The secondary nitrogen atom in the natural substrates, linking fructose and amino acid or dipeptide moieties, was substituted in 1a c with a sulfur atom to avoid enzymatic cleavage.
In addition, the indolyl moiety was substituted for naphthalenyl and phenyl.
The reaction of 3-oxo-2-arylhydrazonopropanals 2 with ethyl cyanoacetate and malononitrile 3a,b has led to the formation of 2-amino-5-arylazo-6-aryl 2-amino-5-arylazo-6-aryl 2-amino-5-arylazo-6-aryl 2-amino-5-arylazo-6-aryl 2-amino-5-arylazo-6-aryl 2-amino-5-arylazo-6-arylctron-withdrawing group like Cl, Br, NO2.
The signal at δ 7.12 (1H, J = 2, H-2) appeared as a doublet due to coupling with an indoyl N H, thus suggesting that C-3 on the indoyl moiety is substituted, as confirmed by the absence of an H-3 resonance at ca. δ 6.50 [7, 8].
In addition, the aromatic rings of the diphenylamine moiety were substituted with different electron donating or withdrawing groups.
The key structural difference between HI-6 and K027 is that the oxime moiety is substituted at the 2-position of the pyridinium ring of HI-6 and at the 4-position for K027.
A derivative of NO-ASA in which the NO-donating moiety was substituted by diethylphosphate also induced oxidative stress (Kashfi and Rigas, 2007; Sun Y, Rigas B, unpublished data).
The hydroxyl groups of CNCs are substituted with anionic-moieties from acid which alters its interfacial interaction with PLA matrix, as predicted from dispersion surface energy and work of adhesion values.
This erroneous prediction could probably be attributed to the R2 position, whereas, the majority of compounds are substituted by an indole linked to another moiety at this position this compound has just an indole moiety at the R2 position.
We synthesised a series of analogues of glutathione (l-γ-Glu-l-Leu-X) where the glycine moiety has been substituted for other amino acids.
