Қазақ ұлттық қыздар педагогикалық университеті / Казахский национальный женский педагогический университет

Постоянный URI для этого сообществаhttps://cris.qyzpu.kz/handle/123456789/1

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2022 - 20233

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    Тип записи:Публикация,
    Physicochemical and Antioxidant Properties of Humic Acids from Low-Sulfur Kazakhstan Shales
    (Pleiades Publishing, 2022-09-01)
    S.M. Suimbayeva
    ;
    Ж. К. Каирбеков
    ;
    A. S. Maloletnev
    ;
    K. O. Kishibayev
    ;
    Индира Мухаметкеримовна Джелдыбаева
    The structural, chemical, and physicochemical characteristics and antioxidant properties of humic acids isolated from shale in the Kenderlyk and Kiin fields are determined. Negative values of the acids’ oxidation are found: –3.62 and –4.06 for Kenderlyk and Kiin shale, respectively. Thus, the shale-based humic acids are reducing agents. IR spectroscopic data show clear absorption bands of hydroxyl, functional, and carbonyl groups. ESR spectroscopy indicates a high content of paramagnetic centers in the humic acids: 9.3 × 10 17 and 9.5 × 10 17 spin/g for Kenderlyk and Kiin shale, respectively. The paramagnetic centers in the molecular structure of the humic acids indicate that they are promising as antioxidants.
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    Тип записи:Публикация,
    Physicochemical and Antioxidant Properties of Humic Substances from Coals of the Oy-Karagay and Kiyakty Deposits in the Republic of Kazakhstan
    (Pleiades Publishing, 2022-12-01)
    Индира Мухаметкеримовна Джелдыбаева
    ;
    Ж. К. Каирбеков
    ;
    A. S. Maloletnev
    ;
    Didar Zamanbekovna Abilmazhinova
    ;
    S.M. Suimbayeva
    Abstract The results of studies on the physicochemical and antioxidant properties of humic acids (HAs) and hymatomelanic acids (HMAs) from brown coals of deposits in the Republic of Kazakhstan are presented. It was found that the molecular structure of HAs from coals of the Oy-Karagay and Kiyakty deposits has functional groups of carbonyl, hydroxyl, and aliphatic nature as structural elements. The test samples of coals and HAs were characterized by the occurrence of paramagnetic centers (PMCs) with the Lande spectroscopic splitting factor values above 2.00, which indicate the presence of free radicals caused by a strongly delocalized electron cloud in the molecules of coals and HAs. The results of the amperometric determination of the antioxidant properties of HMAs indicated that the HMAs exhibit antioxidant activity, which will allow them to be used as a biologically active additive in the production of pharmaceutical preparations.
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    Тип записи:Публикация,
    Antioxidant Activity and Bioavailability of Humic Substances of Low-Mineralized Sulphide Mud
    (2023-01-01)
    Ж. К. Каирбеков
    ;
    S.M. Suimbayeva
    ;
    Индира Мухаметкеримовна Джелдыбаева
    ;
    Manshuk Z. Esenalieva
    ;
    А.Ж. Каирбеков
    Humic substances (HS) are natural compounds, the formation of which occurs in natural environments as a result of chemical and biological decomposition.HS accounts for 60% to 80% of organic matter in soil and aquatic environment.Therefore, we obtained samples of HS isolated from low-mineralized sulphide mud deposits of Tuzkol Lake (Republic of Kazakhstan) were obtained.HS samples have been characterized by instrumental methods: EPR spectroscopy and amperometry.Analysis of the concentration of paramagnetic centers shows that the minimum number of free radicals contains molecules of fulvic acids, and the maximum number of free radicals contains molecules of humic acids (HA) of peloids.The antioxidant activity and bioavailability of humic preparations in the form of sodium humates depending on the concentration of HS have been investigated.The information obtained indicates that HS have antioxidant activity and bioavailability, the value of which increases when the concentration of the solution grows.Dialysis of silver humate has been carried out in the presence of dimethyl sulfoxide (DMSO) at concentrations of 0.1; 1.0; 5.0 and 10% w/w.For HA and silver humate, a 10% concentration of DMSO is optimal, which allows a maximum yield of peloid preparations and a 1.6-fold increase in permeability.Dialysis of silver humate is 1.2 times more intensive than dialysis of HA.It has been shown that the change in the total content of antioxidants in various fractions of humic substances increases in the series; fulvic -humic -gimatomelanic acids.
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