Optical absorption of the antitrypanocidal drug benznidazole in water

Efficacy of a Zn-based metalorganic framework doped with benznidazole on acute experimental Trypanosoma cruzi infection

Metal-Organic Frameworks (MOFs) have been shown to enhance the activity of encapsulated compounds by facilitating their passage across cell membranes, thereby enabling controlled and selective release. This study investigates the efficacy of BNZ@Zn-MOFs against the acute phase of Trypanosoma cruzi infection in a mouse model. The particles were synthesized by electroelution (EL), doped with BZN via mechanochemistry, and characterized using scanning electron microscopy (SEM), infrared spectroscopy (FTIR), and X-ray diffraction (XRD). BNZ@Zn-MOFs released 80% of the encapsulated BZN within 3 h, demonstrating no cytotoxicity in NIH-3T3 and HeLa cells. Furthermore, in a model of acute experimental T. cruzi-infection in BALB/c mice, the delivery system exhibited antiparasitic activity at a significantly lower BZN concentration compared to free BZN treatment. PCR analysis of treated mice revealed no parasite DNA in their tissues, and hematoxylin-eosin staining showed no apparent damage to tissue architecture. Additionally, serum levels of liver function enzymes remained unchanged, indicating no adverse effects on liver function. This delivery system, utilizing suboptimal BZN doses, enables the preservation of drug activity while potentially facilitating a substantial decrease in side effects associated with Chagas disease treatment.

Spectroscopic (FT-IR and FT-Raman) and quantum chemical study on monomer and dimer of benznidazole from DFT and molecular docking approaches

This work presents the quantum chemical calculations of the monomer and dimer of benznidazole using density functional theory (DFT) at the B3LYP/6-311++G(d,2p) level of theory. A one-dimensional potential energy surface scan was carried out across flexible bonds to find the minimum energy structure. The structure with minimum energy was taken as a monomer and dimer is constructed based on intermolecular hydrogen bonding N-H…O. The vibrational analysis was conducted by comparing the calculated FT-IR and FT-Raman spectra of the monomer and dimer with the experimental ones. The red shift in the spectra of amide and carbonyl functional groups indicates their involvement in intermolecular hydrogen bonding in crystal packing, while the other peaks showed good agreement with the experimental result. The intra- and intermolecular interactions in the monomer and dimer were analyzed using various tools. The steric effects and van der Waals forces in the dimer were found to be more effective than the monomer. The dimer in the gaseous medium was found to have a lower Frontier molecular orbital energy (ΔEL-H) value than the monomer, suggesting that it is more reactive in a gaseous medium. The ELF value for hydrogen in monomer and dimer around the ring was found to be more which confirms that the electrons in these regions are more localized. The negative value of the overlap population density of states (OPDOS) both in monomer and dimer indicate that there are anti-bonding orbitals between the acetamide and the benzyl groups of the compound. The drug potential of benznidazole was evaluated by molecular docking with carbonic anhydrase XII, which shows the highest binding affinity of (-8.3 kcal/mol) with 6YH8, indicating that benznidazole is its potent inhibitor.

Cocrystal screening of benznidazole based on electronic transition, molecular reactivity, hydrogen bonding, and stability

CONTEXT

Screening of cocrystals of active pharmaceutical ingredients is important in the development of pharmaceutical compounds because it improves bioavailability, stability, solubility, and many other physicochemical properties. In this work, quantum chemical calculations were utilized for the computational evaluation of the cocrystal screening of benznidazole (BZN) API via hydrogen bonding with four coformers (maleic acid, malonic acid, oxalic acid, and salicylic acid), and they contain carboxylic groups. The nitrogen of the imidazole ring in benznidazole and the carboxylic group of the coformer form a hetero-synthon connected by a strong hydrogen bond. The strength of the hydrogen bonding interaction O-H…N was measured using various tools. It was found that in comparison to BZN cocrystals with malonic acid, oxalic acid, and salicylic acid, the O-H…N interaction in the BZN-maleic acid cocrystal had higher interaction energy, indicating it had stronger hydrogen bonding. The strength of the hydrogen bond O-H…N for synthons was discovered to be more beneficial than the C-H…O interaction, as confirmed by ESP analysis. The BZN-salicylic acid cocrystal was found to be more reactive and polarizable, whereas the BZN-malonic acid cocrystal was more stable. Cocrystals of benznidazole exhibited better physicochemical characteristics than API benznidazole, as indicated by electron transition properties between the most significant orbitals.

METHODS

The computational evaluation for the screening of benznidazole cocrystals was performed in Gaussian 16 software using density functional theory (DFT) with the hybrid functional B3LYP and the basis set 6-311 +  + G(d,p). The UV-Vis absorption spectrum in solvent water was analyzed using the TD-DFT/6-311 +  + G(d,p) method to determine the influence of the solvent in cocrystals using a polarizable continuum model. The strength of the hydrogen bonding interactions O-H…N in each of those mentioned cocrystals was used to screen the cocrystals using tools such as thermodynamic probability, ESP analysis, QTAIM analysis, and NBO analysis. The pairing energy of interaction was measured by determining H-bond donor ( α max ) and H-bond acceptor( β max ) parameters for hydrogen bonds from maxima and minima on the ESP surface. GaussView 06 software was used to create, visualize, and plot the optimized structure of the cocrystal and HOMO-LUMO orbitals. The AIMALL (10.05.04) software package generated the molecular graph for intra- and intermolecular interactions. The RDG-scatter plot, MEP map, and ELF plot were rendered from Multiwfn 8.0 and VMD 1.9.1 software.

Multicomponent Anti-Kasha's Rule Emission from Nanotubular Metal-Organic Frameworks for Selective Detection of Small Molecules

The peak photoluminescence (PL) of conventional fluorophores is independent of the excitation wavelength (called Kasha's rule), while the search of metal-organic framework materials with the so-called anti-Kasha's rule emission remains very limited. Herein, we report the observation of anti-Kasha's rule emission in a multicomponent PL three-dimensional nanotubular metal-organic framework (abbr. MOF-NT), [Zn(μ-L)(μ-bix)]_n·0.33nH₂O [H₂L = biphenyl-3,5-dicarboxylic acid; bix = 1,4-bis(imidazole-1-ylmethyl)benzene]. The MOF-NT crystalline sample represents a notable example of strong excitation-dependent fluorescence from the ultraviolet to the visible spectral region. Moreover, by virtue of electronic flexibility and high PL efficiency, MOF-NT shows a discriminative PL response between isomeric nitroaromatic compounds. The work demonstrated the intrinsic anti-Kasha's rule emission in the crystalline-state MOF materials, providing new visions for the development of advanced solid-state emissive materials.

Nanoencapsulation of benznidazole in calcium carbonate increases its selectivity to Trypanosoma cruzi

Chagas disease is a public health problem, affecting about 7 million people worldwide. Benznidazole (BZN) is the main treatment option, but it has limited effectiveness and can cause severe adverse effects. Drug delivery through nanoparticles has attracted the interest of the scientific community aiming to improve therapeutic options. The aim of this study was to evaluate the cytotoxicity of benznidazole-loaded calcium carbonate nanoparticles (BZN@CaCO3) on Trypanosoma cruzi strain Y. It was observed that BZN@CaCO3 was able to reduce the viability of epimastigote, trypomastigote and amastigote forms of T. cruzi with greater potency when compared with BZN. The amount of BZN necessary to obtain the same effect was up to 25 times smaller when loaded with CaCO3 nanoparticles. Also, it was observed that BZN@CaCO3 enhanced the selectivity index. Furthermore, the cell-death mechanism induced by both BZN and BZN@CaCO3 was evaluated, indicating that both substances caused necrosis and changed mitochondrial membrane potential.

The vibrational properties of the bee-killer imidacloprid insecticide: A molecular description

The chemical imidacloprid belongs to the neonicotinoids insecticide class, widely used for insect pest control mainly for crop protection. However, imidacloprid is a non-selective agrochemical to the insects and it is able to kill the most important pollinators, the bees. The high toxicity of imidacloprid requires controlled release and continuous monitoring. For this purpose, high performance liquid chromatography (HPLC) is usually employed; infrared and Raman spectroscopy, however, are simple and viable techniques that can be adapted to portable devices for field application. In this communication, state-of-the-art quantum level simulations were used to predict the infrared and Raman spectra of the most stable conformer of imidacloprid. Four molecular geometries were investigated in vacuum and solvated within the Density Functional Theory (DFT) approach employing the hybrid meta functional M06-2X and the hybrid functional B3LYP. The M062X/PCM model proved to be the best to predict structural features, while the values of harmonic vibrational frequencies were predicted more accurately using the B3LYP functional.

Computational electronic structure of the bee killer insecticide imidacloprid

One conformer of imidacloprid in vacuum and three conformers in the aqueous phase were obtained by a DFT approach, and their structural and electronic properties were discussed.