RESUMO
In the present study, an ultrasound-assisted extraction (UAE) method was developed for the efficient extraction of Galantamine from the bulbs of Galanthus woronowii L. Five independent variables, including pH of the extraction solvent, solvent/material ratio, ultrasound time, ultrasound temperature and ultrasound power were studied by single factor experiments. The central composite design and response surface methodology were employed to investigate the effect of three key parameters (ultrasound time, ultrasound temperature and solvent/material ratio) on the extraction efficiency. The 3-level, 3-factorial Central-Composite Design was employed to study three main extraction conditions: extraction time (15-45 min), extraction temperature (30–70°C) and solvent/material ratio (30–50 mL/g sample). The present analysis revealed that a quadratic polynomial model can be used to express the response dependent variable yield of Galantamine. The optimal extraction conditions were found to be solvent/material ratio of 40.70 mL/g sample, with an extraction time of 32.89 min and a temperature of 51.04°C. Theoretical optimal yield was recorded 0.469% with a mentioned extraction conditions and the yield of Galantamine was found to be 0.470% which is in a very good agreement with the theoretically predicted one.
RESUMO
Eukaryotic elongation factor 2 (eEF-2) can undergo ADP-ribosylation in the absence of diphtheria toxin. The binding of free ADP-ribose and endogenous transferase-dependent ADP-ribosylation were distinct reactions for eEF-2, as indicated by different findings. Incubation of eEF-2 tryptic fragment 32/33 kDa (32F) with NAD was ADP-ribosylated and gave rise to the covalent binding of ADP-ribose to eEF-2. 32F was revealed to be at the C-terminal by Edman degradation sequence analysis. In our study, the elution of 32F from SDS-PAGE was ADP-ribosylated both in the presence and absence of diphtheria toxin. These results suggest that endogenous ADP-ribosylation of 32F might be related to protein synthesis. This modification appears to be important for the cell function.