scholarly journals Deep Eutectic Solvents as Effective Reaction Media for the Synthesis of 2-Hydroxyphenylbenzimidazole-Based Scaffolds en Route to Donepezil-Like Compounds

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 574 ◽  
Author(s):  
Luca Piemontese ◽  
Roberta Sergio ◽  
Federica Rinaldo ◽  
Leonardo Brunetti ◽  
Filippo M. Perna ◽  
...  

An unsubstituted 2-hydroxyphenylbenzimidazole has recently been included as a scaffold in a series of hybrids (including the hit compound PZ1) based on the framework of the acetylcholinesterase (AChE) inhibitor Donepezil, which is a new promising multi-target ligand in Alzheimer’s disease (AD) treatment. Building upon these findings, we have now designed and completed the whole synthesis of PZ1 in the so-called deep eutectic solvents (DESs), which have emerged as an unconventional class of bio-renewable reaction media in green synthesis. Under optimized reaction conditions, the preparation of a series of 2-hydroxyphenylbenzimidazole-based nuclei has also been perfected in DESs, and comparison with other routes which employ toxic and volatile organic solvents (VOCs) provided. The functionalization of the aromatic ring can have implications on some important biological properties of the described derivatives and will be the subject of future studies of structure-activity relationships (SARs).

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2015 ◽  
Author(s):  
Noel Nebra ◽  
Joaquín García-Álvarez

This mini-review presents a general overview of the progress achieved during the last decade on the amalgamation of CuAAC processes (copper-catalyzed azide-alkyne cycloaddition) with the employment of sustainable solvents as reaction media. In most of the presented examples, the use of water, glycerol (Gly), or deep eutectic solvents (DESs) as non-conventional reaction media allowed not only to recycle the catalytic system (thus reducing the amount of the copper catalyst needed per mole of substrate), but also to achieve higher conversions and selectivities when compared with the reaction promoted in hazardous and volatile organic solvents (VOCs). Moreover, the use of the aforementioned green solvents also permits the improvement of the overall sustainability of the Cu-catalyzed 1,3-dipolar cycloaddition process, thus fulfilling several important principles of green chemistry.


2010 ◽  
Vol 1247 ◽  
Author(s):  
Rocío Calderón-Villajos ◽  
Carlos Zaldo ◽  
Concepción Cascales

AbstractControlled reaction conditions in simple, template-free hydrothermal processes yield Tm-Lu2O3 and Tm-GdVO4 nanocrystals with well-defined specific morphologies and sizes. In both oxide families, nanocrystals prepared at pH 7 reaction media exhibit photoluminescence in ∼1.95 μm similar to bulk single crystals. For the lowest Tm3+ concentration (0.2 % mol) in GdVO4 measured 3H4 and 3F4 fluorescence lifetimes τ are very near to τrad.


2016 ◽  
Vol 11 (1) ◽  
pp. 10-35
Author(s):  
Joseph Azize

The various published biographies and biographical notices of G.I. Gurdjieff (c.1865-1949) are of diverse style, quantity and content. While some have made considerable contributions to the subject, most attempts have reacted for or against Gurdjieff’s status as what might call an ‘Enlightened Master’. Little biographical writing on Gurdjieff has questioned the scope, reliability and prejudices of the sources. Further, possible resources have been neglected. The development in Gurdjieff’s ideas is often overlooked, his life is not sufficiently related to that development, and the lack of comparative research has failed to highlight Gurdjieff’s unique contributions. This article is structured in four parts. The first is an introduction, followed by an overview of existing biographical studies of Gurdjieff. The third part addresses bias in these studies, and this is followed by suggestions for future studies. It is concluded that fieldwork regarding the biography of Gurdjieff has been hampered by imperfect methodology. However, with better use of the source material, some of which has only recently been discovered, and a rigorous use of sources, a more balanced and nuanced picture of Gurdjieff’s life, and the development of his ideas and methods, should emerge.


2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.


Author(s):  
Maryam Aisyah Abdullah ◽  
Siti Munirah Mohd Faudzi ◽  
Nadiah Mad Nasir

Abstract:: Medicinal chemists have continuously shown interest in new curcuminoid derivatives, the diarylpentadienones, owing to their enhanced stability feature and easy preparation using a one-pot synthesis. Thus far, methods such as Claisen-Schmidt condensation and Julia-Kocienski olefination have been utilised for the synthesis of these compounds. Diarylpentadienones possess a high potential as a chemical source for designing and developing new and effective drugs for the treatment of diseases, including inflammation, cancer, and malaria. In brief, this review article focuses on the broad pharmacological applications and the summary of the structure-activity relationship of molecules which can be employed to further explore the structure of diarylpentadienone. The current methodological developments towards the synthesis of diarylpentadienones are also discussed.


2019 ◽  
Vol 19 (17) ◽  
pp. 1392-1406
Author(s):  
Suvarna G. Kini ◽  
Ekta Rathi ◽  
Avinash Kumar ◽  
Varadaraj Bhat

Diphenyl ethers (DPE) and its analogs have exhibited excellent potential for therapeutic and industrial applications. Since the 19th century, intensive research is perpetuating on the synthetic routes and biological properties of DPEs. Few well-known DPEs are Nimesulide, Fenclofenac, Triclosan, Sorafenib, MK-4965, and MK-1439 which have shown the potential of this moiety as a lead scaffold for different pharmacological properties. In this review, we recapitulate the diverse synthetic route of DPE moiety inclusive of merits and demerits over the classical synthetic route and how this moiety sparked an interest in researchers to discern the SAR (Structure Activity Relationship) for the development of diversified biological properties of DPEs such as antimicrobial, antifungal, antiinflammatory & antiviral activities.


2019 ◽  
Vol 15 (4) ◽  
pp. 373-382 ◽  
Author(s):  
Ralph C. Gomes ◽  
Renata P. Sakata ◽  
Wanda P. Almeida ◽  
Fernando Coelho

Background: The most important cause of dementia affecting elderly people is the Alzheimer’s disease (AD). Patients affected by this progressive and neurodegenerative disease have severe memory and cognitive function impairments. Some medicines used for treating this disease in the early stages are based on inhibition of acetylcholinesterase. Population aging should contribute to increase the cases of patients suffering from Alzheimer's disease, thus requiring the development of new therapeutic entities for the treatment of this disease. Methods: The objective of this work is to identify new substances that have spatial structural similarity with donepezil, an efficient commercial drug used for the treatment of Alzheimer's disease, and to evaluate the capacity of inhibition of these new substances against the enzyme acetylcholinesterase. Results: Based on a previous results of our group, we prepared a set of 11 spirocyclohexadienones with different substitutions patterns in three steps and overall yield of up to 59%. These compounds were evaluated in vitro against acetylcholinesterase. We found that eight of them are able to inhibit the acetylcholinesterase activity, with IC50 values ranging from 0.12 to 12.67 µM. Molecular docking study indicated that the spirocyclohexadienone, 9e (IC50 = 0.12 µM), a mixedtype AChE inhibitor, showed a good interaction at active site of the enzyme, including the cationic (CAS) and the peripheral site (PAS). Conclusion: We described the first study aimed at investigating the biological properties of spirocyclohexadienones as acetylcholinesterase inhibitors. Thus, we have identified an inhibitor, which provided valuable insights for further studies aimed at the discovery of more potent acetylcholinesterase inhibitors.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ana Bjelić ◽  
Brigita Hočevar ◽  
Miha Grilc ◽  
Uroš Novak ◽  
Blaž Likozar

AbstractConventional biorefinery processes are complex, engineered and energy-intensive, where biomass fractionation, a key functional step for the production of biomass-derived chemical substances, demands industrial organic solvents and harsh, environmentally harmful reaction conditions. There is a timely, clear and unmet economic need for a systematic, robust and affordable conversion method technology to become greener, sustainable and cost-effective. In this perspective, deep eutectic solvents (DESs) have been envisaged as the most advanced novel polar liquids that are entirely made of natural, molecular compounds that are capable of an association via hydrogen bonding interactions. DES has quickly emerged in various application functions thanks to a formulations’ simple preparation. These molecules themselves are biobased, renewable, biodegradable and eco-friendly. The present experimental review is providing the state of the art topical overview of trends regarding the employment of DESs in investigated biorefinery-related techniques. This review covers DESs for lignocellulosic component isolation, applications as (co)catalysts and their functionality range in biocatalysis. Furthermore, a special section of the DESs recyclability is included. For DESs to unlock numerous new (reactive) possibilities in future biorefineries, the critical estimation of its complexity in the reaction, separation, or fractionation medium should be addressed more in future studies.


2021 ◽  
Vol 14 (5) ◽  
pp. 428
Author(s):  
Douglas Kemboi Magozwi ◽  
Mmabatho Dinala ◽  
Nthabiseng Mokwana ◽  
Xavier Siwe-Noundou ◽  
Rui W. M. Krause ◽  
...  

Plants of the genus Euphorbia are widely distributed across temperate, tropical and subtropical regions of South America, Asia and Africa with established Ayurvedic, Chinese and Malay ethnomedical records. The present review reports the isolation, occurrence, phytochemistry, biological properties, therapeutic potential and structure–activity relationship of Euphorbia flavonoids for the period covering 2000–2020, while identifying potential areas for future studies aimed at development of new therapeutic agents from these plants. The findings suggest that the extracts and isolated flavonoids possess anticancer, antiproliferative, antimalarial, antibacterial, anti-venom, anti-inflammatory, anti-hepatitis and antioxidant properties and have different mechanisms of action against cancer cells. Of the investigated species, over 80 different types of flavonoids have been isolated to date. Most of the isolated flavonoids were flavonols and comprised simple O-substitution patterns, C-methylation and prenylation. Others had a glycoside, glycosidic linkages and a carbohydrate attached at either C-3 or C-7, and were designated as d-glucose, l-rhamnose or glucorhamnose. The structure–activity relationship studies showed that methylation of the hydroxyl groups on C-3 or C-7 reduces the activities while glycosylation loses the activity and that the parent skeletal structure is essential in retaining the activity. These constituents can therefore offer potential alternative scaffolds towards development of new Euphorbia-based therapeutic agents.


Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 61
Author(s):  
Thomas J. Ainscough ◽  
Darren L. Oatley-Radcliffe ◽  
Andrew R. Barron

Groundwater contamination by chlorinated hydrocarbons represents a particularly difficult separation to achieve and very little is published on the subject. In this paper, we explore the potential for the removal of chlorinated volatile and non-volatile organics from a site in Bedfordshire UK. The compounds of interest include trichloroethylene (TCE), tetrachloroethylene (PCE), cis-1,2-dichloroethylene (DCE), 2,2-dichloropropane (DCP) and vinyl chloride (VC). The separations were first tested in the laboratory. Microfiltration membranes were of no use in this separation. Nanofiltration membranes performed well and rejections of 70–93% were observed for synthetic solutions and up to 100% for real groundwater samples. Site trials were limited by space and power availability, which resulted in a maximum operating pressure of only 3 bar. Under these conditions, the nanofiltration membrane removed organic materials, but failed to remove VOCs to any significant extent. Initial results with a reverse osmosis membrane were positive, with 93% removal of the VOCs. However, subsequent samples taken demonstrated little removal. Several hypotheses were presented to explain this behavior and the most likely cause of the issue was fouling leading to adsorption of the VOCs onto the membrane and allowing passage through the membrane matrix.


Sign in / Sign up

Export Citation Format

Share Document