496-98-0Relevant academic research and scientific papers
Detection of reaction intermediates during human cystathionine β-synthase-monitored turnover and H2S production
Yadav, Pramod Kumar,Banerjee, Ruma
, p. 43464 - 43471 (2012)
Human cystathionine β-synthase (CBS), a novel heme-containing pyridoxal 5′-phosphate enzyme, catalyzes the condensation of homocysteine and serine or cysteine to produce cystathionine and H2O or H 2S, respectively. The presence of he
Influence of Sulfur-Containing Diamino Acid Structure on Covalently Crosslinked Copolypeptide Hydrogels
Raftery, Eric D.,Gharkhanian, Eric G.,Ricapito, Nicole G.,McNamara,Deming, Timothy J.
, p. 3547 - 3553 (2018/09/25)
Biologically occurring non-canonical di-α-amino acids were converted into new di-N-carboxyanhydride (di-NCA) monomers in reasonable yields with high purity. Five different di-NCAs were separately copolymerized with tert-butyl-l-glutamate NCA to obtain covalently crosslinked copolypeptides capable of forming hydrogels with varying crosslinker density. Comparison of hydrogel properties with residue structure revealed that different di-α-amino acids were not equivalent in crosslink formation. Notably, l-cystine was found to produce significantly weaker hydrogels compared to l-homocystine, l-cystathionine, and l-lanthionine, suggesting that l-cystine may be a sub-optimal choice of di-α-amino acid for preparation of copolypeptide networks. The di-α-amino acid crosslinkers also provided different chemical stability, where disulfide crosslinks were readily degraded by reduction, and thioether crosslinks were stable against reduction. This difference in response may provide a means to fine tune the reduction sensitivity of polypeptide biomaterial networks.
Thiabendazole-based Rh(III) and Ir(III) biscyclometallated complexes with mitochondria-targeted anticancer activity and metal-sensitive photodynamic activity
Pérez-Arnaiz, Cristina,Acu?a, María Isabel,Busto, Natalia,Echevarría, Igor,Martínez-Alonso, Marta,Espino, Gustavo,García, Bego?a,Domínguez, Fernando
supporting information, p. 279 - 293 (2018/08/17)
Two pairs of Rh(III) and Ir(III) biscyclometallated complexes with thiabendazole (L1), named [Ir-a]Cl and [Rh-a]Cl, and N-benzyl-thiabendazole (L2), named [Ir-b]Cl and [Rh-b]Cl, have been designed and synthesized to explore the photophysical and biological effects that arise from changing both the metal center and the ancillary ligand. In the dark, the four metal complexes exhibit greater cytotoxicity than cisplatin against human colon (SW480) and human lung (A549) adenocarcinoma cell lines. Moreover, the pair of complexes bearing the ligand L2 is markedly more cytotoxic and present higher uptake values than complexes with L1, thereby their biological properties were studied further to determine their mechanism of action. Interestingly, in spite of the different metal center both the [Ir-b]Cl and [Rh-b]Cl complexes are responsible for the loss of mitochondrial functionality and the activation of apoptotic cell death pathways. Moreover, the photodynamic activity of the four complexes, [Ir-a,b]Cl and [Rh-a,b]Cl, was tested using visible blue light (460 nm) under soft irradiation conditions (20 min, 5.5 mW cm?2). While the Rh complexes are not photopotentiated, the phototoxicity index (IC50 non-irradiated/IC50 irradiated) of [Ir-a]Cl and [Ir-b]Cl complexes was 15.8 and 3.6, respectively. We also demonstrate that only the Ir derivatives are capable of photocatalyzing the oxidation of S-containing L-amino acids under blue light irradiation, [Ir-a]Cl being more active than [Ir-b]Cl, which provides a reasonable mechanism for their biological action (oxidative stress could be selectively promoted through a photocatalytic action) upon irradiation. This different PDT behaviour depending on the metal center and the ancillary substituent may be useful for future rational design of metal-based photosensitizers.
Stereoselective synthesis of lanthionine derivatives in aqueous solution and their incorporation into the peptidoglycan of Escherichia coli
Denoel, Thibaut,Zervosen, Astrid,Gerards, Thomas,Lemaire, Christian,Joris, Bernard,Blanot, Didier,Luxen, Andre
, p. 4621 - 4628 (2014/10/16)
The three diastereoisomers - (R,R), (S,S) and meso - of lanthionine were synthesized in aqueous solution with high diastereoselectivity (>99%). The (S) and (R) enantiomers of two differently protected sulfamidates were opened by nucleophilic attack of (R) or (S)-cysteine. Acidification and controlled heating liberated the free lanthionines. Using the same chemistry, an α-benzyl lanthionine was also prepared. The proposed method, which avoids the need of enrichment by recrystallization, opens the way to the labelling of these compounds with 35S. Furthermore, in vivo bioincorporation into Escherichia coli W7 was studied. No incorporation of α-benzyl lanthionine was observed. In contrast, meso-lanthionine can effectively replace meso-diaminopimelic acid in vivo, while in the presence of (R,R)-lanthionine the initial increase of bacterial growth was followed by cell lysis. In the future, meso-[35S]lanthionine could be used to study the biosynthesis of peptidoglycan and its turnover in relation to cell growth and division.
Kinetic studies on oxidation of l-cysteine and 2-mercaptoethanol by a trinuclear Mn(IV) species in aqueous acidic media
Chakraborty, Maharudra,Mandal, Pulak Chandra,Mukhopadhyay, Subrata
, p. 77 - 82 (2013/05/21)
In aqueous media, the trinuclear MnIV complex, [Mn IV3(μ-O)4(phen)4(H 2O)2]4+ (phen = 1,10-phenanthroline) (1) behaves like a monobasic acid, equilibrates with its deprotonated conjugate base (2) (12 + H+, pKa = 4.00 (± 0.15) at 25.0 °C, I = 1.0 M, maintained with NaNO3). An aqueous solution of 1 in the pH range 2.2-4.0 smoothly oxidizes 2-mercaptoethanol (mercap) and l-cysteine (cys) to their respective disulfides; itself being reduced to [Mn(phen) 3]2+ in presence of excess 1,10-phenanthroline which also masks Cu2+, if any, present in the reaction media as impurity as well as acting as a buffer that controls pH range during the reaction. The observed rate constants in H2O media were found to be considerably lowered in media enriched with D2O and a proton-coupled single electron transfer rate step is proposed. Interestingly, we found that deprotonated oxidant (2) reacts faster than the protonated species (1) in oxidizing both the thiols.
Triply bridged (1,3,5) cyclophanes from cystine and lanthionine linkers-a comparison
Ranganathan,Venkateshwarlu,Babu,Reddy,Basha,Sarma,Vijay,Sastry
experimental part, p. 3923 - 3929 (2010/07/05)
The condensation of benzene 1,3,5-tricarbonylchloride with cystine-di-Me [H2N-CH(COOMe)-CH2-S-S-CH2-CH(COOMe)-NH 2] yielded triply bridged (1,3,5) cyclophane 1, which was shown by detailed spectral studies and molecular orbital calculations to have a D3 symmetry with conformationally identical linkers and a spherical topology. In sharp contrast, the (1,3,5) cyclophane 2 from the rarely studied lanthionine di-Me [H2N-CH(COOMe)-CH2-S-CH2-CH(COOMe)-NH 2], showed only a equatorial twofold symmetry. This work highlights the special properties of the -S-S- bridge in cystine, which makes it an exceptional synthon in nature and organic synthesis.
N-Salicylideneamino acidato complexes of oxovanadium(IV). the cysteine and penicillamine complexes
Pessoa, Joao Costa,Calhorda, Maria J.,Cavaco, Isabel,Costa, Paulo J.,Correia, Isabel,Costa, Dina,Vilas-Boas, Luis F.,Felix, Vitor,Gillard, Robert D.,Henriques, Rui T.,Wiggins, Robert
, p. 2855 - 2866 (2007/10/03)
Oxovanadium(iv) complexes with ligands derived from the reaction of salicylaldehyde with L-cysteine and with D- and D,L-penicillamine are prepared. The compounds are characterised by elemental analysis, spectroscopy (UV-VIS, CD, EPR), TG, DSC and magnetic susceptibility measurements (9-295 K). We discuss several aspects related to the structure of these complexes in the solid state and in solution; in particular, the possibility of forming thiazolidine complexes, and their comparison with the characterised complexes is studied by molecular mechanics and density functional theory calculations. The solution structures depend on pH and solvent, and while with L-Cys the spectroscopic results show trends similar to those of the L-Ala and L-Ser systems up to ca. pH 8-9, where thiolate coordination starts being detected, the penicillamine system is quite distinct, namely thiolate coordination occurs for pH > 6.5. In the presence of salicylaldehyde and VIVO the desulfydration of cysteine proceeds rapidly, but no similar reaction occurs with penicillamine, although its decomposition is also activated. The DFT calculations do not indicate any energetic basis for this distinct reactivity, which possibly results from different complexes present in the Cys and Pen systems. In the cysteine system, the N-salicylidene dehydroalanine-VIVO complex V is believed to form in an intermediate stage of the desulfydration. Further, addition of several nucleophiles to the cysteine reaction mixtures produce amino acid derivatives by a Michael-type base-catalysed addition, a result compatible with the formation of V. The products of these reactions were analysed by TLC and HPLC, and in some cases isolated.
Design and synthesis of dimeric HIV-1 integrase inhibitory peptides
Krajewski, Krzysztof,Long, Ya-Qiu,Marchand, Christophe,Pommier, Yves,Roller, Peter P.
, p. 3203 - 3205 (2007/10/03)
Dimers of known HIV-1 integrase inhibitory hexapeptide H-His-Cys-Lys-Phe-Trp-Trp-NH2 containing different lengths of cross linkers in the place of cysteine residue, were designed, and synthesized. The inhibitory potency of these dimeric peptides is consistently higher than the lead hexapeptide. The dimeric peptide with djenkolic acid linker exhibited IC50 values of 5.3 and 6.5 μM, for 3′-end processing and strand transfer, respectively.
Syntheses of optically pure α-amino acids from 3-amino-2-oxetanone salts
-
, (2008/06/13)
A process for the preparation of optically pure α-amino acids comprising the nucleophilic ring-opening of 3-amino-2-oxetanone salts. N-Protected serine β-lactones are deprotected to form heretofore unknown 3-amino-2-oxetanone and its corresponding salts. In turn these previously unknown 3-amino-2-oxetanone salts may be used in the synthesis of other novel or rare stereochemically-pure free amino acids.
