scholarly journals Synthesis and Evaluation of Novel Iminosugars Prepared from Natural Amino Acids

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 394
Author(s):  
Alejandro Puet ◽  
Gema Domínguez ◽  
Francisco Javier Cañada ◽  
Javier Pérez-Castells
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Molecular Recognition ◽  
Inhibitory Activity ◽  
Inhibition Activity ◽  
Ring Closing Metathesis ◽  
Stereogenic Centers ◽  
Activity Enhancement ◽  
Natural Amino Acids

Cyclopropanated iminosugars have a locked conformation that may enhance the inhibitory activity and selectivity against different glycosidases. We show the synthesis of new cyclopropane-containing piperidines bearing five stereogenic centers from natural amino acids l-serine and l-alanine. Those prepared from the latter amino acid may mimic l-fucose, a natural-occurring monosaccharide involved in many molecular recognition events. Final compounds prepared from l-serine bear S configurations on the C5 position. The synthesis involved a stereoselective cyclopropanation reaction of an α,β-unsaturated piperidone, which was prepared through a ring-closing metathesis. The final compounds were tested as possible inhibitors of different glycosidases. The results, although, in general, with low inhibition activity, showed selectivity, depending on the compound and enzyme, and in some cases, an unexpected activity enhancement was observed.

Multifunctional lubricant additives derived from natural amino acids and methyl oleate

RSC Advances ◽  
2015 ◽  
Vol 5 (95) ◽  
pp. 77538-77544 ◽  
Author(s):  
Arukali Sammaiah ◽  
Korlipara V. Padmaja ◽  
Shiva Shanker Kaki ◽  
Rachapudi B. N. Prasad
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Oleate ◽  
Thioglycolic Acid ◽  
Methyl Esters ◽  
Lubricant Additives ◽  
Acid Methyl ◽  
Multifunctional Additives ◽  
Natural Amino Acids ◽  
Amino Acid Methyl Esters

Novel multifunctional additives were synthesized from methyl oleate via thioglycolic acid addition followed by condensation with different amino acid methyl esters.

Amino-terminal TACE prodomain attenuates TNFR2 cleavage independently of the cysteine switch

2005 ◽  
Vol 288 (6) ◽  
pp. L1132-L1138 ◽  
Author(s):  
Caitriona A. Buckley ◽  
Farshid N. Rouhani ◽  
Maryann Kaler ◽  
Barbara Adamik ◽  
Feras I. Hawari ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Inhibitory Activity ◽  
Catalytic Domain ◽  
Amino Terminus ◽  
Mucin Production ◽  
Inactive State ◽  
Amino Terminal ◽  
Switch Mechanism ◽  
Cysteine Switch

TNF-α-converting enzyme (TACE, ADAM17) cleaves membrane-associated cytokines and receptors and thereby regulates inflammatory and immune events, as well as lung development and mucin production. For example, the TACE-mediated cleavage of the type II 75-kDa TNF receptor (TNFR2) generates a soluble TNF-binding protein that modulates TNF bioactivity. TACE is synthesized as a latent proenzyme that is retained in an inactive state via an interaction between its prodomain and catalytic domain. Although the formation of an intramolecular bond between a cysteine in the prodomain and a zinc atom in the catalytic site had been thought to mediate this inhibitory activity, it was recently reported that the cysteine-switch motif is not required. Here, we hypothesized that the amino terminus of the TACE prodomain might contribute to the ability of the prodomain to maintain TACE in an inactive state independently of a cysteine-switch mechanism. We synthesized a 37-amino acid peptide corresponding to TACE amino acids 18–54 (N-TACE18–54) and assessed whether it possessed TACE inhibitory activity. In an in vitro model assay system, N-TACE18–54 attenuated TACE-catalyzed cleavage of a TNFR2:Fc substrate. Furthermore, N-TACE18–54 inhibited constitutive TNFR2 shedding from a human monocytic cell line by 42%. A 19-amino acid, leucine-rich domain, corresponding to TACE amino acids 30–48, demonstrated partial inhibitory activity. In summary, we have identified a subdomain within the amino terminus of the TACE prodomain that attenuates TACE catalytic activity independently of a cysteine-switch mechanism, which provides new insight into the regulation of TACE enzymatic activity.

Synthesis of Chiral N-(Purin-6-yl)amino Acid Derivatives by using Natural Amino Acids as Starting Materials

2012 ◽  
Vol 1 (3) ◽  
pp. 238-244 ◽  
Author(s):  
Hong-Ying Niu ◽  
Shi-Xia Bai ◽  
Shan Wu ◽  
Gui-Rong Qu ◽  
Hai-Ming Guo
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Derivatives ◽  
Natural Amino Acids

The functional capacity of the natural amino acids for molecular recognition

2010 ◽  
Vol 6 (7) ◽  
pp. 1186 ◽  
Author(s):  
Sara Birtalan ◽  
Robert D. Fisher ◽  
Sachdev S. Sidhu
Keyword(s):  
Amino Acids ◽  
Molecular Recognition ◽  
Functional Capacity ◽  
Natural Amino Acids

scholarly journals Synthesis and Atiplatelet of 2-(ethyl amino acid esters), Amino pyridyl 1,3- oxzine

2006 ◽  
Vol 2 (2) ◽  
pp. 91-97
Author(s):  
Mohamad Alajelee
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Elemental Analysis ◽  
Inhibitory Activity ◽  
Amino Acid Esters ◽  
Improved Method ◽  
Acid Esters

2-(N-glycyl ,Alanyl , leucinyl , isoleacinyl , methionyl , phenyl alanyl,  vilinyl methyl ester) , 2-Amino and 4- Amino pyrideyl -1,3- Benzoxazine -4- one were synthesized from the reaction of the corresponding amino acids ester , Amino pyridines with methyl cyano salicylate using improved method. The resulted benzoxazine derivative were tested for their Antiplatelet inhibitory activity , their IR , NMR (1H , 13C) were also studied and checked by elemental analysis.

Formylglycine-generating enzymes for site-specific bioconjugation

2019 ◽  
Vol 400 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Tobias Krüger ◽  
Thomas Dierks ◽  
Norbert Sewald
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Recombinant Proteins ◽  
The State ◽  
Protein Scaffolds ◽  
Site Specific ◽  
Catalytic Mechanisms ◽  
Consensus Motifs ◽  
State Of Research ◽  
Natural Amino Acids

Abstract Site-specific bioconjugation strategies offer many possibilities for directed protein modifications. Among the various enzyme-based conjugation protocols, formylglycine-generating enzymes allow to posttranslationally introduce the amino acid Cα-formylglycine (FGly) into recombinant proteins, starting from cysteine or serine residues within distinct consensus motifs. The aldehyde-bearing FGly-residue displays orthogonal reactivity to all other natural amino acids and can, therefore, be used for site-specific labeling reactions on protein scaffolds. In this review, the state of research on catalytic mechanisms and consensus motifs of different formylglycine-generating enzymes, as well as labeling strategies and applications of FGly-based bioconjugations are presented.

scholarly journals Development of natural and unnatural amino acid delivery systems against hookworm infection

2020 ◽  
Vol 3 (1) ◽  
pp. 471-482 ◽  
Author(s):  
Stacey Bartlett ◽  
Mariusz Skwarczynski ◽  
Xin Xie ◽  
Istvan Toth ◽  
Alex Loukas ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Single Molecule ◽  
Cell Epitope ◽  
Unnatural Amino Acid ◽  
Nippostrongylus Brasiliensis ◽  
Peptide Fragments ◽  
Specific Pathogen ◽  
Hydrophobic Amino Acids ◽  
Natural Amino Acids

Peptide-based vaccines consist of short antigen fragments derived from a specific pathogen. Alone, these peptide fragments are poorly or non-immunogenic; however, when incorporated into a proper delivery system, they can trigger strong immune responses. To eliminate the need for toxic and often ineffective oral adjuvants, we designed single molecule-based self-adjuvating vaccines against hookworms using natural and unnatural hydrophobic amino acids. Two vaccine conjugates were synthesized, consisting of B-cell epitope p3, derived from the hookworm Na-APR-1 protein; universal T-helper peptide P25; and either double copies of unnatural lipoamino acid (2-amino-D,L-eicosanoic acid), or ten copies of the natural amino acid leucine. After challenge with the model hookworm, Nippostrongylus brasiliensis, mice orally immunized with the conjugates, but without adjuvant, generated antibody responses against the hookworm epitope, resulting in significantly reduced worm and egg burdens compared to control mice. We have demonstrated that vaccine nanoparticles composed exclusively of natural amino acids can be effective even when administered orally.

An Efficient Method for Constructing Cyclic β-Amino Acids Bearing Quaternary Stereocenters

Synlett ◽  
2019 ◽  
Vol 30 (05) ◽  
pp. 593-599 ◽  
Author(s):  
Shende Jiang ◽  
Guang Yang ◽  
Shuanglin Qin ◽  
Tongtong Liu ◽  
Yunhao Luo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Efficient Method ◽  
Ester Group ◽  
Chiral Auxiliary ◽  
Allyl Ester ◽  
Stereogenic Centers ◽  
Quaternary Stereocenters ◽  
High Yields ◽  
Quaternary Stereogenic Centers

This paper describes an efficient method for constructing cyclic β-amino acids bearing quaternary stereocenters. NaHMDS-promoted asymmetric α-alkylation was employed to obtain the key intermediates with quaternary stereogenic centers, which were subsequently reduced by NaBH4 in 10% methanol in THF, with high yields and high diastereoselectivities. By removing the allyl ester group and the chiral auxiliary, the corresponding cyclic β-amino acid hydrochlorides were finally obtained.

scholarly journals Intrinsic MRI contrast from amino acid-based paramagnetic ionic liquids

2020 ◽  
Vol 1 (6) ◽  
pp. 1980-1987
Author(s):  
Praveen Singh Gehlot ◽  
Hariom Gupta ◽  
Mangal Singh Rathore ◽  
Kusum Khatri ◽  
Arvind Kumar
Keyword(s):  
Magnetic Resonance Imaging ◽  
Amino Acids ◽  
Ionic Liquids ◽  
Amino Acid ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Dual Mode ◽  
Mri Contrast ◽  
Magnetic Resonance Imaging Mri ◽  
Natural Amino Acids

Paramagnetic ionic liquids (PMILs) comprising of natural amino acids and tetrachloroferrate(iii) as constituent ions were prepared that act as highly efficient dual mode (T1 and T2) responsive contrast agents for magnetic resonance imaging (MRI).

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