New Polymorphic Modification of Y, Ho, Tm and Lu tris-2,2,6,6-tetramethyl-heptane-2,4-dionates: Structure, Volatility and Luminescence

2020 ◽  
Author(s):  
Pavel Aleksandrovich Stabnikov ◽  
Natalia V. Pervukhina ◽  
Natalia V. Kuratieva ◽  
Natalia A. Kryuchkova ◽  
Ilya V. Korolkov ◽  
...  
Keyword(s):  
Polymorphic Modification

New polymorphic modification of Y, Ho, Tm and Lu tris-2,2,6,6-tetramethyl-heptane-2,4-dionates: Structure, volatility and luminescence

Polyhedron ◽  
2021 ◽  
Vol 198 ◽  
pp. 115077
Author(s):  
Pavel A. Stabnikov ◽  
Natalia V. Pervukhina ◽  
Natalia V. Kuratieva ◽  
Natalia A. Kryuchkova ◽  
Ilya V. Korolkov ◽  
...  
Keyword(s):  
Polymorphic Modification

Structural and Proton Conductivity Studies of Fibrous π-Ti2O(PO4)2·2H2O: Application in Chitosan-Based Composite Membranes

2021 ◽  
Author(s):  
Artem A. Babaryk ◽  
Alaa Adawy ◽  
Inés García ◽  
Camino Trobajo ◽  
Zakariae Amghouz ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Proton Conductivity ◽  
Composite Membranes ◽  
Titanium Phosphate ◽  
Polymorphic Modification ◽  
Modification Of Titanium

Although the fibrous polymorphic modification of titanium phosphate, π-Ti2O(PO4)2·2H2O (π-TiP) is known for decades, its crystal structure has remained unsolved. Herewith we report the crystal structure of π-TiP at a...

Polymorphism control of active pharmaceutical ingredients

2021 ◽  
pp. 37-54
Author(s):  
Roman Petrovich Terekhov ◽  
Denis Igorevich Pankov ◽  
Ekaterina Aleksandrovna Anfinogenova ◽  
Irina Anatolievna Selivanova
Keyword(s):  
Active Pharmaceutical Ingredient ◽  
Development Stage ◽  
Poor Quality ◽  
Polymorphic Modification ◽  
High Tech ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
Medicinal Substances ◽  
The Usa ◽  
Economic Union

Рolymorphism is receiving increasing attention due to its influence on the physicochemical and pharmacological properties of the active pharmaceutical ingredients (API) while maintaining the molecular structure. This review is devoted to the problem of APIs phase state control both at the development stage and during the circulation of the drug. The term «polymorphism» has different definitions depending on the branch of science. There is no unambiguous solution to this issue in the regulatory documentation of pharmaceutical industry either. Based on the analysis of literary sources, the article presents a comparison of pharmacopeia methods, recommended in Russian and foreign regulatory documents for the analysis of polymorphism of medicinal substances, including state pharmacopeias of Russia, Belarus, Kazakhstan, the USA, and Japan, as well as international pharmacopeias of the European Economic Union and the Eurasian Economic Union. The trend on using a complex of high-tech equipment is revealed. A systematic approach to analysis based on X-ray diffraction, thermal, spectral, microscopic, biological, and physical methods for determining constants makes it possible not only to identify the polymorphic modification of API, but also to characterize its structure, morphology, physicochemical properties and pharmacological activity. In the Russian Federation, the phenomenon of polymorphism is being studied especially intensively, and some control methods, such as biological methods, are validated only in Russian pharmacopeia. A promising direction for further research is the improvement and harmonization of regulatory documentation within the framework of this chemical and technological field of pharmacy. A global approach will help to reduce not only the probability of poor-quality products entering the market, but also the costs of establishing the authenticity of the active pharmaceutical ingredient produced.

Human cholinesterases

2020 ◽  
pp. 63-120
Author(s):  
Sergey Varfolomeev ◽  
Bella Grigorenko ◽  
Sofya Lushchekina ◽  
Alexander Nemuchin
Keyword(s):  
Active Site ◽  
The Body ◽  
Polymorphic Modification ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
Mechanism Of Hydrolysis ◽  
The Central Nervous System ◽  
The Stability ◽  
Hydrolysis Of ◽  
Enzyme Reactivity

The work is devoted to modeling the elementary stages of the hydrolysis reaction in the active site of enzymes belonging to the class of cholinesterases — acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The study allowed to describe at the molecular level the effect of the polymorphic modification of BChE, causing serious physiolog ical consequences. Cholinesterase plays a crucial role in the human body. AChE is one of the key enzymes of the central nervous system, and BChE performs protective functions in the body. According to the results of calculations using the combined method of quantum and molecular mechanics (KM/MM), the mechanism of the hydrolysis of the native acetylcholine substrate in the AChE active center was detailed. For a series of ester substrates, a method for estimation of dependence of the enzyme reactivity on the structure of the substrate has been developed. The mechanism of hydrolysis of the muscle relaxant of succininylcholine BChE and the effect of the Asp70Gly polymorph on it were studied. Using various computer simulation methods, the stability of the enzyme-substrate complex of two enzyme variants with succinylcholine was studied.

New polymorphic modification of the crystal structure of bromopeganol

2009 ◽  
Vol 50 (2) ◽  
pp. 384-386 ◽  
Author(s):  
R. Ya. Okmanov ◽  
A. G. Tozhiboev ◽  
K. K. Turgunov ◽  
B. Tashkhodzhaev ◽  
N. I. Mukarramov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Polymorphic Modification

Influence of ortho-substituent on the molecular and crystal structures of 2-(N-arylimino)coumarin-3-carboxamide: isotypic and polymorphic structures

2019 ◽  
Vol 75 (5) ◽  
pp. 887-902 ◽  
Author(s):  
Svitlana V. Shishkina ◽  
Irina S. Konovalova ◽  
Sergiy M. Kovalenko ◽  
Pavlo V. Trostianko ◽  
Anna O. Geleverya ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Polymorphic Modification ◽  
Aryl Group ◽  
Group Iii ◽  
Pairwise Interactions ◽  
Group I ◽  
Polymorphic Modifications ◽  
Molecular And Crystal Structures

During a comprehensive study of a series of 2-(N-arylimino)coumarin-3-carboxamides with the aryl group substituted in the ortho-position by either a halogen atom, a methyl group or a methoxy group, the existence of three groups of isotypic crystal structures has been revealed. The similarity of crystal structures belonging to the same groups was confirmed by the analysis based on the comparison of pairwise interactions energies obtained from quantum chemical calculations. Group I includes unsubstituted, methyl-substituted and polymorphic modification 1 of fluoro-substituted 2-(N-arylimino)coumarin-3-carboxamide. Structures of polymorphic modification 2 of fluoro-substituted derivative, chloro-substituted and polymorphic modification 1 of bromo-substituted 2-(N-arylimino)coumarin-3-carboxamide may represent group II. Group III contains structures of polymorphic modification 2 of bromo-substituted derivative, iodine- and methoxy-substituted 2-(N-arylimino)coumarin-3-carboxamides. Structures of the same type group have extremely close parameters of the unit cell as well as those of molecular and crystal structures. But they are not identical. Polymorphic modifications of fluoro- and bromo-substituted 2-(N-arylimino)coumarin-3-carboxamides belong to different crystal types mainly due to different arrangement of basic structural motifs separated out using quantum chemical calculations.

Synthesis and characterization of a new polymorphic modification of AlPO4

1986 ◽  
Vol 79 (1-3) ◽  
pp. 232-235 ◽  
Author(s):  
K. Byrappa ◽  
J.Shashidhara Prasad ◽  
S. Srikantaswamy
Keyword(s):  
Polymorphic Modification ◽  
Synthesis And Characterization

Tetragonal polymorphic modification of tetrakis(N,N-diethyldithiocarbamato-S,S′)tellurium(IV)

2000 ◽  
Vol 56 (12) ◽  
pp. e589-e590 ◽  
Author(s):  
Alexander V. Virovets ◽  
Irina V. Kalinina ◽  
Vladimir P. Fedin ◽  
Dieter Fenske
Keyword(s):  
Polymorphic Modification

scholarly journals Investigation of anti-inflammatory and antipyretic activity of polymorphic modification of n-(trifluoromethylphenyl)-4-hydroxy-2,2-dioxo-1h-2λ6,1-benzothiazine-3-carboxamide derivative in rats

2021 ◽  
Vol 25 (1) ◽  
pp. 27-31
Author(s):  
P. S. Bondarenko ◽  
N. І. Voloshchuk
Keyword(s):  
Inflammatory Reaction ◽  
White Male ◽  
Statistical Processing ◽  
Biologically Active ◽  
Inflammatory Activity ◽  
Polymorphic Modification ◽  
Reference Drug ◽  
Antipyretic Effect ◽  
Antipyretic Activity ◽  
Anti Inflammatory

Annotation. Polymorphism among biologically active substances is an extremely important factor that modifies the therapeutic properties of pharmaceutical substances and dosage forms, significantly affects the parameters of their biological activity and pharmacokinetics. Chemical synthesis among the derivatives of 4-R-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acids gave the leader compound N-(4-trifluoromethylphenyl)-4-hydroxy-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamide, the crystalline polymorph of which in the form of plates has a pronounced analgesic activity. The aim of the study was to investigate the anti-inflammatory activity of compound B by its effect on various components of the inflammatory reaction, as well as the antipyretic effect of this compound in rats. The anti-alterative activity was determined on the model of planar skin wounds, the antiproliferative effect - on the model of cotton granuloma, the anti-exudative effect - on the model of toxic pulmonary edema in rats. The antipyretic effect was studied in a model of milk fever in rats. The study was performed on 91 white male Wistar rats. Statistical processing of the obtained results was performed using the program "STATISTICA 6.1" by methods of variation statistics using parametric and nonparametric methods. The results showed that the polymorphic compound B has anti-inflammatory activity on all components of the inflammatory reaction - alteration, exudation and proliferation. In terms of efficacy in the model of experimental inflammation, this substance is superior to meloxicam, as its ED50 when administered orally is 5.2 mg/kg, while the reference drug - 9.1 mg/kg. Compound B exhibits a pronounced antipyretic effect in a rat fever model. Therefore, the polymorphic modification of the carboxamide derivative in the form of plates is promising for further research in order to create on its basis a drug with analgesic, anti-inflammatory and antipyretic properties.

Hydration of polymorphic modification C3S

1981 ◽  
Vol 11 (2) ◽  
pp. 183-190 ◽  
Author(s):  
L. Števula ◽  
J. Petrovič
Keyword(s):  
Polymorphic Modification
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