[Effects of Maxing Shigan Decoction Decocted by Different Methods and Its Drug Containing Serum on Neuraminidase Activity of Influenza A Virus].

Objective To observe the effects of Maxing Shigan Decoction (MSD) decocted by different methods and its drug containing serum on neuraminidase ( NA ) activity of influenza A virus (IAV). Methods The effects of MSD decocted by different methods, its corresponding drug containing serums , and drug containing serum in inhibiting the proliferation of virus on NA activity of IAV were detected using 2-(4-methyl umbelliferyl )-α-D-N-acetyl neuraminic acid (MUNANA) as substrate. Results (1) Effect of MSD on NA activity of IAV: OD value was less in groups with Ephedra decocted 25-min earlier and 30-min earlier than the group with four drugs decocted at the same time (P <0. 05, P <0. 01) ; (2) Effect of MSD on NA activity of IAV: OD value was less in groups with Ephedra decocted 30-min earlier and 40-min earlier than the group with four drugs decocted at the same time (P <0. 05, P <0. 01) ; (3) In the process of inhibiting viral multiplication, effect of MSD containing serum on NA activity of IAV: OD value was less in groups with Ephedra decocted 5 -20 min earlier, 30 min earlier, 35 min earlier than the group with four drugs decocted at the same time (P <0. 05, P <0. 01). In terms of drug concentration, OA value decreased more in 6. 25% and 12. 50% MSD containing serums than in 25. 00% MSD containing serum (P <0. 01). Conclusion MSD decocted by different methods might lead to different anti-IAV effects.

Dinuclear nickel(II) triple-stranded supramolecular cylinders: syntheses, characterization and G-quadruplexes binding properties.

Three dinuclear nickel triple-stranded supramolecular cylinders [Ni2(L1)3][ClO4]4 (1), [Ni2(L2)3][ClO4]4 (2) and [Ni2(L3)3][ClO4]4 (3) with bis(pyridylimine) Schiff base containing triphenyl groups in the spacers as ligands were synthesized and characterized. The human telomeric G-quadruplexes binding properties of cylinders 1-3 were evaluated by means of UV-Vis spectroscopy, circular dichroism (CD) spectroscopy and fluorescence resonance energy transfer (FRET) melting assay. UV-Vis studies revealed that the supramolecular cylinders 1-3 could bind to G-quadruplex DNA with high binding constants (Kb values ranging from 0.11-2.2×10(6) M(-1)). FRET melting studies indicated that the cylinders 1-3 had much stronger stabilizing effect on G-quadruplex DNA (ΔTm up to 24.5°C) than the traditional cylinder Ni2L3(4+) just containing diphenylmethane spacers (ΔTm=10.6 °C). Meanwhile, cylinders 1-3 were found to have a modest degree of selectivity for the quadruplex DNA versus duplex DNA in competition FRET assays. Moreover, CD spectroscopy revealed that complex 1 could induce G-quadruplex formation in the absence of metal ions solution and convert antiparallel G-quadruplex into hybrid structure in Na(+) solution. These results provided a new insight into the development of supramolecular cylinders as potential anticancer drugs targeting G-quadruplex DNA.