Gold Meets Selenium: Dual Activation of Selenium-Containing Propargyl Alcohols Towards the Synthesis of 2H-Chromenes and Mechanistic Insights.

Herein, we report the synthesis of seleno-substituted chromenes from selenoalkynes and phenols. In this cascade reaction, the applied gold catalyst not only functions as a π-acid, but also as a Lewis acid, enabling the propargylic substitution in the first step to connect the oxygen carbon bond. Under the optimal reaction condition a total of 26 chromenes were accessible by this modular access. During scale up experiments, the hydrolysis of the vinylselenium substructure to the corresponding chromenones was observed. By revisiting the electron-rich starting materials, four chromenones were produced following a one-pot reaction using a single gold catalyst. To better understand the interaction of gold and selenium, a series of nuclear magnetic resonance studies and high-resolution mass spectrometry studies were performed, which led to the proposal of a mechanism for this transformation.

Ameliorative effects of Lactobacillus against Aflatoxin B1 / Efeitos benéficos do Lactobacillus contra a Aflatoxin B1

Abstract Lactobacilli are probiotics with Aflatoxin (AF) detoxification ability, found in fermented products, GIT of animals and environment. Purpose of this study was to investigate the ability of broiler isolates of Lactobacillus against Aflatoxin B1 (AFB1). For this purpose, 5 isolates of Lactobacillus from broiler gut were incubated with 100 ppb AFB1 in aqueous environment and effect of different parameters (cell fractions, time, temperature, pH) on detoxification was determined by HPLC. The ameliorative effect of Lactobacillus salivarius (LS) against AFB1 was studied in broiler. The results revealed that LS (CR. 4) showed the best results (in vitro) as compared to other isolates (L. salivarius (CR. 3, CR, 4), L. agilis (CE. 2.1, CE. 3.1) and L. crispatus (CE. 28). Cell debris of CR. 4 showed significantly higher detoxification (P<0.05). Maximum amount of AFB1 was detoxified at 30°C (97%), pH 4.0 (99%) and 6 h (99.97%). In vivo study showed that AFB1 decreased weight gain (1,269 ± 0.04 gm/ bird), feed consumed (2,161 ± 0.08 gm/ bird), serum total protein (2.42 ± 0.34 gm/ dl), serum albumin (0.5 ± 0.2 2 gm/dl) and antibody titer (4.2 ± 0.83). Liver function enzymes were found (alanine transaminase (ALT): 32 ± 10.7 U/L) and aspartate transaminase (AST): 314.8 ± 27 U/L) elevated in AFB1 fed broilers. Treatment with 1% LS not only decreased the toxic effects of AFB1 (group D) but also improved the overall health of broilers due to its probiotic effects (p<0.05) as compared to control negative (group A). The detoxification ability of LS was better than commercial binder (CB) (0.2% Protmyc). It was concluded that detoxification of AFB1 by Lactobacillus was strain, temperature, pH and time dependent. LS has detoxification ability against AFB1 in vivo.

Resumo Os lactobacilos são probióticos com capacidade de desintoxicação da Aflatoxina (AF), encontrados em produtos fermentados, TGI de animais e meio ambiente. O objetivo deste estudo foi investigar a capacidade de isolados de frango de corte de Lactobacillus contra a Aflatoxina B1 (AFB1). Para tanto, 5 isolados de Lactobacillus de intestino de frango foram incubados com 100 ppb AFB1 em meio aquoso, e o efeito de diferentes parâmetros (frações celulares, tempo, temperatura, pH) na desintoxicação foi determinado por CLAE. O efeito melhorador de Lactobacillus salivarius (LS) contra AFB1 foi estudado em frangos de corte. Os resultados revelaram que LS (CR. 4) apresentou os melhores resultados (in vitro) em comparação com outros isolados [L. salivarius (CR. 3, CR. 4), L. agilis (CE. 2.1, CE. 3.1) e L. crispatus (CE. 28)]. Detritos celulares de CR. 4 mostraram desintoxicação significativamente maior (P < 0.05). A quantidade máxima de AFB1 foi desintoxicada a 30 °C (97%), pH 4.0 (99%) e 6 h (99,97%). O estudo in vivo mostrou que AFB1 diminuiu o ganho de peso (1,269 ± 0.04 g / ave), alimento consumido (2,161 ± 0.08 g / ave), proteína total sérica (2.42 ± 0.34 g / dl), albumina sérica (0.5 ± 0.22 gm / dl) e título de anticorpo (4.2 ± 0.83). As enzimas da função hepática foram encontradas (alanina transaminase (ALT): 32 ± 10.7 U / L) e aspartato transaminase (AST): 314.8 ± 27 U / L) elevadas em AFB1 alimentados com frangos. O tratamento com 1% LS não só diminuiu os efeitos tóxicos de AFB1 (grupo D), mas também melhorou a saúde geral dos frangos devido aos seus efeitos probióticos (p < 0.05) em comparação com o controle negativo (grupo A). A capacidade de desintoxicação do LS foi melhor do que o aglutinante comercial (CB) (0.2% Protmyc). Concluiu-se que a desintoxicação de AFB1 por Lactobacillus foi dependente da cepa, temperatura, pH e tempo. LS tem capacidade de desintoxicação contra AFB1 in vivo.

Ameliorative effects of Lactobacillus against Aflatoxin B1

Abstract Lactobacilli are probiotics with Aflatoxin (AF) detoxification ability, found in fermented products, GIT of animals and environment. Purpose of this study was to investigate the ability of broiler isolates of Lactobacillus against Aflatoxin B1 (AFB1). For this purpose, 5 isolates of Lactobacillus from broiler gut were incubated with 100 ppb AFB1 in aqueous environment and effect of different parameters (cell fractions, time, temperature, pH) on detoxification was determined by HPLC. The ameliorative effect of Lactobacillus salivarius (LS) against AFB1 was studied in broiler. The results revealed that LS (CR. 4) showed the best results (in vitro) as compared to other isolates (L. salivarius (CR. 3, CR, 4), L. agilis (CE. 2.1, CE. 3.1) and L. crispatus (CE. 28). Cell debris of CR. 4 showed significantly higher detoxification (P 0.05). Maximum amount of AFB1 was detoxified at 30°C (97%), pH 4.0 (99%) and 6 h (99.97%). In vivo study showed that AFB1 decreased weight gain (1,269 ± 0.04 gm/ bird), feed consumed (2,161 ± 0.08 gm/ bird), serum total protein (2.42 ± 0.34 gm/ dl), serum albumin (0.5 ± 0.2 2 gm/dl) and antibody titer (4.2 ± 0.83). Liver function enzymes were found (alanine transaminase (ALT): 32 ± 10.7 U/L) and aspartate transaminase (AST): 314.8 ± 27 U/L) elevated in AFB1 fed broilers. Treatment with 1% LS not only decreased the toxic effects of AFB1 (group D) but also improved the overall health of broilers due to its probiotic effects (p 0.05) as compared to control negative (group A). The detoxification ability of LS was better than commercial binder (CB) (0.2% Protmyc). It was concluded that detoxification of AFB1 by Lactobacillus was strain, temperature, pH and time dependent. LS has detoxification ability against AFB1 in vivo.

Resumo Os lactobacilos são probióticos com capacidade de desintoxicação da Aflatoxina (AF), encontrados em produtos fermentados, TGI de animais e meio ambiente. O objetivo deste estudo foi investigar a capacidade de isolados de frango de corte de Lactobacillus contra a Aflatoxina B1 (AFB1). Para tanto, 5 isolados de Lactobacillus de intestino de frango foram incubados com 100 ppb AFB1 em meio aquoso, e o efeito de diferentes parâmetros (frações celulares, tempo, temperatura, pH) na desintoxicação foi determinado por CLAE. O efeito melhorador de Lactobacillus salivarius (LS) contra AFB1 foi estudado em frangos de corte. Os resultados revelaram que LS (CR. 4) apresentou os melhores resultados (in vitro) em comparação com outros isolados [L. salivarius (CR. 3, CR. 4), L. agilis (CE. 2.1, CE. 3.1) e L. crispatus (CE. 28)]. Detritos celulares de CR. 4 mostraram desintoxicação significativamente maior (P 0.05). A quantidade máxima de AFB1 foi desintoxicada a 30 °C (97%), pH 4.0 (99%) e 6 h (99,97%). O estudo in vivo mostrou que AFB1 diminuiu o ganho de peso (1,269 ± 0.04 g / ave), alimento consumido (2,161 ± 0.08 g / ave), proteína total sérica (2.42 ± 0.34 g / dl), albumina sérica (0.5 ± 0.22 gm / dl) e título de anticorpo (4.2 ± 0.83). As enzimas da função hepática foram encontradas (alanina transaminase (ALT): 32 ± 10.7 U / L) e aspartato transaminase (AST): 314.8 ± 27 U / L) elevadas em AFB1 alimentados com frangos. O tratamento com 1% LS não só diminuiu os efeitos tóxicos de AFB1 (grupo D), mas também melhorou a saúde geral dos frangos devido aos seus efeitos probióticos (p 0.05) em comparação com o controle negativo (grupo A). A capacidade de desintoxicação do LS foi melhor do que o aglutinante comercial (CB) (0.2% Protmyc). Concluiu-se que a desintoxicação de AFB1 por Lactobacillus foi dependente da cepa, temperatura, pH e tempo. LS tem capacidade de desintoxicação contra AFB1 in vivo.

Ameliorative effects of Lactobacillus against Aflatoxin B1.

Lactobacilli are probiotics with Aflatoxin (AF) detoxification ability, found in fermented products, GIT of animals and environment. Purpose of this study was to investigate the ability of broiler isolates of Lactobacillus against Aflatoxin B1 (AFB1). For this purpose, 5 isolates of Lactobacillus from broiler gut were incubated with 100 ppb AFB1 in aqueous environment and effect of different parameters (cell fractions, time, temperature, pH) on detoxification was determined by HPLC. The ameliorative effect of Lactobacillus salivarius (LS) against AFB1 was studied in broiler. The results revealed that LS (CR. 4) showed the best results (in vitro) as compared to other isolates (L. salivarius (CR. 3, CR, 4), L. agilis (CE. 2.1, CE. 3.1) and L. crispatus (CE. 28). Cell debris of CR. 4 showed significantly higher detoxification (P<0.05). Maximum amount of AFB1 was detoxified at 30°C (97%), pH 4.0 (99%) and 6 h (99.97%). In vivo study showed that AFB1 decreased weight gain (1,269 ± 0.04 gm/ bird), feed consumed (2,161 ± 0.08 gm/ bird), serum total protein (2.42 ± 0.34 gm/ dl), serum albumin (0.5 ± 0.2 2 gm/dl) and antibody titer (4.2 ± 0.83). Liver function enzymes were found (alanine transaminase (ALT): 32 ± 10.7 U/L) and aspartate transaminase (AST): 314.8 ± 27 U/L) elevated in AFB1 fed broilers. Treatment with 1% LS not only decreased the toxic effects of AFB1 (group D) but also improved the overall health of broilers due to its probiotic effects (p<0.05) as compared to control negative (group A). The detoxification ability of LS was better than commercial binder (CB) (0.2% Protmyc). It was concluded that detoxification of AFB1 by Lactobacillus was strain, temperature, pH and time dependent. LS has detoxification ability against AFB1 in vivo.

Double Gold Activation of 1-Ethynyl-2-(Phenylethynyl)Benzene Toward 5-exo-dig and 6-endo-dig Cyclization Reactions.

In this work, a detailed characterization was carried out of the ring-closure mechanism of EPB (1-ethynyl-2-(phenylethynyl)benzene) toward the 5-exo-dig and 6-endo-dig cyclization reactions, catalyzed by two Au-N-heterocyclic carbene (NHC) moieties. It was found that the 5-exo-dig cyclization takes place with a slightly lower activation barrier and larger exothermicity compared to that of the 6-endo-dig cyclization, in agreement with the available experimental data. A phenomenological partition (structural and electronic) for rate constants computed using transition-state theory and the reaction force analysis was used to shed light into the nature of the activation rate constant. It was found that rate constants are influenced by a strong structural component, which is larger for the 5-exo-dig cyclization due to the strain to form the five-membered ring. On the other hand, the gold activation mechanism is evidenced by a σ- and π-coordination of the Au-NHC moieties to the EPB substrate. It was found that differences in the σ-coordination arise on the reaction path for the 5-exo-dig and 6-endo-dig cyclizations. Thus, in the 6-endo-dig cyclization the σ gold-EPB interaction is weakened as a consequence of the formation of the cationic aryl intermediate, while for the 5-exo-dig cyclization this interaction was found to be favored. Furthermore, although minor changes in the Au-EPB coordination occur on the reaction path, these bonds are formally established in the TS vicinity. Results support the concerted nature of the dual gold activation mechanism.

Cardiovascular risk factors after Kawasaki disease: a case-control study.

OBJECTIVES: To determine cardiovascular risk profiles of patients with Kawasaki disease and to relate them to a noninvasive measure of endothelial function. STUDY DESIGN: Case-control study. Cardiovascular risk assessment including brachial artery reactivity was performed in 24 patients 11.3 +/- 1.8 (mean +/- SD) years after Kawasaki disease and in 11 subjects in a normal control group. RESULTS: The case versus control groups were similar regarding age, sex, race, body mass index, and percentage of ideal body weight, although cases had a higher mean z score of body mass index than normal (+1.00 +/- 1.18; P <.001). Cases had normal fasting total cholesterol levels but a higher mean z score of triglyceride levels (+1.35 +/- 2.04; P <.004). The case group had significantly higher mean systolic and diastolic resting blood pressure z scores (+0.76 +/- 1.06; P <.01 and +0.96 +/- 1.19; P <.01, respectively) than the control group and population norms. Endothelial function as indicated by brachial artery reactivity was not significantly different between the case versus control groups. In the case group higher blood pressure, increasing adiposity, and higher fasting triglyceride levels were significantly interrelated but did not relate to brachial artery reactivity or coronary artery abnormalities. CONCLUSIONS: Patients after Kawasaki disease tend to have a more adverse cardiovascular risk profile potentially indicative of an increased predisposition to premature atherosclerotic changes.