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Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
In cells, a peptide is formed when two adjacent amino acids are linked together through the carboxyl (COOH) group of one amino acid with the amino (NH2) group of another to form an amide bond (-CONH-), also called peptide bond. The chain, thus formed, by linking together of many amino acid units is called a peptide chain (36, 38, 41). The two amino acids at the ends of the chain are called N-terminal and C-terminal where the groups NH2 and COOH are not linked – free or intact. Depending on the number of amino acid molecules composing a chain, the peptides may be termed as a dipeptide (containing 2 amino acid units), a tripeptide (containing 3 amino acid units) and so on. If a peptide is made up of no more than ten amino acids, it is called an oligopeptide; beyond that, it is a polypeptide. Peptide chain may possess from 50 to millions of amino acid units. When they are made up of over 100 amino acids, polypepties are sometimes called macro-peptides. Strictly speaking, proteins are polypeptides with more than 100 amino acids (38). However, this classification is arbitrary, and the number of amino acids can vary according to each author.
Interleukins and Metalloproteinases in Arthritis
Published in Thomas F. Kresina, Monoclonal Antibodies, Cytokines, and Arthritis, 2020
Ferreira et al. reported that part of the IL-1β molecule, a Lys-Pro-Thr tripep-tide, had hyperanalgesic activity, and modification of its structure to Lys-D-Pro-Thr produced a tripeptide that inhibited the bilateral hyperanalgesia effects of IL-1β. The tripeptide was not active in animal models of centrally mediated analgesia and had no effect on the synthesis or release of prostaglandins or IL-1β-induced pyrexia. The tripeptide and its congeners represent a new class of analgesic drugs that do not cause gastric lesions, which usually limits the usefulness of nonsteroidal anti-inflammatory agents. Corticosteroids effectively reduce IL-1 production by macrophages and inhibit IL-1-mediated release of proteinases by synovial cells and chondrocytes (45). Skotnicki et al. (94) reported that several 4-aminoquinolines (structurally related to chloroquine), including chloroquine and hydroxychloroquine, inhibited neutral proteinase released by IL-1-treated rabbit chondrocytes (49,90). Similar activities were observed with (((4-chlorophenyl)thio)methylene)bisphosphonic acid. Kadin et al. (95) recently reported that 3-acyl-2-oxoindole-1-carboxamides, which include a clinical candidate (CP-66,248), inhibited cyclo-oxygenase, 5-lipoxygenase, and IL-1 biosynthesis. Cyclo-oxygenase inhibitors suppress neither IL-1 production nor IL-1-induced thymocyte proliferation; however, they do inhibit IL-1-mediated responses that rely on prostaglandin synthesis, such as pyrexia.
Evaluation of Anti-ulcer Potential of Sphenodesme involucrata var. paniculata (C.B. Clarke) Munir Leaves on Various Gastric Aggressive Factors
Published in Parimelazhagan Thangaraj, Phytomedicine, 2020
P. S. Sreeja, K. Arunachalam, Parimelazhagan Thangaraj
Another important anti-oxidant, tripeptide γ-glutamyl-cysteinyl-glycine, glutathione, is also involved in cell protection against oxidative stress (Uys et al. 2014). Glutathione acts as a cofactor of several anti-oxidant enzymes, such as glutathione peroxidase and glutathione transferase, and the glutathione peroxidase has been involved in detoxifying hydrogen peroxide and thus avoiding lipid peroxidation (Jozefczak et al. 2012).
Effects of cinnamaldehyde on glucose-6-phosphate dehydrogenase activity, some biochemical and hematological parameters in diabetic rats
Published in Biomarkers, 2022
Remzi Çelik, Handan Mert, Bahat Comba, Nihat Mert
Vitamin A, E, C, carotene, GSH reductive forms and alternating oxidised forms form the antioxidant defense system (Packer et al.1979, Barclay et al.1983). Glutathione, a tripeptide, is essential for protecting the functional integrity and structure of cells. Protection of the GSH level depends on the activity of various enzymes (glutathione reductase, glutathione S-transferase, G6PD). The increase in G6PD activity results in increased hexosyl monophosphate passage and an increase in NADPH level. The elevated NADPH level also increases the activity of glutathione reductase, which helps maintain GSH levels (Dhuley 1999). GSH can be conjugated to various electrophilic intermediates capable of inducing lipid peroxidation, as well as the ability to directly capture free radicals (Jakoby 1978). In addition, GSH-dependent cytosolic and microsomal factors have been reported to be protective against lipid peroxidation. Kumar et al. (2012) found that liver GSH levels of diabetic animals with sinamaldehyde were significantly higher than diabetic group (p < 0.01).
Multicomponent reactions (MCR) in medicinal chemistry: a patent review (2010-2020)
Published in Expert Opinion on Therapeutic Patents, 2021
Hafiza Amna Younus, Mariya Al-Rashida, Abdul Hameed, Maliha Uroos, Uzma Salar, Sobia Rana, Khalid Mohammed Khan
Enopeptins have gained popularity mainly owing to their potent activity against drug-resistant bacteria such as Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) [54]. The antibiotic action of enopeptins is due to their ability to deregulate the activity of casein lytic protease (ClpP). The routine function of ClpP is to selectively degrade proteins after careful recognition and binding. However, enopeptins bind to ClpP resulting in conformational changes that exposes its active site, hence causing it to degrade folded cytoplasmic proteins without any discrimination which subsequently leads to cell death [55,56]. The structure of enopeptin can be thought to be made up of three components, i) a tripeptide part, ii) an ester part, and iii) a phenylalanine part. The tripeptide fragment is designed and synthesized as given in Scheme 12. Synthetic approaches to prepare pipecolate-derived enopeptin have been provided compounds are given in Scheme 13 and 14 [57]. Structures of some of the derivatives (132–135) synthesized via the above scheme are given in Scheme 15. The synthetic approaches for the synthesis of α,α-disubstituted amino acid derived enopeptitin compounds are given in Scheme 16.
Co-delivery of paclitaxel and anti-VEGF siRNA by tripeptide lipid nanoparticle to enhance the anti-tumor activity for lung cancer therapy
Published in Drug Delivery, 2020
Chuanmin Zhang, Yinan Zhao, Enxia Zhang, Meilin Jiang, Defu Zhi, Huiying Chen, Shaohui Cui, Yuhong Zhen, Jingnan Cui, Shubiao Zhang
Paclitaxel (PTX) was purchased from Meilun biology Company (Dalian, China). Paclitaxel injection (free PTX) was produced by Harbin pharmaceutical group bioengineering co., Ltd. (Harbin, China). Carboxyfluorescein-labeled siRNA (FAM-siRNA), VEGF siRNA (5′–3′ sequence: GGAGUACCCUGAUGAGAUCTT - GAUCUCAUCAGGGUACUCCTT), negative control siRNA (siNC) were obtained from GenePharma Co., Ltd. (Shanghai, China). Tripeptide lipids was prepared in our laboratory. Sucrose laurate (1% monoester, HLB = 1) was purchased from the Kaiteki company (Japan). RPMI1640 and fetal bovine serum (FBS) were purchased from Invitrogen Life Technologies (USA). Cell Counting Kit-8 (CCK-8) was purchased from Beyotime (Beijing, China). β-actin antibodies, VEGF antibodies and secondary antibodies were supplied by Proteintech (Wuhan, China). NCI-H460 cells were obtained from the Institute of Biochemistry and Cell Biology (China). BALB/c nude mice (4–6 weeks) were used for all in vivo studies. The Institutional Animal Care and Use Committee of Dalian Medical University approved all experiments performed on the animals.