Meruyert B. Issabayeva

Ms. Meruyert B. Issabayeva

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 December 2019 in Series of Geology and Technical Sciences
Verified
Journal Article
Closed access
YTYelena Tseshkovskaya
Yelena Tseshkovskaya
EGElena Golubeva
Elena Golubeva
MIMARAT IBRAYEV
MARAT IBRAYEV
AOAigul Oralova
Aigul Oralova
NTNataliya Tsoy
Nataliya Tsoy
MIMeruyert B. Issabayeva
Meruyert B. Issabayeva

27 December 2022 in Plants
Verified
Journal Article
Open access
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MIMARAT IBRAYEV
MARAT IBRAYEV
NANurkenov Oralgazy Aktaevich
Nurkenov Oralgazy Aktaevich
ZRZhanara Rakhimberlinova
Zhanara Rakhimberlinova
ATAltynaray Takibayeva
Altynaray Takibayeva
DTDastan Turdybekov
Dastan Turdybekov
AMAnel Mendibayeva
Anel Mendibayeva
This article has studied the synthesis of a new derivative of the known alkaloid cytisine contained in the seeds of plants of Cytisus laburnum L. and Thermopsis lanceolata R.Br., both of the Lugiminosae family. The new compound has been obtained from two biologically active compounds, such as isoxazole and cytisine. It has been demonstrated that the reaction led to the single-stage method under very mild conditions to obtain 4-[(3,5-dimethyl-1,2-oxazol-4-yl)sulfonyl]cytisine. This class of compounds is promising for obtaining the new biologically active compounds. This article has examined, in detail, a structure with using the 1H and 13C NMR and two-dimensional NMR spectroscopy of COSY (1H-1H), HMQC (1H-13C) and HMBC (1H-13C). As a result, the homo- and heteronuclear spin-spin couplings should be established. The X-ray diffraction analysis has determined the spatial structure of a new derivative based on the cytisine alkaloid. Thus, its hemorheological activity has been studied.

26 June 2026 in Polymers
Verified
Journal Article
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ASAkmaral Sarsenbekova
Akmaral Sarsenbekova
AMAlmagul Makhmutova
Almagul Makhmutova
MZMeruyert Zhunissova
Meruyert Zhunissova
NRNazigul S. Remetova
Nazigul S. Remetova
MIMeruyert B. Issabayeva
Meruyert B. Issabayeva
BABibigul B Ashirbekova
Bibigul B Ashirbekova
The effect of reversible addition–fragmentation chain transfer (RAFT) polymerization on the structure, morphology, and thermal degradation behavior of polypropylene glycol maleate–acrylic acid copolymers (p-PGM:AA) was investigated using 2-cyano-2-propyl dodecyl trithiocarbonate (CPDT) as the RAFT agent. Copolymers synthesized at different CPDT concentrations were characterized by 1H/13C NMR spectroscopy, gel permeation chromatography (GPC), transmission electron microscopy (TEM), thermogravimetric analysis coupled with mass spectrometry (TG–MS), isoconversional kinetic methods, and density functional theory (DFT) calculations. 1H NMR spectroscopy revealed a progressive decrease in the relative intensity of vinyl proton signals with increasing CPDT concentration, indicating enhanced conversion of unsaturated fragments during copolymerization. Alkaline hydrolysis followed by 1H NMR and GPC analysis of the degradation products confirmed cleavage of polyester segments and yielded low-molecular-weight fragments with Mn = 1370 g mol−1 and narrow dispersity (Đ = 1.035), providing additional information on the architecture of the vinyl-polymerized segments. Increasing CPDT concentration resulted in lower molecular weights and narrower molecular weight distributions of the soluble copolymer fractions. TEM analysis demonstrated broader domain size distributions and increased morphological heterogeneity in RAFT-modified samples, accompanied by an increase in swelling degree. Thermogravimetric analysis showed that RAFT-modified systems undergo multi-stage thermal degradation with the appearance of an additional low-temperature stage associated with thermolabile fragments. TG–MS revealed earlier evolution of CO2 and oxygen-containing species and changes in the distribution of volatile products. DFT calculations indicated a decrease in the HOMO–LUMO energy gap and suggested the participation of RAFT-derived fragments in the energetic characteristics of decarboxylation processes. Isoconversional and nonlinear kinetic analyses demonstrated increased kinetic heterogeneity for branched copolymer s synthesized at elevated CPDT concentrations, whereas cross-linked systems exhibited more uniform degradation behavior. The combined experimental and theoretical results demonstrate that RAFT polymerization provides an effective route for tuning the macromolecular architecture, morphology, and thermal degradation pathways of p-PGM:AA copolymers.

15 October 2020 in SERIES CHEMISTRY AND TECHNOLOGY
Verified
Journal Article
Closed access
MIMARAT IBRAYEV
MARAT IBRAYEV
ATAltynaray Takibayeva
Altynaray Takibayeva
SFSerik Fazylov
Serik Fazylov
ZRZhanara Rakhimberlinova
Zhanara Rakhimberlinova
MIMeruyert B. Issabayeva
Meruyert B. Issabayeva
KAKelmyalene A. A.
Kelmyalene A. A.
This article presents studies on the targeted search for new derivatives of azoles, such as benzthiazole, 3,5-dimethylpyrazole, 1,3,4-oxadiazole-2-thione, 1,3,4-thiadiazole. The possibility of combining in one molecule of the azole ring with other cyclic compounds: the alkaloid cytisine, morpholine, furan and some arenes has been studied. To obtain new compounds, the reactions of bromination, acylation, and interaction with isothiocyanates were studied. Optimal synthesis conditions were studied for all reactions. It was found that the reaction of 4-bromo-3,5-dimethylpyrazole with isothiocyanates, in contrast to the previously written derivatives of anilines, takes a longer time and requires heating the reaction mixture. The combination of a pirasol fragment with halide substituents often results in an enhanced therapeutic effect. The synthesized 2-bromine-N-(6-rodanbenzo[d]thiazole-2-yl)acetamide, due to the alkylbromide group, is an important synth in the synthesis of new benzthiazole derivatives. Its derivatives combine in one molecule the rest of rhodanbenzthiazole with alkaloid cytisine and biogenic amine morpholine and are potentially biologically active compounds, since the molecule structure contains several pharmacophoric fragments: benzthiazole and alkaloid (amine) heterocycles, rhodane and urea groups. The mechanism of formation of 1,3,4-oxadiazole-2-tyons from hydrazides under action on them by carbon disulfide was studied and assumed. It was shown that dithiocarbamates in acidic medium decompose with the release of hydrogen sulfide and the formation of highly reactive isothiocyanate group. Then, intra-molecular cyclization occurs, with the formation of end products - 1,3,4-oxadiazole-2-thions. The structures of the synthesized compounds were studied by 1H and 13C NMR spectroscopy. All synthesized substances are potentially biologically active compounds, since they contain several pharmacophore fragments in their structure.

25 October 2022 in Preprints.org
Verified
Preprint
Open access
PDF file
MIMARAT IBRAYEV
MARAT IBRAYEV
NANurkenov Oralgazy Aktaevich
Nurkenov Oralgazy Aktaevich
ZRZhanara Rakhimberlinova
Zhanara Rakhimberlinova
ATAltynaray Takibayeva
Altynaray Takibayeva
DTDastan Turdybekov
Dastan Turdybekov
AKAssel A. Kelmyalene
Assel A. Kelmyalene
This article has been studied the synthesis of a new derivative of the known alkaloid cytisine contained in the seeds of plants of Cytisus laburnum L. and Thermopsis lanceolata R.Br., both of the Lugiminosae family. The new compound has been obtained from two biologically active compounds such as isoxazole and cytisine. It has been demonstrated that the reaction led to the single-stage method under very mild conditions to obtain some 4-[(3,5-dimethyl-1,2-oxazole-4-yl)sulfonyl]amides. This class of compounds is promising to obtain the new biologically active compounds. This article has examined in detail a structure with using the 1H and 13C NMR and two-dimensional NMR spectroscopy of COSY (1H-1H), HMQC (1H-13C) and NMVS (1H-13C). As a result, the homo- and heteronuclear spin-spin couplings should be established. The X-ray diffraction analysis has determined the spatial structure of a new derivative based on cytisine alkaloid. Thus, its hemorheological activity has been studied.