Isolation and amino acid sequence of a serine proteinase inhibitor from common flax (Linum usitatissimum) seeds

LUTI (Linum usitatissimum trypsin inhibitor), a member of the potato inhibitor I family, has been isolated from seeds of flax by ethanol fractionation, ion exchange chromatography on CM-Sephadex C-25, affinity purification on immobilized methylchymotrypsin (alpha-chymotrypsin in which His57 has been converted to 3-methylhistidine) in the presence of 5M NaCl, and finally by reversed-phase HPLC. The 7655 Da inhibitor consists of a single polypeptide chain of 69 residues with one disulfide bridge. The molecule is acetylated at the N terminus. Its primary structure has been determined after limited proteolysis of the native molecule with trypsin at the reactive site, cleavage with cyanogen bromide or arginyl endopeptidase (Arg-gingipain), and alcoholytic deacetylation of the N-terminally blocked serine. The association constants (K(a)) of LUTI with bovine beta-trypsin and alpha-chymotrypsin are 3.58x10(10) M(-1) and 5.02x10(5) M(-1), respectively. High NaCl concentration (3M) increased the association constant of LUTI with alpha-chymotrypsin to 6.64x10(7) M(-1). To our knowledge, LUTI is the first serine-proteinase-type inhibitor isolated from a plant of the Linaceae family.     

Spontaneous formation of polylactide stereocomplex microspheres containing metal ions

Linear poly(l ‐lactides) (PLLAs ) and poly(d ‐lactides) (PDLAs ) with M _n in the range 2000 ? 4300 containing a different number and placement of carboxyl groups were obtained via cationic ring‐opening polymerization and post‐polymerization functionalization. PLA stereoisomers (PLLA ‐(COOH )_x and PDLA ‐(COOH )_x , where x = 1 ? 3) were used for the investigation of stereocomplexation in solution performed in the presence of metal cations such as Ca²⁺, Mg²⁺, Zn²⁺, Fe³⁺. Spherical microparticles with a diameter in the range 0.7 ? 3.0 µm were obtained in all cases which was confirmed on the basis of scanning electron microscopy (SEM ) analysis. The microsphere size and homogeneity were analyzed depending on the stereocomplexation conditions and the molecular weight as well as the number of carboxyl end groups in the PLLA and PDLA used for stereocomplexation. The PLA microspheres obtained were analyzed by Fourier transform IR spectroscopy, wide angle X‐ray spectroscopy and energy‐dispersive X‐ray spectroscopy methods which confirmed the presence of metal cations inside. The application of regular microspheres with metal ions as drug delivery systems is considered. © 2016 Society of Chemical Industry     

Polyhydroxyalkanoate‐based drug delivery systems

Microbial polyhydroxyalkanoates (PHAs) have been a subject of significant research interest in the past few decades. The recent development of novel functionalized PHAs has opened up new possibilities to combine the good biocompatibility of PHA‐based drug delivery systems to, for example, improve drug loading and release properties, targeting or imaging functionalities. This mini‐review presents some recent scientific developments in the preparation of functionalized PHAs, PHA–drug and PHA–protein conjugates, multifunctional PHA nanoparticles and micelles as well as biosynthetic PHA particles for drug delivery. These developments in combination with the generally excellent biocompatibility of PHA materials are expected to further expand the interest in PHA materials for drug delivery and other therapeutic applications. © 2016 Society of Chemical Industry     

The application of organophosphorus flame‐retardants in epoxy resin

The influence of two novel aryl phosphate mixtures on fire retardancy and the thermal stability of epoxy resin were studied. Combustion behavior, decomposition pathway, and thermal and thermo‐oxidative degradation of the epoxy resin were examined by using the limiting oxygen index, vertical burning test (UL‐94), cone calorimeter test, thermogravimetric analysis, and thermogravimetry coupled with Fourier‐transform infrared spectroscopy. The morphology of the residues from the degradation of flame‐retarded epoxy resins was investigated by using scanning electron microscopy. Data from the cone calorimeter test demonstrated that the total heat evolved, heat release rate, and peak heat release rate decreased significantly when the epoxy resin contained these retardants. Moreover, a 20 wt% of both phosphate mixtures in the epoxy resin allowed for a satisfactory oxygen index (30–33%) and for UL‐94 V2 to be achieved. The condensed‐phase and gas‐phase actions of these aryl phosphate flame‐retardants are proposed as the mode of flame‐retardancy in epoxy resins. J. VINYL ADDIT. TECHNOL., 23:142–151, 2017. © 2015 Society of Plastics Engineers     

Reduction of Captan,Boscalid and Pyraclostrobin Residues on Apples Using Water Only,Gaseous Ozone,and Ozone Aqueous Solution

Intensive use of plant protection products in modern agriculture and horticulture often results in increasing residue levels of active ingredients of plant protection products in fruits and vegetables. Even if the maximum residue levels are not exceeded, the synergic effects of various compounds may have a serious impact on consumers' health. In particular, more sensitive consumer groups, e.g., children, may be affected. Therefore, it is important to develop an effective method that could be utilized for reduction of pesticide residue levels in food products of plant origin. In this work, possible application of ozone to reduce pesticide residue levels in apples has been investigated. The fruits were treated with ozone in gaseous state, in ozonized water, and in water alone, which was used for rinsing the fruits. The experiments included tests on apples that were subjected to a protection program using captan, boscalid and pyraclostrobin. The ozonized water and treatment with a gaseous ozone were found to be not more efficient in reducing the pesticide content on the fruits than simple washing procedures, e.g., 81–95% reduction of captan residue or 40–67% reduction of boscalid residue and 20–42% reduction of pyraclostrobin residue. Still, ozonation of water used for rinsing prevented fruits from consecutive contamination by pesticide residues present in water after several rinsing cycles. It was proven that application of ozonation process as a part of post-harvest treatment of apples may be beneficial for the fruit quality.     

A Critical Role for the Presence of Lignocellulosic Material in the Determination of Wood Buffering Capacity

The currently used determinations of wood buffering capacity, which are based on pH-metric titrations of aqueous wood extracts, neglect the effect of lignocellulosic material and the role of its insoluble constituents. This study examined the influence of the presence of wood in a system subjected to titration. A comparison of the results obtained from pine chip extracts and chip suspensions showed that the presence of wood and the wood-to-water ratio were critical factors that affected the measurement of the wood buffering capacity. The evidence showed that the resulting determination may vary by up to six times (0.28–1.99 ml/g), depending upon the conditions of the titration. In addition, it was found that the presence of wood had a neutralizing effect over the course of prolonged pH observations.     

Effects of various roasting conditions on acrylamide,acrolein, and polycyclic aromatic hydrocarbons content in cocoa bean and the derived chocolates

The effect of roasting parameters such as the temperature (135 and 150°C) and relative humidity of air (RH of 0.3 and 5.0%) on acrylamide, acrolein, and polycyclic aromatic hydrocarbon (PAH) levels in whole and crushed cocoa beans and chocolates derived from these beans was studied. Acrylamide was identified in all tested samples of roasted cocoa beans, irrespective of process conditions. Its contents in chocolates produced from these beans were similar. The highest acrylamide concentration was found in whole cocoa beans roasted at 135°C and RH of 5.0%. Small amounts of acrolein were present only in the roasted whole cocoa beans while neither the roasted crushed cocoa beans nor chocolates contained this aldehyde. Roasting conditions significantly affected the profile and content of PAHs in whole and crushed cocoa beans and the richest in PAHs were crushed cocoa beans roasted at 150°C and RH of 5.0%. The chocolates obtained in this study contained significantly higher concentrations of PAHs than the roasted cocoa beans used for their production. The results of the study demonstrate that optimization of roasting conditions may reduce levels of all these harmful substances in cocoa beans.     

The Effectiveness in the Removal of PAHs from Aqueous Solutions in Physical and Chemical Processes: A Review

Polycyclic aromatic hydrocarbons (PAHs) are relatively well-known organic pollutants and due to their carcinogenic and mutagenic properties, their presence in the aqueous environment still attracts a lot of attention. This article presents a critical review of the literature on the application of physical and chemical processes for removal of PAHs from aqueous solution, including water and wastewater. The effectiveness of coagulation, chemical oxidation, photodegradation, sorption, and membrane processes in the degradation or removal of these micropollutants is described. The PAHs removal efficiency (coagulation ～ 99%, chemical oxidation ～ 87%, photodegradation ～ 93%, sorption ～ 100%, and membrane ～ 100%) during the above processes is difficult to compare due to the works conducted under different conditions and using various mediums, e.g., water, wastewater, PAHs model aqueous solutions.