Selenium-catalyzed reductive carbonylation of nitrobenzene with amines as coreagents to give unsymmetric phenylureas

The reductive carbonylation of nitrobenzene catalyzed by selenium to yield unsymmetric phenylureas has been studied. When secondary amines were used as coreagents, a single product, PhNHCONR2, was formed; when primary amines were chosen as coreagents, mixed products, including RNHCONHR, RNHCONHPh and PhNHCONHPh, were obtained. (C) 1999 Elsevier Science Ltd. All rights reserved.

Highly efficient route to diselenides from the reactions of imines and selenium in the presence of carbon monoxide and water

Reactions of selenium with imines ((RRC)-C-1=NR2) of aldehydes and ketones in the presence of carbon monoxide, water and triethylamine lead to reductive selenation, on aerobic work-up, to afford symmetrical diselenides ((RRCHSe)-C-1)(2) in good to excellent yields. The proposed mechanism suggests that both in situ generated carbonyl selenide (SeCO) and hydrogen selenide (H2Se) are involved in the reaction.

Selenium-catalyzed reductive carbonylation of 2-nitrophenols to 2-benzoxazolones

2-Benzoxazolones or 2-benzimidazolones are synthesized in moderate to good yields in the presence of a base (KOH, NaOH, KOAc, NEt3, DBU) at atmospheric pressure or under a high pressure of CO by one-pot reductive carbonylation of 2-nitrophenols or 2-nitroanihne in the presence of selenium as catalyst. Besides the effect of base, the effects of solvent and temperature on the reaction were investigated at high or atmospheric pressure. Contrasting results were obtained for 2-benzoxazolones or 2-benzimidazolone at high and atmospheric pressures. Moreover, phase-transfer catalysis was exhibited. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).

Frutas e produtos hortícolas na prevenção do cancro

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

Longitudinal study of changes in body mass index, anthropometric measures, dietary intake and physical activity in cohorts of school-going Irish adolescents

The prevalence of obesity worldwide has increased dramatically over the last few decades. Poor dietary habits and low levels of exercise in adolescence are often maintained into adulthood where they can impact on the incidence of obesity and chronic diseases. A 3-year longitudinal study of anthropometric, dietary and exercise parameters was carried out annually (2005 - 2007) in 3 Irish secondary schools. Anthropometric measurements were taken in each year and analysed longitudinally. Overweight and obesity were at relatively low levels in these adolescents. Height, weight, BMI, waist and hip circumferences and TST increased significantly over the 3 years. Waist-to-hip ratio (WHR) decreased significantly over time. Boys were significantly taller than girls across the 3 years. A 3-day weighed food diary was used to assess food intake by the adolescents. Analysis of dietary intake data was determined using WISP©. Mean daily energy and nutrient intakes were reported. Mean daily energy and macronutrient intakes were analysed longitudinally. The adolescents’ diet was characterised by relatively high saturated fat intakes and insufficient fruit and vegetable consumption. The dietary pattern did not change significantly over the 3 years. Boys consumed more energy than girls over the study period. A validated questionnaire was used to assess physical activity and sedentary activity levels. Boys were substantially more active and had higher energy expenditure estimates than girls throughout the study. A significant longitudinal decrease in physical activity levels among the adolescents was observed. Both genders spent more than the recommended amount of time (hrs/day) pursing sedentary activities. The dietary pattern in these Irish adolescents is relatively poor. Of additional concern is the overall longitudinal decrease in physical activity levels. Promoting consumption of a balanced diet and increased exercise levels among adolescents will help to reduce future public health care costs due to weight-related diseases.

Cereal products for specific dietary requirements. Evaluation and improvement of technological and nutritional properties of gluten free raw materials and end products

Coeliac disease is one of the most common food intolerances worldwide and at present the gluten free diet remains the only suitable treatment. A market overview conducted as part of this thesis on nutritional and sensory quality of commercially available gluten free breads and pasta showed that improvements are necessary. Many products show strong off-flavors, poor mouthfeel and reduced shelf-life. Since the life-long avoidance of the cereal protein gluten means a major change to the diet, it is important to also consider the nutritional value of products intending to replace staple foods such as bread or pasta. This thesis addresses this issue by characterising available gluten free cereal and pseudocereal flours to facilitate a better raw material choice. It was observed that especially quinoa, buckwheat and teff are high in essential nutrients, such as protein, minerals and folate. In addition the potential of functional ingredients such as inulin, β-glucan, HPMC and xanthan to improve loaf quality were evaluated. Results show that these ingredients can increase loaf volume and reduce crumb hardness as well as rate of staling but that the effect diverges strongly depending on the bread formulation used. Furthermore, fresh egg pasta formulations based on teff and oat flour were developed. The resulting products were characterised regarding sensory and textural properties as well as in vitro digestibility. Scanning electron and confocal laser scanning microscopy was used throughout the thesis to visualise structural changes occurring during baking and pasta making