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Review on Advanced Food Packaging Materials Based on Functional Biopolymer Matrix
Published in Mohd Yusuf, Shafat Ahmad Khan, Biomaterials in Food Packaging, 2022
Md. Aftab Alam, Rizwana Khatoon, Shamsul Huda, Pramod Kumar Sharma
Proteins are complicated structures consisting of amino acids connected via peptide bonds and organized in a three-dimensional structure. It can be derived from crop sources (gluten, wheat, maize, zein, and soy) and animal sources (whey, casein, keratin, and gelatin). Because of the distinctive side chain in their structure, they are extremely desirable to alter the necessary features of packaging products. Moreover, due to their renewable nature, proteins and protein-based materials are used in many industrial applications for biodegradability and their outstanding gas barrier characteristics. However, they are adversely impacted as starch-based polymers by their hydrophilic nature. They, therefore, need to be mixed with other polymers or must be changed chemically or microbiologically [77, 103].
The Prelude of Green Syntheses of Drugs and Natural Products
Published in Ahindra Nag, Greener Synthesis of Organic Compounds, Drugs and Natural Products, 2022
Leonardo Xochicale-Santana, C. C. Vidyasagar, Blanca M. Muñoz-Flores, Víctor M. Jiménez Pérez
Peptides are molecules formed by the union of several amino acids through peptide bonds. Peptides differ from proteins due to their size; their mass is between 10,000 and 12,000 Daltons. These molecules have a broad spectrum of bioactivity such as antibacterial, antitumor, and antidiabetic activity. Furthermore, peptides can be linked to different heterocycles that allow them to improve bioactivity. That is why the pharmaceutical industry has an interest in obtaining these compounds; however, the most common methods for obtaining these species are usually expensive, due to the use of toxic reagents, use of catalysts, and handling of strict conditions. However, in 2018, Hooshmand et al. reported a methodology for obtaining pseudopeptides bound to Rhodamine-combined aliphatic amines, aromatic amines, carbon disulfide, aldehydes, anhydrides, and isocyanides through of one-pot reaction of six components in water using ultrasound irradiation (Scheme 15.17).50 This methodology allows obtaining these compounds in an easy way, avoiding the excessive use of toxic substances and excluding purification methods, in addition to being an eco-friendly method.
Arsenals of Pharmacotherapeutically Active Proteins and Peptides: Old Wine in a New Bottle
Published in Debarshi Kar Mahapatra, Swati Gokul Talele, Tatiana G. Volova, A. K. Haghi, Biologically Active Natural Products, 2020
Peptide Bond: These are covalent bonds which link amino acids together to form a peptide or a protein. The peptide bond forms the backbone of the peptide or the protein. A peptide bond is formed by condensation reaction between −COOH of one amino acid and −NH2 of another amino acid with release of water molecule. The peptide bond has a partial double bond character which provides rigidity as well as planarity to the peptide bond.
Bacteria-targeting chitosan/carbon dots nanocomposite with membrane disruptive properties improve eradication rate of Helicobacter pylori
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Muhammad Arif, Mohamed Sharaf, Quanjiang Dong, Lili Wang, Zhe Chi, Chen-Guang Liu
The cellular disruption observed in the TEM and SEM studies may be attributed to oxidative stress, which is the primary cause of the antibacterial activity of CDs decorated UCPM-NPs [19]. Spherical CDs have been shown to have a significant antibacterial effect due to their ability to penetrate bacterial cell membranes [35]. Furthermore, UCPM-NPs can disrupt bacteria by coming into direct contact with their surface [36]. This interaction will alter the microenvironment around bacteria-NPs, resulting in the production of reactive oxygen species (ROS) that will damage bacterial cells, as shown in Figure 1B. This damage can be caused by peptide bond cleavage or protein-protein cross-linked derivatives created by a reaction between carbon-centred radicals [37].
First studies on the interactions of the C-terminal cystatin C fragment 85–94 with Cu(II) ions
Published in Journal of Coordination Chemistry, 2019
Aneta Szymańska, Aleksandra Marciniak, Edward Krzyżak, Justyna Brasuń
The studied peptide contains two histidine residues separated by a proline residue (FHDQPHLKRK, Scheme 1). Proline is a specific amino acid residue which influences not only the structural properties of the peptide or protein [24] but also has a strong impact on the coordination abilities. When proline’s amino nitrogen is involved in peptide bond formation, coordination of the subsequent amide donor does not take place [25]. Owing to this fact two, potentially independent, Cu(II) binding motifs, N-terminal and C-terminal (Scheme 1), can be found in the studied peptide sequence. Therefore, two possible forms of the dominant complexes can be proposed (Scheme 2).
Expression and characterization of a novel organic solvent tolerant protease from Bacillus sphaericus DS11
Published in Preparative Biochemistry & Biotechnology, 2021
Xincai Wu, Sibtain Ahmed, Xiaolin Cui, Jiahao Hang, Shujun Wang, Shu Liu, Yaowei Fang
Various carboxyl components (Z-AA) and Phe-NH2 were used as substrates to investigate the specificity of the recombinant OSP for the carboxyl component substrates. The Z-AA-Phe-NH2 yields in the presence of 50% (v/v) DMSO are shown in Figure 8. The results showed that the recombinant OSP is able to select phenylalanine (Phe) on the amine side of the peptide bond with broad specificity for the carboxylic acid residue. The yield in the presence of DMSO was 89.33%.