book of abstracts - mount allison university · 2015-03-30 · synthesis and characterization of...

Book of Abstracts Honours Day 2015

Saturday, March 28th

Department of Chemistry & Biochemistry

Speaking Schedule

Time Slot Student Supervisor 9:00 AM OPENING REMARKS Amanda Cockshutt 9:15 AM AW1 Allanach, Jessica R. Cockshutt 9:30 AM AW2 Caron, Hannah R. Westcott 9:45 AM CH1 Kairiss, Michael A. Ghandi 10:00 AM BIOC1 Allen, Garett J. MacCormack 10:15 AM CH2 Scott, Ryan S. Westcott 10:30 AM BREAK 10:45 AM BIOC2 Strong, Kaitlin H. Waller 11:00 AM CH3 Morrissey, Morgan K. Westcott 11:15 AM BIOC3 Pinkham, Ryan Lloyd/MacCormack 11:30 AM CH4 McWhirter, Samantha Meli 11:45 AM – 1:00 PM

LUNCH at the Faculty Club

1:00 PM BIOC4 McQuade, Jacob E. Campbell 1:15 PM CH5 Pettipas, Richard D. Ghandi 1:30 PM BIOC5 Estabrooks, Shelby E. Waller 1:45 PM CH6 Kostelnik, Thomas I. Westcott 2:00 PM CH7 Pickard, Heidi M. Duffy 2:15 PM BREAK 2:30 PM BIOC6 Robart, Tess E. MacCormack 2:45 PM CH8 Gallinger, Jodi R. Ghandi 3:00 PM BIOC7 Reiniger, Jessica E. Waller 3:15 PM CLOSING REMARKS Amanda Cockshutt AW – departmental award winner CH – chemistry student BIOC – biochemistry student

Table of Contents Student Supervisor Page

Allanach, Jessica R. Cockshutt, Amanda 1

Allen, Garett J. P. MacCormack, Tyson J. 4

Caron, Hannah R. Westcott, Stephen A. 2

Estabrooks, Shelby E. Waller, Jeffrey C. 12

Gallinger, Jodi R. Ghandi, Khashayar 16

Kairiss, Michael A. Ghandi, Khashayar 3

Kostelnik, Thomas I. Westcott, Stephen A. 13

MacMillan, John W. S. Ghandi, Khashayar 18

McQuade, Jacob E. Campbell, Douglas A. 10

McWhirter, Samantha M. Meli, M.-Vicki 9

Morrissey, Morgan K. Westcott, Stephen A. 7

Pettipas, Rick Ghandi, Khashayar 11

Pickard, Heidi M. Duffy, Stephen 14

Pinkham, Ryan Lloyd, Vett & MacCormack, Tyson J. 8

Reiniger, Jessica E. Waller, Jeffrey C. 17

Robart, Tess E. MacCormack, Tyson J. 15

Scott, Ryan S. Westcott, Stephen A. 5

Strong, Kaitlin H. Waller, Jeffrey C. 6

1

Confirmation of the Predicted Binding Partners of the Hyperconserved Protein in Prochlorococcus and Synechococcus Using a Bacterial Two-Hybrid System

Jessica R. Allanach and Amanda M. Cockshutt Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

Prochlorococcus and Synechococcus are ancient and abundant picocyanobacteria known to contribute significantly to primary production in marine environments1. Despite massive gene reduction events and genetic divergence between strains of the clade, the Prochlorococcus/Synechococcus Hyperconserved protein (PSHCP) has been retained in perfect conservation at the amino acid level in nearly all picocyanobacteria2,3. However, PSHCP lacks homologs outside this clade and its function remains unknown. Previous experimentation examining the genomic context, expression patterns, biochemical properties and binding partners of PSHCP suggests a possible role in the ribosome and/or photosystem assembly3,4. The aim of the current study is to confirm the potential binding partners of PSHCP ex vivo using a bacterial two-hybrid system to detect protein-protein interactions. The Bacterial Adenylate Cyclase-based Two-Hybrid (BACTH) system used in this study is based on reconstitution of an artificial signal transduction pathway in E. coli that upregulates genes under the control of cyclic AMP (cAMP) as a result of functional complementation between subunits of adenylate cyclase fused to interacting proteins (below)5.

pshcp and genes encoding the potential binding partners RpL2 and PsaD have been successfully amplified from the genome of Prochlorococcus MIT 9313 and subcloned into each of the four BACTH hybrid expression vectors, while gene encoding the third potential partner, Ycf48-like, has been subcloned into one of the expression vectors. The sequences of all thirteen constructed vectors have been confirmed to ensure in-frame expression of the hybrid proteins. Co-transformation of chemically competent cya– E. coli BTH101 with each pair of vectors, followed by incubation on blue/white indicator plates, has revealed an absence of discernable interaction between PSHCP and itself, as well as between PSHCP and photosystem I subunit PsaD. Thus, PSHCP does not appear to form a homodimer or a heterodimer with PsaD under BACTH system conditions. REFERENCES 1. Scanlan, D. J; West, N.J. FEMS Microbiol. Ecol. 2002, 40 (1), 1–12. 2. Dufresne, A.; Garczarek, L.; Partensky, F. Genome Biol. 2005, 6 (2), R14, 3. Zhaxybayeva, O.; Gogarten, J. P.; Doolittle, W. F. FEMS Microbiol. Lett. 2007, 274 (1), 30–34. 4. Whidden, C. E.; DeZeeuw, K. G.; Zorz, J. K.; Joy, A. P.; Barnett, D. A.; Johnson, M. S.; Zhaxybayeva, O.; Cockshutt, A. M. PLoS ONE 2014, 9 (10), e109327. 5. Battesti, A.; Bouveret, E. Methods 2012, 58 (4), 325–334.

2

Synthesis and Characterization of Novel 3,4-Hydroxypyridinato Transition Metal Complexes

Hannah Caron and Stephen A. Westcott Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

Tuberculosis has gained significant attention over the past few years. Despite the fact there are effective treatment plans already established, there has been a rise in tuberculosis incidents. This rise in tuberculosis is even more dramatic in impoverished areas, as well as in patients diagnosed with immunodeficiency diseases, such as AIDS. Additionally, the development of multi-drug resistant strains of tuberculosis further increases the need for a novel, affordable and high efficacy drug.1

This research aims to synthesize new compounds by modifying the structure of isoniazid, a current drug used in the treatment of tuberculosis. A novel 3,4-hydroxypyridinone ligand was synthesized from maltol and isoniazid. The ligand was complexed to various metals including copper, cobalt, nickel and zinc. The compounds were characterized using decomposition points, elemental analysis (compounds 1 and 4), 1H, 13C{1H} NMR (except paramagnetic compounds), UV-Vis and FT-IR spectroscopy. The compounds will be tested for anti-tuberculosis, anti-bacterial and anti-fungal properties.

REFERENCES 1. Ravel, J. P., Shah, A. B., Patel, N. H., Patel, H. V., Patel, P. S., Bhatt, K. K., Desai, K. R. Eur. J. Chem.

2011, 2, 238–242.

3

Breaking Aromaticity of Cyclic Moieties to Synthesize Novel Polymers Michael Kairissa, Zahid Mahimwalla, David Watson,

Felix Baerlocher and Khashayar Ghandia a Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

Polymers are large macromolecules consisting of a number of repeating similar units, known as monomers, bonded together in a long chain (designated ‘p’ in the diagram). Polymers are widely used in industry and are frequently encountered in our daily lives, from the plastics used in our computers to the rubber tires on our vehicles. Diversifying polymers in a way that has negligible environmental impact gives the potential to find novel materials with a wide variety of applications. Thus far, polymer science has excluded aromatic rings as appropriate functional groups for polymerization (see drawing). Here we demonstrate that aromatic rings can in fact be functional groups for polymerization via an energetically undemanding, solvent-free process, revealing a wide range of potentially polymerizable aromatic monomers with an unprecedented number of functionalities and applications. A novel antimicrobial polymer was synthesized and used to make protective coatings and adhesives.

4

Impact of nZnO on the Neural Regulation of the Cardiorespiratory System of White Suckers (Catostomus commersonii) Garett J.P. Allen and Tyson J. MacCormack

Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

Engineered nanomaterials (ENMs) are used in the manufacturing of several marketable products however it is currently unclear if ENMs are significantly toxic. Aquatic environments may act as reservoirs where ENMs released due to pollution and may persist as colloidal suspensions. Zinc oxide nanoparticles (nZnO) are a common additive to sunscreens, cosmetics, and are used in water purification making them a prime candidate for studying aquatic toxicity.1, 3 Previous research in the MacCormack lab has found that nZnO cause bradycardia in white suckers (Catostomus commersonii)1. Bradycardia is a characteristic symptom of hypoxic stress and is induced when O2 chemoreceptors along the first gill arch stimulate the vagus nerve to release acetylcholine at the sinoatrial node of the heart.1, 4 Chronic hypoxic stress in fish may lead to increased predation, reduced ability to catch prey, metabolic depression, and behavioral shifts.4,5

We propose that the white suckers undergo pseudo-hypoxic stress upon exposure to nZnO due to interaction of nZnO with O2 chemoreceptors and/or oxidative damage to the neuroepithelial cells.1, 3,6 This study aims to provide evidence that nZnO induces a hypoxic stress response (bradycardia, hyperventilation, continuous breathing) and explores the potential formation of protein coronae which may inhibit acetylcholinesterase.2 REFERENCES 1. Bessemer RA, Butler KMA, Tunnah L, Callaghan NI, Rundle A, Currie S, Dieni CA, MacCormack TJ

(2014) Nanotoxicology. In-press. DOI: 10.3109/17435390.2014.982737 2. Dieni CA, Stone CJL, Armstrong ML, Callaghan NI, MacCormack TJ (2013) J Nanomater Mol

Nanotechnol. 2:6–17. 3. Song W, Zhang J, Guo J, Zhang J, Ding F, Li L, Sun Z (2010) 199(3):389–97. 4. Taylor EW, Leite CAC, Florindo LH, Belao T, Rantin FT (2009) J Exp Biol. 212:906–13. 5. Wu RSS, Zhou BS, Randall DJ, Woo NYS, Lam PKS (2003) Environ. Sci. Technol. 37:1137–41. 6. Xiong D, Fang T, Yu L, Sima X, Zhu W (2011) Science of the Total Environment. 409(8):1444–52.

5

Synthesis and Characterization of Novel Boron-Containing Thiosemicarbazones Ryan S. Scott and Stephen A. Westcott


To further explore the antifungal activity of boron–containing thiosemicarbazones first reported by Hicks et al.,1 four novel compounds were synthesized. The syntheses of thiosemicarbazones 1 and 2 were achieved by the formic acid catalyzed reaction of 4-ethyl-3-thiosemicarbazide and formylphenyl boronic acid derivatives. These thiosemicarbazones were obtained in excellent yields (96% and 95%, respectively) and were characterized by 1H, 11B{1H}, and 13C{1H} NMR spectroscopy, ATR-FTIR spectroscopy, and melting point. The diazaborine 3 was synthesized (71% yield) by the formic acid catalyzed reaction of 4-ethyl-3-thiosemicarbazide and 2-formylphenyl boronic acid. This compound was characterized using the same methods as 1 and 2. Finally, the copper bis(thiosemicarbazone) complex 4 was synthesized by reacting copper (II) acetate monohydrate with thiosemicarbazone 1 (37% yield). This complex was characterized by melting point and ATR-FTIR spectroscopy. Synthesis of a second copper bis(thiosemicarbazone) complex was attempted using copper (II) acetate monohydrate and thiosemicarbazone 2 but was unsuccessful. In the future, these compounds will be characterized further by elemental analysis and X-ray crystallography, and undergo biological testing for antifungal activity.

REFERENCES 1. Hicks, J. W.; Kyle, C. B.; Vogels, C. M.; Wheaton, S. L.; Baerlocher, F. J.; Decken, A.; Westcott, S. A.

Chem. Biodiv. 2008, 5, 2415.

NH

NH

NH2

S

(HO)2B

OH

H2O / cat. [H+]

/ 2 h

HN

HN N

S

B(OH)21 4-B(OH)22 3-B(OH)2

6

Purification of Methylthioxybutyrate Reductase from the DMSP-Producing Algae Ulva intestinalis

Kaitlin H. Strong and Jeffrey C. Waller Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

Dimethylsulfoniopropionate (DMSP) is a metabolite produced by algae that protects them from environmental stressors1. DMSP breakdown to dimethylsulfide is a significant source of atmospheric sulfur, which participates in cloud formation2. Therefore DMSP metabolism is important for algae and the climate. DMSP is produced through a four-step enzymatic pathway beginning with methionine. Methylthioxybutyrate (MTOB) reductase converts MTOB to methylthiohydroxybutyrate (MTHB) using NADPH as reductant for the second step of the DMSP pathway2. MTOB reductase is known to be a reversible reaction, although there has not been much research done on the characterization of the DMSP synthesis enzymes in algae.

Spectrofluorometric enzyme assays have been used successfully to measure the activity of methionine aminotransferase, the first enzyme in the pathway, using a diaphorase and resazurin coupled enzyme assay. This method was used with the addition of the substrates NADP+ and MTHB to assay MTOB reductase of Ulva intestinalis in the reverse reaction. This method was used to determine the ideal enzyme extraction conditions by testing different extraction buffer components, metals, and protease inhibitors. The ideal extraction condition was determined to be TRIS-HCl (pH 8.5), AEBSF, Leupeptin, E-64 and benzamidine. The spectrofluorometric plate assays was not sensitive enough to measure MTOB reductase activity in ammonium sulfate precipitation fractions.

A high performance liquid chromatography method was then used to assay the forward reaction with fluorescence detection after derivatization of MTOB’s carboxylic acid with 9-chloromethylanthracene3. This method was effective at detecting the production of MTHB. The MTHB produced from a 60-minute assay of salt shocked algae was much lower than expected. Ammonium sulfate fractionation was again tested with MTHB only being produced in the 30 to 45% fraction. This method can be used to continue the purification of MTOB reductase using column chromatography methods such as ion exchange, cofactor-affinity, and gel filtration (Sephacryl S-300). The purified protein can then be characterized for metal dependency, native molecular weight, and number of isoforms. This will help direct investigation of Ulva bioinformatic databases so the MTOB reductase gene(s) can be cloned and characterized. REFERENCES 1. Summers PS, et al. Plant Physiol. 1998. 116: 369–378. 2. Yoch DC. Appl Environ Microbiol. 2002. 68:5804–5815. 3. Xie Z, et al. J Chromatogr Sci. 2012. 50(6):464–8.

7

Synthesis and Characterization of Novel Isonicotinohydrazide Derivatives Morgan K. Morrissey and Stephen A. Westcott


Tuberculosis has newfound attention due to the worrisome impact it has worldwide. Although there are known effective treatment plans, there has been a resurgence in tuberculosis in crowded and impoverished areas. Furthermore, the emergence of multi-drug resistant strains is a growing concern for patients and scientists alike. Multi-drug resistance is a result of the discontinued use of drugs, which is due to the current lengthy and expensive treatment plans. Thus, a novel and efficient drug is desired.

This research combines the knowledge of isoniazid as a powerful first-line anti-tuberculosis drugs, the potential medicinal uses of boron groups, and the biological activities of thiophene and furan compounds to synthesize novel compounds that will be tested for anti-tuberculosis properties. All of the novel compounds were characterized via the use of melting and decomposition points, FT-IR spectroscopy, and NMR spectroscopy.

REFERENCES 1. Parumasivam, T.; Shivashekaregowda, H.; Kumar, N.; Ibrahim, P.; Sadikun, A. J. Pharm. Res. 2013, 7,

313–317. 2. Nielsen, F. J. Trace Elem. Med. Biol. 2014, 28, 1–5. 3. Hou, M.; Erikkson, E.; Svechnikov, K.; Jahnukainen, K.; Soder, O.; Meinhardt, A.; Savendahl, L. Molec.

Cancer 2014, 13, 155.

8

The Effects of Novel HDAC Inhibitors on Viability and Expression in Human Breast Cancer Cells

Ryan M. Pinkhama, Tyson J. MacCormacka, Adrian S. Culfb and Vett K. Lloydc a Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-Mail: [email protected]) b Atlantic Cancer Research Institute, Moncton, NB E1C 8X3, Canada (E-mail: [email protected]) c Mount Allison University, Department of Biology, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

Many forms of cancer are characterized by an increase in histone deacetylase (HDAC) activity. HDACs are responsible for the posttranslational acetylation of many proteins involved in cell cycle control, growth and regulation. In this study, novel HDAC inhibitors were designed by the Atlantic cancer research institute and tested for their efficacy at inhibiting HDAC proteins in vitro, and for their effect on breast cancer cell line mobility and viability.

REFERENCES 1. Bi, G., G. Jiang. 2006. The molecular mechanism of HDAC inhibitors in anticancer effects. Cellular

& Molecular Immunology. 3:285–290. 2. Kornberg, R.D., Y. Lorch. 1999. Twenty-five years of the nucleosome, fundamental particle of the

eukaryote chromosome. Cell. 98:285–294. 3. Witt, O., H. Deubzer, T. Milde, I. Oehme.. 2009. HDAC family: What are the cancer relevant targets?

Cancer Letters. 227:8–21.

9

Determining the Mixing Mechanism of Gold Nanoparticles with Hydrocarbon Oils Samantha McWhirter and M.-Vicki Meli


Interactions between gold nanoparticles (AuNPs) and various substances are of great interest because they are not yet well understood, and can have implications on various nanotechnologies such as nanopatterning and nanocomposite mixtures. Previous studies1 have revealed unexpected conditions that promoted mixing between gold nanoparticles (with alkanethiol ligand shells) and n-alkanes. In particular, conditions promoting an ordered NP ligand shell mixed with longer n-alkane chains would exhibit novel liquid phase film behaviour at the air-water interface. This study aimed to distinguish between two proposed mixing mechanisms: interdigitation (alkane molecules penetrating between alkanethiols of the ligand shell); and void filling (alkane molecules penetrating the ligand shell at voids between facets of the nanoparticle). The results of a multi-faceted experimental approach, including surface enhanced Raman spectroscopy, chain length (mis)match, and hydrocarbon structure changes, will be presented. It was found that the interdigitation mechanism is likely the dominant interaction in the mixing of AuNPs and hydrocarbon oils.

REFERENCES 1. Gagnon, B. P. and Meli, M.-V. Langmuir 2014, 30(1), 179−185.

10

Using Fast Repetition Rate Fluorescence to Estimate Active Photosystem II Content in Marine Prochlorococcus and Synechococcus

Jacob E. McQuade and Douglas A. Campbell Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

As primary producers, cyanobacteria like Prochlorococcus and Synechococcus have a profound affect on marine ecosystems, but are threatened by the uncertainty associated with climate change1. While cyanobacteria can adapt to environmental stresses by manipulating levels of active photosystem II (PSIIa), it is a metabolically costly response2. The aim of this study is to model the relationship between PSIIa and Fo/σPSII in hopes of developing a more convenient method of assessing photosystem II content in Prochlorococcus and Synechococcus. Using flash repetition rate fluorescence (FRRF) it was found that Fo/σPSII could be used to estimate PSIIa in Prochlorococcus (R2 = 0.89)

and Synechococcus (R2 = 0.59) cultures. The model suggests a relationship does exist between PSIIa and Fo/σPSII but it was found to be heavily influenced by density, especially in Synechococcus cultures. Researchers should consider the feasibility of using Fo/σPSII to estimate PSIIa given the importance of monitoring cyanobacteria health, and their affect on marine ecosystems.

REFERENCES 1) Flombaum, P., Gallegos, J. L., Gordillo, R. A. et al. Proc. Natl Acad. Sci. USA, 2013, 110, 9824–9829. 2) Mella-Flores, D., Six, C., Ratin, M., Partensky, F., Boutte, C., Le Corguillè, G., Blot, N., Gourvil, P., Kolowrat, C., Garczarek, L., and Marie, D., Front. Microbiol. 2012, 3, 285.

11

Visible Light Absorbing Protic Ionic Liquids Rick Pettipas, Zahid Mahimwalla, Andrew Grant and Khashayar Ghandi


This presentation describes the synthesis of novel protic ionic liquids capable of absorbing light that reaches Earth’s surface in the 400–500 nm region. Light absorption in this region could allow this material to be used as a pH indicating solvent or electrolyte/dye hybrid for solar cell applications. Protic ionic liquids have previously been used as electrolytes in batteries, solar cells and hydrogen fuel cells as well as solvents for synthesis and catalysis. This presentation features a discussion on the effects that steric interactions can have on physical properties such as ion conductivity, viscosity and melting point of protic ionic liquids.

12

Investigation of Chlorophyte Methylthiooxybutyrate Reductases Shelby E. Estabrooks and Jeffrey C. Waller

Mount Allison University, Department of Chemistry & Biochemistry, Sackville NB, Canada, E4L 1G8 (E-mail: [email protected])

Dimethylsulfoniopropionate (DMSP) is an osmoprotectant1,2 produced by algae to protect against environmental stressors such as high salinity3, low nitrogen, and oxidative stress caused by UV radiation4,5. DMSP can also be broken down to dimethylsulfide (DMS), which is a large source of atmospheric sulfur5. Atmospheric DMS is involved in the formation of solar reflecting clouds and therefore has a critical role in climate regulation5. DMSP synthesis in algae is derived from methionine using a four-step enzymatic pathway1,2. Methylthiooxybutyrate (MTOB) reductase is the second enzyme in the pathway. MTOB reductase is NADPH-dependent and uses this cofactor to reduce MTOB to D-methylthiohydroxybutyrate (D-MTHB)2. There is currently no known MTOB reductase from any species as it has never been purified or cloned. The aim of this research is to determine the gene that encodes MTOB reductase, which needs to be identified to further understand DMSP synthesis.

The objectives of this research project were to 1) produce recombinant diaphorase enzyme and chemically synthesize D-MTHB for a coupled enzyme reaction utilizing the MTOB reductase reverse reaction, 2) investigate the MTOB reductase gene candidates from Ulva linza transcriptome and U. rigida genome databases for gene synthesis, and 3) use an activity screen to search an U. intestinalis cDNA library for gene candidates. The recombinant diaphorase enzyme was assayed by measuring the decrease in absorbance of the redox sensitive 2,6-dichlorophenolindophenol (DCPIP) dye when reduced by NADH. The resulting activity was 25 µmol DCPIP reduced/min/mg protein. D-MTHB was synthesized from D-methionine by reaction with nitrous acid with a yield of D-MTHB of 2.7%. U. linza and U. rigida MTOB reductase gene candidates were investigated using bioinformatic analysis, specifically to see if they occur in other chlorophyte DMSP-producing species and their level of conservation at the amino acid sequence level. The U. intestinalis cDNA library was screened by MTOB reductase activity assayed in the forward direction by high performance liquid chromatography (HPLC). There was some background activity seen in the “empty” bacterial cells in which the cDNA library was transformed into, but this activity was outcompeted by other substrates. Of the six pools of recombinant protein collected from the cells transformed with the cDNA library, one pool showed activity that could not be outcompeted by these substrates, indicating potential MTOB reductase gene candidates in the cDNA library. REFERENCES 1. Gage, D.A.; Rhodes, D.; Nolte, K.D.; Hicks, W.A.; Leustek, T.; Cooper, A.J.; Hanson, A.D. Nature.

1997, 387, 891–894. 2. Summers, P.S.; Nolte, K.D.; Cooper, A.J.; Borgeas, H.; Leustek, T.; Rhodes, D.; Hanson, A.D. Plant

Physiol. 1998, 116, 369–378. 3. Dickson, D.M.; Wyn Jones, R.G.; Davenport, J. Planta. 1980, 150, 158–165. 4. Sunda, W.; Kieber, D.J.; Kiene, R.P.; Huntsman, S. Nature. 2002, 418, 317–320. 5. Sunda, W.; Hardison, R.; Kiene, R.P.; Bucciarelli, E.; Harada, H. Aquat. Sci. 2007, 69, 341–351.

13

Synthesis of Novel Boron-Containing Isoniazid Derivatives Thomas I. Kostelnik and Stephen A. Westcott


The functionalization of isoniazid with boron was attempted utilizing boronic acid- or boronate ester-containing benzaldehyde derivatives. Initially, the prior was the primary goal of this research, however the insufficient solubility of boronic acid led to the use of boronate esters. Five novel Schiff bases were synthesized and isolated through the addition of isoniazid to boron-functionalized benzaldehyde derivatives. Methods were adapted from the work of Charkoudian et al.1 and Tajudeen and Kannappan.2 Our compounds were characterized by melting point, 1H, 13C, 11B NMR spectroscopy and FT-IR (ATR) spectroscopy. Upon further purification, compounds will be sent off for biological testing.

REFERENCES 1. Charkoudian, L. K.; Dentchev, T.; Lukinova, N.; Wolkow, N.; Dunaief, J. L.; Franz, K. J. J. Inorg.

Biochem. 2008, 102, 2130–2135. 2. Tajudeen, S.; Kannappan, G. J. Pharm. Res. 2013, 7, 534–539.

N

HN

NH2O

O

N

HN

NO

-H2O

R

R

R = B(OH)2, BO2C6H12

14

The Partitioning and Mobility of Endosulfan in Soil and Soil Organic Matter Heidi M. Pickard and Stephen Duffy


Endosulfan persists in the environment today due to our previous practices. Therefore it is important to investigate how this molecule continues to interact with the environment over time. It is a globally banned organochlorine insecticide that is moderately volatile in air and has a low solubility in water.1

I used a variety of analytical techniques to analyze and examine how endosulfan interacts with soil and more specifically, soil organic matter in terms of partitioning and mobility. For the partitioning experiments, six series of five samples each comprised of soil or soil organic matter were prepared in contact with air and then water. Varying amounts of endosulfan were added to each of these samples. In total, thirty samples were analyzed repeatedly over time using SPME followed by GC-MS. For the mobility investigation I used two garden soil columns and two columns containing soil organic matter. These were treated with endosulfan over a period of 9 weeks and then various layers were extracted using soxhlets and analyzed on the GC-MS.

From my results, I determined that the partitioning of endosulfan in soil and soil organic matter generally increases towards the soil and soil organic phase over time. The greatest Log KOA value was calculated as 5.10 and the greatest Log KOW value was 5.20, both for organic soil in air and water respectively. I also found that the trend of partitioning followed the order of organic soil > humic acid > garden (inorganic) soil. My mobility analysis results suggested that endosulfan is not very mobile. I found no evidence to indicate that it migrated in the columns under the conditions we used. REFERENCES

1. Weber, J.; Halsall, C.J.; Muir, D.; Teixeira, C.; Small, J.; Solomon, K.; Hermanson, M.; Hung, H.; Bidleman, T. Sci. Total Environ. 2010, 408, 2966–2984.

15

The Effects of Zinc Oxide Nanoparticle Exposure on Maximum Metabolic Rate and Gill Physiology in Catostomus commersonii

Tess E. Robart and Tyson J. MacCormack Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

The accumulation of reactive nanoparticles in aquatic environments presents unknown risks. Zinc oxide nanoparticles (nZnO) have high potential of being released directly into marine environments through waste from various cosmetic, anti-bacterial, anti-fungal, catalytic, and industrial applications. Studies of acute nZnO exposure on Catostomus commersonii (white suckers) reflect indication of oxidative stress in gill tissue, and adversely a decrease in heart rate. This study examines the individual and interactive effects of 1mg/L nZnO acute exposure and hypoxia on the metabolism and gill physiology of white suckers from Silver Lake, NB, using respirometry and scanning electron microscopy (SEM). As the gill is the major organ with the largest surface area of all fish organs responsible for aerobic respiration, any effect of nZnO on gill tissue may have an overall impact on the whole-organism response to aerobic stress. Based on similar studies with white suckers, reflecting a decrease in overall metabolic rate, it was hypothesized that nZnO exposure would lead to a decrease in both aerobic scope and critical oxygen saturation, in response to hypoxic stress. Measurements were taken to examine aerobic scope by comparing maximal and basal metabolic rates (MMR), critical oxygen saturation (Pcrit) under hypoxia, and gill physiology using scanning electron microscopy. Both maximal and basal metabolic rates of the nanoparticle treatment group depict a non-significant, but consistent decrease in rate of oxygen consumption when compared to untreated fish. Treated fish had an average maximal aerobic metabolic rate of 421.32 mg O2/kg/hour while control fish had an average maximal rate of 505.23 mg O2/kg/hour. Critical oxygen saturation measures following nZnO exposure led to a non-significant decrease in Pcrit of treatment fish, which indicates that zinc oxide nanoparticles do not affect hypoxia tolerance. Acute nZnO exposure resulted in an average Pcrit value of 8.10 kPa in fish, while control fish had a Pcrit value of 7.28 kPa. Scanning electron images (SEM) of gill arch tissue indicate possible damage by nZnO through the introduction of concave formations resembling apical-pits on the surface of the gill epithelium. The SEM data gathered from this study indicates that exposure to nZnO may induce physiological change to gill tissue. Further investigation is needed to examine the precise mechanism of nanoparticle action.

REFERENCES 1. Speers-Roesch, B., Richards J. G., Brauner C. J., Farrell A. P., Hickey, A. J. R., Wang, Y. S., Renshaw G. M. C. Journal of Experimental Biology. 2011, 215, 93–102. 2. Sharma, V.; Singh, P.; Pandey, A. K.; & Dhawan, A. Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 2012, 745(1): 84–91. 3. Fernandez, D.; Garcia-Gomez, C.; Babin, M. Science of the Total Environment. 2013, 452, 262–274. 4. Smijs, T. G.; Pavel, S. Nanotechnology Science and Applications. 2011, 4, 95–112.

16

Making the Impossible Possible and the Synthesis of Novel Antimicrobial Natural Polymers

Jodi R. Gallingera, Zahid Mahimwalla,a Felix J. Baerlocherb and Khashayer Ghandia

a Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected], [email protected]) b Mount Allison University, Department of Biology, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

The development of antimicrobial resistance has had huge health impacts worldwide and has resulted in people dying from illnesses that had once been treated with simple antibiotics.1 One way of combatting antimicrobial resistance is the development of antimicrobial polymers.2 Polymers are large macromolecules that consist of a small, repeating unit which is called a monomer. The aim of this work was to attempt the polymerization of known natural antimicrobial compounds and to test the polymer for retained or increased antimicrobial activity. A major class of natural molecules with antimicrobial properties is terpenes, of which a subclass is acyclic monoterpenoids (AMs). AMs have a carbon skeleton as in Figure 1 and also contain at least one double bond and one oxygen group. Members of this class such as linalool (Figure 1) were successfully homopolymerized to low molecular weight polymers despite previous claims in the literature that AMs do not undergo homopolymerization.3–5 The antimicrobial activity of the polymer was also tested and was determined to be improved or approximately the same for a variety of bacteria and fungi. REFERENCES (1) Laxminarayan, R.; Duse, A.; Wattal, C.; Zaidi, A. K. M.; Wertheim, H. F. L.; Sumpradit, N.;

Vlieghe, E.; Hara, G. L.; Gould, I. M.; Goossens, H.; Greko, C.; So, A. D.; Bigdeli, M.; Tomson, G.; Woodhouse, W.; Ombaka, E.; Peralta, A. Q.; Qamar, F. N.; Mir, F.; Kariuki, S.; Bhutta, Z. a; Coates, A.; Bergstrom, R.; Wright, G. D.; Brown, E. D.; Cars, O. Lancet Infect. Dis. 2013, 13, 1057–1098.

(2) Kenawy, E.-R.; Worley, S. D.; Broughton, R. Biomacromolecules 2007, 8, 1359–1384. (3) Shukla, A.; Srivastava, A. K. J. Appl. Polym. Sci. 2004, 92, 1134–1143. (4) Shukla, A.; Srivastava, a. K. J. Macromol. Sci. Part A 2003, 40, 61–80. (5) Shukla, A.; Srivastava, A. K. Polym. Adv. Technol. 2004, 15, 445–452.

Figure 1. Carbon skeleton of AMs and the structure of the AM_ linalool.

17

Development of a Bacterial Osmotolerance Complement Assay for MTHB Methyltransferase Candidate Screening

Jessica E. Reiniger and Jeffrey C. Waller Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail: [email protected])

Dimethylsulfoniopropionate (DMSP) is a highly abundant sulfurous compound synthesised by various algae, phytoplankton and halophilic plants. Great environmental significance has been attributed to both DMSP and its catabolite dimethylsulfide (DMS), in contributing to global sulfur cycling, cloud condensation and global cooling.1 Furthermore, diverse physiological functions have been suggested for DMSP, focusing on stress adaptation, in cryoprotection, hydroxyl radical scavenging, deterring herbivory and osmoprotection.2 In particular both DMSP and dimethylsulfoniohydroxybutyrate (DMSHB) are classified as compatible osmolytes due to their zwitterionic structure and ability to equalize cellular volume offering protection to protein and cytoplasmic structure under dehydrating conditions.2

Within algae radiotracer analysis has elucidated four biosynthetic steps originating from the amino acid methionine.1 The third reaction in this pathway, catalysed by an S-adenosylmethionine dependent S-methyltransferase, converts methylthiohydroxybutyrate (MTHB) to DMSHB. This is the first irreversible and therefore pathway determinant reaction in DMSP synthesis.1 To identify the gene encoding this methyltransferase, DMSHB's long standing association with osmotolerance was exploited. Using K12 Keio collection Escherichia coli BW25113 single gene mutants3 and P1vir bacteriophage lysate transduction a double mutant was constructed (Ec MG1655ΔotsAΔbetA::kan) deficient in trehalose and glycine betaine compatible osmolytes. These mutations were confirmed with flanking region and gene specific primer PCR, and Sanger sequencing. The osmosensitive strain was then used to define complement assay conditions using M63 minimal media with selective inclusion of MTHB, dithiothreitol (DTT) and NaCl. In control trials MTHB did not affect wild type or mutant growth. DMSP inclusion, while producing a negligible effect in unstressed conditions or with wild type strains, produced pronounced growth rate improvement in the mutant under salt stress, visible by 22 hours.

Using the designed complement assay, an existing Ulva intestinalis cDNA library5 was used to transform the osmosensitive mutant and screen for potential MTHB methyltransferase candidates. This system has been successful in producing growth phenotype selectivity and identified colonies are currently undergoing further plasmid restriction digest analysis. This complement assay may be further adapted in the future to identify candidates for the final DMSHB oxidase due to the heightened osmoprotection offered by DMSP relative to DMSHB. REFERENCES 1. Summers, P.S.; Nolte, K.D.; Cooper, A.J.L.; Borgeas, H.; Leustek, T.; Rhodes, D.; Hanson, A.D. Plant

Physiol. 1998 116, 369–378. 2. Sunda, W.; Kieber, D.J.; Kiene, R.P.; Huntsman, S. Nature. 2002, 418, 317–320. 3. Gao, Y.; Schfield, O.M.E.; Leustek, T. Plant Physiol. 2000, 123, 1087–1097.

Figure 1-Reaction catalysed by MTHB S-methyl-transferase

18

Free Radical and Radiation Chemistry of Boron Compounds John W. S. MacMillan, Paul W. Shaver, Yanggang Chen, Zahid Mahimwalla,

Stephen A. Westcott and Khashayar Ghandi Mount Allison University, Department of Chemistry & Biochemistry, Sackville, NB E4L 1G8, Canada (E-mail:[email protected])

Boron compounds have many known applications, including in neutron capture therapy,1 nuclear energy,2 and organic synthesis,3 but knowledge of their fundamental reactivity is currently limited. In this study, the fundamental reactivity of boron compounds with B-B bonds was examined through their reactions with muonium, a light radioisotope of the H atom. These reactions were performed using a cyclotron at the TRIUMF facility in Vancouver. Muonium was found to undergo radical addition at boron sites. In the presence of an aromatic ring in these compounds, muonium also added to the carbon atoms in this ring. Finally, in the absence of double bonds, it reacted at the centre of the two B atoms; to our knowledge, this is the first observation of this type of reactivity of boron compounds. The presence of aromatic rings was observed to promote radical addition to the boron atoms, and to lengthen the lifetime of the product of this addition; comparison between the boron compounds and an approximate carbon analogue revealed that the boron atoms promoted radical addition to aromatic sites closer to these atoms. REFERENCES 1. Barth, R. F.; Vicente, M. G. H.; Harling, O. K.; Kiger, W. S. III; Riley, K. J.; Binns, P. J.; Wagner, F.

M.; Suzuki, M.; Aihara, T.; Kato, I.; Kawabata, S. Radiat. Oncol. 2012, 7, 146–167. 2. Chickering, R. W.; Yoldas, B. E.; Neuman, B. H. Nuclear waste encapsulation in borosilicate glass by

chemical polymerization. Patent US 4422965 A, December 27, 1983. 3. a) Murphy, J. M.; Tzschucke, C. C.; Hartwig, J. F. Org. Lett. 2007, 9, 757–760. b) Suzuki, A. Angew.

Chem. Int. Ed. 2011, 50, 6722–6737. c) Ishiyama, T.; Murata, M.; Miyaura, N. J. Org. Chem. 1995, 60, 7508–7510.

Please note that this presenter will deliver his Honours seminar on Monday, April 6th at 11:30 AM in the

L.H. Cragg Resource Centre (Barclay 215).

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