Pyrroloquinoline quinone: Metabolism and analytical methods
Pyrroloquinoline quinone (PQQ) functions as a cofactor for bacterial oxidoreductases. Whether or not PQQ serves as a cofactor in higher plants and animals remains controversial. Nevertheless, strong evidence exists that PQQ has nutritional importance. In highly purified, chemically defined diets PQQ stimulates animal growth. Further PQQ deprivation impairs connective tissue maturation, particularly when initiated in utero and throughout perinatal development. The study addresses two main objectives: (1) to elucidate basic aspects of the metabolism of PQQ in animals, and (2) to develop and improve existing analytical methods for PQQ. To study intestinal absorption of PQQ, ten mice were administered [[sup 14]C]-PQQ per os. PQQ was readily absorbed (62%) in the lower intestine and was excreted by the kidney within 24 hours. Significant amounts of labeled-PQQ were retained only by skin and kidney. Three approaches were taken to answer the question whether or not PQQ is synthesized by the intestinal microflora of mice. First, dietary antibiotics had no effect on fecal PQQ excretion. Then, no bacterial isolates could be identified that are known to synthesize PQQ. Last, cecal contents were incubated anaerobically with radiolabeled PQQ-precursors with no label appearing in isolated PQQ. Thus, intestinal PQQ synthesis is unlikely. Analysis of PQQ in biological samples is problematic since PQQ forms adducts with nucleophilic compounds and binds to the protein fraction. Existing analytical methods are reviewed and a new approach is introduced that allows for detection of PQQ in animal tissue and foods. PQQ is freed from proteins by ion exchange chromatography, purified on activated silica cartridges, detected by a colorimetric redox-cycling assay, and identified by mass spectrometry. That compounds with the properties of PQQ may be nutritionally important offers interesting areas for future investigation.
- Research Organization:
- California Univ., Davis, CA (United States)
- OSTI ID:
- 7013281
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect
Nutritional complementation of oxidative glucose metabolism in Escherichia coli via pyrroloquinoline quinone-dependent glucose dehydrogenase and the Entner-Doudoroff pathway
Related Subjects
BENZOQUINONES
METABOLISM
ANTIBIOTICS
BACTERIA
CARBON 14
CHEMICAL ANALYSIS
EXCRETION
GROWTH
INTESTINAL ABSORPTION
ION EXCHANGE CHROMATOGRAPHY
MASS SPECTROMETERS
MICE
NUTRITION
OXIDOREDUCTASES
TRACER TECHNIQUES
ABSORPTION
ANIMALS
ANTI-INFECTIVE AGENTS
AROMATICS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON ISOTOPES
CHROMATOGRAPHY
CLEARANCE
DRUGS
ENZYMES
EVEN-EVEN NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MEASURING INSTRUMENTS
MICROORGANISMS
NUCLEI
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PROTEINS
QUINONES
RADIOISOTOPES
RODENTS
SEPARATION PROCESSES
SORPTION
SPECTROMETERS
UPTAKE
VERTEBRATES
YEARS LIVING RADIOISOTOPES
560300* - Chemicals Metabolism & Toxicology