Langmuir-Blodgett monolayers holding a wound healing active compound and its effect in cell culture. A model for the study of surface mediated drug delivery systems

Langmuir and Langmuir-Blodgett films holding a synthetic bioinspired wound healing active compound were used as drug-delivery platforms. Palmitic acid Langmuir monolayers were able to incorporate 2-methyltriclisine, a synthetic Triclisine derivative that showed wound healing activity. The layers proved to be stable and the nanocomposites were transferred to solid substrates. Normal human lung cells (Medical Research Council cell strain 5, MRC-5) were grown over the monomolecular Langmuir-Blodgett films that acted as a drug reservoir and delivery system. The proliferation and migration of the cells were clearly affected by the presence of 2-methyltriclisine in the amphiphilic layers. The methodology is proposed as a simple and reliable model for the study of the effects of bioactive compounds over cellular cultures.EEA Marcos JuárezFil: Fernández, Luciana. Universidad Nacional de Río Cuarto. Departamento de Física y Departamento de Química; ArgentinaFil: Fernández, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reviglio, Ana Lucía. Universidad Nacional de Río Cuarto. Departamento de Física y Departamento de Química; ArgentinaFil: Reviglio, Ana Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Heredia, Daniel A. Universidad Nacional de Río Cuarto. Departamento de Física y Departamento de Química; Argentina.Fil: Heredia, Daniel A. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Morales, Gustavo M. Universidad Nacional de Río Cuarto. Departamento de Física y Departamento de Química; ArgentinaFil: Morales, Gustavo M. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santo, Marisa. Universidad Nacional de Río Cuarto. Departamento de Física y Departamento de Química; ArgentinaFil: Santo, Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Otero, Luis. Universidad Nacional de Río Cuarto. Departamento de Física y Departamento de Química; ArgentinaFil: Otero, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alustiza, Fabrisio Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Liaudat, Ana Cecilia. Universidad Nacional de Río Cuarto. Departamento de Biología Molecular; ArgentinaFil: Bosch, Pablo. Universidad Nacional de Río Cuarto. Departamento de Biología Molecular; ArgentinaFil: Larghi, Enrique L. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Bracca, Andrea B.J. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Kaufman, Teodoro S. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentin

Experimental and theoretical studies of the [3,3]-sigmatropic rearrangement of prenyl azides

[3,3]-Sigmatropic rearrangement of isoprenyl azides has been extensively investigated in an experimental and theoretical level. Prenylazides with different chain lengths and phenyl prenylazide have been synthesized. NMR analysis of each azide has been made to determine the equilibrium composition, showing the predominance of primary allyl azides over the tertiary ones and E over Z isomer, regardless of the chain length, temperature, solvent or the regiochemistry of the precursor isoprenyl alcohol. It was determined that phenyl prenylazides do not experience [3,3]-sigmatropic rearrangement. In order to rationalize the experimental results and to gain insight in the mechanism of the [3,3]-sigmatropic rearrangement of prenylazides a theoretical study was performed using density functional theory and the QTAIM approach

Synthesis and interaction of terminal unsaturated chemical probes with Mycobacterium tuberculosis CYP124A1

A series of C15–C20 isoprenyl derivatives bearing terminal alkenyl and alkynyl groups were synthesized as possible substrates of the methyl-branched lipid ω-hydroxylase CYP124A1 from Mycobacterium tuberculosis. The interactions of each compound with the enzyme active site were characterized using UV–vis spectroscopy. We found that C10 and C15 analogs bind with similar affinity to the corresponding parent C10 and C15 substrates geraniol and farnesol, respectively. Three analogs (C10-ω-ene, C10-ω-yne, C15-ω-yne) interact with the proximal side of the heme iron by coordinating to the oxygen atom of the ferric heme, as judged by the appearance of typical Type-IA binding spectra. On the other hand, the C15-ω-ene analog interacts with the ferric heme by displacing the bound water that generates a typical Type I binding spectrum. We were unable to detect P450-mediated oxidation of these probes following extended incubations with CYP124A1 in our reconstituted assay system, whereas a control reaction containing farnesol was converted to ω-hydroxy farnesol under the same conditions. To understand the lack of detectable oxidation, we explored the possibility that the analogs were acting as mechanism-based inhibitors, but we were unable to detect time-dependent loss of enzymatic activity. In order to gain insight into the lack of detectable turnover or time-dependent inhibition, we examined the interaction of each compound with the CYP124A1 active site using molecular docking simulations. The docking studies revealed a binding mode where the terminal unsaturated functional groups were sequestered within the methyl-binding pocket, rather than positioned close to the heme iron for oxidation. These results aid in the design of specific inhibitors of Mtb-CYP124A1, an interesting enzyme that is implicated in the oxidation of methyl-branched lipids, including cholesterol, within a deadly human pathogen