Variación de la concentración de metanol en cadáveres en función al tiempo

La determinación del metanol en sangre se ha convertido en una de las prácticas analíticas forenses de rutina en los últimos años en el Laboratorio de Toxicología y Química Legal del Instituto de Medicina Legal y Ciencias Forenses de Lima - Ministerio Público, Fiscalía de la Nación, debido a que su consumo se ha incrementado por presentar los mismos efectos que el etanol a un costo muy bajo, sin embargo en la práctica se puede apreciar que en algunos casos hay variaciones en los resultados obtenidos en nuestro laboratorio en relación con otros laboratorios del medio que también realizan análisis del metanol. En el presente trabajo se determinó la concentración de metanol en sangre de los casos de cadáveres en los que se sospechaba de consumo de alcohol metílico, a los cuales se les tomó muestras en cuatro tiempos diferentes evaluándose la posible variación que se da en el transcurso de ese tiempo; así también se describen los aspectos relacionados con la toma de las muestras biológicas para el análisis, su correcta preservación, los factores intrínsecos y extrínsecos a la toma de muestras que pueden generar resultados discordantes a la hora de interpretar los resultados, tales como pérdidas y generación de alcohol en el organismo humano. Para la determinación de la concentración de metanol en sangre se utilizó el método de cromatografía de gases con detector de ionización a la llama (GC-FID). En las 180 muestras analizadas se encontró que la relación de concentración de alcohol metílico no presentó una correlación significativa, por lo que se sugiere que no se debe considerar para hacer cálculos retrospectivos utilizando fórmulas matemáticas con la finalidad de aproximar las posibles concentraciones de alcohol metílico en el momento del deceso, como se pretende hacer en algunos casos a fin de dar un veredicto en casos de litigios de diversa naturaleza. Palabras clave: Etanol, metanol (alcohol metílico), cromatografía de gases, bebidas alcohólicas.The determination of methyl alcohol in the blood has become one of the analytical forensic practices of routine in recent years in the laboratory of Toxicology and Legal chemistry of Institute of Legal Medicine and Forensic Sciences of Lima, Ministry of Public Prosecutor’s Office, Attorney, since its consumption has increased by the same effects as the ethanol and a very low cost but in practice we can see that in some cases there are variations in the results obtained in our laboratory in relation with other laboratories of the way that also realize analysis of blood methyl alcohol level. In the present work the blood methyl alcohol level decided in the cases of corpses in those who were suspected in consumption of methyl alcohol, which took them samples at four different times evaluating possible variation that occurs over the course of that time; It also describes aspects relating to the taking of the biological samples for analysis, its proper preservation, the factors intrinsic and extrinsic to the taking of samples which can produce results differing when interpreting the results, such as loss and generation of alcohol in the human organism. For the determination of the blood methyl alcohol level the method of gas chromatography was in use with detector of ionization to the flame (GC-FID). In 168 Samples found that the ratio of concentration of methyl alcohol did not provide a significant correlation, by which he suggests that is should not be considered to make retrospective calculations using mathematical formulae in order to approximate the potential concentrations of alcohol methyl at the time of death, as intended in some cases in order to deliver a verdict in cases of litigation of diverse nature. Key word: Ethanol, methyl alcohol, gas chromatography, alcoholic drinks.Tesi

A simple one-pot oxidation protocol for the synthesis of dehydrohedione from Hedione

A new method for the oxidation of Hedione 1 to dehydrohedione 2, a high value intermediate in the flavour and fragrance industry, has developed based upon one pot α-chlorination-elimination sequence which can be readily scaled. The spontaneous elimination of the α-chloro in methanol was unprecedented and has allowed for the oxidation, typically performed in multiple steps/reactions, to be carried out as a one-pot protocol. A continuous flow process for performing the reaction utilising sulfuryl chloride has also demonstrated allowing for steady, safe evolution of SO2 gas during the reaction

ACTIVIDAD ANTIOXIDANTE DE Tropaeolum tuberosum RUIZ & PAVÓN (MASHUA) Y SU APLICACIÓN COMO COLORANTE PARA YOGUR

The objective of the study was to evaluate the antioxidant activity and use of ethanol extract of Tropaeolum tuberosum Ruiz & Pavón (mashua) as colorant for yogurt. The antioxidant activity was evaluated using DPPH and ABTS methods. The total content of anthocyanins (TA) and polyphenols (TP) was determined by the method of differential pH and Folin-Ciocalteu, respectively. Parameters of CIEL*a*b* system were used to measure the purple color and concentration of pigment used to color natural yogurt "3500", comparing with yogurt commercial blackberry "6224" which was taken as a reference. Both yogurt samples were stored under refrigeration (4°C ± 1) for 28 days and color and pH were measured every 4 days. For sensory analysis the acceptance test was applied (p<0,05). The contents of TA and TP in the extracts analyzed were 192,63 ± 1,28 mg of cyanidin-3-glucoside/100g fresh weight (FW) and 314,12 ± 1,23 mg of gallic acid/100 g FW, respectively. The antioxidant capacity trolox equivalent obtained was 15,8 ± 0,2 µmol/g FW, using the DPPH assay, and 17,0 ± 0,2 µmol/g FW with ABTS, the extract was added to plain yogurt (1,2 mg/ 100 g) imparting the purple similar to commercial yogurt blackberry color with minimal changes that were not visually apparent; yogurt "3500" was significantly preferred by judges against the yogurt "6224". It is concluded that the extracted pigments tuber Tropaeolum tuberosum Ruiz & Pavon, possess antioxidant activity, appearing as an alternative of colorant aplicable intermediate acidity foods like yogurt.El objetivo del estudio fue evaluar la actividad antioxidante y uso del extracto etanólico de Tropaeolum tuberosum Ruiz & Pavón (mashua) como colorante para yogur. La actividad antioxidante se determinó por los métodos DPPH y ABTS. El contenido total de antocianinas (AT) y polifenoles (PT) fue determinado por el método de pH diferencial y Folin-Ciocalteu, respectivamente. Los parámetros del sistema CIEL*a*b* se utilizaron para medir el color morado y la concentración de pigmento empleado para colorear el yogur natural “3500”, comparándose con yogur comercial de mora “6224”, que fue tomado como referencia. Ambas muestras de yogur se almacenaron bajo condiciones de refrigeración (4°C ± 1) durante 28 días; se les midió color y pH cada 4 días. Para el análisis sensorial se aplicó la prueba de aceptación (p<0,05). El contenido de AT y PT en los extractos analizados fueron 192,63 ± 1,28 mg de cianidina-3-glucósido/100g peso fresco (PF) y de 314,12 ± 1,23 mg de ácido gálico/100g PF, respectivamente. La capacidad antioxidante equivalente al trolox obtenida fue de 15,8 ± 0,2 µmol/g PF, aplicando el ensayo DPPH, y 17,0 ± 0,2 µmol/g PF con ABTS. El extracto se adicionó al yogur natural (1,2 mg/100 g) impartiendo un color morado similar al del yogur comercial de mora con mínimos cambios del color que no fueron visualmente evidentes; el yogur “3500” fue significativamente el preferido por los jueces frente al yogur “6224”. Se concluye que los pigmentos extraídos del tubérculo de Tropaeolum tuberosum Ruiz & Pavón, poseen actividad antioxidante, presentándose como una alternativa de colorante aplicable en alimentos de acidez intermedia como el yogur

Subchronic toxicity and possible teratogenic effect in rats of ethanol extract of Chuquiraga spinosa (huamanpinta)

El presente estudio tuvo como objetivo determinar la toxicidad subcrónica y posible efecto teratogénico del extracto etanólico de Chuquiraga spinosa (huamanpinta) en ratas de raza Holtzmann. Para la determinación de la toxicidad subcrónica se utilizaron 60 ratas (30 machos y 30 hembras); el primer grupo, control, recibió suero fisiológico 4 mL/kg y el segundo grupo 200 mg/kg de extracto durante cuatro meses consecutivos, realizando la evaluación hematológica y bioquímica al segundo, tercer y cuarto mes. Al final del ensayo (cuarto mes) se realizó el examen anatomopatológico. La determinación del posible efecto teratogénico se realizó utilizando 40 ratas hembras y diez ratas machos. Las ratas hembras recibieron 200 mg/kg diariamente durante un mes antes del apareamiento y, hasta el nacimiento de las crías, se evaluaron el número implantaciones a nivel de cuernos uterinos, fetos vivos y muertos, y malformaciones morfológicas externas de las crías. Del estudio fitoquímico se determinó que el extracto etanólico presentó taninos, compuestos fenólicos, alcaloides, flavonoides y saponinas. En el ensayo de toxicidad subcrónica se observó que hubo diferencia significativa en los valores hematológicos y bioquímicos al segundo, tercer y cuarto mes de tratamiento y, a nivel histopatológico, no se evidenciaron alteraciones en hígado, riñón y cerebro. En relación al posible efecto teratogénico no se observaron diferencias en el peso de las ratas gestantes, número de implantaciones fetales, número de fetos vivos y alteraciones morfológicas de las crías al momento del nacimiento ni a dos meses de seguimiento. Se concluye que el extracto etanólico no presentó toxicidad subcrónica ni efecto teratogénico a la dosis de 200 mg/kg.Objective of this experimental study was to determine the subchronic toxicity and possible teratogenic effect of ethanol extract from Chuquiraga spinosa (huamanpinta) in Holtzman rats. Was used for the determination of subchronic toxicity 60 rats (30 males and 30 females); the first, control, group received saline solution 4 mL/kg and the second group extract at 200 mg/kg during four consecutive months, making evaluation hematological and biochemical the second, third and fourth month. At the end of the trial (fourth month) was made pathological examination. The determination of possible teratogenic effect was performed using 40 female rats and ten male rats. Female rats recived 200 mg/kg daily by a month before mating and until the birth of brood, was evaluated the number implementations to uterine horns level, live and dead fetuses, and external morphological abnormalities of the offspring. The phytochemical study found that the ethanolic extract showed tannins, phenolic compounds, alkaloids, flavonoids and saponins. In the chronic toxicity test was observed that there was significant difference in hematological and biochemical values to second, third and fourth month of treatment and no histopathological changes in liver, kidney and brain. Regarding to possible teratogenic effect was observed no difference in the weight of pregnant rats, number of fetal implantations, number of live fetuses and morphological abnormalities of the offspring at birth even two months follow up. Was concluded that ethanolic sxtract not showed sub-chronic toxicity or teratogenic effect at 200 mg/kg dose

Further investigations into imine-mediated formation of allylic nitro compounds

Nitro alkanes are valuable starting materials for functionalisation via their corresponding anions as well as their transformation into other important groups such as ketones via the Nef reaction. Herein, we report a process development study for the construction of a series of cyclic allylic nitro compounds that features a greener solvent and a lower cost, more robust catalyst than previously reported. The process was developed to target the selective synthesis of an important fragrance intermediate, namely, α-dehydroherbac. Process scoping and optimisation involved solvent & catalyst screening along with a basic kinetic investigation to evaluate critical reaction parameters (concentration and reagents ratio). The final optimised conditions were further demonstrated via synthesis of a small collection of additional derivatives to demonstrate scope and utility

Spectroscopic dataset of Hedione's derivatives gathered during process development

The dataset of spectroscopic analysis performed on starting materials, intermediates, and products relating to the synthesis of Hedione are hereby presented. The data were acquired in Durham university during the period between October 2020 and September 2021 for the development of a preparative method to Dehydrohedione. The latter is a key intermediate for the synthesis of cis-Hedione, an important fragrance ingredient. Proton, Carbon-13, and Fluorine-19 Nuclear magnetic resonance of the compounds were recorded employing a Varian 600 MHz, and a Bruker Avance-400 instrument. The IR spectra were recorded in a Perkin Elmer Spectrum Two UATR Two FT-IR and the accurate mass employing a Waters QtoF premier as mass spectrometer

Contact fatigue behavior of a-Al2O3-Ti(C,N) CVD coated WC-Co under dry and wet conditions

The response to cycling contact fatigue load of a WC-6%Co carbide coated with a Ti(C,N)/a-Al2O3 CVD multilayer was investigated in dry and wet conditions. Imprints in dry conditions were characterized by small thin cracks forming a circumference at the maximum radii of the imprint. The damaged coating was totally present in the final imprint of the dry test. Wet indentations showcase an area in the imprint where the a-Al2O3 layer has been removed throughout a ring but was kept at the center of the indentation, suggesting that the coating damage under cycling contact load in wet conditions is dominated by a-Al2O3 degradation, associated with a fretting effect or tangential loads accelerating the fatigue-corrosion of the alumina layer.Peer ReviewedPostprint (author's final draft

Contact fatigue behaviour of CVD coated cemented carbides in dry and wet conditions

Cycling contact fatigue indentation tests in dry and wet conditions were conducted in cemented carbides CVD-coated with Ti(C,N)/a-Al2O3 and Zr(C,N)/a-Al2O3 systems. In dry contact experiments, all imprints presented a deformed area where the coating was still present after the test. Formation of cracks was visible at the edge of the contact point of the imprint. On the other hand, under wet conditions, almost all imprints presented a ring where the a-Al2O3 had been removed, driven by a corrosion-fatigue process. Exceptionally, for Cr-containing cemented carbides combined with Zr(C,N)/a-Al2O3 coating, no delamination of a-Al2O3 was observed after the test under wet conditions. This result suggests that the combination of fine-grained cemented carbides and coating systems with low coefficient of thermal expansion may be of advantage to resist degradation by cyclic contact fatigue. Furthermore, the response to fatigue by contact loads can be enhanced by tailoring/combining cemented carbides and CVD coating systems which present higher chemical stability, and both higher intrinsic plasticity and resistance to plastic deformation.Peer ReviewedPostprint (author's final draft