STUDY OF THE PROCESS OF HYDRATION OF MESITYL OXIDE IN THE PRESENCE OF NANOCATALYZERS

The process of mesityl oxide hydrogenation in the presence of a nickel catalyst prepared by impregnating a support with an aqueous solution of the corresponding salt in a displacement reactor in a gas-liquid-solid catalyst system has been studied. It has been established that the use of the catalyst used in the work makes it possible to selectively obtain methyl isobutyl ketone with complete conversion of mesityl oxide in the temperature range 70-100 ºС.

DEVELOPMENT OF A METHOD FOR PRODUCING (-)-17-ALLYL-4,5Ά-EPOXY-3,14-DIHYDROXYMORPHINAN-6-ONE

Naloxone ((-)-17-allyl-4,5ά-epoxy-3,14-dihydroxymorphinan-6-one) is a pure opiate antagonist of a competitive type devoid of morphine-like activity and is widely used in clinical practice. The main raw material for the production of naloxone is thebaine, which is extracted from plant materials. This study presents a seven-step process for preparing naloxone with a yield of 35% (based on thebaine). Previously known methods of obtaining are characterized by the yield of the target product in terms of thebaine not higher than 20%. The greatest losses are recorded at the stage of obtaining oxycodone from thebaine and at the stage of O-demethylation of codeine. The use of formic acid in the hydrogenation process provides a more complete conversion of the intermediate product, and the use of boron tribromide in the environment of chloroalkanes at the stage of O-demethylation leads to the production of naloxone with a yield of more than 70%. A detailed study of the stages of obtaining oxycodone and noroxycodone allows to reduce the consumption of reagents and the time spent in the reactor, which is essential for reducing the cost of the final product. The proposed method is superior to those known in terms of productivity and economic efficiency and can be used for the development of industrial technology for the production of naloxone and its derivatives.

A Methodology for an Auto-Generated and Auto-Maintained HL7 FHIR OWL Ontology for Health Data Management

The process of maintenance of an underlying semantic model that supports data management and addresses the interoperability challenges in the domain of telemedicine and integrated care is not a trivial task when performed manually. We present a methodology that leverages the provided serializations of the Health Level Seven International (HL7) Fast Health Interoperability Resources (FHIR) specification to generate a fully functional OWL ontology along with the semantic provisions for maintaining functionality upon future changes of the standard. The developed software makes a complete conversion of the HL7 FHIR Resources along with their properties and their semantics and restrictions. It covers all FHIR data types (primitive and complex) along with all defined resource types. It can operate to build an ontology from scratch or to update an existing ontology, providing the semantics that are needed, to preserve information described using previous versions of the standard. All the results based on the latest version of HL7 FHIR as a Web Ontology Language (OWL-DL) ontology are publicly available for reuse and extension.

Reversible bacteriophage resistance by shedding the bacterial cell wall

Phages are highly abundant in the environment and a major threat for bacteria. Therefore, bacteria have evolved sophisticated defense systems to withstand phage attacks. Here, we describe a previously unknown mechanism by which mono- and diderm bacteria survive infection with diverse lytic phages. Phage exposure leads to a rapid and near complete conversion of walled cells to a cell wall-deficient state, which remain viable in osmoprotective conditions and can revert to the walled state. While shedding the cell wall dramatically reduces the number of progeny phages produced by the host, it does not always preclude phage infection. Altogether, these results show that the formation of cell wall-deficient cells prevents complete eradication of the bacterial population and suggest that cell wall-deficiency may limit the efficacy of phage therapy, especially in highly osmotic environments or when used together with antibiotics that target the cell wall.

Characterization of a thermotolerant aryl-alcohol oxidase from Moesziomyces antarcticus oxidizing 5-hydroxymethyl-2-furancarboxylic acid

The development of enzymatic processes for the environmentally friendly production of 2,5-furandicarboxylic acid (FDCA), a renewable precursor for bioplastics, from 5-hydroxymethylfurfural (HMF) has gained increasing attention over the last years. Aryl-alcohol oxidases (AAOs) catalyze the oxidation of HMF to 5-formyl-2-furancarboxylic acid (FFCA) through 2,5-diformylfuran (DFF) and have thus been applied in enzymatic reaction cascades for the production of FDCA. AAOs are flavoproteins that oxidize a broad range of benzylic and aliphatic allylic primary alcohols to the corresponding aldehydes, and in some cases further to acids, while reducing molecular oxygen to hydrogen peroxide. These promising biocatalysts can also be used for the synthesis of flavors, fragrances, and chemical building blocks, but their industrial applicability suffers from low production yield in natural and heterologous hosts. Here we report on heterologous expression of a new aryl-alcohol oxidase, MaAAO, from Moesziomyces antarcticus at high yields in the methylotrophic yeast Pichia pastoris (recently reclassified as Komagataella phaffii). Fed-batch fermentation of recombinant P. pastoris yielded around 750 mg of active enzyme per liter of culture. Purified MaAAO was highly stable at pH 2–9 and exhibited high thermal stability with almost 95% residual activity after 48 h at 57.5 °C. MaAAO accepts a broad range of benzylic primary alcohols, aliphatic allylic alcohols, and furan derivatives like HMF as substrates and some oxidation products thereof like piperonal or perillaldehyde serve as building blocks for pharmaceuticals or show health-promoting effects. Besides this, MaAAO oxidized 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) to FFCA, which has not been shown for any other AAO so far. Combining MaAAO with an unspecific peroxygenase oxidizing HMFCA to FFCA in one pot resulted in complete conversion of HMF to FDCA within 144 h. MaAAO is thus a promising biocatalyst for the production of precursors for bioplastics and bioactive compounds. Key points • MaAAO from M. antarcticus was expressed in P. pastoris at 750 mg/l. • MaAAO oxidized 5-hydroxymethyl-2-furancarboxylic acid (HMFCA). • Complete conversion of HMF to 2,5-furandicarboxylic acid by combining MaAAO and UPO.

Highly selective synthesis of citronellal in water at multigram scale by Pd nanoparticles-catalyzed hydrogenation of citral

The synthesis of citronellal, an added-value chemical for perfumery, was carried out by selective and green hydrogenation of citral into citronellal in water. Aqueous suspensions of spherical ammonium-capped palladium nanoparticles with sizes around 3nm selectively reduced the conjugated carbon-carbon double bond. An excellent selectivity of 95% in citronellal was achieved at complete conversion under mild reaction conditions on a realistic 2 g scale in water. The presence of potassium hydroxide proved crucial to control the selectivity and avoid other hydrogenation co-products. These optimized results were further extended to a 135 g substrate loading with a relevant turnover number (TON) of 10 000.

CuO-Fe2O3 Nanoparticles Supported on SiO2 and Al2O3 for Selective Hydrogenation of 2-Methyl-3-Butyn-2-ol

In this study, novel SiO2- and Al2O3-supported Cu-Fe catalysts are developed for selective hydrogenation of 2-methyl-3-butyne-2-ol to 2-methyl-3-butene-2-ol under mild reaction conditions. TEM, XRD, and FTIR studies of adsorbed CO and TPR-H2 are performed to characterize the morphology, nanoparticle size, and particle distribution, as well as electronic state of deposited metals in the prepared catalysts. The deposition of Fe and Cu metal particles on the aluminum oxide carrier results in the formation of a mixed oxide phase with a strong interaction between the Fe and Cu precursors during the calcination. The highly dispersed nanoparticles of Fe2O3 and partially reduced CuOx, with an average size of 3.5 nm and with strong contact interactions between the metals in 5Cu-5Fe/Al2O3 catalysts, provide a high selectivity of 93% toward 2-methyl-3-butene-2-ol at complete conversion of the unsaturated alcohol.

Dehydration of isopropyl alcohol with activated carbon functionalized with Br- and S-containing reagents

Bromination of activated carbon GSGD was performed and active bromine-containing precursors were obtained, in which bromine is capable of being replaced by sulfur-containing functional groups. Bromination with liquid bromine and a solution of bromine in potassium bromide at room temperature leads to the introduction of 0.44–0.45 mmol g–1 of bromine into the surface layer of activated carbon. The treatment of brominated samples with sulfur-containing reagents with subsequent oxidation allows obtaining carbon samples that are catalytically active in the dehydration reaction of isopropyl alcohol in a gas phase. The temperature of complete conversion of isopropyl alcohol to propylene is a measure of catalytic activity. The concentration of sulfogroups in the prepared samples is up to 0.3 mol g–1. Thermogravimetry and thermoprogrammed desorption with mass spectrometric registration of products were used to study the thermal stability of modified activated carbon samples. The influence of the nature of brominating reagents, hydrolysis conditions and oxidation conditions on the structure, surface concentration of grafted S-containing groups and catalytic properties of the obtained materials was studied. Pre-bromination leads to an increase in the catalytic activity of activated carbon modified with sulfur-containing groups and the temperature of complete conversion of isopropyl alcohol to propylene decreases up to 400C depending on the concentration of sulfogroups.