Structure, vibrational, electronic, NBO and NMR analyses of 4-amino-N-[2-pyridinyl] benzene sulfonamide (sulfapyridine) by experimental and theoretical approach

Chitosan-Gated Fluorescent Mesoporous Silica Nanocarriers for the Real-Time Monitoring of Drug Release

We have constructed a novel gated nanocarrier for the real-time monitoring of drug release, consisting of three parts: (i) mesoporous silica nanoparticles (MSNs) as the drug carrier, (ii) chitosan as the nanovalve to block and unlock the pores, and (iii) 1,8-naphthalimide fluorophore as a connecting arm and fluorescent signal source. In the absence of glutathione (GSH), the integrity of the system results in the formation of pores in a closed state and the sulfone would block the intramolecular charge transfer (ICT) process, leading to no fluorescence emission. However, the nucleophilic attack of GSH can cause the removal of the chitosan and recovery of ICT property, thus triggering drug release and green fluorescence emission. The results demonstrate that the change of GSH concentration in vivo or vitro would lead to a change in drug release as well as a concurrent change in fluorescence signal, which can expand the application of our gated nanocarrier for monitoring different drug release in real time.

Monomer spectroscopic analysis and dimer interaction energies on N-(4-methoxybenzoyl)-2-methylbenzenesulfonamide by experimental and theoretical approaches

In this study, theoretical harmonic vibrational frequencies and geometric parameters of N-(4-methoxybenzoyl)-2-methylbenzenesulfonamide have been investigated by Hartree-Fock (HF), density functional theory (B3LYP hybrid functional) methods with 6-311++G (d,p) basis set, for the first time. Experimental FT-IR (400-4000cm(-1)) and Laser-Raman spectra (100-4000cm(-1)) of title compound in solid phase have been recorded. Interaction energies, N-H⋯O hydrogen bonds, C-H⋯O and aromatic π⋯π stacking interactions in dimer structures of the title compound have been evaluated by the calculation methods. The dimer calculations have aimed to present the efficacy and performance of M06-2X hybrid functional on the intermolecular interactions and more strongly bound systems for the corrected and interaction energy by the counterpoise correction procedure. The interaction energies by M06-2X approach give more stable results than HF and B3LYP, extremely. The more strongly bonds, especially, on N-H⋯O hydrogen bonds and π⋯π interaction for the both dimer structure have also supported that the M06-2X functional of density functional is more effective.