Determination of Pyrroloquinoline Quinone in DNA Binding by LC

Abstract

A simple and repeatable liquid chromatography method with UV detection is described for the determination of pyrroloquinoline quinone in DNA binding studies first. Binding of pyrroloquinoline quinone to DNA was measured indirectly by determining unbound pyrroloquinoline quinone. Pyrroloquinoline quinone was chromatographed on a reversed-phase column using gradient elution with mobile phases of 0.1% trifluoroacetic acid (TFA) in deionized water and 0.1% TFA in acetonitrile at a flow-rate of 0.8 mL min -1 and detected at 249 nm. The mean content of unbound pyrroloquinoline quinone to three DNA in (hydroxymethyl) aminoethane(Tris-HCl) media were dropped from 99.3 to 80.3% in 250 min, and than to 64.8% at 1200 min, but the binding remained constant in deionized water. The method precision were validated with RSD 1.05 and 0.69% for peak areas and retention times. Validation of the method showed that the assay was linear from 25 to 2,000 lM and 5 to 2,000 lM pyrroloquinoline quinone in Tris-HCl and deionized water, respectively. The accuracy for three concentrations of pyrroloquinoline quinone with different types DNA in two media were within the given range of 80.9-113.6%.

Evaluation of thermal stability of quinones by thermal analysis techniques

“…Quinones analyses are, in general, performed by gas chromatography with mass spectrometry (GC-MS) [5,9] or high performance liquid chromatography (HPLC) with several detectors [10][11][12]. Recent analytical developments incorporate chemical derivatization to enhance GC-MS and LC-MS methodologies [13].…”

Ion-Pair LC Analysis of Pyrroloquinoline Quinone in Neurotransmitter Amino Acid Incubations: Determination of Chemical Kinetics

“…99m Tc-PQQ has been described as a potential marker for the molecular imaging of NMDAR in psychical disorders [15]. In addition, binding studies between PQQ and DNA have provided information for research into the disease-resistant mechanisms of PQQ [16]. To investigate the effects of PQQ in regulating neurotransmitters, our laboratory established an improved ion-pair HPLC method for determining the levels of PQQ in reaction mixtures with neurotransmitter amino acids including Gly, D-Ser, Glu, Asp, and GABA.…”