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PHOSPHORUS SEQUESTRATION AND BIOREMEDIATION: PHOSPHORUS-31 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY
Title
PHOSPHORUS SEQUESTRATION AND BIOREMEDIATION: PHOSPHORUS-31 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY.
Creator
Duersch, Bobby G., Louda, J. William, Florida Atlantic University, Department of Chemistry and Biochemistry, Charles E. Schmidt College of Science
Abstract/Description
Eutrophication is an increase in primary plant nutrients (Nitrogen [N] and Phosphorus [P]) in oceans, estuaries and lakes. The consequences of eutrophication are harmful algal blooms (HABs), resulting in algal toxin production and the depletion of oxygen as the extensive biomass decays. P is often the limiting nutrient and is viewed as a significant environmental problem. Most of the excess P that enters aquatic ecosystems originates from anthropogenic sources such as fertilizers, sewage,...
Show moreEutrophication is an increase in primary plant nutrients (Nitrogen [N] and Phosphorus [P]) in oceans, estuaries and lakes. The consequences of eutrophication are harmful algal blooms (HABs), resulting in algal toxin production and the depletion of oxygen as the extensive biomass decays. P is often the limiting nutrient and is viewed as a significant environmental problem. Most of the excess P that enters aquatic ecosystems originates from anthropogenic sources such as fertilizers, sewage, animal wastes, compost, crop residues, and wastewater. Over time, one of the main reservoirs of P becomes organic P (Po). We investigated the chemical nature and dynamics of P in cyanobacteria, horse manure, stormwater treatment areas, and rice fields. To better understand the chemical nature of P, the identification of specific P compounds was required, which was achieved through 31P nuclear magnetic resonance (NMR) spectroscopy. We investigated how paramagnetic metals and quadrupolar nuclei cause severe line broadening, peak shifts, and decreased the signal to noise ratio. Results revealed that certain Po forms are readily bioavailable to Microcystis aeruginosa. Additionally, the potential heterotrophic use of the organic portion (e.g., glucose, glycerol) of these P compounds are indicated for the growth and persistence of Microcystis aeruginosa. We showed that the cultivation of rice (Oryza sativa L.) had been found to effectively reduce P from agrarian soil and water through plant uptake and, therefore, minimizing downstream eutrophication. Soil, water, sugarcane, and rice plants at two different stages were analyzed for twelve different elements. Finally, we examined how a “relic” agrarian ditch in Stormwater Treatment Area 1 East (STA-1E) can be used for the retention and sequestration of P and other nutrients. The STAs were established to capture P from agricultural and other sources before reaching the Everglades. Retained P is primarily stored in the wetland soils and sediments, generated through a collection of interrelated physical, chemical, and biological processes.
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Date Issued
2020
PURL
http://purl.flvc.org/fau/fd/FA00013594
Subject Headings
Nuclear magnetic resonance spectroscopy, Eutrophication, Phosphorus--Environmental aspects, Bioremediation
Format
Document (PDF)
Hemisynthesis and Characterization of Cyclopheophorbides
Title
Hemisynthesis and Characterization of Cyclopheophorbides.
Creator
Mortezaei-Rad, Mitra, Florida Atlantic University, Louda, J. William, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description
Cyclopheophorbides absorb light at higher wavelengths (> 670 run) as compared to their precursor pyropheophorbides ( ~ 666 run) and are strong antioxidants. Therefore they could potentially be used as photosensitizers in photodynamic therapy, although this study does not focus on the pharmacology aspect of this class of compounds. The overall goal of this study was to hemisynthesize, purify and characterize certain cyclopheophorbides from both chlorophyll a and b families. The known...
Show moreCyclopheophorbides absorb light at higher wavelengths (> 670 run) as compared to their precursor pyropheophorbides ( ~ 666 run) and are strong antioxidants. Therefore they could potentially be used as photosensitizers in photodynamic therapy, although this study does not focus on the pharmacology aspect of this class of compounds. The overall goal of this study was to hemisynthesize, purify and characterize certain cyclopheophorbides from both chlorophyll a and b families. The known hemisynthesis of 13^2,17^3-cyclopheophorbide a enol was repeated. A major success in the purification process was achieved by utilizing polystyrene divinylbenzene (PS-DVB a.k .a. PRP-1 TM) as the stationary phase in reversed phase flash chromatography. Altering (TMS)2-NNa with (TMS)2-NLi was found to increase yields. 13^2,17^3 -mesocyclopheophorbide a enol was successfully hemisynthesized as a novel compound. Methyl-3-devinyl-3-[1-hexyloxy]ethyl pyropheophorbide a (HPPH-ME), was prepared, purified and molecular characteri zation on the compound was performed. Hemisynthesis ofHPPH-CYCLO from HPPH-ME was attempted, but was unsuccessful. Zinc and copper pyropheophorbide a methyl esters were prepared with the intent of forming of zinc and copper CYCLO. Hemisynthesis of corresponding metalloCYCLO from both insertion of the metal inside the CYCLO core and cyclizations of metal derivatives of pyropheophorbide a methyl ester were unsuccessful. Chlorophyll b was successfully extracted from green algae Chiarella and purified in mg lots (100%) utilizing RP-LPLC and with a binary solvent gradient program. Pheophorbide b methyl ester and pyropheophorbide b methyl ester were made and characterized. Hemisynthesis of CYCLO-b was unsuccessful likely due to the altered reactivity of pyropheophorbide b (vs. -a) methyl ester. To reduce the reactivity, reduction of formyl group of pyropheophorbide b methyl ester with NaBH4 was performed. Still, formation of a CYCLO derivative was not achieved. Chromatographic purification, mass and NMR characterization of CYCLO, mesoCYCLO, HPPH-ME and all precursor compounds are reported. 2D NMR of most of these compounds are reported here for the first time.
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Date Issued
2007
PURL
http://purl.flvc.org/fau/fd/FA00000872
Subject Headings
High performance liquid chromatography, Organometallic chemistry, Organic compounds--Spectra, Organophosphorus compounds
Format
Document (PDF)