Magnetic Nanosystem for Cancer Therapy Using Oncocalyxone A,an Antitomour Secondary Metabolite Isolated from a Brazilian Plant

This paper describes the investigation and development of a novel magnetic drug delivery nanosystem (labeled as MO-20) for cancer therapy. The drug employed was oncocalyxone A (onco A), which was isolated from Auxemma oncocalyx, an endemic Brazilian plant. It has a series of pharmacological properties: antioxidant, cytotoxic, analgesic, anti-inflammatory, antitumor and antiplatelet. Onco A was associated with magnetite nanoparticles in order to obtain magnetic properties. The components of MO-20 were characterized by XRD, FTIR, TGA, TEM and Magnetization curves. The MO-20 presented a size of about 30 nm and globular morphology. In addition, drug releasing experiments were performed, where it was observed the presence of the anomalous transport. The results found in this work showed the potential of onco A for future applications of the MO-20 as a new magnetic drug release nanosystem for cancer treatment.     

A Silica Gel Based Method for Extracting Insect Surface Hydrocarbons

Here, we describe a novel method for the extraction of insect cuticular hydrocarbons using silica gel, herein referred to as “silica-rubbing”. This method permits the selective sampling of external hydrocarbons from insect cuticle surfaces for subsequent analysis using gas chromatography–mass spectrometry (GC-MS). The cuticular hydrocarbons are first adsorbed to silica gel particles by rubbing the cuticle of insect specimens with the materials, and then are subsequently eluted using organic solvents. We compared the cuticular hydrocarbon profiles that resulted from extractions using silica-rubbing and solvent-soaking methods in four ant and one bee species: Linepithema humile, Azteca instabilis, Camponotus floridanus, Pogonomyrmex barbatus (Hymenoptera: Formicidae), and Euglossa dilemma (Hymenoptera: Apidae). We also compared the hydrocarbon profiles of Euglossa dilemma obtained via silica-rubbing and solid phase microextraction (SPME). Comparison of hydrocarbon profiles obtained by different extraction methods indicates that silica rubbing selectively extracts the hydrocarbons that are present on the surface of the cuticular wax layer, without extracting hydrocarbons from internal glands and tissues. Due to its surface specificity, efficiency, and low cost, this new method may be useful for studying the biology of insect cuticular hydrocarbons.     

Samarium‐Promoted Asymmetric Aldol–Tishchenko Reaction: Synthesis of Amino Acid‐Derived 4‐Amino‐1,3‐diols

A samarium‐mediated novel synthesis of enantiopure 4‐amino‐1,3‐diols is carried out through a samarium‐promoted aldol–Tishchenko reaction starting from chiral α′‐amino‐α‐chloro ketones (derived from natural α‐amino acids) and aldehydes. The process takes place with moderate levels of stereoselectivity and in high yields. A mechanism is proposed to explain these results while the absolute configuration and structure of the aldol–Tishchenko adducts were established by X‐ray analysis. This method has also been utilized for the synthesis of enigmols, 1‐deoxysphingoid base analogues.     

Discovery of BAY 94-8862: A Nonsteroidal Antagonist of the Mineralocorticoid Receptor for the Treatment of Cardiorenal Diseases

Aldosterone is a hormone that exerts manifold deleterious effects on the kidneys, blood vessels, and heart which can lead to pathophysiological consequences. Inhibition of the mineralocorticoid receptor (MR) is a proven therapeutic concept for the management of associated diseases. Use of the currently marketed MR antagonists spironolactone and eplerenone is restricted, however, due to a lack of selectivity in spironolactone and the lower potency and efficacy of eplerenone. Several pharmaceutical companies have implemented programs to identify drugs that overcome the known liabilities of steroidal MR antagonists. Herein we disclose an extended SAR exploration starting from cyano‐1,4‐dihydropyridines that were identified by high‐throughput screening. Our efforts led to the identification of a dihydronaphthyridine, BAY 94‐8862, which is a potent, selective, and orally available nonsteroidal MR antagonist currently under investigation in a clinical phase II trial.     

Study of the anticancer properties of tin(IV) carboxylate complexes on a panel of human tumor cell lines

A group of organotin(IV) complexes were prepared: [SnCy₃(DMNI)] ( 1 ), [SnCy₃(BZDO)] ( 2 ), [SnCy₃(DMFU)] ( 3 ), and [SnPh₂(BZDO)₂] ( 4 ), for which DMNIH=2,6‐dimethoxynicotinic acid, BZDOH=1,4‐benzodioxane‐6‐carboxylic acid, and DMFUH=2,5‐dimethyl‐3‐furoic acid. The cytotoxic activities of compounds 1 – 4 were tested against pancreatic carcinoma (PANC‐1), erythroleukemia (K562), and two glioblastoma multiform (U87 and LN‐229) human cell lines; they show very high antiproliferative activity, with IC₅₀ values in the 150–700 nM range after incubation for 72 h. Distribution of cellular DNA upon treatment with 1 – 4 revealed that whereas compounds 1 – 3 induce apoptosis in most of the cell lines, compound 4 does not affect cell viability in any cell line tested, indicating a possible difference in cytotoxic mechanism. Studies with the daunomycin‐resistant K562/R cell line expressing P‐glycoprotein (Pgp) showed that compounds 1 – 4 are not substrates of this protein efflux pump, indicating that these compounds do not induce acquisition of multidrug resistance, which is associated with the overexpression of Pgp.     

Magnetic communication through functionalized nanotubes: a theoretical study

Functionalized nanotubes are good candidates to promote communication between paramagnetic centers at large distances through a highly delocalized pi system. Our study using theoretical methods based on density functional theory predicts the presence of surprisingly strong coupling at very large distances for this kind of system. To reach such strong couplings the system has to fulfill two conditions, the presence of highly charged metal cations and a metallic character of the nanotube.     

Gasification of a pulverized sub-bituminous coal in CO2 at atmospheric pressure in an entrained flow reactor

Char gasification by CO₂ may play an important role in oxy-fuel applications and affect particle temperature histories and overall reaction rates during combustion. This paper presents the results of a complete set of experiments of char gasification in CO₂ performed with a pulverized Indonesian sub-bituminous coal in an entrained flow reactor under realistic conditions; series of burnout curves at different reactor temperatures (1040–1300 °C) and CO₂ concentrations (0.7–100%) reveal consistent trends in the gasification rates. The study included also devolatilization and oxidation tests with this coal in the same experimental facility. The data are used to derive apparent kinetics for the three processes, in a manner similar to that followed in a previous work for the oxidation of a pulverized coal. The gasification kinetic parameters and reaction rates measured are then compared with values taken or derived from previous works by others, obtained by thermogravimetric analysis or experiments in entrained flow reactors. Finally, the relevance of char gasification in the overall reaction rate under conditions representative of those in an industrial boiler is explored, in particular for the case of oxy-coal combustion.     

Inactivation of Escherichia coli O157:H7 in fruit juices by combined treatments of citrus fruit essential oils and heat

This work approaches the possibility of combining mild heat treatments with citrus fruit essential oils (EOs) to improve the effectiveness of heat treatments and thus to reduce treatment intensity. Concentrations between 10 and 200μL/L of lemon, mandarin, or orange EO were tested at 54°C for 10min in laboratory media, determining that 200μL/L of each EO was necessary to achieve a 5 log(10) reduction of the initial Escherichia coli O157:H7 concentration. A relationship could be established between sublethally injured cells after the heat treatment and inactivated cells after the combined process. In apple juice, the synergism in the inactivation of E. coli O157:H7 when adding 200μL/L of lemon EO might suppose a reduction in the treatment temperature (of 4.5°C) or in the treatment time (by 5.7 times) within the range of temperature assayed (54-60°C). Addition of 75μL/L of lemon EO was determined to achieve the same synergistic effect of the combined treatment when the initial inoculum was reduced from 3×10(7) to 3×10(4)CFU/mL. Since the addition of lemon EO did not decrease the hedonic acceptability of apple juice, the proposed combined treatment could be further studied and optimized for the production of new minimally processed juices.     

Rapid discrimination of Bifidobacterium animalis subspecies by matrix-assisted laser desorption ionization-time of flight mass spectrometry

Currently, the species Bifidobacterium animalis consists of two subspecies, B. animalis subsp. lactis and B. animalis subsp. animalis. Among these two subspecies, B. animalis subsp. lactis is especially important because it is widely used in the manufacture of probiotic dairy products. The application of these microbes in the food industry demands fast, accurate and low cost methods to differentiate between species and strains. Although various genotypic methods have been employed to discriminate between these two subspecies, they are not easily adapted for rapid identification in the industry. The purpose of this study was to evaluate the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to differentiate between the two subspecies of B. animalis, and for discrimination at strain level. We identified twenty-three strains of B. animalis at subspecies and strain level by genotypic methods and by proteomics using MALDI-TOF MS. The proteomics identification by MALDI-TOF was nearly identical to that obtained by genotypic identification using comparison of tuf and atpD gene sequences, and single-nucleotide polymorphisms (SNPs), insertions, and deletions (INDELs). We identified four protein markers, L1, L2, A1, and A2, which are useful for discriminating between both subspecies. Proteomics identification using MALDI-TOF MS was therefore an accurate method for discriminating and identifying these bacteria. Given the speed in which this method is achieved (~20 min including sample preparation), MALDI-TOF MS is promising as a tool for rapid discrimination of starter cultures and probiotics.