Research Project in Chemistry Abstracts (CHEM-4701)

Monday April 8, 2019
Location:  1RC15
Time:  2:30

Abstracts

Synthesis and Physical Property Analysis of Ca3B2GeV2O12Garnet Oxides        (B= Cu, Ni, Mn)

Brooke Richtik, Cole Mauws, Joey Lussier, Megan Rutherford, Kelsey Duncan, Chris Wiebe

Department of Chemistry, The University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada, R3B 2E9

Magnetic materials where lattice symmetries are unable to satisfy spin constraints are broadly known as geometrically frustrated materials.Interest in geometrically frustrated materials has exponentially grown in recent years due to their tendency to display unique and exotic magnetic properties. Geometric frustration can be modeled with garnet oxides. Using standard solid state synthesis techniques, three garnet systems were prepared: Ca3Cu2GeV2O12,Ca3Ni2GeV2O12, and Ca3Mn2GeV2O12. By varying the identity of the B site, the effect of the magnitude of the spin on the physical properties of the system is demonstrated. As the magnitude of the spin increases, the ordering temperature of each system increases. Of particular interest is the copper garnet as it displays lack of magnetic ordering down to 0.35K. The copper(II) spins (S=1/2) within Ca3Cu2GeV2O12 form a body centred cubic lattice.  The copper garnet displays a Weiss temperature of -0.9K indicating frustrated antiferromagnetic order and implies significant J1-J2competition. Powder neutron diffraction was conducted at low temperatures which confirm no long range magnetic ordering.  This places Ca3Cu2GeV2O12as a new spin liquid candidate.

Analysis of Medicinal Compounds from Natural Products: Extraction, Isolation, and Purification of Antimicrobials Released by Bacterial Strain acquired from Compost and Structure Determination of Compound Isolated from SapiumPlant

Fatima AlmiraF. Deuna1, Paul Holloway2and Athar Ata1

1Department of Chemistry, 2Department of Biology,  The University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada, R3B 2E9

In this research, a series of experiments were done to analyze naturally derived compounds for their possible medicinal characteristics. Extraction, isolation, as well as purification of a potential antibiotic from bacteria, as well as determination of the structure of an unknown isolated from the Sapium plant species was performed. XAD7 adsorbent molecules and methanol was used in order to extract bioactive compounds released by the bacteria, then HPLC was performed to separate molecules and isolate one single compound. Structure determination for the unknown acquired from the plant Sapium was done through Nuclear Magnetic Resonance Spectroscopy (NMR). HMBC, HSQC, NOESY, Cosy-45, 1H, and 13C-APT was experiments was conducted on the sample and the signals were analyzed to find a proposed structure. Initial HPLC results successfully separated antimicrobial molecules and only fractions 2, 7, and 8 exhibited antibiotic activity. Further HPLC treatment was able to isolate one peak, hence one molecule, from the crude sample. The peak comes out of the column at 4.706 minutes in an isocratic run of 100% solvent methanol with a flow rate of 1.0mL/min. Further research is necessary in order to find the structure of the possible antibiotic. This could be done through NMR. If the compound is novel, it is a prospect for a new antibiotic and further analysis of its chemical characteristics must be done. Using similar procedures, secondary metabolites can be extracted, isolated, purified and identified in discovery of medicinal compounds that could potentially be used to improve treatment in a variety of diseases.   

Phytochemical Studies on Carissa opaca

Gurleen CheemaSania Izharand Athar Ata

Department of Chemistry, The University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada, R3B 2E9

An understanding of the ethno-pharmacological propertiesplants has led to the discovery of effective drug-like compounds that can be used in clinical practices. The project was designed to isolate and study the phytochemical constituents of the roots of plant Carissa opaca. Our detailed phytochemical studies on methanolic extract of roots of thisplant usingchromatography, 1H-NMR, 13C-NMR, and 2D-NMR spectroscopyafforded three compounds;6-methoxy-7-hydroxycoumarin (Compound A), 7β(H),10β-eudesm-4-en-3-on-11-ol (Compound B), and a flavonoid (Compound C).  Structure of the flavonoid and the antioxidant, antibacterial and anti-enzymatic activities of the compounds are yet to be investigated.

Isolation of an Antimicrobial Agent from Compost Bacteria and Structure Elucidation of a Molecule Isolated from Macaranga capensis

Harjot Sidhu1, Paul Holloway2and Athar Ata1

1Department of Chemistry, 2Department of Biology,  The University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada, R3B 2E9

    Due to an increase in the frequency of isolation of antibiotic resistant bacteria, a need for structurally novel antibiotics has been highlighted. Continuation of the successful treatment of bacterial infections with antibiotics depends on the discovery of novel antibiotics towards which pathogenic bacteria have no defenses. Previously, many bacterial strains were isolated from compost and shown to have antimicrobial activity against either Gram-positive, Gram-negative, or both classes of bacteria. Looking specifically at compost bacterial isolate 204b1, the antimicrobial agent responsible for said activity was extracted and partially purified. The antimicrobial agent was extracted from the fermentation broth using various resin and solvent combinations, with an Amberlite XAD7HP and methanol combination being ideal. Successful extraction of the antimicrobial agent was determined by performing a growth-inhibition disc diffusion assay. The methanol extract of isolate 204b1 had antimicrobial activity against both Gram-positive and Gram-negative bacteria; was specifically tested against common human pathogens. High-pressure liquid chromatography (HPLC) was used to purify the antimicrobial. HPLC was performed using a C18 column and the solvent system was altered from 100 CH3OH to 80 H2O: 20 CH3OH. The parameters used to purify and concentrate the antimicrobial agent were a gradient of 80 H2O: 20 CH3OH to 100 CH3OH for 20 minutes with an additional 10 minutes of isocratic CH3OH. The antimicrobial agent was eluted in the 17.2-22.0 minutes interval. A sufficient quantity has not been isolated for NMR experiments.

Another healthcare concern is the rising incident of type II diabetes mellitus. As such potential α-glucosidase inhibitors were previously isolated from Macaranga capensis. α-glucosidase inhibitors decrease the rate at which glucose is absorbed in the small intestine, thus a sharp increase in blood glucose levels is not seen after a meal. The structure for one particular isolate was elucidated using C13APT, H1 NMR, COSY-45, HMBC, and HSQC. The isolate was identified as 3-acetylaleuritolic acid.

Analysis of Temperature Effects on E. colib Glucuronidase Activity Using Single-Molecule Assays and Capillary Electrophoresis-Induced Luminescence

Jennifer Lischynskiand Doug Craig

Department of Chemistry, The University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada, R3B 2E9

Enzyme kinetics and those factors that influence these characteristics have been critical in understanding the intricate protein structures that preform these thousands of metabolic reactions. An enzyme common in many microbial and mammalian species is β-glucuronidase, an enzyme responsible for the hydrolysis of glucuronide sugar moieties from other biomolecules such as proteins or modified xenobiotics within the human gastrointestinal tract. Further interest has been sparked by the role of bacterial β-glucuronidase in metabolism of drugs leading to damage to the large intestine as well as this enzymes presence among cultures taken from cases of human urinary tract infections. This enzyme has functioned as a marker for the presence of bacterial coliforms within drinking water and bacterial infections due to the vast expression of the enzyme within E.coli species. Understanding the activity of this enzyme as a function of changing conditions was the lead of this study to further develop a sensitive qualitative analysis of β-glucuronidase isolated from samples of E.coli using capillary electrophoresis laser-induced luminescence. The study was used to determine how temperature may affect conformational changes amongst each enzyme molecule and thus how this affects the catalytic rate of each individual enzyme. In this study, a sensitive assay for the presence, quantity, and general activity of the enzyme β-glucuronidase was established. This study determined that as growth temperatures for E.colicells increased, the number of potential conformational isomers of the β-glucuronidase enzyme increased as well. This study showed variation from the traditional enzyme kinetic dogma typically faced in that each individual enzyme molecule possessed a unique catalytic rate which was drastically pronounced upon reaching growth temperatures of 45°C.

Truce-Smiles Rearrangement: The Synthesis of Benzamide Derivatives from Amide Precursors

Rachel Willimand Tabitha Wood

Department of Chemistry, The University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada, R3B 2E9

The Truce-Smiles rearrangement was studied in the synthesis of benzamide derivatives from amide precursors, utilizing directed-ortho metalation, lithium-halogen exchange, and acetyl-enolate anion formation as carbanion formation methods. Microwave-assisted synthesis of the benzamide precursor molecules was explored in comparison to conventional heating methods and the use of cyanuric chloride, as an activating agent for the reaction between carboxylic acid and an amine, was also utilized.

Synthesis of the Dugganite Ba3TeCo3P2O14and its Characterization by X-Ray Diffraction and Heat Capacity Measurements

Robby Renz Abeysinghe, Joey Lussier, Cole Mauws and Chris Wiebe

Department of Chemistry, The University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada, R3B 2E9

 

Polycrystalline Pb3TeCo3P2O14, a reportedly purple-colored dugganite, was synthesized. Another dugganite, Ba3TeCo3P2O14was synthesized to replace the Pb2+in Pb3TeCo3P2O14while retaining the purple color of the compound. Both materials were synthesized through a standard solid state synthesis route, and their structures were characterized using X-ray powder diffraction and Rietveld refinement. Dugganites being a subclass of the langasites, which are known for their magnetic properties, Ba3TeCo3P2O14was further characterized using low temperature magnetic heat capacity measurements. Their diffraction patterns and Rietveld refinement confirmed the structures of the dugganites but Pb3TeCo3P2O14was bright indigo while Ba3TeCo3P2O14was dark purple in color. The heat capacity measurements under zero-field revealed a phase transition, due to antiferromagnetic ordering, occurring at 20.9 K. The temperature at which the anomaly appears decreases as the applied magnetic field increases. Another anomaly appears at a lower temperature at around 11 K under zero-field, and its occurrence at a particular temperature does not follow a trend when the magnitude of the applied magnetic field increases. The nature of this anomaly is unknown in origin.