Controlling platinum, ruthenium, and osmium reactivity for anticancer drug design

The main task of the medicinal chemist is to design molecules that interact specifically with derailed or degenerating processes in a diseased organism, translating the available knowledge of pathobiochemical and physiological data into chemically useful information and structures. Current knowledge of the biological and chemical processes underlying diseases is vast and rapidly expanding. In particular the unraveling of the genome in combination with, for instance, the rapid development of structural biology has led to an explosion in available information and identification of new targets for chemotherapy. The task of translating this wealth of data into active and selective new drugs is an enormous, but realistic, challenge. It requires knowledge from many different fields, including molecular biology, chemistry, pharmacology, physiology, and medicine and as such requires a truly interdisciplinary approach. Ultimately, the goal is to design molecules that satisfy all the requirements for a candidate drug to function therapeutically. Therapeutic activity can then be achieved by an understanding of and control over structure and reactivity of the candidate drug through molecular manipulation

Новий формат співробітництва (Договір про співробітництво між Національною академією наук України і Національною академією наук Киргизької Республіки)

A one-pot method has been developed for the oxidative cleavage of internal alkenes into aldehydes by using 0.5 mol % of the nonheme iron complex [Fe(OTf)2(mix-bpbp)] (bpbp=N,N′-bis(2-picolyl)-2,2′-bipyrrolidine) as catalyst and 1.5 equivalents of hydrogen peroxide and 1 equivalent of sodium periodate as oxidants. A mixture of diastereomers of the chiral bpbp ligand can be used, thereby omitting the need for resolution of its optically active components. The cleavage reaction can be performed in one pot within 20 h and under ambient conditions. Addition of water after the epoxidation, acidification and subsequent pH neutralization are crucial to perform the epoxidation, hydrolysis, and subsequent diol cleavage in one pot. High aldehyde yields can be obtained for the cleavage of internal aliphatic double bonds with cis and trans configuration (86–98 %) and unsaturated fatty acids and esters (69–96 %). Good aldehyde yields are obtained in reactions of trisubstituted and terminal alkenes (62–63 %). The products can be easily isolated by a simple extraction step with an organic solvent. The presented protocol involves a lower catalyst loading than conventional methods based on Ru or Os. Also, hydrogen peroxide can be used as the oxidant in this case, which is often disproportionated by second- and third-row metals. By using only mild oxidants, overoxidation of the aldehyde to the carboxylic acid is prevented

Проблеми ісламу України в їх науковому відтворенні

The Pd/TOMPP-catalysed (TOMPP = tris(2-methoxyphenyl)phosphine) telomerisation of 1,3-butadiene was studied under solvent- and base-free conditions with phenolic substrates that can be potentially derived from lignin. Large differences in catalytic activity were observed, with reactivity increasing in the order of phenol, p-cresol, guaiacol, creosol and syringol. This reactivity trend can be attributed to the substrates’ relative nucleophilicities, as induced by the donating effects of the p-methyl and o-methoxy substituents. The chosen reaction conditions, i.e. temperature, ligand/metal and butadiene/substrate ratios, strongly influenced both the conversion and selectivity of the reaction. Remarkably, the composition of the reaction medium, i.e. the butadiene/substrate ratio, exerted a strong influence on the linear/branched ratio. High conversions and selectivities to the linear products are obtained when excess butadiene is used. The linear telomer products could be readily converted from O-alkylated to Calkylated phenolics via the thermal Claisen rearrangement. High conversions and selectivities were observed after 2 hours at 200 1C. Branched o-octadienyl phenols were obtained in all cases except for the syringol telomer which gave the linear p-octadienyl product exclusively

Robust Bayes-Like Estimation: Rho-Bayes estimation

We consider the problem of estimating the joint distribution $P$ of $n$ independent random variables within the Bayes paradigm from a non-asymptotic point of view. Assuming that $P$ admits some density $s$ with respect to a given reference measure, we consider a density model $\overline S$ for $s$ that we endow with a prior distribution $\pi$ (with support $\overline S$) and we build a robust alternative to the classical Bayes posterior distribution which possesses similar concentration properties around $s$ whenever it belongs to the model $\overline S$. Furthermore, in density estimation, the Hellinger distance between the classical and the robust posterior distributions tends to 0, as the number of observations tends to infinity, under suitable assumptions on the model and the prior, provided that the model $\overline S$ contains the true density $s$. However, unlike what happens with the classical Bayes posterior distribution, we show that the concentration properties of this new posterior distribution are still preserved in the case of a misspecification of the model, that is when $s$ does not belong to $\overline S$ but is close enough to it with respect to the Hellinger distance.Comment: 68 page

Атеросклероз: патогенетические механизмы и принципы лечения

Проведен анализ факторов риска развития атеросклероза, дана оценка ряда теорий, объясняющих появление атеросклеротических изменений коронарных артерий. Подчеркивается роль эндотелиальной дисфункции в прогрессировании и обострении сердечно−сосудистых заболеваний. Проанализированы современные подходы к лечению атеросклероза.Risk factors of atherosclerosis development are described, a number of theories explaining atherosclerotic changes appearance in the coronary arteries are analyzed critically. The role of endothelial dysfunction in progress and exacerbation of cardiovascular diseases is emphasized. Contemporary approaches to atherosclerosis treatment are discussed

Розробка мобільної технології ремонту низьковуглецевих стальних труб низького та високого тиску методом пайки низькотемпературними припоями

Розроблено технологію безвогневого ремонту дефектів конструкцій з низьковуглецевих сталей шляхом пайки низькотемпературними припоями. Розроблено та заявлено новий склад легкоплавкого припою на базі олова з домішками міді та вісмуту. Припій оптимально поєднує властивості рідкоплинності, корозійної стійкості, міцності та адгезійної міцності. Технологію пайки сталей низькотемпературними припоями із застосуванням високочастотного генератора електричного струму доведено до стану практичного застосування.Разработана технология безогневого ремонта дефектов конструкций из низкоуглеродистых сталей путем пайки низкотемпературными припоями. Разработан и заявлен новый состав легкоплавкого припоя на базе олова, с добавками меди и висмута. Припой оптимально объединяет свойства жидкотекучести, коррозионной стой кости, прочности и адгезионной прочности. Технологию пайки сталей низкотемпературными припоями с применением высокочастотного генератора электрического тока доведено до состояния практического применения.The technology of out fire defects repair in low carbon steel constructions by soldering with low- temperature solders is developed. The new fusible tin rich solder composition containing copper and bismuth additives is developed and declared. The solder has optimum properties of liquid stream, corrosion resistance, durability and adhesion strength. The low carbon steel soldering technology with application of high-frequency electric current generator is carried to practical application

Techno-economic competitiveness of renewable fuel alternatives in the marine sector

The maritime sector accounts for almost 3% of global greenhouse gas emissions and is under increasing pressure to decarbonise rapidly. Renewable fuels represent a promising pathway for decarbonisation, but their high costs hinder adoption. Carbon Capture and Storage (CCS) can further augment marine fuel decarbonisation but adds to the cost. This work presents a harmonised cost comparison of four promising renewable carbon fuels (methanol, dimethyl ether (DME), liquefied natural gas (LNG) and bio-oil) produced either from routes utilising biomass (biofuels, including CCS) or CO2 (e-fuels). The differing technology status of the fuel production routes has been accounted for using the RAND Corporation method to estimate the cost of pioneer plants. Additionally, the impact of different levels of carbon taxation (15 or 140 €/t CO2) on the economic viability of the alternative fuels has been examined. None of the renewable fuels were found to be close to the incumbent fuels without carbon taxation, which needs to be considerable to adequately bridge the cost gap. Methanol and DME produced using point CO2 capture are the lowest cost choices if full scale sale of the oxygen by-product is considered. The biofuel routes remain at a premium to the existing fuels, while the direct air capture (DAC)-based fuels are the most expensive among the options studied, besides requiring completely renewable electricity for their carbon footprint to not exceed that of fossil fuels. Renewable LNG has a particularly high cost gap, bringing its status as a potential bridging fuel into doubt

High-Yield 5-Hydroxymethylfurfural Synthesis from Crude Sugar Beet Juice in a Biphasic Microreactor

5-Hydroxymethylfurfural (HMF) is an important biobased platform chemical obtainable in high selectivity by the hydrolysis of fructose (FRC). However, FRC is expensive, making the production of HMF at a competitive market price highly challenging. Here, it is shown that sugar beet thick juice, a crude, sucrose-rich intermediate in sugar refining, is an excellent feedstock for HMF synthesis. Unprecedented high selectivities and yields of '90 % for HMF were achieved in a biphasic reactor setup at 150 °C using salted diluted thick juice with H2SO4 as catalyst and 2-methyltetrahydrofuran as a bioderived extraction solvent. The conversion of glucose, obtained by sucrose inversion, could be limited to '10 mol %, allowing its recovery for further use. Interestingly, purified sucrose led to significantly lower HMF selectivity and yields, showing advantages from both an economic and chemical selectivity perspective. This opens new avenues for more cost-effective HMF production

High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to γ-valerolactone

The catalytic hydrogenation of ​levulinic acid, a key platform molecule in many biorefinery schemes, into ​γ-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, selective and stable supported metal catalysts for this reaction and on the beneficial effects of metal nano-alloying. Bimetallic random alloys of ​gold-palladium and ​ruthenium-palladium supported on ​titanium dioxide are prepared with a modified metal impregnation method. ​Gold-palladium/​titanium dioxide shows a marked,~27-fold increase in activity (that is, turnover frequency of 0.1 s−1) compared with its monometallic counterparts. Although ​ruthenium-palladium/​titanium dioxide is not only exceptionally active (that is, turnover frequency of 0.6 s−1), it shows excellent, sustained selectivity to ​γ-valerolactone (99%). The dilution and isolation of ruthenium by palladium is thought to be responsible for this superior catalytic performance. Alloying, furthermore, greatly improves the stability of both supported nano-alloy catalysts