Abiotic Formation of Amide Bond via Surface‐Supported Direct Carboxyl‐Amine Coupling

Bioactive peptides are short chain of amino acids (usually 2-20) that are linked by amide bond in a specific sequence which have some biological effects in animals or humans. These can be of diverse origin like plant, animal, fish, microbe, marine organism or even synthetic. They are successfully used in the management of many diseases. In recent years increased attention has been raised for its effects and mechanism of action in various disease conditions like cancer, immunity, cardiovascular disease, hypertension, inflammation, diabetes, microbial infections etc. Bioactive peptides are more bioavailable and less allergenic when compared to total proteins. Food derived bioactive peptides have health benefits and its demand has increased tremendously over the past decade. This review gives a view on last two years research on potential bioactive peptides derived from food which have significant therapeutic effects.

Download Full-text

Diethylphosphoryl-OxymaB (DEPO-B) as a Solid Coupling Reagent for Amide Bond Formation

Letters in Organic Chemistry ◽

10.2174/1570178615666180612074420 ◽

2018 ◽

Vol 16 (1) ◽

pp. 30-33

Author(s):

Ashish Kumar ◽

Yahya E. Jad ◽

Ayman El-Faham ◽

Beatriz G. de la Torre ◽

Fernando Albericio

Keyword(s):

Bond Formation ◽

Hydrolytic Stability ◽

Solid Material ◽

Amide Bond ◽

Amide Bond Formation ◽

Coupling Reagent

A new phosphonium based coupling reagent DEPO-B has been synthesized from 5- (hydroxyimino)-1,3-dimethylpyrimidine-2,4,6 (1H,3H,5H)-trione (Oxyma B) and diethyl chlorophosphate in presence of base. It is a solid material and the hydrolytic stability and solubility was evaluated for confirming its capability for usage in automated peptide synthesizer.

Download Full-text

A Review of Amide Bond Formation in Microwave Organic Synthesis

Current Organic Synthesis ◽

10.2174/1570179411666140321180857 ◽

2014 ◽

Vol 11 (4) ◽

pp. 592-604 ◽

Cited By ~ 18

Author(s):

Natalia Lukasik ◽

Ewa Wagner-Wysiecka

Keyword(s):

Organic Synthesis ◽

Bond Formation ◽

Amide Bond ◽

Amide Bond Formation

Download Full-text

Biotin-Containing Third Generation Glucoheptoamidated Polyamidoamine Dendrimer for 5-Aminolevulinic Acid Delivery System

International Journal of Molecular Sciences ◽

10.3390/ijms22041982 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1982 ◽

Cited By ~ 1

Author(s):

Aleksandra Kaczorowska ◽

Małgorzata Malinga-Drozd ◽

Wojciech Kałas ◽

Marta Kopaczyńska ◽

Stanisław Wołowiec ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Aminolevulinic Acid ◽

Reactive Oxygen ◽

Pamam Dendrimer ◽

Variable Number ◽

Amide Bond ◽

Oxygen Species ◽

Nmr Spectrum ◽

Guest Molecules ◽

Amine Groups

Polyamidoamine PAMAM dendrimer generation 3 (G3) was modified by attachment of biotin via amide bond and glucoheptoamidated by addition of α-D-glucoheptono-1,4-lacton to obtain a series of conjugates with a variable number of biotin residues. The composition of conjugates was determined by detailed 1-D and 2-D NMR spectroscopy to reveal the number of biotin residues, which were 1, 2, 4, 6, or 8, while the number of glucoheptoamide residues substituted most of the remaining primary amine groups of PAMAM G3. The conjugates were then used as host molecules to encapsulate the 5-aminolevulinic acid. The solubility of 5-aminolevulinic acid increased twice in the presence of the 5-mM guest in water. The interaction between host and guest was accompanied by deprotonation of the carboxylic group of 5-aminolevulinic acid and proton transfer into internal ternary nitrogen atoms of the guest as evidenced by a characteristic chemical shift of resonances in the 1H NMR spectrum of associates. The guest molecules were most likely encapsulated inside inner shell voids of the host. The number of guest molecules depended on the number of biotin residues of the host, which was 15 for non-biotin-containing glucoheptoamidated G3 down to 6 for glucoheptoamidated G3 with 8 biotin residues on the host surface. The encapsulates were not cytotoxic against Caco-2 cells up to 200-µM concentration in the dark. All encapsulates were able to deliver 5-aminolevulinic acid to cells but aqueous encapsulates were more active in this regard. Simultaneously, the reactive oxygen species were detected by staining with H2DCFDA in Caco-2 cells incubated with encapsulates. The amount of PpIX was sufficient for induction of reactive oxygen species upon 30-s illumination with a 655-nm laser beam.

Download Full-text

4-[(2,4-Dichlorophenyl)carbamoyl]butanoic Acid

Molbank ◽

10.3390/m1227 ◽

2021 ◽

Vol 2021 (2) ◽

pp. M1227

Author(s):

Bibi Hanifa ◽

Muhammad Sirajuddin ◽

Zafran Ullah ◽

Sumera Mahboob ◽

See Mun Lee ◽

...

Keyword(s):

Torsion Angle ◽

Acid Amide ◽

Spectroscopic Characterization ◽

Amide Bond ◽

Amide Hydrogen ◽

Butanoic Acid ◽

X Ray ◽

Amide Derivative

The synthesis and spectroscopic characterization of the glutaric acid-amide derivative, 2,4-Cl2C6H3N(H)C(=O)(CH2)3C(=O)OH (1), are described. The X-ray crystal structure determination of (1) shows the backbone of the molecule to be kinked about the methylene-C–N(amide) bond as seen in the C(p)–N–C(m)–C(m) torsion angle of −157.0(2)°; m = methylene and p = phenyl. An additional twist in the molecule is noted between the amide and phenyl groups as reflected in the C(m)–N–C(p)–C(p) torsion angle of 138.2(2)°. The most prominent feature of the molecular packing is the formation of supramolecular tapes assembled through carboxylic acid-O–H…O(carbonyl) and amide-N–H…O(amide) hydrogen bonding.

Download Full-text

Assessing Surface Coverage of Aminophenyl Bonding Sites on Diazotised Glassy Carbon Electrodes for Optimised Electrochemical Biosensor Performance

Nanomaterials ◽

10.3390/nano11020416 ◽

2021 ◽

Vol 11 (2) ◽

pp. 416

Author(s):

Zari Tehrani ◽

Hina Yaqub Abbasi ◽

Anitha Devadoss ◽

Jonathan Edward Evans ◽

Owen James Guy

Keyword(s):

Carboxylic Acid ◽

Surface Coverage ◽

Electrochemical Biosensor ◽

Electrochemical Techniques ◽

Differential Pulse ◽

Second Step ◽

Glassy Carbon Electrodes ◽

Potential Marker ◽

Pulse Voltammetry ◽

Amine Coupling

Electrochemical biosensors using carbon-based electrodes are being widely developed for the detection of a range of different diseases. Since their sensitivity depends on the surface coverage of bioreceptor moieties, it necessarily depends on the surface coverage of amine precursors. Electrochemical techniques, using ferrocene carboxylic acid as a rapid and cheap assay, were used to assess the surface coverage of amino-phenyl groups attached to the carbon electrode. While the number of electrons transferred in the first step of diazotisation indicated a surface coverage of 8.02 ± 0.2 × l0−10 (mol/cm2), and those transferred in the second step, a reduction of nitrophenyl to amino-phenyl, indicated an amine surface coverage of 4–5 × l0−10 (mol/cm2), the number of electrons transferred during attachment of the amine coupling assay compound, ferrocene carboxylic acid, indicated a much lower available amine coverage of only 2.2 × l0−11 (mol/cm2). Furthermore, the available amine coverage was critically dependent upon the number of cyclic voltammetry cycles used in the reduction, and thus the procedures used in this step influenced the sensitivity of any subsequent sensor. Amine coupling of a carboxyl terminated anti-beta amyloid antibody specific to Aβ(1-42) peptide, a potential marker for Alzheimer’s disease, followed the same pattern of coverage as that observed with ferrocene carboxylic acid, and at optimum amine coverage, the sensitivity of the differential pulse voltammetry sensor was in the range 0–200 ng/mL with the slope of 5.07 µA/ng·mL−1 and R2 = 0.98.

Download Full-text