Note
Includes bibliography.
Member of
Publisher
Florida Atlantic University
Date Issued
2007
EDTF Date Created
2007
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
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.
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.
Language
Type
Form
Extent
195 p.
Subject (Topical)
Identifier
FA00000872
Additional Information
Includes bibliography.
Dissertation (Ph.D.)--Florida Atlantic University, 2007.
FAU Electronic Theses and Dissertations Collection
Charles E. Schmidt College of Science
Date Backup
2007
Date Created Backup
2007
Date Text
2007
Date Created (EDTF)
2007
Date Issued (EDTF)
2007
Extension
FAU
IID
FA00000872
Organizations
Attributed name: Charles E. Schmidt College of Science
Attributed name: Department of Chemistry and Biochemistry
Person Preferred Name
Mortezaei-Rad, Mitra
Graduate College
Physical Description
application/pdf
195 p.
Title Plain
Hemisynthesis and Characterization of Cyclopheophorbides
Use and Reproduction
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Origin Information
2007
2007
Florida Atlantic University
Boca Raton, Fla.
Physical Location
Florida Atlantic University Libraries
Place
Boca Raton, Fla.
Sub Location
Digital Library
Title
Hemisynthesis and Characterization of Cyclopheophorbides
Other Title Info
Hemisynthesis and Characterization of Cyclopheophorbides