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Chemistry and chemical engineering.

Chair: Ramaiver Venjatraman, Jackson State University

Vice-chair: Hossain Alamgir, Jackson State University

THURSDAY MORNING

Room 218B

8:50 WELCOME

O3.01

9:00 USE OF COMBINED HPLC-MS TECHNIQUES TO OPTIMIZE PLE REACTION CONDITIONS

Maureen Smith (1), Souvik Banerjee (1), Yongliang Shi (1), Marlen Schmidt (3), Uwe Bornscheur (2), Douglas Masterson (1)

(1) The University of Southern Mississippi, (2) Greifswald University, (3) Enzymicals AG

Enzymes, such as Pig Liver Esterase (PLE), are commonly used in organic synthesis due to their low cost, stability, and ability to hydrolyze a wide range of substrates. PLE is composed of a mixture of at least 6 different isoenzymes, which have recently been isolated. However, the role of each individual isoenzyme in the PLE mixture has not been determined thus far. It has been demonstrated that the addition of organic co-solvents to the aqueous buffer can dramatically alter the enantiomeric excess (ee) of the hydrolysis reaction. While this effect has been studied with crude PLE, it has not been studied with the individual isoenzymes. In this study, compounds (1) and (2) are hydrolyzed while varying the co-solvent content of the buffer and the enzyme used (crude PLE or isoenzyme). The resulting products were then analyzed using a combination of HPLCMS techniques developed in our lab. Using this method, the enantiomeric excess of compound 1 was improved from 23 %ee to 85 %ee with the addition of the appropriate co-solvent. Additionally, compound 1 was hydrolyzed with isoenzyme 1, resulting in an improvement from 85 %ee to 95 %ee with the same co-solvent. Interestingly, addition of co-solvent to several of the isoenzymes (3-6) resulted in a solvent induced inversion of chirality. For example, for isoenzyme 6, the (S)-enantiomer was formed without cosolvent in 53 %ee. Upon addition of co-solvent, the (K)-enantiomer was formed in approximately 58 %ee. These results and the results of the other isoenzymes and co-solvents will be discussed.

O3.02

9:30 A METHODOLOGY FOR

SYNTHESIZING NUMEROUS UNNATURAL LYSINE ANALOGUES FROM A COMMON OPTICALLY PURE SYNTHON

Souvik Banerjee, Maureen Smith, Douglas Masterson

The University of Southern Mississippi

Our goal is to synthesize enantiomerically enriched [alpha]-methyl lysine analogues from a common synthon. Enzymatic hydrolysis (using PLE) of achiral compound diethyl-2-methyl-2-((1, 3-dioxoisoindoline-2-yl) methyl) malonate (phthalimido protected [alpha]-methyllysine diester) gives us 2-(ethoxycarbonyl)-2-((1, 3-dioxoisoindolin-2-yl) methyl) Propanoic acid (phthalimido protected [alpha]-methyllysine halfester) with high optical purity. Our synthetic strategy allows us to vary the "R" group of lysine from 1-5 methylene units and backbone of lysine as well from "[alpha]" to "[beta]" to "[gamma]", from the same common synthon. We have been able to get high optical purity in case of enzymatic hydrolysis of [alpha]-methyllysinediesters with 2, 3 and 4 methylene group in the side chain. Out of them 1, 3 and 4 Carbon lysine half-esters are predominantly with "R" enantiomers. We have also been able to obtain highly enantimerically enriched (ee 93%) t-Boc-Fmoc protected [alpha]-methyl-[alpha]-Lysine and hetero nuclear protected [alpha]-methyl-[beta]-Lysine ester from the same common synthetic intermediate. Our research strategy will be discussed in detail.

O3.03

10:00 DETECTION OF NANOPARTICLE STABILITY: FRACTINATION OF CADMIUM AND CADMIUM SELENIDE NANOPARTICLES IN ANIMALS TISSUES

Zikri Arslan, Mehmet Ates, Wanaki McDuffy

Jackson State University

Nanoparticles of CdSe are of serious health concern because of the presence of toxic cadmium. A critical but still an unknown point is the metabolic stability of the CdSe NPs in the body. Unstable NPs release free Cd that accumulates in the liver and kidney with an average half life of 15 years in the body. However, detection of free Cd from tissues is challenging task without decomposing NPs. In this study, we developed a procedure to determine levels of free Cd and CdSe NPs from liver and kidney samples of rats to understand stability in the body. Sprague Dawley rats were exposed to CdSe nanoparticles. The liver and kidney were removed after sacrificing the animals. Organs were solubilized in tetramethyl ammonium hydroxide (TMAH) to extract intact CdSe NPs and free Cd. Nanoparticles decomposed when treated in 1% HCl to produce free Cd, but were stable in 25% TMAH under heat. Extraction of Cd from tissues by TMAH was validated with Dogfish Liver CRM (DOLT-4) and

then applied to the liver and kidney samples from Sprague Dawley rats exposed CdSe NPs. ICP-MS analysis showed that total Cd content was higher in the liver but free Cd was consistently higher in the kidney. This result indicates that CdSe NPs are prone to metabolic degradation to yield free Cd in the body. Higher levels of free Cd in the kidney could be due to preferential accumulation or gradual mobilization of Cd in the liver to the kidney.

10:30 BREAK

O3.04

10:45 NOVEL CHEMOTHERAPEUTIC AGENTS OF VANADIUM(IV) WITH THIOSEMITHIOCARBAZONES AND SCHIFF BASES AS LIGANDS: STRUCTURAL ASPECTS AND IN VITRO STUDIES

Nerissa Lewis (1), Fang Liu (5), Tony Magnusen (1), Travis Erves (1), Faye Arca (1), Floyd Beckford (3), Ramaiyer Venkatraman (2), Antonio Gonzalez Sarrias (4), Liya Li (4), Suman Parajuli (1), Navindra Seeram (4), Aimin Liu (5), William Jarret (1), Wujian Miao (1), Alvin Holder (1)

(1) University of Southern Mississippi, (2) Jackson State University, (3) Lyon College, (4) University of Rhode Island, (5) Georgia State University

A series of novel mixed-ligand vanadium (IV) complexes containing thiosemicarbazones and Schiff bases as ligands were synthesized and characterized. The novel complexes were characterized by elemental analysis, ESI MS, IR, UV-visible, EPR, and [sup.1]H and [sup.13]C NMR spectroscopy, and electrochemistry. [sup.51]V NMR spectroscopy was used to prove that vanadium(V) species were formed in DMSO solutions on standing at room temperature. In vitro studies were carried on three colon cancer cell lines, viz., HTC-116, Caco-2, and HT-29, with a comparative anti-proliferative activity on non-cancerous colonic myofibroblasts, CCD18-Co. All three compounds exhibited less inhibitory effects in human normal CCD-18Co cells, indicating a possible cytotoxic selectivity towards colon cancer cells. In general, those compounds which exhibited anti-proliferative activity on cancer cells but did not affect normal cells may have a potential in chemoprevention.

O3.05

11:15 QUANTIFICATION OF HOMOCYSTEINE BY USING LIGAND DISPLACEMENT METHOD

Xiaoxia Li (1), Dongmao Zhang (1), Siyam Ansar (1)

(1) Mississippi University for Women, (2) Mississippi State University

Organo thiol such as homocysteine, cysteine and glutathione are implicated in a variety of physiological and pathological roles. Current analytical methods for determination of organothiol are dominantly MS and/or HPLC based that involves costly equipment and tedious sample preparation. Using homocysteine (Hcy) as a model organothiol, we have recently developed a novel, UV-vis based method, which we called ligand displacement method (LDM) for label-free quantification of organothiol in solution. With this method, known amount of probe ligand that is mercaptobenzimidazole (MBI) in our experiment, is first mixed with a sample solution containing Hcy, and then the known amount of mixture is added to gold nanoparticle of known concentration. Because of Hcy competes with MBI for the AuNP surface, the concentration of Hcy in solution can be deduced according to amount of reduced MBI adsorption onto AuNP. Current quantification limit is ~3 mM and with a dynamic range up to 60 mM. Compared to existing Hcy detection method, this ligand displacement method is accurate and easy to perform.

THURSDAY AFTERNOON

INVITED SYMPOSIUM

O3.06

1:30 MULTIFUNCTIONAL BRANCHED GOLD NANOSTRUCTURES FOR IMAGING AND THERAPY OF BIOLOGICAL TOXIN

Paresh Ray, Dulal Senapati, Sadia Khan, Wongton Lu, Anant Singh

Jackson State University

Past couple of decades one of the most important goals of nano-science, is the design of materials with tailored shape and size, driven both by the excitement of understanding new science and by the potential hope for applications and economic impacts. Here we will discuss synthesis of different shapes of gold nanoparticles and the mechanisms on how shape control works . We will also discuss our recent reports on the use of antibody and aptamers-conjugated nanotechnology-driven approach using branched shape gold nanoparticle to selectively target and destroy pathogenic bacteria and different cancer cells. The mechanism of selectivity and photothermal lysis will be discussed. Our experimental results will be discussed here open up a new possibility of rapid and reliable diagnosis of pathogen bacteria and cancer cell lines using multifunctional gold nanosystems. Ideally, our nanotechnology based reported assay would have enormous potential for rapid, on-site detection capability to avoid distribution of contamination and it may be the next avenue for exploration.

O3.07

2:30 PHOTOCHEMISTRY AND

PHOTOTOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS

Hongtao Yu

Jackson State University

Polycyclic aromatic hydrocarbons (PAHs) are components of crude oil, and a large quantity of PAHs may have been released into the environment during the Gulf Oil Spill. PAHs can induce mutations and lead to tumor formation via metabolic activation in the body. Photochemically, PAHs can produce reactive species which induce damages to the cellular proteins, DNA, and lipids. The phototoxicity is related to the photochemical reaction of the PAHs and reactive species formed during photolysis, which are determined by the intrinsic PAH structure, solvent used, co-existing chemicals, and light sources. Therefore, identification, characterization, and remediation are of great concern. Photoreaction of PAHs mainly produces oxygenated compounds in aqueous solutions, and the structure of the products depends on the structure of the PAHs, i.e. how the rings are arranged. The phototoxicity of PAHs in skin cells is directly related to its excited state property such as the excited state singlet/triplet energy or the HOMO-LUMO gap. The potency of a PAH to cause light-induced DNA cleavage also depends on the HOMO-LUMO gap as shown in methyl substituted benz[a]anthracenes (MBAs). Light-induced lipid peroxidation by MBAs shows that it does not correlate to the HOMO-LUMO gap as does the light-induced DNA single strand cleavage.

3:30 BREAK

O3.09

3:45 APPLICATIONS OF PHOTOINDUCED NO BOND CLEAVAGE IN NITROGEN ONIUM-SALTS

Wolfgang Kramer, Emily Stewart, Woods Curry, Austin Baker, GeNita Finley, Malika Shettar

Millsaps College

The goal in our lab is the design, synthesis and testing of a photodynamic therapy reagent that does not rely on oxygen in the tissue. All FDA approved photodynamic therapy drugs are singlet oxygen sensitizers which is reducing their efficiency in highly hypoxic tumor tissues. Our approach uses the photofragmentable nitrogen-oxygen bond of a nitrogen onium salt derived from aromatic heterocycles. The photoreaction yields two transient species, an alkoxy radical and an aromatic radical cation. The cleavage efficiency is about 0.6, determined by laser flash photolysis trapping experiments. A new method to monitor the efficiency is the pH control of the irradiation solution. Both of the transient species have been shown to cleave DNA, each with a different mechanism. To increase ground-state with DNA and ultimately DNA cleavage, a known DNA binder, 1,8-naphthalimide was synthetically attached. DNA binding is determined by titrations monitored by UV/VIS, fluorescence and CD spectroscopy. The results are used to optimize the synthesis of further bifunctional nitrogen onium salts. The DNA cleaving efficiency is tested with supercoiled plasmid DNA and gel electrophoresis analysis after irradiation. The results are surprising, because the supposedly photostable Nethyl derivatives are more efficient DNA cleavers in long-term irradiation than the reactive N-methoxy onium salts, which are more efficient at short irradiation times. This project allows undergraduate students an interdisciplinary research experience as they can work on synthesis, photochemistry, photophysics, DNA binding and DNA cleaving subprojects and see the direct impact of their results on the overall outcome.

4:45 CLOSING REMARKS

THURSDAY EVENING

POSTER SESSION

P3.01

THEORETICAL CALCULATION OF THE N-H STRETCH IN AMMONIA

Micah Davis, Ver Geshia Johnson, Joseph Bentley

Delta State University

The potential energy curve for the N-H stretch in the ammonia (NH3) molecule is modeled

by fitting a data set generated by GAUSSIAN. The GAUSSIAN calculation was a restricted Hartree-Fock calculation with a 6-31G(d) basis set. The fitted potential energy curve was compared with the output from GAUSSIAN. Subsequently, the stretching vibrational wavenumbers were calculated using a one-dimensional model with a set of DVR points as a basis set. Additionally, progress is reported on developing a two-dimensional ammonia potential energy surface.

P3.02

PREDICTING CYTOCHROME P450 SITES OF METABOLISM THROUGH 3D MOLECULAR MODELING

Tamera Hughes (1), Pahk Thepchatri (2), Serdar Kurtkaya (2), Edjohnier Phillips (1), Jim Snyder (2)

(1) Tougaloo College, (2) Emory University

Cytochrome P450 (CYP) is a superfamily of powerful detox enzymes. CYPs are capable of catalyzing the metabolism of many organic substances including lipids and steroidal hormones, as well as xenobiotic substances such as drugs and other toxic chemicals. Thus, CYP plays a significant role in the metabolism of therapeutic drugs, thus preventing these compounds from binding to their intended targets. Collectively, the various isoforms of CYP are involved in 90% of drug degradations and, therefore, have garnered significant attention in the pharmaceutical industry. Accordingly, it is important to identify CYP's essential receptor recognition elements and develop methods to predict sites of metabolism for a variety of drug-like scaffolds. This study will focus on the ability of 3D computational docking techniques to identify the etabolism site points of mercaptoimidazole-containing molecules with known experimental metabolic data. Methodology developed from this study will then be applied to other mercaptoimidazole compounds currently under investigation at the Emory Chemistry Department and the Emory Institute for Drug Discovery.

P3.03

DISTRIBUTION OF NANOPARTICLES AND METAL IONS IN ORGANS OF RATS EXPOSED TO CADMIUM SELENIDE NANOPARTICLES

Wanaki McDuffy, Mehmet Ates, Zikri Arslan, Ibrahim Farah

Jackson State University

Cadmium selenide nanoparticles are highly attractive materials for optical probing due to their novel optoelectronic properties. However, exposure to these NPs is concerning since extremely small particles coulbe easily be distributed to entire body through blood. Formation of toxic Cd ions is also an impartant health risk if NPs degrade in the body. In this study, we examined the distribution pattern of CdSe NPs and also probed into the fractions of Cd ions to answer the questions about metabolic stability. Samples collected from Sprague Dawley rats were analyzed for total Cd and free Cd by ICP-MS. Total Cd analysis showed that NPs mainly accumulate in the liver and kidney. To achieve detection of free Cd from the liver and kidney samples, a series of experiments were performed for quantitative extraction of free Cd without affecting intact NPs. Dissolution in tetramethyl ammonium hydroxide (TMAH) under mild heating proved to be the most efficient for extracting Cd into solution from the tissues. Accuracy was verified by analysis of Dogfish Liver Certified Reference Material (DOLT-4). Recoveries for Cd were greater than 90%. Effects of TMAH on stability of CdSe NPs were investigated by treating NP suspensions in TMAH under same conditions. No significant degradation was detected from treated NPs (p

P3.04

UPTAKE AND TOXICITY PATTERNS OF ZINC OXIDE NANOPARTICLES ON ARTEMIA SALINA LARVAE

Mehmet Ates, James Daniels, Zikri Arslan

Jackson State University

Zinc oxide (ZnO) nanoparticles (NPs) are receiving increasing attention due to their widespread applications. However, limited information is available about their effects on biota and aquatic species. In this study, Artemia salina larvae were used to determine toxicity and uptake profile of ZnO NPs of different sizes (10-30 nm and 200 nm). Acute exposure was conducted on A. salina larvae in seawater for a period of 30 h. Larvae were exposed to three different concentrations (100, 500 and 1000 mg/L) of ZnO NPs that were prepared by sonication and suspended in the water. TEM images confirmed that ZnO NPs aggregated to some extent in water to form larger particles as large as 1.0 [micro]M. Up to 100 mg/L, no adverse effects were observed, while both 500 and 1000 mg/L levels exhibited detectable toxicity. Mortality at 100 mg/L was not significant from controls (p<0.05), whereas about 20-23% mortality occurred at 500 and 1000 mg/L levels. Accumulation of NPs within the body was confirmed by phase contrast microscopy. Total ZnO (10-30 nm) NP content was determined by ICP-MS from A. salina, and were 1.55, 1.95 and 2.56 mg/g for 100, 500 and 1000 mg/L ZnO NPs, respectively. On the other hand, total NP content was 1.44, 8.45 and 10.1 mg/g for 100, 500 and 1000 mg/L for 200 nm ZnO NPs, respectively. Data indicated that smaller NPs were accumulated and excreted at similar rates. But larger NPs due to aggregation were difficult to excreted and thus accumulated to greater levels

P3.05

A COMPARISON OF OPTICAL ROTATION ANGLES OF ANIMAL- AND PLANT-DERIVED BIODIESELS

Charles Smithhart, David Clark

Delta State University

It has been known for some time that the optical rotation of fossil petroleum is associated with its degree of geologic maturation (Rosenfeld, Journal of the American Oil Chemist's Society, Vol. 44, 1967). This study compared the optical rotation angles of soybean-derived and animal-derived biodiesels from the National Institute of Standards and Technology (NIST). A statistical comparison of means and variance of optical rotation angles was made between SRMs 2772 and 2773 using data acquired from a Rudolph Research Autopol III automated polarimeter. Correlations of the experimental data with known biodiesel parameters will be discussed.

P3.06

DETERMINATION OF PLASTIC DENSITIES

Joseph Dycus, Kourtney Ayles, Louis Somlai, Alline Somlai

Delta State University

Industries across the world use polymers to create a variety of plastic products. This study attempts to examine both polymer resins and plastic products made from these resins to determine if the processing (injection molding) changes the density of the plastic, specifically resins of linear low density polyethylene, polypropylene, polyvinyl chloride, and polycarbonate. Densities of the plastics were determined using solvent displacement methods. Results from solvent displacement methods were compared to results obtained using gradient density column measurements.

P3.07

DETERMINATION OF CALORIC VALUES OF AGRICULTURAL CROPS AND CROP WASTE BY ADIABATIC BOMB CALORIMETRY

Hugh Broome (1), Subhi Younces (1), Michele Stover (1), Marcus Steele (1), Gretchen Sassenrath (2), Jason Corbitt (2)

(1) William Carey University, (2) Mid-South USDA-ARS Research Center

Calorific values of agricultural crops and their waste were measured by adiabatic bomb calorimetry. Sustainable farming techniques require that all potential sources of revenue be utilized. A wide variety of biomass is beginning to be used as alternative fuels all over the world. The energy potential of low value crops and crop residue has the capacity of making a small farm self sustaining in times of low market value. The caloric value of all portions of the crop product was measured individually to evaluate its potential as an energy source. Rice, corn, soybeans, cotton, wheat, rye, and sweet potatoes were included in this study. All crops were grown and harvested under the care of scientists at the USDA-ARS Research Center in Stoneville, MS. The experimental procedure was based on that used by Nunez-Regueira et al. [Thermochimica Acta Volume 371, Issues 1-2, 26 April 2001, Pages 23-31]. Additional parameters evaluated were moisture content, density, and ash content. The experimental results, with calorific values exceeding 16 kJ [g.sup.-1], make it feasible to use these materials as alternative fuels.

P3.08

SYNTHESIS OF ISOXAZOLINES AND ISOXAZOLES VIA 1, 3-DIPOLAR CYCLOADDITION REACTIONS IN AQUEOUS MEDIA: A GREEN APPROACH

Lenore Holmes, Ashton Hamme

Jackson State University

The current paradigm in organic chemistry is that organic reactions are performed in organic solvents. This premise is based upon the "like dissolves like" concept meaning, in order for a reaction to occur, all of the reactants must react in a homogeneous solution. Though this basis has been successful for many years, most organic solvents are hazardous, toxic and environmentally harmful. Water is the most environmentally benign solvent that can be used as a reaction medium. However, solubility issues that arise between organic compounds and reagents with water make water an unattractive solvent for organic reactions. We investigated the incorporation of water soluble Lewis acids that promote a 1, 3-dipolar cycloaddition reaction between organic molecules in water. Specifically, we have examined the use of metal-containing Lewis acid promoters to bring about the formation of nitrile oxides from the analogous [alpha]-chlorobenzaldoximes. These nitrile oxides were then reacted with alkenes to afford isoxazoline and isoxazole compounds in good isolated yields. We will discuss how Lewis acids affect the reaction rates and yields for the 1, 3-dipolar cycloaddition reaction of our substrates in the universal solvent, water.

P3.09

A NEW MACROCYCLE FOR ANION SENSING

Marcy Pilate (1), Md. Alamgir Hossain (1), Douglas Powell (2)

(1) Jackson State University, (2) University of Oklahoma

In recent years, the field of anion binding has attracted a special interest, since anions play a fundamental role in a wide range of chemical and biological process [1,2] Currently, there are several hazardous anions in the environment, such as sulfate, chloride, and perchlorate which are associated with a number of health related problems. In order to develop selective hosts for anions, we have synthesized a new macrocycle L, from the reaction of isophthalaldehyde and N'-methyl-2, 2'-diaminodiethylamine under high dilution conditions in methanol, followed by diborane reduction. 1H NMR titrations have been performed to study the binding ability of this ligand for various inorganic anions in solution. We have also been successful to isolate chloride and perchlorate complexes of the ligand, which have been analyzed by X-ray crystallography. Detailed solution and solid state binding aspects of the new ligand will be focused in this presentation. Acknowledgements: The project described was supported by Grant Number G12RR013459 from the National Center for Research Resources. This material is based upon work supported by the National Science Foundation under CHE-0821357.

References

(1.) Hossain, M. A. "Inclusion Complexes of Halide Anions with Macrocyclic Receptors" Curr. Org. Chem. 2008, '2('4), 1231-1256.

(2.) Mendy, J. S.; Pilate, M.; Horne, T.; Day, V. W.; Hossain, M. A. "Encapsulation and selective recognition of sulfate anion in an azamacrocycle in water". Chem. Commun. 2010, 2010, 46, 6084-6086.

P3.10

MOLECUAR ENCAPSULATION AND RECOGNITION OF SULFATE ION IN AN AZAMACROCYCLE

John S. Mendy (1), Marcy L. Pilate (1), Toyketa Horne (1), Victor W Day (2), Md. Alamgir Hossain (1)

(1) Jackson State University, (2) University of Kansas

Because sulfate is a key anion in both environment and biology, we have been interested to explore selective receptors for binding of sulfate in both solution and solid states. During our study, we synthesized a new compound and isolated a sulfate complex encapsulated in the macrocycle. [sup.1]HNMR titration studies were performed at pH 2.0 for different halides and ox anions ([I.sup.-] [Cl.sup.-] [Br.sup.-] N[O.sub.3.sup.-] Cl[O.sub.4.sup.-]S[O.sub.4.sup.2-] in water and our results suggest the significant selectivity of sulfate over other anions. Details of the structural aspects and binding properties will be presented in this poster. Acknowledgements: [The project described was supported by Grant Number G12RR013459 from the National Center for Research Resources. This material is based upon work supported by the National Science Foundation under CHE-0821357].

P3.11

SHORT AND LONG TERM IMPACT OF SILVER NANOPARTICLES ON ARTEMIA SALINA LARVAE

James Daniels, Mehmet Ates, Zikri Arslan

Jackson State University

Silver nanoparticles (Ag NPs) exhibit antibacterial activity and cleansing action. These features increased concerns about their deleterious effects on the environment and human health. In this study, Artemia salina larvae were used to test the impact of Ag NPs. Acute and chronic exposures were conducted on A. salina larvae in seawater for a period of 24h and 120h. Larvae were exposed to 10, 50 and 100 ppm concentrations of Ag NPs (20-30 nm). Nanoparticle stability, toxicity and uptake were evaluated. It was found that Ag NPs aggregated in water to form larger particles as large as 300 nm. The magnitude of aggregation increased with increasing NP concentration such that more than 50% of NPs were greater than 30 nm in water. Ag NPs were more toxic to A. salina in the long-term exposure. Short-term mortality rates were 14.5%, 24.5% and 30.5%, and that for long-term were 59%, 94% and 100% for 10, 50 and 100 ppm Ag NPs. Accumulation of NPs within the body was confirmed by phase contrast microscopy that showed visible deformation at 100 ppm level. Total Ag content ranged from 0.60, 1.3 and 1.54 mg/g (10, 50 and 100 ppm) for short-tem exposure and 5.38 and 10.3 mg/g (10 and 50 ppm Ag NP). No measurement was done for 100 ppm level since A. salina culture died. These results showed that Ag NPs are highly toxic to A. salina larvae both under short- and long-term exposure. At higher levels lethal effects become more pronounced.

P3.12

DEFINING THE ROLE OF OXALATE METABOLISM IN ESCHERICHIA COLI

Lauren Gabreski, Jonathan Ebelhar, Cory Toyota

Millsaps College

The Escherichia coli enzymes YfdW and YfdU are an oxalate:formyl-CoA transferase and an oxalyl-CoA decarboxylase, respectively. Coupled, these enzmes catalyze the decarboxylation of oxalate to yield formate. Together with the yhjX gene product, a putative oxalate:formate antiporter, these three proteins are theoretically sufficient to provide E. coli with an oxalate-dependent acid resistance system similar to the well-known AR2 and AR3 glutamate- and arginine-dependent acid resistance systems and/or the ability to metabolize oxalate as a carbon and energy source. Reports have shown that knockdown of YfdW/U results in reduced acid resistance in E. coli and yhjX has also been linked to acid response.

Pathogenic bacteria like enterohemorrhagic E. coli O157:H7 must survive passage through the harsh acid environment of the stomach and so further understanding acid resistance in E. coli has clear health implications. Humans have no innate mechanism for metabolizing oxalate, thus, oxalate-degrading enzymes and microbes are of interest as a possible form of therapy for calcium oxalate stones, the most prevalent form of kidney stone in man. E. coli has never been shown to metabolize oxalate, but if it can be induced to degrade oxalate in the gut, this may offer a possible therapeutic treatment for kidney stones. We investigated the roles that YfdW, YfdU, and YhjX play in E. coli. Specifically, mRNA expression levels were assessed in response to oxalate exposure and survival after acid-shock is monitored to test if E. coli is capable of using oxalate as a metabolite in a new acid resistance mechanism.

P3.13

DECARBOXYLATIVE PHOTOCYCLIZATION OF CATIONIC [omega]-CARBOXYLIC ACIDS

Philip Schwartz, Eli Smith, David Sandlin, Wolfgang Kramer

Millsaps College

The decarboxylative photocyclization has been used to synthesize hetercyclic ring systems allowing several functional groups and ring sizes up to 36 members. The synthetic potential of the reaction is diminished by the incorporation of the phthalimide nitrogen into the product. To expand the versatility of the decarboxylase photocyclization we are using cationic precursors as well as different chromophors. Cationic precursors are not expected to interfere with the cyclization reaction which involves electron transfer from the donor to the exited acceptor. The use of different chromophors will allow the synthesis of multiple target molecules while the cationic chracter might enable us to use chiral auxiliaries. It has been shown that electron transfer fluorescence quenching does take place in quinoline betaines compounds. The synthesis of the precursors as well as the photochemical transformations are discussed.

P3.14

SYNTHESIS AND PHOTOCHEMISTRY OF A LIBRARY OF BIFUNCTIONAL DNA-CLEAVING REAGENTS

Brooke Lassiter, GeNita Finley, Woods Curry, Wolfgang Kramer

Millsaps College

Nitrogen onium salts based on aromatic heterocycles have a potential as photodynamic therapy drugs. The light-induced homolytical nitrogen-oxygen bond cleavage yields a radical cation of the aromatic heterocycle and an alkoxy radical. Both of these transient species are highly reactive and can induce oxidation reactions (radical cation) and radical reactions (alkoxy radical). Both of the species are produced with a quantum yield of about 0.6. Energy wasting steps appear to be the geminate pair recombination to form several isomers of the methoxy substituted aromatic heterocycle. To expand the library of 1,8-naphthalmide linked onium salts we attempt to modify the spacer length as well as the attached aromatic heterocycle. Several synthesis attempts have been made to extend the methylen spacer length. Mitsunobu transformation of alcohols into the phthalimides was interfered by the nucleophilic pyridine nitrogen. Variation of the heterocycle can be accoplished by Friedlaender quinoline synthesis. The precursors were synthesized by Swern oxidation and aniline reduction. After the synthesis, oxidation yielded the heteroaromatic N-oxide which was alkylated by trimethyloxonium tetrafluoroborate to give the photoreactive N-methoxy salt. The isoelectronic, photostable N-ethyl derivative was obtained by direct alkylation of the parent heterocycle. The synthesis and photochemistry of the novel compounds are investigated and discussed.

P3.15

BIFUNCTIONAL DNA-CLEAVING REAGENTS: DNA GROUND STATE ASSOCIATION AND CLEAVAGE

Adi Sabharwal, Lee Wink, Austin Baker, Emily Stewart, Wolfgang Kramer

Millsaps College

The light-induced homolytic nitrogen-oxygen bond cleavage of N-methoxy nitrogen onium salts produces two transient species, each of which has been shown to damage DNA. Each species is reacting with a different mechanism. While the formed radical cation targets the DNA bases, the methoxy radical damages the DNA backbone via hydrogen abstraction. The efficiency of this reaction has been analyized by the determination of the quantum yield of ion formation. Each transient species if produced with a yield of about 0.6, the energy wasting step being geminate pair recombination to yield methoxy-substituted heterocycles. To effectively cleave DNA, a high ground-state association is desired. DNA binding is determined by UV/VIS, fluorescence and CD spectroscopy titrations. Interestingly, the changes in the CD spectrum can give information about the binding mode. The influence of the spacer length and the heterocycle is evaluated and the synthesis of bifunctional onium salts is optimized with those results. In addition, we are discussing several DNA binding models, based on the McGhee/von Hippel model. In vitro DNA cleaving efficiency is determined compared to a known photochemical DNA cleaver by gel electrophoresis with ethidium bromide staining.

P3.16

SIZE DEPENDENT LINEAR AND NON LINEAR OPTICAL PROPERTIES OF NANO MATERIAL

Sadia A. Khan, Anant K. Singh, Paresh C. Ray

Jackson State University

Present interest on size dependent linear and non-linear optical properties of nano material is due to the collective oscillation of the electron in the conduction band which is known as surface Plasmon. When this oscillation matches the incoming electromagnetic radiation there is a huge enhancement of excitation called surface Plasmon resonance. The synthesis of size controlled nano material can be promising for future photonic and optoelectronic devices. The non-linear optical properties of nano material is measured using hyper Rayleigh scattering technique. We have shown that both linear and non-linear optical properties of silver triangle nanoprism is highly size dependent. So by controlling the size of nano structure we can improve the NLO properties of nano material. We have also provided experimental evidence for the sensitivity and selectivity of the NLO Assay in detecting the biological and chemical species.

P3.17

SELECTIVE AMINE HOSTS FOR ANION

Whitney Quinn, Musabbir Saeed, Alamgir Hossain

Jackson State University

Synthesis of amine based host has become an important aim in inorganic chemistry due to its ability to retract health threatening anions. Tren based amine hosts or macrocyclic receptors are able to recognize anions and characterize them by selectively binding to various anions[1]. An anthracene-based amine host was synthesized from the condensation of Tren and with anthra-aldehyde, followed by a sodium borohydride reduction. The compound was characterized and binding studies were performed by [sup.1]H NMR titrations in chloroform. The neutral ligand was protonated from the reaction with p-toluenesulfonic acid giving a triply charged chemosensor that was examined for its anion binding ability toward fluoride, chloride, bromide, sulfate and nitrate by the fluorescence spectroscopy in DMSO. Meanwhile, the complexes of sulfate and perchlorate with Tren were isolated and their structures were determined by X-ray crystal structure analysis. The addition of an anion to the ligand resulted in an enhancement in fluorescence intensity at the excitation of 310 nm. Analysis of the spectral changes suggested that the ligand formed a 1:1 complex with strong affinity for fluoride and sulfate in DMSO. The unsubstituted tren was reacted with sulfuric acid forming a sulfate complex, determined by X-ray crystallography. Analysis of the complex revealed that three sulfates are held between two ligands by hydrogen bonding interactions with protonated amines. These same synthetic processes were performed to synthesize an amine-based macrocycle with similar biological purposes.

Reference:

[1] Hossain, M.A "Inclusion Complexes of Halide Anions with Macrocyclic Receptors" Curr. Org. Chem. 2008, 12(14), 1231-1256.

P3.18

BINDING AND SELECTIVITY ASPECTS OF AN EXPANDED AZAMACROCYCLE FOR ANIONS

Toyketa Horne, Kalpana Dey, Alamgir Hossain

Jackson State University

An expanded azamacrocycle L, containing four secondary and two tertiary amines was synthesized, and its binding ability towards chloride, bromide, iodide, sulfate, nitrate and perchlorate anions were determined by [sup.1]H NMR titrations in [D.sub.2]O at pH 1.7. The results suggest that the ligand is capable of forming a complex with each of the anions examined, showing a selectivity for sulfate in water. Crystal growth formed in perchlorate and iodide complexes. X-ray diffraction analysis of the perchlorate complex of L suggests that the ligand is tetraprotonated and is involved in interacting anions from both sides forming a ditopic complex with strong NH ... O bonds. In the packing diagram, the macracycles and external perchlorates are alternatively linked through hydrogen bonding to form an ID chain.

[Acknowledgements. The project described was supported by Grant Number G12RR013459 from the National Center for Research Resources. This material is based upon work supported by the National Science Foundation under CHE-0821357]

P3.19

EXTRACTION METHODS AND TRANSESTERIFICATION TECHNIQUES ON OIL FROM USED COFFEE GROUNDS FOR USE AS BIOFUEL FEEDSTOCK

Michael McNatt, Kimberly Simmons

William Carey University

Coffee is the second most traded commodity in the world, just behind petroleum. Research estimates show that if the oil from waste coffee grounds from the Starbucks in the U.S. were converted to biodiesel it could amount to 2.9 million gallons of biodiesel a year. If waste coffee grounds from the world's coffee production were used, ~208 million gallons of biodiesel could be produced annually. Biodiesel is often not as economical as petroleum diesel largely due to the production cost of the biofuel crop itself. A low valued biofuel feedstock such as used coffee grounds cuts production costs to be comparable to petroleum diesel. Biodiesels are commonly manufactured by the transesterification of renewable oils, fats and fatty acids. In this work we compare acetone extraction of the oil from used coffee grounds to the standard use of hexane for extraction. We investigate the energy content and makeup of the oil itself and then convert it to biodiesel via transesterifaction with methanol. This last is done comparatively between acid catalyzed and base catalyzed methods, including the novel use of the ion-exchange resin p-toluenesulfonic acid. Typically NaOH or sodium methoxide are the catalysts of choice. Characterization of the oil and its fatty acid ester biofuel product include bomb calorimetry, NMR, IR and UV-vis spectroscopy. Preliminary results show that the efficiency and cost of the oil extraction is better with acetone.

P3.20

MODIFIED CELLULOSE ESTERS

Joel Epler, Robert Lochhead, Samy Madbouly

University of Southern Mississippi

The objective of this project was to cast clear films of cellulose esters from aqueous solutions. The cellulose esters that are currently available have a degree of acetate substitution of 2.5 to 3. These products are soluble in ethanol but they precipitate when 20 weight percent of water is added. Initial attempts to solubilize the polymers using acylglutamate and lecithin surfactants were only partially successful and the film quality deteriorated. A solubility diagram was constructed to identify the range of suitable solvents. Therefore, we have hydrolyzed the polymers to varying degrees of substitution, which we have determined by NMR. Films were cast and their properties measured by rocker hardness test, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis. The interaction of these polymers with carboxylate and sulfate surfactants were measured by constructing plots of surface tension versus surfactant concentration

P3.21

THE DEVELOPMENT OF HIGH THROUGHPUT METHODS FOR THE STUDY OF POLYMER/SURFACTANT INTERACTION; THE EFFECT OF SALT ON THE POLYQUATERNIUM-10/SLES/WATER SYSTEM

Lauren LaBeaud, Kathleen Davis, Lisa Gandolfi, Robert Lochhead

University of Southern Mississippi

Deposition from anionic surfactant systems is frequently achieved by the formation of complex coacervates of cationic polymers and anionic surfactants. Since these coacervates are formed by ionic association, it is expected that the presence of salts would shield the interaction. On the other hand, higher Hofmeister series salts would be expected to be water-structuring and to enhance the association of the hydrophobic moieties of the surfactants. The question posed in this research was "which of these two opposing effects would dominate the overall behavior of the compositions?"

Phase diagrams were constructed for the ternary system of cationic cellulose, sodium lauryl ether sulfate and water. The order of addition produced large changes in the phase behavior of the compositions. These changes could be rationalized by considering the effect of salt on either the micelles or the polymer and on which component was initially exposed to salt by each the order of addition.

P3.22

THE DEVELOPMENT OF HIGH THROUGHPUT METHODS FOR STUDY OF POLYMER/SURFACTANT INTERACTION

Kathleen Davis, Lauren LaBeaud, Lisa Gandolfi, Robert Lochhead

University of Southern Mississippi

Formulators of complex mixtures have long known that the characteristics of their final formulation and the position of "equilibrium" often depends critically upon the order of addition of ingredients and the precise processing conditions under which the formulation was made. Modern formulations require a precision in ingredient selection and processing conditions and the number of possible choices is astronomical. Conventional formulation is severely limited by the number of compositions that can be investigated in a reasonable time. Therefore, it behooves us to seek methods that quickly allow the formulator to scan the compositional and processing landscape for optimum formulations. Phase diagrams were constructed for the ternary system of cationic cellulose, sodium lauryl ether sulfate and water. The order of addition produced large changes in the phase behavior of the compositions. These changes could be explained on the basis of micelle structure and polymer conformation at the time of mixing.

Friday, February 18. 2011

Room 218B

O3.10

9:00 PROFILING UPTAKE AND TOXICITY OF TITANIUM OXIDE NANOPARTICLES ON BRINE SHRIMP

Zikri Arslan, Mehmet Ates

Jackson State University

Titanium oxide (Ti[O.sub.2]) nanoparticles (NPs) are by far the most common nanomaterials used in consumer products that are mainly released to water resources. In this study, Artemia salina larvae were used to test toxicity and uptake of TiO2 NPs (10-30 nm). Acute exposure was conducted on A. salina larvae in seawater for a period of 30 h in the absence of food. Larvae were exposed to three different concentrations (100, 500 and 1000 mg/L) of TiO2 NPs that were prepared by sonication for 3 min and suspended in the water. Nanoparticle stability, toxicity and uptake were evaluated. It was found that TiO2 NPs aggregated substantially in water to form larger particles as large as 2 um. The magnitude of aggregation increased with increasing NP concentration such that more than 50% of the particles were greater than 200 nm (0.2 [micro]m) in water. Suspensions were, however, not toxic to A. salina, even at 1000 mg/L level for which visibility was almost completely lost. Mortality ranged from 8 to 14% which was found to be insignificant (p<0.05). Total TiO2 NP content ranged from 2.15 [+ or -] 0.20 to 7.78 [+ or -] 1.10 mg/g for 100 and 1000 mg/L TiO2 NP, respectively. Uptake remained relatively constant (e.g., saturation) above 500 mg/L. This result suggested that A. salina larvae were unable to excrete all TiO2 NPs accumulated. Though no adverse effects were found from acute exposure, the levels taken up by A. salina suggest that substantial amounts NPs may be transported in marine food chain.

O3.11

9:20 EXPLORATION IN OXOMETALLIC FULLERENES

Mary Mackey, Steven Stevenson

University of Southern Mississippi

Research groups around the world have taken an interest in the synthesis, purification, characterization, and functionalization of the newly discovered Oxometallic Fullerenes (OMFs). These molecules, which consist of a carbon cage containing a metal oxide cluster, are the focus of our current research. In this presentation, we have developed a novel approach for the separation of Metallic Nitride Fullerenes and the enrichment of Oxometallic fullerenes via selective precipitation of fullerenes. We discuss the effect of concentration, reaction time, and precipitating agent in this technique. We will also touch on the role of the solvent in this reaction, as we have discovered that performing these experiments in certain solvents results in adduct formation.

O3.12

9:40

ELECTROCHEMICAL AND SPECTROSCOPI C STUDIES OF BI- AND TETRA-NUCLEAR RUTHENIUM(II) CONTAINING COMPLEXES

LaCrissia Bridges, Suman Parajuli, Nerissa Lewis, Alvin Holder, Wujian Miao

University of Southern Mississippi

Bi- and tetra-nuclear ruthenium(II) containing complexes were synthesized and characterized by elemental analysis, ESI-MS, IR, UV-visible, fluorescence, and [sup.1]H and [sup.13]C NMR spectroscopy. Electrochemical studies of the complexes were carried out in organic solvents at various electrodes, and the electrogenerated chemiluminescent (ECL) investigations were realized with a coreactant ECL approach in which both tri-n-propylamine (TPrA) and 2-(dibutylamino)ethanol (DBAE) were used as the ECL coreactant. Comparisons of the ECL efficiencies obtained from the complexes using TPrA and DBAE coreactants and their ECL and fluorescent spectra will be presented with proposed mechanisms.

O3.13

10:00 SYNTHESIS OF SPIRO-ISOXAZOLINES VIA INTRAMOLECULAR CYCLIZATION

Ashton Hamme, Prasanta Das, Ann Omollo, Lungile Sitole

Jackson State University

Psammaplysins A-E are a family of natural products that were isolated from marine sponges of the order Verongida. Many of these natural products display antiviral and antineoplastic activities. The most interesting structural motifs of the psammaplysins are the oxipin and isoxazoline ring systems which are connected in a spirocyclic array. The synthesis of this type of ring system was accomplished in two steps. These synthetic processes involve a 1,3-dipolar cycloaddition and an intramolecular ring closure of a pendant alkoxide or carboxylate ion onto an activated isoxazole. The 1,3-dipolar cycloaddition of an alkyne with a nitrile oxide from the analogous alpha-chlorobenzaldoxime afforded the desired isoxazole. Intramolecular cyclization was achieved through the reaction of the isoxazole ring with pyridinium tribromide. The proposed mechanism of intramolecular cyclization involves the activation of the isoxazoline ring with bromine to form a bromonium ion. Neighboring group participation of the oxygen can cause an opening of the bromonium ion intermediate thereby giving rise to an oxonium ion. Intramolecular attack of the alkoxide or carboxylate ion onto the oxonium ring system then affords the spiro-isoxoline. The synthesis, mechanistic details, and isolated yields for the synthesis of our spiro-isoxoline compounds will be discussed. Acknowledgments: We thank the National Institutes of Health RCMI program (G12RR13459 (NMR and Analytical CORE facilities)), the NSF-RISE program (HRD-0734645).

10:20 BREAK

O3.14

10:30 REDUCTION OF SODIUM CONTENT IN MEATS BY SOAKING IN WATER

Lakeshia Allen

Mississippi Valley State University

The purpose of this experiment is to study of how much sodium can be removed from processed meats by soaking. Sodium is an essential nutrient for bodily functioning and for flavor modification, needed in very little amounts of less than 2400mg daily within a 2000 calorie diet. Most people consume much more than is required which leads to health problems, hypertension in particular. Processed meats become enriched in sodium as a result of processing. In this study we investigate the feasibility of reducing the sodium content of processed meats by soaking in water. We used an atomic spectrometer called the Flame Atomic Absorption and a conductivity meter to determine the amount of sodium removed from the meat sample by soaking. By comparison of both data points, we developed an estimate of the percent removal of sodium from the processed meat by soaking. Doing this study we found that the meat is at approximately 800mg/L (ppm). Data charts are used to show the relation of standard samples and meat samples. Meat samples result in the curve between 100ppm standard and 1000ppm standard. This is shown with correlation of absorption and conductivity. In conclusion, soaking does have a significant effect on sodium content of meat. Based on our study, we found that approximately fifty-three percent of the sodium content may be extracted from bologna after soaking forty-eight hours. Sodium was significantly reduced showing a result of 800ppm in sodium extraction. Soaking meats does have a direct affect.

O3.15

10:50 A NOVEL CHEMOSENSOR FOR SELECTIVE DETECTION OF PHOSPHATE IN WATER

Musabbir A. Saeed (1), Douglas R. Powell (2), Md. Alamgir Hossain (1)

(1) Department of Chemistry and Biochemistry, Jackson State University, (2) Department of Chemistry and Biochemistry, University of Oklahoma

Selective and sensitive sensing of anion is a current challenge in the area of supramolecular chemistry. Sensing of biologically relevant anions is an important step to understand the detailed mechanisms of our living system. Because of the interesting geometry and the orientation of metal ions in a macrocyclic ligand, a dinuclear metal complex is potential to bind an anion. Anion sensing of a receptor could be enhanced using fluorescence indicator displacement assay, and this technique is often useful to show the selectivity of a particular anion (1). During the course of our study, we synthesized a new macrocyclic dinuclear copper complex which showed strong sensitivity and selectivity towards phosphate over sulfate, nitrate, perchlorate and halides in water at physiological pH. This poster will focus the structural and selectivity aspects of this new macrocyclic chemosensors for anions. Acknowledgements: The project described was supported by Grant Number G12RR013459 from the National Center for Research Resources. This material is based upon work supported by the National Science Foundation under CHE-0821357. (1) Saeed, M. A.; Powell, D. R.; Hossain, M. A. Tetrahedron Letters 2010, 51, 4904-4907.

O3.16

11:10 A NEW TRIPODAL TRIS-UREA RECEPTOR FOR HALIDE BINDING

Avijit Pramanik (1), Douglas R. Powell (2), Md. Alamgir Hossain (1)

(1) Jackson State University, (2) University of Oklahoma

An interest in anion binding chemistry is growing rapidly due to the important roles that negatively charged species play in biological processes [1.2]. Anions are also significant in chemical, medicine, catalysis, and environmental science. In particular, urea based ligands have shown to demonstrate as effective receptors for a variety of anionic species [3]. This class of receptors is capable to bind anions through hydrogen bonding integrations (NH...anion) in aprotoic solvent which can be useful for application oriented field. We recently synthesized a new receptor based on tripodal tris-urea with p-cyano groups, which have six ureido -NHs. Our crystallographic analysis suggests that the ligand is capable to bind both chloride and bromide with four hydrogen bonds. In this poster, we will present detailed solution and solid state binding of halides.

References:

[1.] J. L. Sessler, P. A. Gale, W.-S. Cho, Anion Receptor Chemistry, Royal Society of Chemistry, Cambridge, 2006.

[2.] Mangani, M. Ferraroni, in: A. Bianchi, K. Bowman-James, E. Garcia-Espana (Eds.), Supramolecular Chemistry of Anions, Wiley VCH, New York, 1997.

[3.] R. Custelcean, B. A. Moyer and B. P. Hay, Chem. Commun. 2005, 5971-5973.

O3.17

11:30 DECARBOXYLATIVE PHOTOCYCLIZATION OF CATIONIC PHTHALIMIDE AND QUINOLINE/ISOQUINOLINE [omega]-CARBOXYLIC ACIDS

Eli Smith, David Sandlin, Philip Schwartz, Wolfgang Kramer

Millsaps College

The decarboxylative photocyclization is an elegant photochemical way to synthesize small to medium sized heterocycles. The product is a pyrrolizidine annelated structure. Several functional groups are tolerated and ring sizes up to 36 members have been isolated with appropriate precursors. The synthetic potential of the reaction is diminished by the incorporation of the phthalimide nitrogen into the product. To expand the versatility of the decarboxylative photocyclization we are cationic precursors as well as different chromophors. Cationic precursors will enable us to use chiral biomolecules, such as DNA, as chiral auxiliaries as well as explore potential interactions in the course of the reaction. In one example, the phthalimide chromophor is attached to a nonconjugated pyridinium moiety which carries the positive charge. The use of different chromophors will greatly increase the synthetic potential of the cyclization reaction. The simple chromophors quinoline, isoquinoline or phenanthridine will give access to new classes of compounds. It has been shown that electron transfer fluorescence quenching does take place in quinoline betaines compounds. The synthesis of the precursors as well as the photochemical transformations are discussed.

11:50 ELECTION OF NEW CHAIR AND VICE CHAIR

12:00 CLOSING REMARKS
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Publication:Journal of the Mississippi Academy of Sciences
Geographic Code:1USA
Date:Jan 1, 2011
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