Temperature-induced spectral anomalies in doxorubicin-A Raman study.

Area of Science:

• Spectroscopy
• Computational Chemistry
• Chemotherapeutics

Background:

• Doxorubicin (DOX) is a vital chemotherapeutic agent.
• Understanding DOX's structural dynamics and interactions is crucial for optimizing its efficacy.
• Spectroscopic methods offer insights into molecular behavior.

Purpose of the Study:

• To investigate temperature-induced changes in Doxorubicin's Raman spectra.
• To elucidate the underlying mechanisms of spectral variations using computational methods.
• To correlate spectral changes with molecular dynamics and resonance effects.

Main Methods:

• Temperature-dependent Raman scattering experiments (100–300 K).
• Density Functional Theory (DFT)-based simulations (R2SCAN/def2-TZVP with D3 corrections).
• Analysis of resonance Raman spectra and comparison with experimental data using the SARA algorithm.

Main Results:

• Pronounced spectral intensity variations and luminescence background changes observed with temperature.
• Temperature-dependent resonance effects identified as the primary cause of spectral changes.
• High agreement (91%-94%) between experimental and simulated spectra across temperatures.
• Redistribution of Raman intensities with increasing temperature, favoring ring modes over hydrogen-bond related modes.

Conclusions:

• Temperature significantly influences Doxorubicin's spectroscopic properties through resonance effects.
• Computational modeling accurately predicts experimental observations.
• Spectral changes reflect temperature-dependent alterations in molecular dynamics, particularly hydrogen bonding and ring conformations.