Four New Flavonoid C-Glycosides Isolated from Achyranthes aspera and Their Nitric Oxide Production Inhibitory Activities.

A chemical study of the methanol extract of the aerial parts of Achyranthes aspera led to the isolation of four new flavonoid C-glycosides (1-4) along with eight known analogs (5-12). Their structures were elucidated by a combination of spectroscopic data analysis, HR-ESI-MS, 1D and 2D NMR spectra. All the isolates were evaluated their NO production inhibitory activity in LPS-activated RAW264.7 cells. Compounds 2, 4, and 8-11 showed significant inhibition with IC50 values ranging from 25.06 to 45.25 µM, compared to that of the positive control compound, L-NMMA, IC50 value of 32.24 µM, whereas the remaining compounds were weak inhibitory activity with IC50 values over 100 µM. This is the first report of 7 from Amaranthaceae family, and 11 from the genus Achyranthes.

Synthesis and Characterization of Polypyrrole Film Doped with Both Molybdate and Salicylate and Its Application in the Corrosion Protection for Low Carbon Steel.

Polypyrrole (PPy) films doped with molybdate and salicylate have been successfully electropolymerized on low carbon steel in aqueous solutions containing both molybdate and salicylate in a one-step process that did not require any pre-treatment of the steel substrate. Salicylate-doped PPy films were synthesized in the same way for comparison. The steel surface was rapidly inhibited and the PPy-based films were formed on it easily. The PPy-based films were characterized by Fourier transform infrared, scanning electron microscopy, energy dispersive X-ray, and thermal gravimetric analysis methods. The corrosion protection performance of the coatings was investigated with electrochemical impedance spectroscopy, open circuit potential (OCP), salt spray test, and Tafel polarization. It was found that in the presence of both molybdate and salicylate as dopants, the films on steel could present a better corrosion resistance than PPy film doped with only salicylate. The self-healing property of PPy-based films was observed on the OCP measurement with the fluctuation of rest potential. The salt spray test results showed that the PPy film doped with both salicylate and molybdate was more salt-resistant than the PPy film doped with only salicylate. The results suggest that the PPy coatings doped with both molybdate and salicylate are potential for application as metallic anti-corrosion coatings.