25191-13-3Relevant academic research and scientific papers
Cyclopeptide alkaloids from Heisteria nitida
El-Seedi, Hesham R.,Gohil, Suresh,Perera, Premila,Torssell, Kurt B.G.,Bohlin, Lars
, p. 1739 - 1744 (1999)
Integerrenine, and a new cyclopeptide alkaloid, containing the unusual amine oxide function, anorldianine 27-N oxide, stigmasterol, β-sitosterol, lupeol, (+)-catechin, (-)-epicatechin and 4-hydroxy-2-methoxy benzoic acid were isolated from the Ecuadorian medicinal plant Heisteria nitida (Engl.), Olacaceae. The structures were determined by UV, IR, NMR and mass spectroscopic investigations and chemical transformations. The cyclopeptide alkaloids have been isolated and characterized for the first time in the family Olacaceae.
Squamins C–F, four cyclopeptides from the seeds of Annona globiflora
Sosa-Rueda, Javier,Domínguez-Meléndez, Vanihamin,Ortiz-Celiseo, Araceli,López-Fentanes, Fernando C.,Cuadrado, Cristina,Fernández, José J.,Daranas, Antonio Hernández,Cen-Pacheco, Francisco
, (2021/08/04)
Four cyclic octapeptides, squamins C–F, were isolated from the seeds of Annona globiflora Schltdl. These compounds share part of their amino acid sequence, -Pro-Met(O)-Tyr-Gly-Thr-, with previously reported squamins A and B. Their structures were determined using NMR spectroscopic techniques together with quantum mechanical calculations (QM-NMR), ESI-HRMS data and a modified version of Marfey's chromatographic method. All compounds showed cytotoxic activity against DU-145 (human prostate cancer) and HeLa (human cervical carcinoma) cell lines. Clearly, A. globiflora is an important source of bioactive molecules, which could promote the sustainable exploitation of this undervalued specie.
Direct monitoring of biocatalytic deacetylation of amino acid substrates by1H NMR reveals fine details of substrate specificity
De Cesare, Silvia,McKenna, Catherine A.,Mulholland, Nicholas,Murray, Lorna,Bella, Juraj,Campopiano, Dominic J.
supporting information, p. 4904 - 4909 (2021/06/16)
Amino acids are key synthetic building blocks that can be prepared in an enantiopure form by biocatalytic methods. We show that thel-selective ornithine deacetylase ArgE catalyses hydrolysis of a wide-range ofN-acyl-amino acid substrates. This activity was revealed by1H NMR spectroscopy that monitored the appearance of the well resolved signal of the acetate product. Furthermore, the assay was used to probe the subtle structural selectivity of the biocatalyst using a substrate that could adopt different rotameric conformations.
MODIFIED INTERLEUKIN-7 PROTEINS AND USES THEREOF
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, (2021/10/22)
Provided are a modified IL-7 polypeptide and a fusion protein containing the modified IL-7 polypeptide. The fusion protein of the modified IL-7 includes: a first domain containing an interleukin-7 polypeptide; a second domain containing an oligopeptide having 1 to 10 amino acid residues (with proviso that the second domain excludes the oligopeptide consisting of methionine and/or glycine); and (c) a third domain which prolongs the half-life of the IL-7 fusion protein. The modified IL-7 polypeptide is composed of the (a) first domain and the (b) second domain. The modified IL-7 polypeptide and the fusion protein are expressed in a higher yield than the wild-type IL-7 and shows increased stability.
COMPOSITIONS AND METHODS FOR USING FIXED BIOLOGICAL SAMPLES IN PARTITION-BASED ASSAYS
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, (2021/06/26)
The present disclosure provides compositions and methods for using fixed biological samples in partition-based assays. In at least one embodiment, the disclosure provides a composition comprising a fixed biological sample and an un-fixing agent contained in a partition, such as a discrete droplet. In some embodiments, the disclosure provides un-fixing agent compounds capable of catalytically cleaving crosslinks in fixed biological samples, particularly crosslinked nucleic acids, such as RNA.
Leveraging Peptaibol Biosynthetic Promiscuity for Next-Generation Antiplasmodial Therapeutics
Lee, Jin Woo,Collins, Jennifer E.,Wendt, Karen L.,Chakrabarti, Debopam,Cichewicz, Robert H.
supporting information, p. 503 - 517 (2021/03/01)
Malaria remains a worldwide threat, afflicting over 200 million people each year. The emergence of drug resistance against existing therapeutics threatens to destabilize global efforts aimed at controlling Plasmodium spp. parasites, which is expected to leave vast portions of humanity unprotected against the disease. To address this need, systematic testing of a fungal natural product extract library assembled through the University of Oklahoma Citizen Science Soil Collection Program has generated an initial set of bioactive extracts that exhibit potent antiplasmodial activity (EC50 25 μM, selectivity index > 250). The unique chemodiversity afforded by these fungal isolates serves to unlock new opportunities for translating peptaibols into a bioactive scaffold worthy of further development.
Genomics-driven discovery of a new cyclodepsipeptide from the guanophilic fungusAmphichorda guana
Liang, Min,Lyu, Hai-Ning,Ma, Zi-Ying,Li, Er-Wei,Cai, Lei,Yin, Wen-Bing
, p. 1960 - 1964 (2021/03/16)
Two potential non-ribosomal peptide synthetases (NRPSs) were identified in the genome of a guanophilic fungusAmphichorda guanaby bioinformatics analysis and gene knockout experiments. Liquid chromatography coupled with mass spectrometry (LC-MS) guided isolation led to the discovery of a new cyclodepsipeptide isaridin H (1) and seven known analogs, desmethylisaridin E (2), isaridin E (3), isariin A (4), iso-isariin B (5), iso-isariin D (6), isariin E (7), and nodupetide (8). The absolute configuration of isaridin H (1) was achieved by Marfey's method. Isaridin H (1) showed significant antifungal activity againstBotrytis cinereaandAlternaria solani.
Irreversible inhibitors of the proline racemase unveil innovative mechanism of action as antibacterial agents against Clostridioides difficile
Barbut, Frédéric,Blondel, Arnaud,Gateau, Cécile,Gouault, Nicolas,Melo, Guilherme D.,Minoprio, Paola,Renault, Jacques,Tasseau, Olivier,Uriac, Philippe
, (2022/01/11)
Proline racemases (PRAC), catalyzing the l-proline and d-proline interconversion, are essential factors in eukaryotic pathogens such as Trypanosoma cruzi, Trypanosoma vivax, and Clostridioides difficile. If the discovery of irreversible inhibitors of T.?cruzi PRAC (TcPRAC) led to innovative therapy of the Chagas disease, no inhibitors of CdPRAC have been discovered to date. However, C.?difficile, due to an increased incidence in recent years, is considered as a major cause of health threat. In this work, we have taken into account the similarity between TcPRAC and CdPRAC enzymes to design new inhibitors of CdPRAC. Starting from (E) 4-oxopent-2-enoic acid TcPRAC irreversible inhibitors, we synthesized 4-aryl substituted analogs and evaluated their CdPRAC enzymatic inhibition against eleven strains of C.?difficile. This study resulted in promising candidates and allowed for identification of (E)-4-(3-bromothiophen-2-yl)-4-oxobut-2-enoic acid 20 that was chosen for complementary in vivo studies and did not reveal in vivo toxicity.
Isolation, Structure Determination, and Total Synthesis of Hoshinoamide C, an Antiparasitic Lipopeptide from the Marine Cyanobacterium Caldora penicillata
Iwasaki, Arihiro,Ohtomo, Keisuke,Kurisawa, Naoaki,Shiota, Ikuma,Rahmawati, Yulia,Jeelani, Ghulam,Nozaki, Tomoyoshi,Suenaga, Kiyotake
, p. 126 - 135 (2021/01/13)
Hoshinoamide C (1), an antiparasitic lipopeptide, was isolated from the marine cyanobacterium Caldora penicillata. Its planar structure was elucidated by spectral analyses, mainly 2D NMR, and the absolute configurations of the α-amino acid moieties were determined by degradation reactions followed by chiral-phase HPLC analyses. To clarify the absolute configuration of an unusual amino acid moiety, we synthesized two possible diastereomers of hoshinoamide C and determined its absolute configuration based on a comparison of their spectroscopic data with those of the natural compound. Hoshinoamide C (1) did not exhibit any cytotoxicity against HeLa or HL60 cells at 10 μM, but inhibited the growth of the parasites responsible for malaria (IC50 0.96 μM) and African sleeping sickness (IC50 2.9 μM).
Komesuamide and odopenicillatamide, two linear lipopeptides from the marine cyanobacterium Caldora penicillata
Ozaki, Kaori,Jinno, Atsuhide,Natsume, Noriyuki,Sumimoto, Shimpei,Iwasaki, Arihiro,Suenaga, Kiyotake,Teruya, Toshiaki
, (2021/04/05)
The linear lipopeptides komesuamide (1) and odopenicillatamide (2) were isolated from Caldora penicillata a marine cyanobacterium collected in Okinawa. The structures of these compounds were established by spectroscopic analyses, and the absolute configurations were determined by HPLC analyses of the acid hydrolysates. Both compounds showed glucose uptake activity at 40 μM in cultured L6 myotubes.
