&amp;lt;i&amp;gt;In Situ&amp;lt;/i&amp;gt; Characterization of Lopinavir by ATR-FTIR Biospectroscopy

Alireza Heidari

doi:10.4236/cc.2020.83004

Abstract

Lopinavir is an antiretroviral of the protease inhibitor class (Figure 1 and Figure 2). It is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir (lopinavir/ritonavir). In the current research, the stimulated ATR-FTIR biospectroscopy of liquid sample of Lopinavir was investigated. The stimulated ATR-FTIR diffractions emitted through focusing the second harmonic laser beam Nd:YAG into the sample were recorded by Echelle spectrometer and ICCD detector. Increasing the energy of laser beam from 2.6 (mJ) to 16 (mJ) led to increase in stimulated ATR-FTIR signal but after breakdown threshold of liquid sample, further increasing energy led to the decrease in stimulating ATR-FTIR signals and for energies higher than 20 (mJ), they were disappeared.

Highlights

ATR-FTIR biospectroscopy is a vibration biospectroscopy based on the influence of ATR-FTIR [2]-[17]
The stimulated ATR-FTIR diffractions emitted through focusing the second harmonic laser beam Nd:YAG into the sample were recorded by Echelle spectrometer and ICCD detector
Increasing the energy of laser beam from 2.6 to 16 led to increase in stimulated ATR-FTIR signal but after breakdown threshold of liquid sample, further increasing energy led to the decrease in stimulating ATR-FTIR signals and for energies higher than 20, they were disappeared

Summary

Introduction

ATR-FTIR biospectroscopy is a vibration biospectroscopy based on the influence of ATR-FTIR [2]-[17]. The pumping threshold limit for stimulated ATR-FTIR depends on ATR-FTIR active material [82]-[98]. The present in silico study was designed to evaluate the effects of anti-HIV-1 proteases inhibitors, approved for clinical applications by US FDA, on SARS proteinase inhibition. In the present study, docking and molecular dynamic experiments were applied to examine the effect of inhibitors on coronavirus proteinase under physiological conditions of similar pH, temperature, and pressure in aqueous solution. Hex software version 5.1 and GROMACS 4.5.5 were used for docking analysis throughout this work The calculated parameters such as RMSD, RMSF, MSD, dipole moment, diffusion coefficient, binding energy, and binding site similarity indicated effective binding of inhibitors to SARS proteinase resulting in their structural changes, which coincide with proteinase inhibition. Lopinavir and Saquinavir were the most and the least powerful inhibitors of cronovirus proteinase, respectively

Experimental Arrangement

Results and Discussion

Heidari DOI