Synthesis of 5'-O-phosphonomethyl derivatives of biologically active nucleosides

1990 ◽  
Vol 55 (s1) ◽  
pp. 125-128
Author(s):  
J. Brokeš ◽  
A. Holý
Keyword(s):  
Biologically Active ◽  
Derivatives Of

SOME DIRECTIONS IN THE MODIFICATION OF AZOLES

2020 ◽  
Vol 5 (443) ◽  
pp. 85-91
Author(s):  
Ibrayev M.K., ◽  
◽  
Takibayeva A.T., ◽  
Fazylov S.D., ◽  
Rakhimberlinova Zh.B., ◽  
...  
Keyword(s):  
13C Nmr Spectroscopy ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Active Compounds ◽  
Synthesis Conditions ◽  
Alkaloid Cytisine ◽  
Azole Ring ◽  
Cyclic Compounds ◽  
New Compounds ◽  
Derivatives Of

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.

scholarly journals Quantum-Chemical Search for Keto Tautomers of Azulenols in Vacuo and Aqueous Solution

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 497
Author(s):  
Ewa D. Raczyńska
Keyword(s):  
Aqueous Solution ◽  
Quantum Chemical ◽  
Biologically Active ◽  
Deprotonation Reaction ◽  
Chemical Studies ◽  
Quantum Chemical Studies ◽  
Scanty Information ◽  
Derivatives Of ◽  
Common Anion ◽  
Tautomeric Mixture

Keto-enol prototropic conversions for carbonyl compounds and phenols have been extensively studied, and many interesting review articles and even books appeared in the last 50 years. Quite a different situation takes place for derivatives of biologically active azulene, for which only scanty information on this phenomenon can be found in the literature. In this work, quantum-chemical studies have been undertaken for symmetrically and unsymmetrically substituted azulenols (constitutional isomers of naphthols). Stabilities of two enol (OH) rotamers and all possible keto (CH) tautomers have been analyzed in the gas phase {DFT(B3LYP)/6-311+G(d,p)} and also in aqueous solution {PCM(water)//DFT(B3LYP)/6-311+G(d,p)}. Contrary to naphthols, for which the keto forms can be neglected, at least one keto isomer (C1H, C2H, and/or C3H) contributes significantly to the tautomeric mixture of each azulenol to a higher degree in vacuo (non-polar environment) than in water (polar amphoteric solvent). The highest amounts of the CH forms have been found for 2- and 5-hydroxyazulenes, and the smallest ones for 1- and 6-hydroxy derivatives. The keto tautomer(s), together with the enol rotamers, can also participate in deprotonation reaction leading to a common anion and influence its acid-base properties. The strongest acidity in vacuo exhibits 6-hydroxyazulene, and the weakest one displays 1-hydroxyazulene, but all azulenols are stronger acids than phenol and naphthols. Bond length alternation in all DFT-optimized structures has been measured using the harmonic oscillator model of electron delocalization (HOMED) index. Generally, the HOMED values decrease for the keto tautomers, particularly for the ring containing the labile proton. Even for the keto tautomers possessing energetic parameters close to those of the enol isomers, the HOMED indices are low. However, some kind of parallelism exists for the keto forms between their relative energies and HOMEDs estimated for the entire molecules.

Synthesis of biologically active derivatives of cyclopenteno[d]-selenazole and their thioanalogs

1982 ◽  
Vol 16 (6) ◽  
pp. 460-463
Author(s):  
A. A. Tsurkan ◽  
Z. F. Gromova ◽  
�. A. Rudzit ◽  
G. N. Neshchadit ◽  
D. A. Kulikova
Keyword(s):  
Biologically Active ◽  
Derivatives Of ◽  
Biologically Active Derivatives

Chemical modification and Physicochemical properties of new derivatives 5-(thiophen-3-ilmethyl)-4-R1-1,2,4-triazole-3-thiol

2021 ◽  
pp. 4621-4629
Author(s):  
O.A. Bihdan ◽  
V.V. Parchenko
Keyword(s):  
Physicochemical Properties ◽  
High Reactivity ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Active Compounds ◽  
Triazole Derivatives ◽  
Pharmaceutical Ingredients ◽  
Current Trends ◽  
Wide Range ◽  
Derivatives Of

Current trends in the search for new biologically active compounds among synthetic molecules have arguably proved a priority in studies of the heterocyclic 1,2,4-triazole system. For many years, 1,2,4-triazole derivatives remain the object of close attention of scientists of various scientific fields. The unique properties of 1,2,4-triazole derivatives include high reactivity, which allows different modification of this system, practical absence of toxicity of these derivatives and the presence of a wide range of biological, pharmacological properties, which in the complex provides the prerequisites for the creation of new biologically active compounds, and in the future, active pharmaceutical ingredients (AFI). The aim of our work is to investigate some transformations in a number of derivatives of 5-(thiophen-3-ylmethyl) -4-R1-1,2,4-triazole-3-thiol, to study the physicochemical properties of the new synthesized compounds. A well-known fact remains the successful attempt of many scientists involved in the study of the heterocyclic 1,2,4-triazole system to synthesize potential biologically active compounds. The process of creating new molecules is very painstaking and requires considerable effort. The chemical approaches for the synthesis of the starting compounds required for further transformations are well known and described. Therefore, we used the corresponding N-R1-2 as intermediates for the synthesis of new 5-(thiophen-3-ylmethyl) -4-R1-1,2,4-triazole-3-thiols appropriate ones were used N-R1-2-(2-(thiophen-3-yl) acetyl) hydrazinocarbothioamide.

TYRAMINE, HISTAMINE, AND TRYPTAMINE CONTENT OF CHEESE

1974 ◽  
Vol 37 (7) ◽  
pp. 377-381 ◽  
Author(s):  
M. N. Voigt ◽  
R. R. Eitenmiller ◽  
P. E. Koehler ◽  
M. K. Hamdy
Keyword(s):  
Cheddar Cheese ◽  
The United States ◽  
Quantitative Information ◽  
Biologically Active ◽  
Blue Cheese ◽  
Physiological Importance ◽  
Fluorescence Measurements ◽  
Soft Cheese ◽  
Layer Chromatography ◽  
Derivatives Of

Because of the increasing knowledge of the physiological importance of biologically active amines in man and the importance of the presence of these amines in cheese, this study was done to obtain quantitative information for tyramine, tryptamine, and histamine in cheese available in the United States. The tyramine, histamine, and tryptamine contents of 156 samples of cheese purchased at retail stores were quantitated by thin-layer chromatography and fluorescence measurements of NBD-chloride derivatives of the amines. Tyramine was found in 81 of 85 Cheddar cheese samples examined. Extra-sharp, sharp, and medium Cheddar cheese samples contained average tyramine values of 0.27, 0.21, and 0.24 mg/g, respectively. Average tyramine contents were lower in mild and processed Cheddar (0.09 and 0.11 mg/g, respectively). The highest Cheddar cheese tyramine content was 0.7 mg/g. Tyramine was consistently found in all cheeses except in unripened soft cheese (Cottage). Histamine concentrations varied from nondetectable amounts to 2.6 mg/g in a Sap-Sago cheese sample. Twenty-four Cheddar cheese samples contained histamine with the highest amount being 1.3 mg/g. A domestic Blue cheese contained 2.3 mg/g. Tryptamine was uniformly low or completely absent in the Cheddar cheese samples. The highest tryptamine concentration (1.1 mg/g) was detected in a Blue cheese.

scholarly journals The molecular design of biologically active derivatives of N-phenylanthranilic acid

2018 ◽  
Vol 16 (1(61)) ◽  
pp. 49-53
Author(s):  
O. M. Svechnikova ◽  
S. V. Kolisnyk ◽  
O. F. Vinnyk ◽  
T. A. Kostina ◽  
T. V. Zhukova
Keyword(s):  
Molecular Design ◽  
Biologically Active ◽  
Derivatives Of ◽  
Biologically Active Derivatives

scholarly journals The effect of the solvent nature on the quinoline derivatives physicochemical characteristics

2019 ◽  
Vol 60 (11) ◽  
pp. 31-39
Author(s):  
Vladimir V. Shcherbakov ◽  
◽  
Svetlana V. Kurbatova ◽  
Margarita N. Zemtsova ◽  
◽  
...  
Keyword(s):  
Dipole Moment ◽  
Surface Area ◽  
Chemical Nature ◽  
Solvation Energy ◽  
Biologically Active ◽  
Quinoline Derivatives ◽  
Polar Surface Area ◽  
Polar Surface ◽  
Solvent Nature ◽  
Derivatives Of

The influence of the solvent nature on some physicochemical parameters of the quinoline derivatives molecules is investigated. It was noted that a variety of intermolecular interactions arising between the dissolved substance and the solvent and often accompanied by the phenomena of solvation, association, etc. leads to a variety of structural and energy changes in such systems and complicating their description. The most urgent problems of solutions include issues related to the solubility and bioavailability of biologically active compounds and drugs, the study of their ability to dissolve, the permeability of biological barriers, targeted delivery, etc., as well as the problems associated with the study of sorption of organic compounds from aqueous-organic eluents, for example, in liquid chromatography. Derivatives of quinoline (4-carboxy- and 4-aminoquinoline), known as potential drugs with various types of pharmacological action, were used as research objects. Using quantum chemical calculations, the dipole moment of the amino and carboxy derivatives of quinoline was determined, and the data obtained for vacuum and in solvents of various chemical nature were compared. A significant effect of solvent polarity on the dipole moment of quinoline derivatives dissolved in these solvents was found. The values of the solvation energy of quinoline derivatives in solvents of various chemical nature are calculated. It is shown that a change in the solvation energy is determined both by the structure of the molecules of the quinoline derivatives and by the polarity of the solvent. A nonlinear change in the energy of solvation with a change in the polarity of the solvent is established. A comparison is made of the values of the quinoline derivatives molecules polar surface area in solvents of various chemical nature. It was found that the polar surface area of the studied compounds changes slightly with a change in the nature of the solvent.

scholarly journals Synthesis of New 6,7(N,O)-Heterocyclic 1,4-Naphthoquinones

2021 ◽  
Vol 11 (6) ◽  
pp. 13903-13910
Keyword(s):  
Amino Acid ◽  
High Activity ◽  
Biologically Active ◽  
Amino Acid Derivatives ◽  
Antimicrobial Substances ◽  
Derivatives Of

As a result of the carried out research it was synthesized an order of new potentially biologically active modified N-,O-contained heterocycles on the base of amino acid derivatives of 2,6,7-nitrogen substituted-3-chloro-1,4-naphthoquinone. It was established that among synthesized compounds, there are potential antimicrobial substances with high activity.

scholarly journals Synthesis of New Antibiotics Derivatives by the Photocatalytic Method: A Screening Research

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1102
Author(s):  
Wojciech Baran ◽  
Ewa Masternak ◽  
Dominika Sapińska ◽  
Andrzej Sobczak ◽  
Ewa Adamek
Keyword(s):  
Quantum Yield ◽  
Biologically Active ◽  
Quantum Yields ◽  
Photocatalytic Process ◽  
Experimental Conditions ◽  
New Antibiotics ◽  
Photocatalytic Reactions ◽  
Kinetics Of ◽  
Derivatives Of ◽  
Uva Radiation

The aim of our study was to assess the possibility of using the photocatalytic process conducted in the presence of TiO2 to obtain new stable derivatives of antibacterial drugs. The possibility of introducing hydroxyl, chlorine, or bromide groups into antibiotics molecules was investigated. The experiments were conducted in aqueous solutions in the presence of TiO2-P25 as a photocatalyst, Cl− and Br- ions, and antibiotics belonging to eight different chemical classes. All experiments were initiated by UVa radiation. The kinetics of photocatalytic reactions and their quantum yield were determined, and the stable products were identified. All of the antibiotics used in the experiments underwent a photocatalytic transformation, and the quantum yields were in the range from 0.63 to 22.3%. The presence of Br- or FeCl3 significantly increased the efficiency of the photocatalytic process performed in the presence of TiO2, although Br- ion also acted as an inhibitor. Potentially biologically active chlorine derivatives from Trimethoprim, Metronidazole, Chloramphenicol, and bromine derivatives from Trimethoprim, Amoxicillin were obtained under experimental conditions. The potentially inactive halogen derivatives of Sulfamethoxazole and hydroxyl derivatives described in the literature were also identified.

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