scholarly journals Synthesis and Chemical Properties of 3-Phosphono-coumarins and 1,2-Benzoxaphosphorins as Precursors for Bioactive Compounds

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2030 ◽  
Author(s):  
Ana I. Koleva ◽  
Nevena I. Petkova-Yankova ◽  
Rositca D. Nikolova

Coumarins are an important class of natural heterocyclic compounds that have attracted considerable synthetic and pharmacological interest due to their various biological activities. This review emphasizes on the synthetic methods for the preparation of dialkyl 2-oxo-2H-1-benzo- pyran-3-phosphonates and alkyl 1,2-benzoxaphosphorin-3-carboxylates. Their chemical properties as acceptors in conjugate addition reactions, [2+2] and [3+2] cycloaddition reactions are discussed.

2016 ◽  
Vol 1 (1) ◽  
pp. 29 ◽  
Author(s):  
Mohammad Asif

Pyridopyridazine compounds are important nitrogen atom containing heterocyclic compounds due to their pharmacological versatility. This heterocycle system characterized a structural feature for different types of bioactive compounds that exhibiting various types of biological activities which make it an attractive scaffold for the design and development of new drug molecules. This article provided information about the pharmacological properties of pyridopyridazines derivatives.


Author(s):  
Ebuka Leonard Onyeyilim ◽  
Mercy Amarachi Ezeokonkwo ◽  
David Izuchukwu Ugwu ◽  
Chiamaka Peace Uzoewulu ◽  
Florence Uchenna Eze ◽  
...  

: Carbohydrazides and their Schiff bases are important class of heterocycles that are not only employed in the area of organic chemistry, but also have tremendous applications in physical and inorganic chemistry. A series of potential bioactive compounds, containing carbohydrazide functionality and their hydrazone derivatives have been synthesized and screened for antibacterial, anticancer, antifungal and anti-inflammatory etc. This brief review discloses some synthetic route to so many reported carbohydrazides, their Schiff bases, their biological activities and their structure activity relationship.


Author(s):  
Luana da S. M. Forezi ◽  
Acácio S. de Souza ◽  
Carolina G. S. Lima ◽  
Amanda A. Borges ◽  
Patricia G. Ferreira ◽  
...  

: Naphthoquinones are important molecules belonging to the general class of quinones, and many of these compounds have become drugs that are in the pharmaceutical market for the treatment of several diseases. A special subclass of compounds is that of the bis(naphthoquinones), which have two linked naphthoquinone units. In the last few years, several synthetic approaches toward such valuable compounds have been described, as well as their evaluation against numerous important biological targets. In this review, we provide a thorough discussion on the various synthetic methods reported for the synthesis of bis(naphthoquinone) analogues, also highlighting the biological activities of these substances.


2018 ◽  
Vol 15 (1) ◽  
pp. 3-20 ◽  
Author(s):  
Vahideh Zadsirjan ◽  
Majid M. Heravi

Background: The most frequently used chiral auxiliaries, oxazolidinones (Evans' oxazolidinones) have been employed in 1,4-congugate addition reactions to α,β-unsaturated carbonyl compounds. Supplementary to our previous reports in this mini-review, we attempted to underscore the applications of this strategy in a step (steps) in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Objective: In this mini-review, we try to underscore the applications of oxazolidinones (Evans’ oxazolidinones) in 1,4-congugate addition reactions to α,β-unsaturated carbonyl in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Conclusion: In spite of well-known superiority of asymmetric catalyzed reactions, the use of auxiliarycontrolled reactions are still considered as commanding, vital and sometimes as only tools in the generation of stereogenic centers during the construction of complex molecules and total synthesis of naturally occurring compounds. The commercial availability, or readily accessibility of a wide variety of chiral amino alcohols as starting materials to synthesize a wide range of oxazolidinones is the merits of them. In addition, the ease of removal and subjection to various and diverse stereoselective reactions make oxazolidinones as the ideal and superior chiral auxiliaries. In this regard, they were successfully used in asymmetric 1,4-conjugate addition reactions with high stereoselectivities. The high degree of asymmetric induction can be attributed to the rigid chelation of N-acyloxazolidinones with metal ions, as well as the covering of one face of the system by the bulkiness of 4-substituent. In summary, in this report, the importance of the applications of chiral oxazolidinones as suitable chiral auxiliaries in the stereoselective, 1,4-conjugate addition reactions in asymmetric synthesis and in particular, the total synthesis of naturally occurring compounds and some complex molecules were underscored. Noticeably, in these total syntheses, this chiral auxiliary is controlling the stereochemistry of a newly created stereogenic center as well as preserving the configuration of other chiral centers, which already have been presented in the precursor. General methods have been established for the attachment of the chiral auxiliary as a moiety to the substrate molecule in high to excellent yields. At the end of these reactions, this auxiliary can be easily removed leaving various desired reactive motifs for the next step in multi-step synthesis.


2019 ◽  
Vol 41 (6) ◽  
pp. 1046-1046
Author(s):  
Omar A Shareef Omar A Shareef ◽  
Said A Said and Ali Y Abdulrazaq Said A Said and Ali Y Abdulrazaq

The wide biological activities of flavanones are mainly depends on their physical and chemical properties, thus a number of substituted 2-Hydroxy chalcones have been synthesized, and their isomerization to their corresponding flavanones was studied. In order to determine the rate constant, kinetic experiments were performed using HPLC technique in (9:1) (CH3CN:H2O) medium at different temperature (298-318) K. The obtained results were interpreted by four steps mechanism, which considered the existence of phenoxide ion as the key intermediate. This study performed with a pseudo first order ( reaction in which the rate for the studied compounds follow the sequence 5 andgt; 2 andgt; 1 andgt; 4 andgt; 3, the activation energy have the same sequence for these compounds .The effect of substituents on the rate showed that electronic and steric factors play reasonable role on the stability of the product .


2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Zhanjie Xu ◽  
Peng Du ◽  
Peter Meiser ◽  
Claus Jacob

Proanthocyanidins represent a unique class of oligomeric and polymeric secondary metabolites found ubiquitously and in considerable amounts in plants and some algae. These substances exhibit a range of rather surprising physical and chemical properties which, once applied to living organisms, are translated into a multitude of biological activities. The latter include antioxidant properties, cancer chemoprevention, anti-inflammatory and anti-diabetic effects as well as some exceptional, yet highly interesting activities, such as anti-nutritional and antimicrobial activity. Despite the wide range of activities and possible medical/agricultural applications of proanthocyanidins, many questions still remain, including issues related to bioavailability, metabolism and the precise biochemical, extra- and intracellular targets and mode(s) of action of these highly potent materials. Among the various physical and chemical interactions of such substances, strong binding to proteins appears to form the basis of many of their biological activities. Once easy-to-use synthetic methods to produce appropriate quantities of pure proanthocyanidins are available, it will be possible to identify the prime biological targets of these oligomers, study oligomer-protein interactions in more detail and develop possible practical applications in medicine and agriculture.


2019 ◽  
Vol 800 ◽  
pp. 36-41
Author(s):  
Evija Rolava ◽  
Jevgeņija Lugiņina ◽  
Māris Turks

Oxazolidinones are an important class of heterocyclic compounds that are used as chiral auxiliaries in asymmetric synthesis and as biologically active pharmaceutical agents. Moreover, carbohydrates are ideal scaffolds to generate libraries of bioactive compounds due the presence of defined configuration. We report here asymmetric alkylation studies on N-derivatized glucose-and allose-based spirooxazolidinones which do act as chiral auxiliaries.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5666
Author(s):  
Valéria Verebová ◽  
Jiří Beneš ◽  
Jana Staničová

Photosensitive compounds found in herbs have been reported in recent years as having a variety of interesting medicinal and biological activities. In this review, we focus on photosensitizers such as hypericin and its model compounds emodin, quinizarin, and danthron, which have antiviral, antifungal, antineoplastic, and antitumor effects. They can be utilized as potential agents in photodynamic therapy, especially in photodynamic therapy (PDT) for cancer. We aimed to give a comprehensive summary of the physical and chemical properties of these interesting molecules, emphasizing their mechanism of action in relation to their different interactions with biomacromolecules, specifically with DNA.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yadian Xie ◽  
Duygu Kocaefe ◽  
Chunying Chen ◽  
Yasar Kocaefe

The nanomaterials have been widely used in various fields, such as photonics, catalysis, and adsorption, because of their unique physical and chemical properties. Therefore, their production methods are of utmost importance. Compared with traditional synthetic methods, the template method can effectively control the morphology, particle size, and structure during the preparation of nanomaterials, which is an effective method for their synthesis. The key for the template method is to choose different templates, which are divided into hard template and soft template according to their different structures. In this paper, the effects of different types of templates on the morphology of nanomaterials during their preparation are investigated from two aspects: hard template and soft template, combined with the mechanism of action.


2019 ◽  
Vol 9 (3) ◽  
pp. 184-188
Author(s):  
Collen Musara ◽  
Alfred Maroyi

Gethyllis afra is an important medicinal plant species in South Africa. The current study critically reviewed the botany, ethnobotanical uses, biological and chemical properties of G. afra. Information on the botany, ethnobotanical uses, biological and chemical properties of G. afra was collected from multiple internet sources which included Scopus, Google Scholar, Elsevier, Science Direct, Web of Science, Pubmed, SciFinder and BMC. Additional information was gathered from pre-electronic sources such as journal articles, scientific reports, books and book chapters obtained from the University library. This study showed that G. afra is mainly used as food, aphrodisiac, and herbal medicine for colic, indigestion, stomach-ache, boils, bruises, insect bites, toothache, convulsions, heart problems and sleeplessness. Major compounds isolated from the fruits of G. afra include ?-pinene, n-butyl n-butyrate, isoamyl acetate, ?-pinene and 2-methylbutyl butyrate. There is need to validate the documented ethnomedicinal uses of G. afra through phytochemical and pharmacological studies. Therefore, future studies should focus on these knowledge gaps particularly evaluating the chemical and biological activities of G. afra crude extracts and compounds isolated from the species.


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