Characterization and optimization of heroin hapten-BSA conjugates: method development for the synthesis of reproducible hapten-based vaccines

A potential new treatment for drug addiction is immunization with vaccines that induce antibodies that can abrogate the addictive effects of the drug of abuse. One of the challenges in the development of a vaccine against drugs of abuse is the availability of an optimum procedure that gives reproducible and high yielding hapten-protein conjugates. In this study, a heroin/morphine surrogate hapten (MorHap) was coupled to bovine serum albumin (BSA) using maleimide-thiol chemistry. MorHap-BSA conjugates with 3, 5, 10, 15, 22, 28, and 34 haptens were obtained using different linker and hapten ratios. Using this optimized procedure, MorHap-BSA conjugates were synthesized with highly reproducible results and in high yields. The number of haptens attached to BSA was compared by 2,4,6-trinitrobenzenesulfonic acid (TNBS) assay, modified Ellman’s test and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Among the three methods, MALDI-TOF MS discriminated subtle differences in hapten density. The effect of hapten density on enzyme-linked immunosorbent assay (ELISA) performance was evaluated with seven MorHap-BSA conjugates of varying hapten densities, which were used as coating antigens. The highest antibody binding was obtained with MorHap-BSA conjugates containing 3–5 haptens. This is the first report that rigorously analyzes, optimizes and characterizes the conjugation of haptens to proteins that can be used for vaccines against drugs of abuse. The effect of hapten density on the ELISA detection of antibodies against haptens demonstrates the importance of careful characterization of the hapten density by the analytical techniques described. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00216-014-8035-x) contains supplementary material, which is available to authorized users

Análisis de la viabilidad de la implementación de un sistema fotovoltaico en una vivienda rural en Cusco

El sector de energía es uno de los más importantes para el desarrollo económico, social y cultural en pueblos originarios y zonas rurales a través de la educación de calidad y la generación de oportunidades de trabajo que brindan desarrollo económico. No obstante, también es uno de los entes responsables del calentamiento global debido a la gran cantidad de gases de efecto invernadero, que se producen en la generación de energía de manera convencional, es decir, de la quema de combustibles fósiles. Es así que nace la importancia de evaluar la viabilidad de la implementación de paneles solares en zonas rurales del departamento de Cusco para reducir el daño ambiental al consumir energía eléctrica limpia, además de asegurar la producción de electricidad necesaria para el desarrollo de la vida cotidiana, con diversos artefactos como un televisor, radio, interruptores y focos de luz. Entonces, como resultado del trabajo de investigación, se obtiene que el sistema fotovoltaico resulta competente tanto técnica como económicamente gracias a que brinda lo mínimo necesario en época de menor rendimiento que es durante el invierno, además de ser competitivo económicamente pues al tener una duración de vida de 20 años, el gasto que implica la compra e instalación del sistema se recupera a lo largo de su vida útil, ya que no es necesario el empleo de mano de obra especializada para su mantenimiento

Allenyl Azide Cycloaddition Chemistry: Application to the Total Synthesis of (±)-Meloscine

The pentacyclic alkaloid (±)-meloscine was prepared in 19 steps through a reaction sequence that features a putative azatrimethylenemethane intermediate, generated through cascade cyclization of an allenyl azide substrate, to deliver the core azabicyclo[3.3.0]octadiene substructure. Subsequent manipulation of the peripheral functionality then delivered (±)-meloscine

Regioselectivities of (4+3) cycloadditions between furans and oxazolidinone-substituted oxyallyls

The (4 + 3) cycloadditions of oxazolidinone-substituted oxyallyls and unsymmetrically substituted furans lead to syn regioselectivity when the furan has a 2-Me or 2-COOR substituent, while anti regioselectivity is obtained with a 3-Me or 3-COOR group. DFT calculations are performed to explain the selectivities. The reactivities and regioselectivities are consistent with the ambiphilic reactivity of amino-oxyallyls with furans