DFT STUDY ON THE MECHANISTIC, ENERGETIC AND STRUCTURAL ASPECTS OF ADSORPTION OF TIRAPAZAMINE ONTO PRISTINE AND FUNCTIONALIZED CARBON NANOTUBES

Using density functional theory, noncovalent interactions and two mechanisms of covalent functionalization of drug tirapazamine with pristine, COOH and COCl functionalized carbon nanotube (NT, NTCOOH and NTCOCl) have been investigated. Quantum molecular descriptors of noncovalent configurations were studied. It was specified that binding of drug tirapazamine with NTCOOH has more binding energy than NTCOCl and NT, so NTCOOH can act as a favorable system for tirapazamine drug delivery within biological and chemical systems (noncovalent). NTCOOH and NTCOCl can bond to the amino group of tirapazamine through OH (COOH mechanism) and Cl (COCl mechanism) groups, respectively. The activation parameters of two pathways were calculated and compared with each other. The activation parameters related to COOH mechanism are higher than those related to COCl mechanism and therefore COCl mechanism is suitable for covalent functionalization. These results could be generalized to other similar drugs

Structural and Mechanistic Studies of γ-Fe2O3 Nanoparticle as Hydroxyurea Drug Nanocarrier

In this study, the noncovalent interactions and four mechanisms of covalent functionalization of hydroxyurea have been examined using the density functional theory. Quantum molecular descriptors were also studied in noncovalent interactions. Hydroxyurea is an anticancer drug that, when loaded onto the γ-Fe2O3 nanoparticles, will have additional properties and efficacy in the medical applications. The Lumo-Homo energy gap of hydroxyurea is greater than that of noncovalent configurations, indicating the high reactivity of hydroxyurea. Hydroxyurea can bond to the γ-Fe2O3 nanoparticles through various functional groups such as the CO (k1 mechanism), the NH2 (k2 mechanism), the OH (k3 mechanism) and the NH (k4 mechanism). These reactions were considered to calculate the activation energies, the activation enthalpies and the activation Gibbs free energies. Using these calculations, the product of k4 mechanism was found to be a thermodynamic and kinetic product. These results can be applied to other similar medications. DOI: http://dx.doi.org/10.17807/orbital.v11i3.1367 </p

DFT STUDY ON THE MECHANISTIC, ENERGETIC AND STRUCTURAL ASPECTS OF ADSORPTION OF TIRAPAZAMINE ONTO PRISTINE AND FUNCTIONALIZED CARBON NANOTUBES

<div><p>Using density functional theory, noncovalent interactions and two mechanisms of covalent functionalization of drug tirapazamine with pristine, COOH and COCl functionalized carbon nanotube (NT, NTCOOH and NTCOCl) have been investigated. Quantum molecular descriptors of noncovalent configurations were studied. It was specified that binding of drug tirapazamine with NTCOOH has more binding energy than NTCOCl and NT, so NTCOOH can act as a favorable system for tirapazamine drug delivery within biological and chemical systems (noncovalent). NTCOOH and NTCOCl can bond to the amino group of tirapazamine through OH (COOH mechanism) and Cl (COCl mechanism) groups, respectively. The activation parameters of two pathways were calculated and compared with each other. The activation parameters related to COOH mechanism are higher than those related to COCl mechanism and therefore COCl mechanism is suitable for covalent functionalization. These results could be generalized to other similar drugs.</p></div