The four O-H bands of ascorbic acid could be assigned by means of infrared investigations. It could be shown by electron spin resonance and nuclear magnetic resonance measurements that the radical sodium ascorbate is formed by a cyclic side-chain structure resulting in a loss of C(6)-OH and C(3)-OH. The C(2) = C(3) double bond is still maintained as could be shown by infrared and ultraviolet absorption spectroscopy. In the case of complete oxidation of ascorbic acid to dehydroascorbic acid, C(6)-OH is reestablished (indicating the reopening of the furanoid ring), while C(2)-OH as well as the C(2) = C(3) double bond have disappeared due to the deprotonation of C(2)-OH and C(3)-OH. In the case of isoascorbic acid and its radical potassium isoascorbate similar results are obtained with one distinct difference: in the case of isoascorbic acid, C(2)-OH does not appear while C(3)-OH exhibits a shoulder.
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http://dx.doi.org/10.1111/j.1432-1033.1984.tb07941.x | DOI Listing |
Front Plant Sci
January 2025
College of Agronomy and Life Sciences, Zhaotong University, Zhaotong, China.
Environmental conditions significantly influence the metabolic composition and quality attributes of fruits. This study investigated the impact of altitude-associated environmental variation on flavonoid profiles and fruit quality parameters by comparing the "Red Face" strawberry variety grown in two distinct locations: high-altitude-associated environmental conditions in Zhaotong and low-altitude conditions in Dandong. Using LC-MS/MS analysis, we identified 163 bioactive flavonoids, comprising 85 flavonols, 37 flavanones, 33 flavones, and 8 flavanonols.
View Article and Find Full Text PDFNanoscale
January 2025
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424 Depok, West Java, Indonesia.
This study reports on the development of a highly sensitive non-enzymatic electrochemical sensor based on a two-dimensional TiCT/MWCNT-OH nanocomposite for the detection of paraoxon-based pesticide. The synergistic effect between the TiCT nanosheet and the functionalized multi-walled carbon nanotubes enhanced the sensor's conductivity and catalytic activity. The nanocomposite demonstrates superior electrochemical and electroanalytical performance compared to the pristine TiCT and MWCNT-OH in detecting paraoxon-ethyl in fruit samples (green and red grapes), with a linear response range from 0.
View Article and Find Full Text PDFAppl Biochem Biotechnol
January 2025
Department of Chemistry, College of Sciences for Women, University of Baghdad, Baghdad, Iraq.
Azo dye was used to prepare a new series of complexes with chlorides of rhodium (Rh), ruthenium (Ru), and corona (Au). The prepared materials were subjected to infrared, ultraviolet-visible, and mass spectrometry, as well as thermogravimetric analysis, differential calorimetry, and elemental analysis. Conductivity, magnetic susceptibility, metal content, and chlorine content of the complexes were also measured.
View Article and Find Full Text PDFCurr Pharm Des
January 2025
Department of Horticulture and Life Science, Yeungnam University, Republic of Korea.
Introduction: Datura stramonium (DS) possesses strong medicinal and therapeutic potential but has been rarely evaluated in this context.
Methods: The present study was intended to evaluate the antioxidant, hepatoprotective, and nephroprotective potential of the crude methanolic leaf extract and ethyl acetate, chloroform, n-hexane, and aqueous fractions of DS in paracetamol-intoxicated rabbits. Paracetamol (2 g/Kg BW) was applied to induce liver and kidney injury in rabbits while the methanolic extract and fractions of DS were applied in the dose range of 150 mg/Kg to 300 mg/Kg body weight for 21 days.
Biol Trace Elem Res
January 2025
Faculty of Science, Department of Chemistry, University of Sarajevo, Sarajevo, Bosnia and Herzegovina.
The total content of heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in chamomile sample, metals content in water chamomile infusions and water infusions with additions of ascorbic acid and lemon juice at different temperatures (70, 80, and 100 °C) and steeping times (3, 5, and 7 min), were determined. The content of heavy metals was determined by flame atomic absorption spectrometry (FAAS). Mean total concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were 0.
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