scholarly journals Biocatalysis in the Chemistry of Lupane Triterpenoids

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2271
Author(s):  
Jan Bachořík ◽  
Milan Urban
Keyword(s):  
Organic Synthesis ◽  
Biological Activities ◽  
Natural Occurrence ◽  
Chemical Transformations ◽  
Large Space ◽  
Lupane Triterpenoids ◽  
Current State ◽  
State Of Research ◽  
Living Organisms ◽  
Derivatives Of

Pentacyclic triterpenes are important representatives of natural products that exhibit a wide variety of biological activities. These activities suggest that these compounds may represent potential medicines for the treatment of cancer and viral, bacterial, or protozoal infections. Naturally occurring triterpenes usually have several drawbacks, such as limited activity and insufficient solubility and bioavailability; therefore, they need to be modified to obtain compounds suitable for drug development. Modifications can be achieved either by methods of standard organic synthesis or with the use of biocatalysts, such as enzymes or enzyme systems within living organisms. In most cases, these modifications result in the preparation of esters, amides, saponins, or sugar conjugates. Notably, while standard organic synthesis has been heavily used and developed, the use of the latter methodology has been rather limited, but it appears that biocatalysis has recently sparked considerably wider interest within the scientific community. Among triterpenes, derivatives of lupane play important roles. This review therefore summarizes the natural occurrence and sources of lupane triterpenoids, their biosynthesis, and semisynthetic methods that may be used for the production of betulinic acid from abundant and inexpensive betulin. Most importantly, this article compares chemical transformations of lupane triterpenoids with analogous reactions performed by biocatalysts and highlights a large space for the future development of biocatalysis in this field. The results of this study may serve as a summary of the current state of research and demonstrate the potential of the method in future applications.

Identification of promising objects for the synthesis of thiosulphonate derivatives of benzoquinone and hydroquinone

2021 ◽  
Vol 4 (2) ◽  
pp. 47-53
Author(s):  
N. Y. Monka ◽  
◽  
N. E. Stadnytska ◽  
I. R. Buchkevych ◽  
K. O. Kaplia ◽  
...  
Keyword(s):  
Biological Activity ◽  
Biological Activities ◽  
Experimental Studies ◽  
New Drugs ◽  
Reduced Form ◽  
Free Form ◽  
Wide Range ◽  
On Line ◽  
Living Organisms ◽  
Derivatives Of

Benzoquinone and its reduced form hydroquinone belong to phenolic compounds and are found in living organisms in free form or in glycosides. They are active substances of some medicinal plants and have a pharmacological effect on the human body. Accordingly, their derivatives are important objects for chemical synthesis and development of new drugs. This article presents the findings of the structural design of substances with benzoquinone or hydroquinone fragment and sulfur-containing compound. By use of appropriate on-line programs a predictive screening of the biological activity and cytotoxicity of thiosulfonate derivatives of benzoquinone and hydroquinone has been conducted. It has been found that they have immense methodological potential to be synthesized by substances with a wide range of biological activities and a high value of probable activity, which substantiates the feasibility of conducting experimental studies on their biological activity, particularly anticancer.

The Use of Electrophilic Cyclization for the Preparation of Condensed Heterocycles

Synthesis ◽  
2021 ◽  
Author(s):  
Mikhailo Slivka ◽  
Mikhailo Onysko
Keyword(s):  
Biological Effects ◽  
Electrophilic Cyclization ◽  
Chemical Transformations ◽  
Cyclization Reactions ◽  
Reaction Conditions ◽  
Electrophilic Reaction ◽  
Partially Saturated ◽  
Current State ◽  
Derivatives Of ◽  
Condensed Heterocycles

AbstractCondensed heterocycles are well-known for their excellent biological effects and they are undeniably important compounds in organic chemistry. Electrophilic cyclization reactions are widely used for the synthesis of mono-heterocyclic compounds. This review highlights the utility of electrophilic cyclization reactions as an effective generic tool for the synthesis of various condensed heterocycles containing functional groups that are able to undergo further chemical transformations, such as nucleophilic substitution, elimination, re-cyclization, cleavage, etc. This review describes the reactions of unsaturated derivatives of different heterocycles with various electrophilic agents (halogens, arylsulfanyl chlorides, mineral acids) resulting in annulation of an additional partially saturated heterocycle. The electrophilic reaction conditions, plausible mechanisms and the use of such transformations in organic synthesis are also discussed. The review mainly focuses on research published since 2002 in order to establish the current state of the art in this area. 1 Introduction2 Electrophilic Cyclization Pathways Involving a Nitrogen Nucleo­philic Center3 Electrophilic Cyclization Pathways Involving a Chalcogen Nucleophilic Center3.1 Sulfur Centers3.2 Oxygen Centers3.3 Selenium Centers4 Strategies and Mechanisms5 Conclusion

Versatile Synthesis of Organic Compounds Derived from Ascorbic Acid.

2021 ◽  
Vol 08 ◽  
Author(s):  
Aparna Das ◽  
Bimal Krishna Banik
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Organic Compounds ◽  
Organic Synthesis ◽  
Biological Activities ◽  
Wide Range ◽  
Derivatives Of

: Ascorbic acid, also known as Vitamin C, is the essential vitamin observed in diverse food. Ascorbic acid has various applications in several fields. Studies have depicted that in organic synthesis, it can be used as a mediator or substrate. The derivatives of ascorbic acid have been found to possess numerous biological activities. In this review, we report the crucial derivatives of ascorbic acid, which have significant biological activities. Various studies are considered in this review to prove its wide range of availability.

Cyanoacetylenic alcohols, molecules of interstellar origin in the biomimetic synthesis of life relevant heterocycles, amino acids, nucleobases and nucleosides: towards prebiotic chemistry

Synthesis ◽  
2021 ◽  
Author(s):  
Boris Trofimov ◽  
Anastasiya Mal’kina
Keyword(s):  
Amino Acids ◽  
Organic Synthesis ◽  
Prebiotic Chemistry ◽  
Aqueous Media ◽  
Biomimetic Synthesis ◽  
Hydroxyl Group ◽  
Chemical Transformations ◽  
Molecular Architecture ◽  
The Past ◽  
Derivatives Of

Cyanoacetylenic alcohols, R1R2C(OH)C≡C-CN, the closest derivatives of cyanoacetylene, an interstellar abundant molecule, are now becoming acknowledgeable in modern organic synthesis which tends to mimic nature. Highly reactive C≡C and C≡N bonds in close vicinity of the hydroxyl group makes these molecules a chemical trinity of mutually influencing functions ensuring an endless number of chemical transformations. All reactions of cyanoacetylenic alcohols parallel modern organic synthesis, being biomimetic. They do not need transition metals (and in most cases, the metals at all except for physiologically indispensible Na+, K+), proceed at ambient temperature and often in aqueous media. Fundamentally, these reactions are 100% atom-economic because they are almost exclusively addition processes. Usually, in the cyanoacetylenic alcohols, cyano, acetylene and hydroxyl functions behave as inseparable entity providing the multiple functionalizations of the forming molecules. This allows hydroxyl, carbonyl, carboxylic, imino, amino, amido, cyanoamido, cyano, various P-containing, ether and ester functions, along with the double bonds and different fundamental heterocycles (furans, furanones, pyrazoles, oxazoles, pyridines, pyrimidines, purins, etc.) and diverse polycyclic systems to be integrated in a one molecular architecture. This review focuses on analysis and generalization of the knowledge accumulated in the chemistry of these cyanoacetylenic alcohols, mostly over the past 15 years.

scholarly journals Green Tamarind Extract Catalyzed Synthesis of 4-Amino-1,2,4-Triazole Derivatives and Their In-vitro Antimicrobial Activity

2020 ◽  
pp. 44-56
Author(s):  
Diksha Verma ◽  
Sunita Sharma ◽  
Tanvi Sahni ◽  
Geetika Arora
Keyword(s):  
Antimicrobial Activity ◽  
Green Chemistry ◽  
Organic Synthesis ◽  
Glacial Acetic Acid ◽  
Catalytic Amount ◽  
Spectroscopic Techniques ◽  
Chemical Transformations ◽  
Chemical Waste ◽  
Derivatives Of

In several organic synthesis and chemical transformations, the use of green chemistry has decreased the reaction time and chemical waste. Due to the tremendous advantages of green chemistry, the paper presents the synthesis of benzylidene derivatives of 4-amino-1,2,4-triazole by reacting it with various substituted aldehydes/benzaldehydes using different catalytic amount(ln mL) of tamarind extract/glacial acetic acid as a catalyst by conventional and microwave method.  All the synthesized compounds (1-7) were characterized using spectroscopic techniques viz. UV, IR, and 1H NMR. Antimicrobial activity of all the compounds was done using negative gram bacteria i.e. Pseudomonas aeruginosa, Klebsiella sp., and Enterobacter sp. against standard Ampicillin. Compound 2 containing 4-nitro substitution increased the antimicrobial activity as compared to other Enterobacter sp, but none of them showed better In-vitro antimicrobial potential than standard ampicillin. All the synthesized Schiff bases differed significantly from one another within the range of test concentrations.

Culturally Responsive Pedagogy in Mathematics

2020 ◽  
Vol 2 ◽  
pp. 145-158
Author(s):  
Kenta Nagasawa
Keyword(s):  
Professional Development ◽  
Teacher Education ◽  
Culturally Responsive ◽  
Latino Students ◽  
Culturally Responsive Pedagogy ◽  
Mathematics Teacher Education ◽  
Development Program ◽  
Current State ◽  
Responsive Pedagogy ◽  
State Of Research

Purpose: This paper is a thematic literature review to examine the current state of research about Culturally Responsive Pedagogy in mathematics. The main themes are students’ perception, teacher education for pre-service teacher and professional development for teachers. Research methods/ approach: Literature was collected from Eric, which is a research engine of the education field. Also, Google Scholar is used to find articles of major scholars introduced by Dr. Rich Milner, who is the instructor of this course. Findings: Students faced microaggressions in mathematics class, which discouraged them to learn mathematics. The effect of teacher education was inconsistent in terms of the awareness of culturally responsive pedagogy and lesson plans. Research of professional development mentioned that mathematics was cultural. Implications for research and practice: It is more interesting to conduct long term or follow-up research to find the teacher’s practice after a taking professional development program. Also, it is critical to expand research scope besides African American and Latino students. Finally, evidence-based research is needed to change the political situation. Keywords: culturally responsive teaching, mathematics, teacher education, professional development, student’s perception

Editorial

2013 ◽  
Vol 1 (2) ◽  
pp. 1-3
Author(s):  
João José Pinto Ferreira ◽  
Anne-Laure Mention ◽  
Marko Torkkeli
Keyword(s):  
Economic Development ◽  
Education Research ◽  
Research And Development ◽  
Research Integrity ◽  
Academic Community ◽  
Human Knowledge ◽  
Academic Institutions ◽  
Current State ◽  
State Of Research ◽  
Successive Generations

The expansion of human knowledge in all areas is largely the outcome of the activity of academic institutions and the result of their mission to contribute to the cultural, intellectual and economic development of the society, involving education, research and university extension activities. For many years, the academic community has been organizing itself in all different ways to respond to current and future needs, ensuring research integrity and recognition, and building on successive generations of peers to validate and support the launching and development of novel research streams. We owe the current state of research and development of our society to generations of scholars and scientists that have brought all of us here.(...)

ORGANOPHOSPHORUS NEUROTOXINS

2020 ◽  
Author(s):  
Mariya Andriyanova ◽  
Aslanli Aslanli ◽  
Nataliya Basova ◽  
Viktor Bykov ◽  
Sergey Varfolomeev ◽  
...  
Keyword(s):  
Crop Protection ◽  
Chemical Warfare Agents ◽  
Agricultural Crop ◽  
Current State ◽  
Physicochemical Biology ◽  
Chemical Agents ◽  
Warfare Agents ◽  
History Of ◽  
Physicochemical Methods ◽  
State Of Research

The collective monograph is devoted to discussing the history of creation, studying the properties, neutralizing and using organophosphorus neurotoxins, which include chemical warfare agents, agricultural crop protection chemical agents (herbicides and insecticides) and medicines. The monograph summarizes the results of current scientific research and new prospects for the development of this field of knowledge in the 21st century, including the use of modern physicochemical methods for experimental study and theoretical analysis of biocatalysis and its mechanisms based on molecular modeling with supercomputer power. The book is intended for specialists who are interested in the current state of research in the field of organophosphorus neurotoxins. The monograph will be useful for students, graduate students, researchers specializing in the field of physical chemistry, physicochemical biology, chemical enzymology, toxicology, biochemistry, molecular biology and genetics, biotechnology, nanotechnology and biomedicine.

Synthesis, characterization and biological activities of 1,3,4-oxadiazole derivatives of nalidixic acid and their copper complexes

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Nalidixic Acid ◽  
Copper Complexes ◽  
Biological Activities ◽  
Bidentate Coordination ◽  
Antibacterial And Antifungal Activities ◽  
Elemental Analyses ◽  
Oxadiazole Derivatives ◽  
Antibacterial And Antifungal ◽  
Derivatives Of ◽  
Substituted 1

A series of novel 1, 3, 4-oxadiazole analogues was synthesized from cyclization of hydrazones of substituted 1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carbohydrazides were prepared from nalidixic acid. The structures of synthesized oxadiazole derivatives and their copper complexes were elucidated on the basis of FTIR, elemental analyses, 1H-NMR and atomic absorption spectral analysis. It was observed from spectral data that metal ligand ratio was 1:1 in all copper complexes and they were bidentate, coordination was found to be done through oxygen of 4-oxo group and nitrogen of oxadiazole ring. The synthesized compounds were further evaluated with biological activities and compared with parent hydrazones. Copper complexes possess antibacterial and antifungal activities better than the oxadiazoles while they have better antioxidant activity then copper complexes. Parent hydrazones were better in all biological activities than synthesized oxadiazoles.

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