Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


Химия

Synthesis and properties of grafted copolymers of xanthan and glucomannan with acrylic monomers

Graft copolymers of polysaccharides with acrylic monomers combine biodegradability, biocompatibility, the environmental friendliness of natural polymers and the increased thermal stability, chemical and mechanical resistance of synthetic polymers. This paper describes our search and analysis of the literature in English for 2002–2022 devoted to the graft polymerization of acrylamide, acrylic acid and 2-acrylamido2-methylpropanesulfonic acid onto xanthan and glucomannan macromolecular chains.

Synthesis of spiropyrrolizidines containing quinoxaline and pyrrole fragments

The reaction of 1,3-dipolar cycloaddition azomethine ylides obtained by the in situ interaction of 11H-indeno[1,2-b]quinoxalin-11-one and proline, and 3-phenyl-1-pyrrolyl-2-en-1-ones has been used for the synthesis of substituted spiropyrrolizidines in continuation of the study the use of new enones as dipolarophiles. The conditions for the implementation of a three-component synthesis (temperature regime, solvent, activation method) are selected. The best performance has been obtained by refl uxing the reaction mixture in ethanol.

Complex organomineral fertilizers and meliorants – a new eco-friendly approach to phosphogypsum utilization

One of the modern approaches to solving environmental problems of accumulation and deposition of production and consumption waste is the implementation of “green economy” and “closed cycle” economy models. This approach makes it possible to increase the resource utilization rate and reduce the negative impact on the environment. The study of the possibility of joint disposal of waste from various industries, for example agricultural and industrial waste, is promising in this area.

Cycvalone in the synthesis of nitrogen-, oxygen-containing heterocycles

Cycvalone is an analogue of curcumin (EE conformation), exhibits a wide range of biological activity (antioxidant, hepatoprotective, membrane stabilizing, anti-ulcer) and is used in medical practice as a choleretic. Numerous methods of producing cycvalone are known, including industrial ones, but its reactions have been studied much less. Some reactions of cycvalone with N, C-nucleophiles (hydrazines, malononitrile) have been carried out.

Novel degradable photocatalysts for wastewater treatment

The weakening of the manmade load on the environment has become a global goal of humanity. The accumulation of toxic substances in effl uents can increase the acceleration of pollution of the planet’s watersheds, resulting in biota pollution. To solve this problem, it is necessary to create photocatalysts that cause self-excitation under the ignition of light. Also, important parameters of photocatalysts are simple synthesis and low cost. This article demonstrates a one-step approach to the synthesis of carbon nanostructures (CNS) with photocatalytic activity.

Description of the chemical interaction in the system CaO-Al2O3-SiO2

In this study the construction of a phase tree and the description of the chemical interaction for the ternary oxide system CaO-Al2 O3 -SiO2 are given. Particular interest to a system consisting of oxides of calcium, aluminum and silicon is associated with the production of highly demanded functional materials with desired properties. Melts of the CaO-Al2 O3 -SiO2 system are of great theoretical and applied importance. This is due to the signifi cant role of melts of these oxides and their mixtures in metallurgy, ceramics production, and other industries.

Determination of nitrates in fresh vegetables and their processed products

The number of nitro compounds of the anthropogenic origin in the general nitrogen cycle is steadily increasing, which leads to an increase in nitrates in products and increases the nitrate-nitrite load on the human body. The aim of the study was to determine the amount of nitrates in raw vegetables and their processed products. Vegetables with high (beetroot, cilantro, radish, green onion), medium (zucchini, carrot, cucumber) and low nitrate content (potato, tomato, onion) have been selected as the objects of the study.

Сравнение двух типов подвижных фаз для определения витаминов группы В методом тонкослойной хроматографии

Методом тонкослойной хроматографии (ТСХ) изучено влияние ряда факторов (природы неподвижной фазы, природы и концентрации органических растворителей и поверхностно-активных веществ, рН буферного раствора) на хроматографические характеристики витаминов группы В: В1 (тиамин), В6 (пиридоксин), В12 (цианокобаламин). В качестве неподвижных фаз (НФ) использовали пластины с полярным (Сорбфил на полимерной (высокоэффективные пластины, ВТСХ) и алюминиевой подложках, слабополярным (Полиамид-6) и неполярным (RP-18 на алюминиевой подложке) сорбентами.

ИСПОЛЬЗОВАНИЕ ГЛАУКОНИТОВЫХ ПЕСКОВ МАБИКАНСКОГО МЕСТОРОЖДЕНИЯ ДЛЯ УЛУЧШЕНИЯ СВОЙСТВ АММИАЧНОЙ СЕЛИТРЫ

Аммиачная селитра используется как в качестве удобрения в сельском хозяйстве, так и в качестве ингредиента для промышленных взрывчатых веществ (для карьеров, шахтных туннелей и т.д.). Вещество стабильно в нормальных условиях использования, хранения и транспортировки, но, несмотря на эту стабильность, в прошлом столетии произошло несколько несчастных случаев, связанных с большим количеством нитрата аммония, что привело к многочисленным смертельным случаям и травмам людей.

Оценка активности пероксидаз, содержащихся в различных растительных источниках

В данной работе была проведена ферментативная деструкция красителя бромфенолового синего в присутствии пероксида водорода и пероксидазы, содержащейся в корнеплодах хрена обыкновенного (Armoracia rusticana), редиса (Raphanus sativus var. radicula), репы желтой (Brassica napobrassica), дайкона (Raphanus sativus), редьки черной (Raphanus sativus 'Niger'), редьки зеленой (Raphanus), либо кочерыжке капусты белокочанной (Brassica capitata).

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