Multidimensional infrared spectroscopy reveals the vibrational and solvation dynamics of isoniazid

Abstract

The results of infrared spectroscopic investigations into the band assignments, vibrational relaxation, and solvation dynamics of the common anti-tuberculosis treatment Isoniazid (INH) are reported. INH is known to inhibit InhA, a 2-trans-enoyl-acyl carrier protein reductase enzyme responsible for the maintenance of cell walls in Mycobacterium tuberculosis but as new drug-resistant strains of the bacterium appear, next-generation therapeutics will be essential to combat the rise of the disease. Small molecules such as INH offer the potential for use as a biomolecular marker through which ultrafast multidimensional spectroscopies can probe drug binding and so inform design strategies but a complete characterization of the spectroscopy and dynamics of INH in solution is required to inform such activity. Infrared absorption spectroscopy, in combination with density functional theory calculations, is used to assign the vibrational modes of INH in the 1400-1700 cm(-1) region of the infrared spectrum while ultrafast multidimensional spectroscopy measurements determine the vibrational relaxation dynamics and the effects of solvation via spectral diffusion of the carbonyl stretching vibrational mode. These results are discussed in the context of previous linear spectroscopy studies on solid-phase INH and its usefulness as a biomolecular probe.

A 100 kHz Pulse Shaping 2D-IR Spectrometer Based on Dual Yb:KGW Amplifiers

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2D-IR Spectroscopy Shows that Optimized DNA Minor Groove Binding of Hoechst33258 Follows an Induced Fit Model

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Quantifying Secondary Structure Changes in Calmodulin Using 2D-IR Spectroscopy

“…Fourier Transform (FT)-IR absorption spectra were obtained using a Bruker Vertex 70v spectrometer with a resolution of 1 cm –1 and were the average of 20 coadded scans. 2D-IR spectra were acquired using the ULTRA laser system , via the FT-2D-IR method, reported previously, in which the mid-IR pulses were arranged in a pseudo pump–probe geometry. , The waiting time at which all spectra were acquired was 250 fs.…”