In Silico Designing and Interaction of Coumarin-Amino Acid(s) Conjugates with Integrin Like Protein of Cryptococcus neoformans: Insights on Antifungal Drug Design

In the present work, a library of 117 coumarin-amino acid(s) conjugates was designed, and molecular docking study was performed to investigate their possible role as fungal integrin like receptor antagonists. The objective of this study is in-silico designing and docking of coumarin-amino acid conjugates against integrin like protein of Cryptococcus neoformans. In the absence of a crystallographic structure of integrin of the fungal pathogen, a homology model of protein OXH63806.1 of Cryptococcus neoformans was developed using the currently available X-ray structure of human integrin as a template. The quality of the 3D model obtained by homology modeling was evaluated by the PROCHECK program. A docking study using coumarin-amino acid(s) conjugates as ligands on the binding site of the modeled receptor was carried out to understand the protein-ligand binding interactions. Some of the compounds have shown very good binding energies ranging from -10.32 to -10.94 Kcal/mol towards the target receptor. These results may be helpful in the designing and development of new antifungal agents as integrin like protein antagonists.

A new synthetic protocol for coumarin amino acid

The hydrochloride of the racemic amino acid (2-(7-hydroxycoumarin-4-yl)ethyl)glycine, which can serve as a fluorescent probe in proteins, and two halogen derivatives of it, were synthesized by using a new synthetic protocol in five steps. It is less costly and relatively easy to prepare this kind of fluorescent amino acid with the new synthetic method. Furthermore, it can be applied to synthesize other derivatives of the coumarin amino acid with some specific properties.

1H and 13C NMR spectral assignments of an amino acid-coumarin hybrid

Synthesis and detailed spectral analysis of a new 4-substituted coumarin-amino acid derivate are presented in this paper. A new glycine derivate of (3-nitro-2-oxo-2H-chromen-4-yl)amino]acetate was prepared by condensation of 4-chloro-3-nitrocoumarin and ethyl glycinate hydrochloride. The complete assignment of 1H and 13C NMR chemical shifts of the synthesized compound was carried out by the aid of a combination of 1D (1H and 13C NMR) and 2D (1H-1H-COSY, NOESY, HSQC and HMBC) NMR experiments.