We describe the development of quinolylnitrones(QNs)as multifunctional ligands inhibiting cholinesterases(ChEs:acetylcholinesterase and butyrylcholinesterase—h BChE)and monoamine oxidases(hMAO-A/B)for the therapy of ...
详细信息
We describe the development of quinolylnitrones(QNs)as multifunctional ligands inhibiting cholinesterases(ChEs:acetylcholinesterase and butyrylcholinesterase—h BChE)and monoamine oxidases(hMAO-A/B)for the therapy of neurodegenerative diseases.We identified QN 19,a simple,low molecular weight nitrone,that is readily synthesized from commercially available 8-hydroxyquinoline-2-carbaldehyde.Quinolylnitrone 19 has no typical pharmacophoric element to suggest ChE or MAO inhibition,yet unexpectedly showed potent inhibition of h BChE(IC50=1.06±0.31 nmol/L)and h MAO-B(IC_(50)=4.46±0.18μmol/L).The crystal structures of 19 with hBChE and hMAO-B provided the structural basis for potent binding,which was further studied by enzyme kinetics.Compound 19 acted as a free radical scavenger and biometal chelator,crossed the blood—brain barrier,was not cytotoxic,and showed neuroprotective properties in a 6-hydroxydopamine cell model of Parkinson's disease.In addition,in vivo studies showed the anti-amnesic effect of 19 in the scopolamine-induced mouse model of AD without adverse effects on motoric function and coordination.Importantly,chronic treatment of double transgenic APPswe-PS1δE9 mice with 19 reduced amyloid plaque load in the hippocampus and cortex of female mice,underscoring the disease-modifying effect of QN 19.
Zebra mussel Dreissena polymorpha is a Ponto-Caspian species invasive in Europe and North America, with great environmental impact. It lives byssally attached to hard substrata in large aggregations, which is often ex...
详细信息
Zebra mussel Dreissena polymorpha is a Ponto-Caspian species invasive in Europe and North America, with great environmental impact. It lives byssally attached to hard substrata in large aggregations, which is often explained by its preferences for conspecifics, though direct evidence for such preferences has been rather limited so far. We studied the reactions of zebra mussels to conspecifics, hypothesizing that they may either be attracted to one another or form aggregations only in the absence of alternative attachment sites. In Experiment 1, we tested mussel tendency to detach from existing druses depending on druse size (2-25 individuals) and substratum type (soft: sand; hard: glass). Mussels detached significantly more often on the hard substratum and from larger druses compared to soft substratum and smaller druses, respectively. This indicates that mussels tended to avoid conspecifics at high density, particularly when alternative substratum was available. In Experiment 2, we tested the responses of single mussels to distant (3 or 15 cm) conspecifics (0, 3, 15 individuals per 2.5 l tank) on the sandy substratum. The presence of conspecifics, regardless of their distance and density, resulted in single unattached mussels staying more often in their initial positions. Mussels did not move preferentially towards or away from the conspecifics. Thus, even on unsuitable substratum mussels were not attracted by conspecifics and probably exhibited an avoidance reaction by reducing their movement. This suggests that dense mussel aggregations are formed due to the lack of available alternative attachment sites rather than due to their preferences for conspecifics.
暂无评论