Natural Xanthones from Garcinia mangostana with Multifunctional Activities for the Therapy of Alzheimer's Disease.

Natural xanthones have diversity pharmacological activities. Here, a series of xanthones isolated from the pericarps of Garcinia mangostana Linn, named α-Mangostin, 8-Deoxygartanin, Gartanin, Garciniafuran, Garcinone C, Garcinone D, and γ-Mangostin were investigated. Biological screening performed in vitro and in Escherichia coli cells indicated that most of the xanthones exhibited significant inhibition of self-induced ß-amyloid (Aß) aggregation and also ß-site amyloid precursor protein-cleaving enzyme 1, acted as potential antioxidants and biometal chelators. Among these compounds, α-Mangostin, Gartanin, Garcinone C and γ-Mangostin showed better antioxidant properties to scavenge Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) free radical than Trolox, and potent neuroprotective effects against glutamate-induced HT22 cell death partly by up-regulating HO-1 protein level and then scavenging reactive oxygen species. Moreover, Gartanin, Garcinone C and γ-Mangostin could be able to penetrate the blood-brain barrier (BBB) in vitro. These findings suggest that the natural xanthones have multifunctional activities against Alzheimer's disease (AD) and could be promising compounds for the therapy of AD.

Construction of multifunctional electrochemical sensor based on electroactivity-adjustable poly (ionic liquids)/reduced graphene oxide.

In this article, a novel electroactivity-adjustable poly (ionic liquids)/reduced graphene oxide (PIL-GP) was developed and utilized for the fabrication of multifunctional, high stable electrochemical sensors. The structure, morphology and surface charge properties of PIL-GP have been systematically studied. And the selective detection performance of dopamine (DA) on PIL-GP modified glassy carbon electrode (GCE) were further explored by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). More importantly, by virtue of the anion exchange property of PIL, electroactive Fe(CN)63-/PIL-GP/GCE and Polyoxometalates (PWA)/PIL-GP/GCE were easily fabricated and their electrochemical detection performance of ascorbic acid (AA) and bromate were investigated respectively. The results showed that PIL-GP/GCE based electrochemical sensors provided higher sensitivity, lower detection limits and outstanding anti-interference ability in certain detection system. It was indicated that this general approach to construct electroactivity-adjustable sensors with various electroactive anions possessed a broad application prospect.