The synthesis of chlorophyll-a biosynthetic precursors and methyl substituted iron porphyrins
The biosynthetic intermediates were incubated in a plant system. The activity levels calculated show that magnesium 6-acrylate porphyrins and one of the magnesium 6-{beta}-hydroxypropionate porphyrins are not intermediates. In addition, plant systems incubated with {sup 18}O{sub 2} were found to synthesize magnesium 2,4-divinyl pheoporphyrin-a{sub 5} incorporated with {sup 18}O at the 9-carbonyl oxygen. Mass spectroscopy confirmed the presence of the oxygen label, thus eliminating one of two hypothesized pathways to chlorophyll-a. An overall description is given of iron porphyrins and iron porphyrin containing proteins. The function of the propionic side chains of the heme prosthetic group during electron transport reactions will be investigated. The synthesis of a series of iron(III) hexamethyl porphyrins with increasingly longer substituents in the remaining two peripheral positions of the porphyrin is described. Models for NMR studies of iron chlorin containing enzymes are discussed. Iron(III) pyropheophorbide-a and methyl pyropheophorbide-a were synthesized in addition to 5-CD{sub 3}, 10-CD{sub 2} iron(III) pyropheophorbide-a and methyl pyropheophorbide-a. Together, these pyropheophorbides were used to assign NMR resonances and ultimately provide a model for other iron chlorins. The synthesis of nickel(II) anhydro-mesorhodoporphyrin from zinc(III) anhydromesorhodochlorin is described; this nickel porphyrin was used as a standard for ring current calculations of reduced nickel analogs of anhydromesorhodoporphyrin.
- Research Organization:
- California Univ., Davis, CA (USA)
- OSTI ID:
- 7147306
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHLOROPHYLL
BIOSYNTHESIS
PORPHYRINS
BIOLOGICAL FUNCTIONS
BIOLOGICAL PATHWAYS
ELECTRON TRANSFER
IRON
MASS SPECTROSCOPY
MATHEMATICAL MODELS
NMR SPECTRA
OXYGEN 18
PLANTS
PRECURSOR
TRACER TECHNIQUES
CARBOXYLIC ACIDS
ELEMENTS
EVEN-EVEN NUCLEI
FUNCTIONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
METALS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN ISOTOPES
PHYTOCHROMES
PIGMENTS
PROTEINS
SPECTRA
SPECTROSCOPY
STABLE ISOTOPES
SYNTHESIS
TRANSITION ELEMENTS
550201* - Biochemistry- Tracer Techniques