35671-84-2Relevant academic research and scientific papers
Development of a Visible Light Triggerable Traceless Staudinger Ligation Reagent
Hu, Peng,Berning, Karsten,Lam, Yun-Wah,Ng, Isabel Hei-Ma,Yeung, Chi-Chung,Lam, Michael Hon-Wah
, p. 12998 - 13010 (2018/11/20)
A series of substituted 9-methylenylanthracene photocages for diphenylphosphinothioesters have been synthesized to explore their photo-uncaging properties by visible light. Substituents such as phenyl, p-trifluoromethylphenyl, p-methoxyphenyl, ethyn-1-ylbenzene, and 3,3-dimethylbut-1-yn-1-yl have been introduced in order to extend the π-conjugation of the photocage and to shift the wavelength response of the uncaging process to the visible spectral range. Among these new photocages, the (10-(3,3-dimethylbut-1-yn-1-yl)anthracen-9-yl)methyl has been shown to have the best performance in terms of fast photo-uncaging and minimal byproduct formation. It is responsive to both UV and visible photoexcitation. Quantum yields of the photoinduced heterolytic anthracenylmethyl-phosphorus bond cleavage at 366 and 416 nm were found to be 0.08 and 0.025, respectively. This photocage enables traceless Staudinger ligation to be triggered by photoirradiation in the visible spectral range for bioconjugation applications. We demonstrate this with a series of visible-light-induced oligopeptide syntheses via the conjugation of amino acid/oligopeptide building blocks by the characteristic peptide linkage attained by traceless Staudinger ligation. Yields of the resultant conjugated oligopeptides ranged from 31 to 43%. This new photocage opens up the possibility of in situ synthesis of functional proteins/peptides mediated by visible-light-induced photoclick processes for the regulation of cellular/metabolic functions of life systems.
Fragmentation-Rearrangement of Peptide Backbones Mediated by the Air Pollutant NO2.
Gamon, Luke F.,Nathanael, Joses G.,Taggert, Bethany I.,Henry, Fraser A.,Bogena, Jana,Wille, Uta
, p. 14924 - 14930 (2015/10/20)
The fragmentation-rearrangement of peptide backbones mediated by nitrogen dioxide, NO2., was explored using di-, tri-, and tetrapeptides 8-18 as model systems. The reaction, which is initiated through nonradical N-nitrosation of the peptide bond, shortens the peptide chain by the expulsion of one amino acid moiety with simultaneous fusion of the remaining molecular termini through formation of a new peptide bond. The relative rate of the fragmentation-rearrangement depends on the nature of the amino acids and decreases with increasing steric bulk at the α carbon in the order Gly>Ala>Val. Peptides that possessed consecutive aromatic side chains only gave products that resulted from nitrosation of the sterically less congested N-terminal amide. Such backbone fragmentation-rearrangement occurs under physiologically relevant conditions and could be an important reaction pathway for peptides, in which sections without readily oxidizable side chains are exposed to the air pollutant NO2.. In addition to NO2.-induced radical oxidation processes, this outcome shows that ionic reaction pathways, in particular nitrosation, should be factored in when assessing NO2. reactivity in biological systems.
