Novel donors of nitric oxide derived of S-nitrosocysteine possessing antioxidant activities

Novel S-nitrosothiols possessing a phenolic function were investigated as nitric oxide (NO) donors. A study of NO release from these derivatives was carried out by electron spin resonance (ESR). All compounds gave rise to a characteristic three-line ESR signal in the presence of the complex [Fe(II)(MGD)2], revealing the formation of the complex [Fe(II)(MGD)2(NO)]. Furthermore, tests based on cytochrome c reduction were performed in order to study the ability of each phenolic disulfide, the final organic decomposition product of S-nitrosothiols, to trap superoxide radical anion (O2-). This study revealed a high reactivity of 1b and 3b towards O2-. For these two compounds, the respective inhibitory concentration (IC) 50 values were 92 µM and 43 µM

Pyridine-3,4-dicarboximide as starting material for the total synthesis of the natural product eupolauramine and its isomer iso-eupolauramine endowed with anti-tubercular activities

A direct and convenient synthetic pathway for preparation of the key intermediate aza-isoindolinone 4a/4b, which could be ready obtained from pyridine-3,4-dicarboximide was described. This approach was valorized in the total synthesis of the natural product eupolauramine 7b and in the first synthesis of the position analog iso-eupolauramine 7a, which was obtained after 6 steps in an overall yield of 13%. The developed strategy represents the first synthetic approach employing a starting material already embedding the pyridine and the lactam cycles (cycles D and C, respectively) of the azaphenanthrene lactam framework. These compounds, mainly the new non-natural product, showed a good inhibitory activity against Mycobacterium tuberculosis growth