Enhancing the Membranolytic Activity of Chenopodium quinoa Saponins by Fast Microwave Hydrolysis

Saponins are plant secondary metabolites. There are associated with defensive roles due to their cytotoxicity and are active against microorganisms. Saponins are frequently targeted to develop efficient drugs. Plant biomass containing saponins deserves sustained interest to develop high-added value applications. A key issue when considering the use of saponins for human healthcare is their toxicity that must be modulated before envisaging any biomedical application. This can only go through understanding the saponin-membrane interactions. Quinoa is abundantly consumed worldwide, but the quinoa husk is discarded due to its astringent taste associated with its saponin content. Here, we focus on the saponins of the quinoa husk extract (QE). We qualitatively and quantitively characterized the QE saponins using mass spectrometry. They are bidesmosidic molecules, with two oligosaccharidic chains appended on the aglycone with two different linkages; a glycosidic bond and an ester function. The latter can be hydrolyzed to prepare monodesmosidic molecules. The microwave-assisted hydrolysis reaction was optimized to produce monodesmosidic saponins. The membranolytic activity of the saponins was assayed based on their hemolytic activity that was shown to be drastically increased upon hydrolysis. In silico investigations confirmed that the monodesmosidic saponins interact preferentially with a model phospholipid bilayer, explaining the measured increased hemolytic activity.

EXTRACTING SUBERIN ACIDS FROM BIRCH BARK WHEN EXPOSED TO A MICROWAVE FIELD

The present study focuses on the identification of the components included in the suberin of birch bark, as well as the development of the method of intensification of hydrolysis of birch bark in the allocation of suberin.Identification suberin derived from the technical of birch bark in conditions the microwave field was conducted the method of IR-spectroscopy (IRS). In the study of the chemical composition of suberin acids using gas chromatomass spectrometry (GC/MS) revealed the following dominant acid: docosanedioic (phellogenic) acid and 22-hydroxydocosanoic (phellonic) acid.It is established that processing of birch bark in a microwave field allows 2 times to reduce the duration of process of water-alkaline hydrolysis. By the planned experiment, mathematical description of the process of hydrolysis of birch bark in conditions of microwave radiation was obtained; the influence of the main parameters was installed and the optimal conditions for suberin acids secretion were determined. Concentration of alkali, %; power, W; duration, min were selected How were the independent variables. It is noted that the increase in alkali concentration and duration of hydrolysis leads to a positive result. On the basis of economic considerations, the optimum concentration of KOH for microwave hydrolysis is 5%, duration – 15 min, power – 600 W. The power consumption is 37,5 kWh/kg birch bark.

Determination of Free and Total Choline and Carnitine in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS): Single-Laboratory Validation, First Action 2015.10

Analytical methods for the analysis of both L-carnitine and choline are needed for reliable and accurate determination in infant formula and adult/pediatric nutritional formula. These compounds are different in how they are utilized by the human body, but are structurally similar. L-carnitine and choline are quaternary ammonium compounds, enabling both to be retained under acidic conditions with strong cation exchange (SCX) chromatography. This method analyzes both compounds simultaneously as either the free forms or as a total amount that includes bound sources such as phosphatidylcholine or acetylcarnitine. The free analysis consists of water extraction and analysis by LC/MS/MS, while the total analysis consists of extraction by acid assisted microwave hydrolysis and analysis by LC/MS/MS. Calibration standards used for calculations are extracted with all samples in the batch. A single laboratory validation (SLV) was performed following the guidelines of the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) utilizing the kit of materials provided. The results achieved meet the requirements of SMPR 2012.010 and 2012.013 for L-carnitine and total choline, respectively.

Study on the Hydrolysis of PET Catalyzed by Carbonates under Microwave Irradiation

A study for optimizing the experimental conditions for the hydrolysis of polyethylene terephthalate (PET) catalyzed by carbonates was performed. The main influence factors of PET microwave hydrolytic reaction, such as the reaction temperature, time and catalyst dosage, were confirmed and these effects on the catalysis of PET microwave hydrolysis were studied in detail. The results showed that the sequence of influence factors was reaction temperature>reaction time> catalyst dosage. The optimal experimental conditions under the catalyst of basic zinc carbonate were that the catalyst dosage, 0.75%; the reaction time, 210 min; the reaction temperature, 200°C.

Synthesis of ZnO Nanorod Arrays by Chemical Solution and Microwave Method for Sensor Application

One-dimensional ZnO semiconductor nanomaterials have been attracting increasing attention due to their outstanding properties, which are different from bulk materials. ZnO has a direct band gap of 3.37 eV and large exciton binding energy hence its nanowires and nanorods have been regarded as one of the most promising materials for nanoscale electronic and optoelectronic devices such as ultraviolet laser diodes, optical detectors and gas sensor. ZnO nanowires and nanorods have been successfully synthesized by various techniques such as evaporation, sputtering and pyrolysis. In this paper we report the preparation of nanorod arrays of ZnO on ITO glass substrates which were pre-coated with ZnO nanoparticles by using low temperature chemical solution method and the result was compared with microwave hydrolysis process. The morphology and structure of ZnO nanorod arrays were investigated using field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The ZnO nanorod arrays with a diameter of 40-70 nm were successfully synthesized. In microwave hydrolysis method, the diameter, density and surface roughness was found to depend on the microwave power. The microwave method is far superior in producing ZnO nanostructure growth.