ChemInform Abstract: Design of Novel Hybrid Vitamin C Derivatives: Thermal Stability and Biological Activity.

ChemInform ◽  
2010 ◽  
Vol 28 (11) ◽  
pp. no-no
Author(s):  
K. MORISAKI ◽  
S. OZAKI
Keyword(s):  
Thermal Stability ◽  
Biological Activity ◽  
Vitamin C

scholarly journals Influence of ZrO2 Addition on Structural and Biological Activity of Phosphate Glasses for Bone Regeneration

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4058
Author(s):  
M. Mohan Babu ◽  
P. Syam Prasad ◽  
P. Venkateswara Rao ◽  
S. Hima Bindu ◽  
A. Prasad ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Biological Activity ◽  
Incubation Time ◽  
Sample Surface ◽  
Glass Forming Ability ◽  
Phosphate Glasses ◽  
Bioactive Materials ◽  
Glass Forming ◽  
Before And After ◽  
Thermal Stability Of

Zirconium doped calcium phosphate-based bioglasses are the most prominent bioactive materials for bone and dental repair and regeneration implants. In the present study, a 8ZnO–22Na2O–(24 − x)CaO–46P2O5–xZrO2 (0.1 ≤ x ≤ 0.7, all are in mol%) bioglass system was synthesized by the conventional melt-quenching process at 1100 °C. The glass-forming ability and thermal stability of the glasses were determined by measuring the glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm), using differential thermal analysis (DTA). The biological activity of the prepared samples was identified by analyzing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy-energy dispersive spectra (SEM-EDS), before and after immersion in simulated body fluid (SBF) for various intervals of 0, 1 and 5 days, along with the magnitude of pH and the degradation of glasses also evaluated. The obtained results revealed that the glass-forming ability and thermal stability of glasses increased with the increase in zirconia mol%. The XRD, FTIR, and SEM-EDS data confirmed a thin hydroxyapatite (HAp) layer over the sample surface after incubation in SBF for 1 and 5 days. Furthermore, the development of layer found to be increased with the increase of incubation time. The degradation of the glasses in SBF increased with incubation time and decreased gradually with the increase content of ZrO2 mol% in the host glass matrix. A sudden rise in initial pH values of residual SBF for 1 day owing to ion leaching and increase of Ca2+ and PO43− ions and then decreased. These findings confirmed the suitability of choosing material for bone-related applications.

A novel vitamin C analog, 2-O-(β-D-Glucopyranosyl)ascorbic acid: examination of enzymatic synthesis and biological activity

2005 ◽  
Vol 99 (4) ◽  
pp. 361-365 ◽  
Author(s):  
Yoshiko Toyada-ono ◽  
Mitsuru Maeda ◽  
Masahiro Nakao ◽  
Makiko Yoshimura ◽  
Namino Sugiura-tomimori ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Biological Activity ◽  
Vitamin C ◽  
Enzymatic Synthesis

scholarly journals The influence of N-acetylneuraminic acid on the properties of human orosomucoid

1986 ◽  
Vol 236 (1) ◽  
pp. 149-153 ◽  
Author(s):  
M L Friedman ◽  
J R Wermeling ◽  
H B Halsall
Keyword(s):  
Thermal Stability ◽  
Biological Activity ◽  
Fluorescence Spectroscopy ◽  
Ligand Binding ◽  
Protein Conformation ◽  
Acid Content ◽  
Acetylneuraminic Acid ◽  
Water Of Hydration ◽  
Hydrophobic Binding ◽  
A Charge

Little is known of the relationships that may exist among the three principal functionalities of glycoproteins. Orosomucoids of closely defined N-acetylneuraminic acid content were examined for evidence of influence of N-acetylneuraminic acid content on the physical properties of the glycoprotein. Fluorescence spectroscopy gave no indication of conformational change in the protein core upon desialylation. Small changes in the chromatographic partition coefficient, sigma, and thermal stability, Td, are interpreted to reflect loss of water of hydration and increased glycan stem-protein interaction without a major repositioning of the chains. Ligand-binding measurements indicate no alteration in the hydrophobic binding domain and a possible interaction between chlorpromazine and N-acetylneuraminic acid. All changes seen are progressive and occur through a region where changes in biological activity are not found. It is suggested that the dependence of biological activity on N-acetylneuraminic acid content in orosomucoid reflects, not coupled changes in protein conformation, but a charge-density-related interaction such that, below a contribution of four or five N-acetylneuraminic acid residues, activity is modified.

scholarly journals EFFECT OF CHLOROPHYLL ON THE BIOLOGICAL ACTIVITY OF VITAMIN C

1956 ◽  
Vol 2 (2) ◽  
pp. 111-114
Author(s):  
CHOTEN INAGAKI ◽  
KIYOKO YAMAZAKI
Keyword(s):  
Biological Activity ◽  
Vitamin C

scholarly journals Thermal stability, antioxidant, and anti-inflammatory activity of curcumin and its degradation product 4-vinyl guaiacol

2015 ◽  
Vol 6 (3) ◽  
pp. 887-893 ◽  
Author(s):  
Tuba Esatbeyoglu ◽  
Katrin Ulbrich ◽  
Clemens Rehberg ◽  
Sascha Rohn ◽  
Gerald Rimbach
Keyword(s):  
Thermal Stability ◽  
Biological Activity ◽  
Degradation Product ◽  
Inflammatory Activity ◽  
Anti Inflammatory

The curcumin degradation product 4-vinyl guaiacol exhibits biological activity.

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