Phosphorene and Na-, Ca-, and Fe-doped phosphorene as candidates for delivery of mercaptopurine and fluorouracil anticancer drugs.

Phosphorene ability for delivery of mercaptopurine and fluorouracil was investigated by the density functional theory (DFT) method. However, the effects of Na, Ca, and Fe as dopants on phosphorene electronic properties such as HOMO and LUMO energies, density of states, chemical potential, electrophilicity index, softness, hardness, and its ability for drug delivery were studied. Natural bond orbital (NBO) analysis was performed. Our findings indicate that metallic dopants can improve the ability of phosphorene. Calcium-doped phosphorene has the greatest adsorption energy.

Adsorption of light mercaptans over metal (Co, Cu, Fe, Ni) doped hexagonal boron nitride nanosheets: a first-principles study.

Light mercaptans (R-SH, R = C1-C4) as volatile malodorous and toxic compounds were theoretically adsorbed on metal (Co, Cu, Fe, Ni) doped hexagonal boron nitride (h-BN) nanosheets to obtain the adsorption energies of the mercaptans and electronic structures of the sheets before and after adsorption using the density functional theory method. The results indicate that doping B/N vacancy h-BN sheets with the metals decreased Eg compared to the pristine h-BN. Adsorption energies showed strong chemisorption of light mercaptans over metal doped h-BN. It is found that by increasing the alkyl chain in mercaptan the adsorption energy increases. Charge analysis and study of the correlation between variation of charge in the sulfur atom and the adsorption energy of mercaptan are presented.

First-principles study of terpyrrole as a potential hydrogen cyanide sensor: DFT calculations.

The sensitivity of terpyrrole (TPy; used as a polypyrrole model) to toxic hydrogen cyanide (HCN) adsorption was studied by using DFT to perform geometry optimization and to calculate the adsorption energy of HCN on TPy as well as orbital properties. The interaction of terpyrrole with HCN was studied for different relative orientations of the molecules. The adsorption energy, charge analysis, and the density of states were used to evaluate the ability of TPy to sense HCN in these different relative orientations. The adsorption energy was calculated to be -3.9 and -3.1 kcal mol(-1) for two possible relative orientations. Frontier molecular orbitals and energies indicated that some hybridization occurs during the adsorption of HCN on TPy when the molecules have appropriate relative orientations, resulting in an increase in conductivity. Considering the changes in the HOMO-LUMO energy gap that were calculated to occur during HCN adsorption, it is clear that TPy is sensitive to HCN adsorption, suggesting that TPy has the potential to act as an HCN sensor. Graphical abstract HCN adsorption on TPy.

A theoretical study of substitution effect on an electrocyclization reaction.

A theoretical study of substitution effect on an electrocyclization reaction was performed using DFT method at B3LYP level of theory with 6-311G* basis sets. Equilibrium molecular geometries and harmonic vibrational frequencies of the reactant, transition state (TS), and product were calculated. The considered rate constants and activation thermodynamic parameters were calculated. The results indicated the reaction is low dependent to the temperature. These calculations showed that the reaction proceeds through an asynchronous non concerted mechanism and functional group has a major effect on the reaction.

Isolation and characterization of bioactive compounds from the bark of Litsea costalis.

The bark of Litsea costalis affords two new compounds named 4,4'-diallyl-5,5'-dimethoxy-[1,1'-biphennyl]-2,2'-diol, biseugenol A (1) and 2,2'-oxybis (4-allyl-1-methoxybenzene), biseugenol B (2) along with two known compounds (3-4), namely 5-methoxy-2-Hydroxy Benzaldehyde (3), and (E)-4-styrylphenol (4). The structures of 1 and 2 were determined using 1D and 2D NMR data. Also, the IR and NMR data were combined with quantum chemical calculations in the DFT approach using the hybrid B3LYP exchange-correlation function to confirm the structures of the compounds. Compounds showed fairly potent anticancer activity against cell lines and antioxidant (DPPH).