Four novel cyclic undecapeptides, lyngbyazothrins A (1), B (2), C (3), and D (4), were isolated from the cultured Lyngbya sp. 36.91 as binary mixtures (1/2 and 3/4). Their structures were elucidated by analysis of 1D (1H and 13C) and 2D (COSY, TOCSY, ROESY, NOESY, HMQC, and HMBC) NMR spectra, ESIMSMS, ESITOFMS, and amino acid analyses. Three unusual amino acids were present and identified as 4-methoxyhomophenylalanine in 1 and 3, homophenylalanine in 2 and 4, and 3-amino-2,5,7,8-tetrahydroxy-10-methylundecanoic acid (Aound) in all compounds, while 3 and 4 have an additional N-acetyl-N-methyltyrosine unit. The mixture of lyngbyazothrins A (1) and B (2) shows only low antimicrobial activity against Micrococcus flavus, whereas the mixture of lyngbyazothrins C (3) and D (4) was active against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Serratia marcescens. It seems that the acyl residue at C-5 of the Aound unit plays an important role in antimicrobial activity.
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ACS Omega
October 2024
Department of Pharmacy, Birla Institute of Technology and Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana State 500078, India.
Am J Physiol Cell Physiol
July 2024
Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, India.
Activation of incretin receptors by their cognate agonist augments sustained cAMP generation both from the plasma membrane as well as from the endosome. To address the functional outcome of this spatiotemporal signaling, we developed a nonacylated glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor dual agonist I-M-150847 that reduced receptor internalization following activation of the incretin receptors. The incretin receptor dual agonist I-M-150847 was developed by replacing the tryptophan cage of exendin-4 tyrosine substituted at the amino terminus with the C-terminal undecapeptide sequence of oxyntomodulin that placed lysine 30 of I-M-150847 in frame with the corresponding lysine residue of GIP.
View Article and Find Full Text PDFAnal Bioanal Chem
October 2022
Department of Pharmacy, Copenhagen University, Universitetsparken 2, 2100, Copenhagen Ø, Denmark.
Therapeutic peptides are a fast-growing class of pharmaceuticals. Like small molecules, the costs associated with their discovery and development are significant. In addition, since the preclinical data guides first-in-human studies, there is a need for analytical techniques that accelerate and improve our understanding of the absorption, distribution, metabolism, and excretion (ADME) characteristics of early drug candidates.
View Article and Find Full Text PDFJ Cell Sci
February 2021
Instituto de Biología y Medicina Experimental-Consejo Nacional de Investigaciones, Científicas y Técnicas (CONICET), Buenos Aires C1428ADN, Argentina
Cyclophilin A (CyPA, also known as PPIA) is an abundant and ubiquitously expressed protein belonging to the immunophilin family, which has intrinsic peptidyl-prolyl-()-isomerase enzymatic activity. CyPA mediates immunosuppressive action of the cyclic undecapeptide cyclosporine A and is also involved in multiple cellular processes, such as protein folding, intracellular trafficking, signal transduction and transcriptional regulation. CyPA is abundantly expressed in cancer cells, and, owing to its chaperone nature, its expression is induced upon the onset of stress.
View Article and Find Full Text PDFCurr Med Chem
July 2021
Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove 50003, Czech Republic.
Cyclosporine A (CsA) is a cyclic undecapeptide with strong immunosuppressive potency. Firstly marketed in the mid-1980s, CsA was widely used in transplantation and greatly improved the survival rates of patients and grafts after solid-organ transplantation. Unfortunately, CsA administration can be associated with a number of side effects due to its high toxicity.
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