Development of a Comprehensive Approach to Quality Control of Dermorphin Derivative-Representative of Synthetic Opioid Peptides with Non-Narcotic Type of Analgesia

Peptides occupy a significant share of the pharmaceutical market and are among the top-200 selling drugs in the group of non-insulin drugs with analgesic, antibacterial and cardiovascular effects. The aim of this work is to develop a comprehensive analytical approach for quality control of novel synthetic peptides with non-narcotic types of analgesia and to provide docking simulations of dermorphin complex formation at the mu-opioid receptor (MOR) binding site. The materials and methods used include the pharmaceutical substance dermorphin tetrapeptide (DMTP) (tyrosyl-D-arginyl-phenylalanyl-glycinamide); Fourier transform infrared spectroscopy (FT-IR); static and dynamic laser light scattering (DLS, LALLS); scanning optical microscopy (SEM); X-ray fluorescence elements analysis; polarimetry for optical activity determining; and Spirotox method for sample biotesting. FT-IR-Spectra indicated specific amino acid chemical groups in the tetrapeptide sequence at 3300-2700 cm-1, 1670 cm-1. UV-absorption spectra of aqueous solutions of dermorphin tetrapeptide showed an absorption maximum at 275 nm, which is in good agreement with the presented spectrum of the bovine serum albumin (BSA) standard; the Pearson's r of calibration line "A-C%" in 0.0125% to 0.0500% concentration range is 0.999; and the calculated specific extinction value E1cm 1% = 18.38 +/- 0.23. Of the 11 elements detected by X-rays, the elements copper (Cu) and cobalt (Co) have the highest X-ray intensity. Dispersion characteristics of dermorphin solutions were studied in the submicron and micron range. Conglomerates and druzes were detected by SEM, ranging in size from 2 mu m to 100 mu m. The specific optical activity index was calculated alpha D20 = +36.18 +/- 2.04 [degreesmLg-1dm-1], according to Biot's Law. Additionally, the orientation and conformation of the dermorphin molecule in the active binding site of the 8E0G receptor were predicted using molecular modeling, revealing that the contact area affects the key amino acid residue arginine (ARG 182). This comprehensive approach to analytical methods for qualitative and quantitative analysis of dermorphin tetrapeptide can be applied in pharmacies to enhance the understanding of its biological activity and aid in the development of regulatory documentation for a new, non-narcotic analgesic based on the dermorphin tetrapeptide.