of these reactions is limited. In this work, we present the thiol-assisted formation of guanidines, which has a mechanism analogous to that of native chemical ligation. Using this reaction, we designed autocatalytic and oscillatory reaction networks that form substituted guanidines from thiouronium salts. The thiouronium salt-based oscillator show good stability of oscillations within a broad range of experimental conditions. By using nitrile-containing starting materials, we constructed an oscillator where the concentration of a bicyclic derivative of dihydropyrimidine oscillates. Moreover, the mixed thioester and thiouronium salt-based oscillator show unique responsiveness to chemical cues. The reactions developed in this work expand our toolbox for designing out-of-equilibrium chemical systems and link autocatalytic and oscillatory chemistry to the synthesis of guanidinium derivatives and the products of their transformations including analogs of nucleobases.

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