Glycaemic activity of chromium(III)–β-nicotinamide adenine dinucleotide phoshate complex and its presence in yeast extracts

Abstract

Two main stable chromium complexes were detected in the aqueous extract of Cr-rich yeast using high-performance liquid chromatographic (HPLC) separation on a reversed-phase RP-8 column and atomic absorption spectrometric detection of chromium. However, the complexes could not be separated and purified sufficiently to allow their reliable identification. Both complexes behaved like ionic or very polar substances with a weak affinity to the reverse-phase column. Yeast extract was then spiked with some synthetic Cr complexes which were prepared considering known data (UV spectra, molecular mass, etc.) on candidates glucose tolerance factor (GTF) compounds. Among the complexes tested, attention was paid especially to the complex of Crm with beta-nicotinamide adenine dinucleotide phosphate (NADP), which accompanies one of two Cr complexes in yeast extract during the HPLC separation. The complex with a Cr:NADP stoichiometric ratio 1:2 has not previously been reported. The complex was tested for its glycaemic activity using glucose tolerance test on rabbits. Significant hyperglycaemia was caused in the animals. Considering the NADP is generally present in tissues of nearly all living organisms, its complexes with transient metals could play a very important role in oxidation-reduction processes of metabolic pathways.

Comparison of Hypoglycemic Activity and Toxicity of Vanadium (IV) and Vanadium (V) Absorbed in Fermented Mushroom of Coprinus comatus

“…This result is consistent with the findings of another study by Han [13]. The possible mechanism could be that vanadium influences the stability of cell membranes as well as the syntheses of nucleic acids and the stability of the double helix of DNA while forming hydrogen bonds [21,22].…”

Comparison of Hypoglycemic Activity of Fermented Mushroom of Inonotus obliquus Rich in Vanadium and Wild-Growing I. obliquus

“…This result was consistent with the findings of another study by Han et al [7]. The possible mechanism could be that vanadium influences the stability of cell membranes, as well as the syntheses of nucleic acids and the stability of the double helix of DNA while forming hydrogen bonds [21,22]. The content of vanadium accumulated in the mycelia was 3.0 mg/g when the concentration of vanadium in the medium was 0.6%.…”

Vanadium Uptake by Biomass of Coprinus comatus and Their Effect on Hyperglycemic Mice

“…But it is also known that some metal ions may influence the stability of cell membranes, as well as the syntheses of nucleic acids and the stability of the double helix of DNA while forming hydrogen bonds. [14,15]. During the fermentation, the addition of vanadium into C. comatus cells is of particular interest.…”