Rapid detection of <Emphasis Type="Italic">Aspergillus flavus</Emphasis> in rice using biofunctionalized carbon nanotube field effect transistors

Popularity of new psychoactive substances, known as legal highs or herbal highs, is continuously growing. These products are typically sold via internet and in so-called head shops. The aim of this study was to identify active ingredients of herbal highs and to compare their chemical composition. Twenty-nine various products seized by the police in one of the “head shops” were analysed. Herbal mixtures (0.2 g) were prepared by ultrasonic-assisted extraction with 2.0 ml of ethanol for 2 h. The extracts were analysed by gas chromatography coupled to mass spectrometry (GC/MS). The main active compounds of the herbal mixtures were synthetic cannabinoids: JWH-018, JWH-073 and cannabicyclohexanol (CP-47,497-C8-homolog). Their content differed between the products; some contained only one cannabinoid whereas the others contained two or more. Cluster analysis and principal component analysis revealed that chemical composition of many products was very similar. The similarity was connected with their flavour and not the common name. This statement was true for the synthetic cannabinoids, other potential agonists of cannabinoid receptors (amides of fatty acids) and ingredients of natural origin and confirms that herbal highs are a threat to human health because the purchaser has no information on their real composition.     

Studies on the adsorption of cell impurities from plasmid-containing lysates to phenyl boronic acid chromatographic beads

Plasmid DNA (pDNA) is purified directly from alkaline lysis-derived Escherichia coli (E. coli) lysates by phenyl boronate (PB) chromatography. The method explores the ability of PB ligands to bind covalently, but reversibly, to cis-diol-containing impurities like RNA and lipopolysaccharides (LPS), leaving pDNA in solution. In spite of this specificity, cis-diol free species like proteins and genomic DNA (gDNA) are also removed. This is a major advantage since the process is designed to keep the target pDNA from binding. The focus of this paper is on the study of the secondary interactions between the impurities (RNA, gDNA, proteins, LPS) in a pDNA-containing lysate and 3-amino PB controlled pore glass (CPG) matrices. Runs were designed to evaluate the role of adsorption buffer composition, feed type (pH, salt content), CPG matrix and sample pretreatment (RNase A, isopropanol precipitation). Water was chosen as the adsorption buffer over MgCl(2) solutions since it maximised pDNA yield (96.2±4.9%) and protein removal (61.3±3.0%), while providing for a substantial removal of RNA (65.5±3.5%) and gDNA (44.7±14.1%). Although the use of pH 3.5 maximised removal of impurities (~75%), the best compromise between plasmid yield (~96%) and RNA clearance (~60-70%) was obtained for a pH of 5.2. Plasmid yield was maximal (>96%) when the concentration of acetate and potassium ions in the incoming lysate feed were 1.7 M and 1.0 M, respectively. The pre-treatment of lysates with RNase A deteriorated the performance since the resulting oligoribonucleotides lack the cis-diol group at their 3' termini. Overall, the results support the idea that charge transfer interactions between the boron atom at acidic pH and electron donor groups in the aromatic bases of nucleic acids and side residues of proteins are responsible for the non-specific removal of gDNA, RNA and proteins.     

Regio- and stereoselective methoxyselenenylation of chiral 2-vinyl perhydro-1,3-benzoxazines promoted by selenium-heteroatom nonbonded interactions

Regio- and diastereoselective methoxyselenenylations of double bonds attached to the N,O-ketalic carbon of chiral perhydrobenzoxazines occur in high yields by reaction with benzeneselenenyl chloride in dichloromethane-methanol. The diastereoselection is dependent on the reaction conditions and the structure of the starting compounds and can be rationalized by accepting the coordination of the selenium to the oxygen atom of the heterocycle.     

A synthetic, chloride-selective channel that alters chloride transport in epithelial cells

An Ussing chamber was used to demonstrate that synthetic amphiphilic anion transporters function as chloride transporters in mammalian airway epithelial cells.     

Efficient and green telescoped process to 2-methoxy-3-methyl-[1,4]benzoquinone

A telescoped process for the preparation of 2-methoxy-3-methyl-[1,4]benzoquinone is disclosed. When this novel process is compared to the prevailing method that utilizes Na2Cr2O7 as the oxidant, the novel process represents a high yielding (95%), green, and environmentally benign alternative with H2O2 and HNO3 as the oxidants and CH3COOH as the reaction medium.     

Phase transfer catalyzed enantioselective Strecker reactions of alpha-amido sulfones with cyanohydrins

A study into the use of a chiral phase-transfer catalyst in conjunction with acetone cyanohydrin to effect the enantioselective formation of alpha-amino nitriles from alpha-amido sulfones is described. This novel catalytic asymmetric Strecker reaction is analyzed with regard to the possible mechanistic basis.     

Placement and characterization of pairs of luminescent molecules in spatially separated regions of nanostructured thin films

Methods of making mesostructured sol-gel silicate thin films containing two different molecules deliberately placed in two different spatially separated regions in a one-step, one-pot preparation are developed and demonstrated. When the structure-directing agent is the surfactant cetyltrimethylammonium bromide, the structure is 2-D hexagonal with lattice spacings between 31.6 and 42.1 angstroms depending on the dopant molecules and their concentrations. The three general strategies that are used to place the molecules are philicity (like dissolves like), bonding, and bifunctionality. These strategies take advantage of the different chemical and physical properties of the regions of the films. These regions are the inorganic silicate framework, the hydrophobic organic interior of the micelles, and the ionic interface between them. Luminescent molecules that possess the physical and chemical properties appropriate for the desired strategies are chosen. Lanthanide and ruthenium complexes with condensable trialkoxysilane groups are incorporated into the silicate framework. 1,4-Naphthoquinone, pyrene, rhodamine 6G and coumarin 540A, and lanthanides with no condensable trialkoxysilanes occupy the hydrophobic core of micelles by virtue of their hydrophobicity. The locations of the molecules are determined by luminescence spectroscopy and by luminescence lifetime measurements. In all cases, the long-range order templated into the thin film is verified by X-ray diffraction. The simultaneous placement of two molecules in the structured film and the maintenance of long-range order require a delicate balance among film preparation methodology, design of the molecules to be incorporated in specific regions, and concentrations of all of the species.     

Synthesis of alpha-hydrazino ketones via regio- and stereoselective electrophilic amination of manganese enolates and enamines

A straightforward procedure for the regio- and stereoselective synthesis of alpha-hydrazino ketones is described. Manganese enolates and manganese enamines derived from ketones and from the corresponding N-sulfinylimines react with azodicarboxylate esters (DTBAD and DEAD) in a regioselective fashion to afford in good to excellent yields the kinetic alpha-hydrazino ketones as sole or highly prevalent products. When enantiopure N-sulfinyl manganese enamines were used the stereoselectivity of these reactions ranged from 40% to 68% ee.     

Synthesis and biological evaluation of rigid polycyclic derivatives of the Diels-Alder adduct tricyclo[6.2.1.02,7]undeca-4,9-dien-3,6-dione

Part of our research program concentrates on the discovery of new bioactive compounds prepared either by total synthesis or molecular transformation of compounds with bioactivity profiles. In this work we have focused our interest on chemical transformations of the Diels-Alder adduct tricyclo[6.2.1.0(2,7)]undeca-4,9-dien-3,6-dione in order to obtain cage-like compounds and derivatives, followed by an evaluation of their biological activity.