Thesis--Ohio State University. / Includes bibliographical references.

abstract: Background: Twenty-four hour urinary sucrose and fructose (24uSF) has been developed as a dietary biomarker for total sugars intake. Collection of 24-h urine is associated with high costs and heavy participant burden, while collection of spot urine samples can be easily implemented in research protocols. The aim of this thesis is to investigate the utility of uSF biomarker measured in spot urine. Methods: 15 participants age 22 to 49 years completed a 15-day feeding study in which they consumed their usual diet under controlled conditions, and recorded the time each meal was consumed. Two nonconsecutive 24-hour urines, where each urine void was collected in a separate container, were collected. Four timed voids (morning, afternoon, evening, and next day) were identified based on time of void and meal time. Urine samples were measured for sucrose, fructose and creatinine. Variability of uSF excretion was assessed by coefficient of variation (%CV) and variance ratios. Pearson correlation coefficient and multiple linear regression were used to investigate the association between uSF in each timed void and corresponding 24uSF excretion. Results: The two-day mean uSF was 50.6 mg (SD=29.5) for the 24-h urine, and ranged from 4.5 to 7.5 mg/void for the timed voids. The afternoon void uSF had the lowest within-subject variability (49.1%), and lowest within- to between-subject variance ratio (0.2). The morning and afternoon void uSF had the strongest correlation with 24-h uSF for both mg/void (r=0.80 and r=0.72) and mg/creatinine (r=0.72 and r=0.67), respectively. Finally, the afternoon void uSF along with other covariates had the strongest predictive ability of 24-h uSF excretion (mg/void) (Adjusted R2= 0.69; p=0.002), whereas the morning void had the strongest predictive ability of 24-h uSF excretion (mg/g creatinine) (adjusted R2= 0.58; p=0.008). Conclusions: The afternoon void uSF had the most favorable reproducibility estimates, strong correlation with 24uSF excretion, and explained greatest proportion of the variability in 24uSF. USF in mg/void may be better to use than uSF in mg/g creatinine as a biomarker in spot urine. These findings need to be confirmed in a larger study, and in a study population with a wide range of sugars intake. / Dissertation/Thesis / Masters Thesis Nutrition 2018

No description available.

Molybdenum is very important in the life processes of both plants and animals. It acts as a catalyst in promoting and controlling many biological reactions in living cells, but exactly what it does and how it functions are not well understood. In the past because of the obvious complexity of the reactions concerned and the extremely minute quantities of molybdenum involved, its presence was long undetected. Lately, molybdenum has drawn special attention on account of its effects on metabolic processes, particularly of plants. In this regard, molybdenum has been shown to be present in four enzymes: nitrate reductase (JJ), xanthine oxidase (39), aldehyde oxidase (28), and hydrogenase (41).

This study concerns an investigation of nitrous acid deamination of various amino sugar derivatives. Deamination reagents have also been used for the diazotization of aromatic compounds. Nitrous acid deamination was used in the deamination of amino acids pinacolic amino alcohols and amino sugars.

No description available.

Call number: LD2668 .T4 1978 M78 / Master of Science

Difficulties in controlling and forecasting avocado fruit ripening and the highly perishable nature of the crop once harvested, are the major causes of concern for avocado traders. In particular, the simultaneous presence of many suppliers may account for increased fruit variability during ripening. Avocado is a climacteric fruit with consistent ethylene production after harvest which is also related to high perishability. However, the mechanisms regulating ethylene biosynthesis and mesocarp softening are not completely understood. In order to study such effects, avocado fruit from different growing areas and harvested at various maturity stages, were investigated and the biochemical and physiological changes during ripening at both 18 and 23°C were studied. Mesocarp softening and fatty acid content discriminated fruit maturity and growing area, respectively, whereas C7 sugars (D-mannoheptulose and perseitol) discriminated length of fruit shelf life. For the first time, oleic acid content presents in the oil mesocarp was found to depend on fruit sources making of this a suitable indicator of avocado fruit growing area. In contrast, sugar content declined along fruit maturity and ripening. In particular the mannoheptulose presents in avocado mesocarp might be use to estimate avocado fruit shelf life. Indeed, fruit harvested late in season were found to have a lower C7 content than earlier harvest fruit and a faster softening, regardless fruit source. However, sugars content changed between growing area, thus a general C7 threshold defining fruit storability seems to be not definable. Furthermore, other possible indicators of fruit maturity and/or ripening stage have been searched in the cell wall constituents of avocado mesocarp. Thus, the structural carbohydrates profile of avocado mesocarp investigated with a new immunological method changed during ripening and harvest time (early and late season), suggesting a possible effect of cell wall composition on fruit ripening regulation. Also, the possible use of ethylene application in reducing the high heterogeneity noted on imported fruit from South Africa was also evaluated through different consignments. Results showed ethylene efficacy changed depending on harvest time and fruit dimension with less efficacy of the treatment on fruit harvested at the end of the season and characterised by smaller size.One of the most commercialized avocado cultivars, Hass, is peculiar in that its skin colour changes from green to deep purple as ripening progresses. The most common ripening indicator of avocado fruit is the mesocarp firmness and the destructive nature of this evaluation increases losses in the avocado industry. The availability of a non-destructive indicator of fruit ripening represents an important advantage for avocado consumers and importers. Thus, the possible relationship between mesocarp softening, skin colour were objectively evaluated (C*, L*, and H°), and the main pigment, cyanidin 3-O-glucoside, was investigated. Cyanidin 3-Oglucoside was confirmed to be the main anthocyanin present in avocado cv. Hass peel, regardless of preharvest factors. However, differences in its content were noted between shelf life temperatures. A higher relationship between hue angle and firmness was detected in late harvest fruit, whereas no correlation was found between anthocyanin content and firmness. Avocado skin is also involved in defence mechanisms due to the presence of antifungal and phenolic compounds. These phenolic compounds represent a natural protection against pathogenic infections and seem to be down regulated during ripening. The main phenolics were identified and quantified, using a new analytical method which was validated and optimised. Epicatechin, chlorogenic acid and procyanidin B2 were found to be present in the skin tissue and quantified using this assay and found to vary during shelf life and seasons. Although phenolics were present in minor amounts, in avocado pulp they are involved in mesocarp discoloration incidence, and therefore with fruit postharvest quality. Due to a lack of information, a new straightforward method for the identification and quantification of the main phenolics present in avocado mesocarp was developed. Finally, a commercial trial was undertaken to ensure that the results obtained in the laboratory can be reproduced in the market place. In conclusion, postharvest markers can define avocado fruit maturity and growing area and give guidelines in the control of avocado shelf life. Moreover, new methods for the investigation of the phenolic profiles (peel and mesocarp) and the characterisation of cell wall structures can be further tools in the management of avocado fruit postharvest quality.

This thesis describes a new method for the synthesis of pseudodisaccharides containing a carbasugar analogue attached to a "true" sugar. The methodology is based on a Diels-Alder cycloaddition of vinyl sugars and appropriately substituted pyran-2-ones, followed by chemical manipulation of the resulting cycloadducts. The thesis also describes the synthesis of inhibitors of Golgi α-mannosidase II and glucokinase. The first chapter is a comprehensive survey of the reported synthetic routes to pseudodisaccharides from the literature. The results and discussions are presented in chapter 2. This chapter starts by discussion of the preparation of vinyl sugars and pyran-2-ones and the regio- and stereoselectivity of their cycloadditions. This is followed by reporting the chemical manipulations of these cycloadducts and the synthesis of a pseudodisaccharide. Cycloadducts are shown to lose carbon dioxide at elevated temperatures to afford dihydrobenzenes. The loss of the bridging carbon dioxide from the cycloadducts is experimentally and computationally investigated. The resulting dihydrobenzenes are shown to also be useful as precursors in the synthesis of pseudodisaccharides. The chemical manipulation of these dihydrobenzenes is used towards the synthesis of a pseudodisaccharide. The third and fourth chapters focus on the synthesis of new inhibitors of Golgi α-mannosidase II and glucokinase respectively. A range of 6-aminoglucose and mannose derivatives were prepared and tested for the inhibition of Jack bean α-mannosidase, but were found to lack any inhibition. Similarly, a range of 6-triazologlucose derivatives were prepared but were found to lack any cytotoxicity. The fifth chapter contains the details of the preparation, experimental procedures and spectroscopic characterisation of the synthesised chemical compounds. Rate calculations are reported in Appendix I and the X-ray crystallographic data are presented in the Appendix II.

A comunidade de insetos visitantes de flores de clones do eucalipto urograndis (Eucalyptus grandis x E. urophylla) foi estudada em um plantio localizado na Fazenda Areão, em Piracicaba, SP (22° 41 41 S e 47° 38 5 3 W ) por meio de levantamentos semanais com rede entomológica, durante os florescimentos de 2007 e de 2008 com a finalidade de caracterizar seu potencial apícola com a determinação de sua apifauna associada, e das características de néctar produzidos por suas flores. A comunidade antófila nos dois anos do levantamento foi representada por 29.492 indivíduos pertencentes a 6 ordens, 21 famílias, 43 gêneros e 52 espécies. A apidofauna foi representada por 24.882 indivíduos pertencentes a 11 gêneros e 10 espécies. A abelha africanizada Apis mellifera, o visitante mais efetivo em todo o levantamento (80,96%), seguida do sirfídeo Ornidia obesa (5,29%) e do mantispídeo Zeugomantispa virescens (4,26%). Os índices de diversidade (H) e equitabilidade (E); foram distintos nos dois levantamentos indicando distribuição de espécies mais uniforme na coleta de 2007 em relação à de 2008. Dentre as demais espécies predominantes, destacaram-se as abelhas Trigona spinipes (irapuá), Tetragonisca angustula (jataí), e Nannotrigona testaceicornis (iraí). As concentrações médias encontradas por clones foram inferiores ao relatado na literatura, sendo os valores máximos variando entre 13 e 14%. As diferenças encontradas entre alguns clones possivelmente foram influenciadas pela altura de algumas plantas. / The community of insect flower visitors of eucalyptus urograndis clones (Eucalyptus grandis x E. urophylla) was studied in an plantation located at Areão farm, in Piracicaba, São Paulo state, Brazil (22° 41 41 S e 47° 38 53 W ). Weekly collections were conducted using hand net during the bloom periods of 2007 and 2008 in order to characterize the potential for beekeeping by determining the associated apifauna and the nectar characteristics produced by the flowers.The anthophilous community in the two-year survey was represented by 29,492 individuals belonging to 6 orders, 21 families, 43 genera and 52 species. The apidofauna was represented by 24,882 individuals belonging to 11 genera and 10 species. The Africanized honey bee Apis mellifera. This species was the most effective visitor throughout the survey (80.96%) followed by the syrphid Ornidia obesa (5.29%) and the mantispid Zeugomantispa virescens (4.26%). The diversity (H\') and equitability (E) indices were different between the two surveys showing that species distribution was more uniform in the collecting of 2007 when compared to the 2008. Among the other dominant species, the bees Trigona spinipes (Irapuá bee), Tetragonisca angustula (jataí bee), and Nannotrigona testaceicornis (Iraí bee) were the main ones. The differences found between some clones were possibly influenced by the height of some plants.