Physical Sciences and Mathematics Commons^™

Towards Completely Automated Glycan Synthesis, Matteo Panza

Dissertations

Carbohydrates are ubiquitous both in nature as biologically active compounds and in medicine as pharmaceuticals. Although there has been continued interest in the synthesis of carbohydrates, chemical methods require specialized knowledge and hence remain cumbersome. The need for development of rapid, efficient and operationally simple procedures has come to the fore. This dissertation focuses on the development of a fully automated platform that will enable both experts and non-specialists to perform the synthesis of glycans. Existing automated methods for the synthesis of oligosaccharides are highly sophisticated, operationally complex, and require significant user know-how. By contrast, high performance liquid chromatography (HPLC) …

Microbial Diversity Of The Symbiotic Colony Of Bacteria And Yeast (Scoby) And Its Impact On The Organoleptic Properties Of Kombucha, Danielle L. St-Pierre

Electronic Theses and Dissertations

Kombucha is an effervescent fermented tea beverage that is gaining popularity for its probiotic nature and purported health benefits. The market for kombucha is expected to reach $1.8 billion by the year 2020. The composition of microbes that compose the symbiotic colony of bacteria and yeast (SCOBY) is highly variable with some species commonly found from the Gluconobacter, Acetobacter, Zygosaccharomyces, Saccharomyces, and Schizosaccharomyces genera.

It was hypothesized that different SCOBYs, obtained from different sources would vary in microbial diversity and produce different biochemical and flavor profiles in the resulting beverage over several generations. Kombucha is a fermented …

The Characterization Of A New Metabolite From A Trichodesmium Bloom, Kelly M. Mcmanus

Senior Honors Projects

Our laboratory has been investigating blooms of Trichodesmium, a genus of ecologically important, nitrogen-fixing cyanobacteria, collected from Padre Island in the Gulf of Mexico. Trichodesmium species are an underexplored biological source of cyanobacteria – a taxa that has been shown to produce chemically diverse secondary metabolites. With our focus on the isolation and structure characterization of new bioactive marine natural products, our research group has discovered over 25 new-to-science compounds over the past three years from these blooms. UV and mass spectrometry-guided isolation of Trichodesmium chromatography fractions were utilized to isolate a new metabolite. Isolation of this metabolite was …

A Study On The Modifications Of [2.2]Paracyclophane And Their Effects On The Enantioselectivity Of The Copper Catalyzed Cyclopropanation Reaction, Yousef Dawoud

Honors Theses

The use of chiral [2.2]paracyclophane Schiff-base ligands has been shown to induce enantioselectivity in the copper catalyzed cyclopropanation of styrene with diazoesters. ¹ Previous research by Dr. Masterson tested Schiff-base ligands based on 4- amino[2.2]paracyclophane with moderate enantioselectivity. In this project, the Schiff-base N- salicylidene-4-amino[2.2]paracyclophane, was modified by way of Grignard addition to the imine carbon and its enantioselective properties were explored with the copper catalyzed cyclopropanation. The methyl Grignard addition to N- salicylidene-4-amino[2.2]paracyclophane was successful in producing the amino alcohol and the amino alcohol was characterized. The amino alcohol was produced from the R enantiomer of the Schiff-base and …

Anthocyanin Stability In Food Products Made With Freeze-Dried Blueberry Powder, Samantha Findley

Food Science Undergraduate Honors Theses

This study evaluated the stability of anthocyanins in six blueberry products (gummy, graham bar, oatmeal bar, rice krispy bar, ice pop and juice) prepared with freeze-dried wild blueberry powder during processing and over eight weeks storage. Total anthocyanins were determined by HPLC before processing and at day 0 and 2, 4, 6, and 8 weeks of storage. Thermal processing of gummy and graham bar products resulted in significant losses of anthocyanins (50% and 31%, respectively). An eight-week storage time also resulted in a significant decrease in anthocyanins (7% to 51%) in products stored at ambient temperature. The ice pop, which …

Anthocyanin Stability In Food Products Made With Freeze-Dried Blueberry Powder, Samantha R. Findley, Luke Howard

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

This study evaluated the stability of anthocyanins in six blueberry products (gummy, graham bar, oatmeal bar, rice krispy bar, ice pop and juice) prepared with freeze-dried wild blueberry powder during processing and over eight weeks storage. Total anthocyanins were determined by HPLC before processing and at day 0 and 2, 4, 6, and 8 weeks of storage. Thermal processing of gummy and graham bar products resulted in losses of anthocyanins (50 and 31%, respectively). An eight-week storage time also resulted in a decrease in anthocyanins (7 to 51%) in products stored at ambient temperature. The ice pop, which was stored …

Evaluating Methods Of Obtaining Male Pheromone From Hymenochirus Sp. Using Analytical Chemistry, Vincent Wing-Kun Leung

University of the Pacific Theses and Dissertations

Male Hymenochirus sp. frogs are known to release pheromone that attracts females of the same species. Four methods for collecting secretions containing pheromone in Hymenochirus sp. were tested: norepinephrine injection, gonadotropin-releasing hormone injection, homogenization of gland tissue, and electrostimulation of the skin over the breeding gland area. The samples collected were analyzed using high-performance liquid chromatography (HPLC) and mass spectrometry. The HPLC chromatograph for the male norepinephrine sample contained a peak at 6.4 min that was not in the female norepinephrine sample HPLC chromatograph. The male norepinephrine sample mass spectrum had a peak of m/z 292.0 not in the female …

Step-By-Step Optimization Of The Hilic Method For Simultaneous Determination Of Abacavir, Lamivudine, And Zidovudine From Dosage Form, Cem Erkmen, Mehmet Gümüştaş, Si̇bel Ayşil Özkan, Bengi̇ Uslu

Turkish Journal of Chemistry

Combined therapy for HIV treatment shows superior efficacy in comparison to single therapy. Furthermore, the separation and determination of the combined dosage forms hold a significant place in the pharmaceutical industry. Not only reverse phase high-performance liquid chromatography (HPLC) but also hydrophilic interaction liquid chromatography (HILIC) can be used for these purposes. Contrary to conventional RP systems, HILIC may be an alternative for the analysis of polar substances. The aim of this study was the step-by-step development of a simple, rapid, and reliable method for the simultaneous determination of antiviral compounds from their marketed formulation (Trizivir). In order to achieve …

Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner

Turkish Journal of Chemistry

A fast and easy method was validated for simultaneous determination of ciprofloxacin hydrochloride monohydrate (CP), levofloxacin hemihydrate (LV), and N-acetylcysteine (NAC) in samples. The analysis was performed on a C$_{18}$ column (250 x 4.6 mm, 5 μm) (Inertsil ODS-3V) using an isocratic elution method with a mobile phase composed of 25 mM KH$_{2}$PO$_{4}$ (pH 3.0) and methanol (72:28, v/v) at a flow rate of 1 mL/min. UV detection was performed at 214 nm for NAC and 293 nm for CP and LV. The method was validated for linearity, accuracy, precision (repeatability and reproducibility), specificity, sensitivity, and stability. The calibration study …