Novel asymmetric benzylidenecyclohexanone photochromic compound as food dye with antioxidant properties

Nature has always been the provider of compounds with unique properties and amazing application within or outside the living organisms [1]. Color is certainly one of the natural features that have always fascinated researchers from almost all fields of knowledge and compounds with such properties have been isolated from raw materials or have been designed and synthesized based thereon [2]. Flavylium derivatives are natural or synthetic compounds responsible for certain color of fruits and flowers and are able to turn from yellow to red and blue depending on the pH of the media [3]. They are also studied for their photochromic behavior when excited with different wavelengths and their network of chemical transformation has been the subject of many research papers [4,5]. We have focused lately on the synthesis of xanthylium derivatives [6], compounds similar in behavior with flavylium ones with symmetrical and asymmetrical substituents on the aromatic rings. The photochromic behavior of the new asymmetric benzylidene cyclohexanone derivative 4-(p-hydroxybenzylidene)-6-hydroxy-1,2,3,4-tetrahydroxanthylium chloride (HTX)in aqueous solution at different pH values was studied using UV-Vis, NMR and fluorescence spectroscopy. In strong acid environment HTX exhibits purple color and a broad absorption band at about 516 nm, corresponding to the presence of the xanthylium cation, while in basic conditions the solutions are red, with an absorption band at about 596 nm. At pH ranging from 9 to 12 HTX is bluish and suffers spontaneous transformations between species involved in the network of chemical reactions. HTX shows good fluorescence behavior at all pH values. HTX has a good antioxidant character of 55.15% determined by DPPH method. The features described above and its curcumin origin would highly recommend it for application in the field of food colorants

New carboxysalicylaldehyde schiff base ligand and its copper(II) complexes

Metal-organic frameworks have become a subject of great interest lately because of their interesting features and applications in the field of catalysis, magnetism and biological studies [1]. Coordination polymers are most commonly the creators of such frameworks, and researchers have devoted great effort to the design of metal-generated networks with tailored properties [2,3]. Our group has recently been involved in the development of by-design structures based on 3d metal coordination complexes derived from Schiff based ligands [4]. Salen-based complexes of 3d metals, in which the Schiff base presents the carboxy substituent on the aromatic moiety, generate infinite coordination polymers in the presence of alkaline bases [5]. In this respect, we have obtained new carboxysalicylaldehyde Schiff base ligand, namely N,N'-bis(5-carboxysalicylidene-aminopropyl)piperazine (CBPP), characterized by NMR and FTIR spectroscopy and TG analysis. Copper(II) complexes of CBPP were synthesized by direct or template synthesis, isolated and characterized by FTIR; preliminary results suggest the formation of polymeric structures

Oscillatory Cortical Activity in an Animal Model of Dystonia Caused by Cerebellar Dysfunction

The synchronization of neuronal activity in the sensorimotor cortices is crucial for motor control and learning. This synchrony can be modulated by upstream activity in the cerebello-cortical network. However, many questions remain over the details of how the cerebral cortex and the cerebellum communicate. Therefore, our aim is to study the contribution of the cerebellum to oscillatory brain activity, in particular in the case of dystonia, a severely disabling motor disease associated with altered sensorimotor coupling. We used a kainic-induced dystonia model to evaluate cerebral cortical oscillatory activity and connectivity during dystonic episodes. We performed microinjections of low doses of kainic acid into the cerebellar vermis in mice and examined activities in somatosensory, motor and parietal cortices. We showed that repeated applications of kainic acid into the cerebellar vermis, for five consecutive days, generate reproducible dystonic motor behavior. No epileptiform activity was recorded on electrocorticogram (ECoG) during the dystonic postures or movements. We investigated the ECoG power spectral density and coherence between motor cortex, somatosensory and parietal cortices before and during dystonic attacks. During the baseline condition, we found a phenomenon of permanent adaptation with a change of baseline locomotor activity coupled to an ECoG gamma band increase in all cortices. In addition, after kainate administration, we observed an increase in muscular activity, but less signs of dystonia together with modulations of the ECoG power spectra with an increase in gamma band in motor, parietal and somatosensory cortices. Moreover, we found reduced coherence in all measured frequency bands between the motor cortex and somatosensory or parietal cortices compared to baseline. In conclusion, examination of cortical oscillatory activities in this animal model of chronic dystonia caused by cerebellar dysfunction reveals a disruption in the coordination of neuronal activity across the cortical sensorimotor/parietal network, which may underlie motor skill deficits

Biodegradation Pattern of Glycopolymer Based on D-Mannose Oligomer and Hydroxypropyl Acrylate

Glycopolymers are polymers with sugar moieties which display biodegradable and/or biocompatible character. They have emerged as an environmentally-friendly solution to classical synthetic polymers and have attracted significant research interest in the past years. Herein, we present the synthesis of a D-mannose based glycopolymer with biodegradable features. The glycopolymer was synthesized by radical copolymerization between a D-mannose oligomer bearing polymerizable double bonds and 2-hydroxypropyl acrylate, in a weight ratio of 1:2. The copolymerization kinetics was investigated by differential scanning calorimetry (DSC) and the activation energy of the process was comparatively assessed by Kissinger–Akahira–Sunose and Flynn–Wall–Ozawa methods. The obtained glycopolymer displayed good thermal behavior, fact proven by thermogravimetrical (TG) analysis and it was submitted to biodegradation inside a bioreactor fed with water from the Bega River as the source of microbial inoculum. The glycopolymer sample degraded by approximately 60% in just 23 days. The biodegradation pattern of the glycopolymer was successfully fitted against a modified sigmoidal exponential function. The kinetic model coefficients and its accuracy were calculated using Matlab and the correlation coefficient is more than promising. The changes inside glycopolymer structure after biodegradation were studied using TG and FTIR analyses, which revealed that the sugar moiety is firstly attacked by the microbial consortia as nutrient source for proliferation