Spider Toxin and Raventoxin Time–Resolved Absorption and Resonance FT–IR and Raman Biospectroscopy and Density Functional Theory (DFT) Investigation of Vibronic–Mode Coupling Structure in Vibrational Spectra Analysis

Spider toxins and Raventoxin are a family of proteins produced by spiders which function as neurotoxins.
The mechanism of many spider toxins and Raventoxin are through blockage of calcium channels. Also,
Raventoxins are neurotoxins from the venom of the spider Macrothele raveni. Parameters such as FT–IR and
Raman vibrational wavelengths and intensities for single crystal Spider Toxin and Raventoxin are calculated
using density functional theory and were compared with empirical results. The investigation about
vibrational spectrum of cycle dimers in crystal with carboxyl groups from each molecule of acid was shown
that it leads to create Hydrogen bounds for adjacent molecules. The current study aimed to investigate the
possibility of simulating the empirical values. Analysis of vibrational spectrum of Spider Toxin and
Raventoxin are performed based on theoretical simulation and FT–IR empirical spectrum and Raman
empirical spectrum using density functional theory in levels of F/6–31G*, HF/6–31++G**, MP2/6–31G,
MP2/6–31++G**, BLYP/6–31G, BLYP/6–31++G**, B3LYP/6–31G and B3LYP6–31–HEG**. Vibration
modes of methylene, carboxyl acid and phenyl cycle are separately investigated. The obtained values
confirm high accuracy and validity of results obtained from calculations.