Antihypertensive activity of indole and indazole analogues: A review

Heterocyclic compounds occupy an important position in chemistry because of their wide range of uses in drug design, photochemistry, agrochemicals, and other fields. Indole and indazole scaffolds are available from natural and synthetic sources, and molecules containing these scaffolds have been shown to have various biological effects, including anti-inflammatory, antibacterial, antiviral, antifungal, analgesic, anticancer, antioxidant, anticonvulsant, antidepressant, and antihypertensive activities. Indole and indazole molecules bind to receptors with high affinity, and thus are useful for the study of bioactive compounds involved in multiple pathways. In this review, we highlight the antihypertensive activity and the mechanisms of action of indole and indazole derivatives. In addition, structure–activity relationship studies of the antihypertensive effect are presented.     

Biological potential of pyrimidine derivatives in a new era

Pyrimidine and its derivatives play a wide role in drug discovery processes and have considerable chemical significance and biological activities. Pyrimidines are the building blocks of many natural compounds such as vitamins, liposacharides, and antibiotics. Pyrimidine is used as parent substance for the synthesis of a wide variety of heterocyclic compounds and raw material for drug synthesis and is also crucial in the theoretical development of heterocyclic chemistry and in organic synthesis. Pyrimidine derivatives are vital in several biological activities, i.e. antihypertensive, anticancer, antimicrobial, anti-inflammatory, and antioxidant activity. This creates interest among researchers who have synthesized a variety of pyrimidine derivatives.     

Synthetic strategies for 1,4,5/4,5-substituted azoles: A perspective review

Azole nucleus represents an important class of biologically active compounds that are gaining more attention in the field of medicinal chemistry due to large number of structure diversity. Among azoles, pyrazoles, and isoxazoles five-membered nitrogen containing heterocyclic compounds are associated wide range of biological activities such as anticancer, antimicrobial, anti-inflammatory, antioxidant, etc. Some of azole derivatives (e.g., 1,4,5-trisubstituted pyrazoles, 4,5-disubstituted isoxazoles, and 4,5-disubstituted-1H-pyrazoles) are still unexplored in literature, these unexplored azoles have fascinated the consideration of many researchers to study their framework synthetically and biologically. This present review is an attempt to update and understand the chemistry of unexplored pyrazoles and isoxazoles along with their medicinal importance. This article would definitely help the researchers to bring further enhancement in the synthesis of biologically active pyrazoles and isoxazoles.     

Thiazole Ring—A Biologically Active Scaffold

Background: Thiazole is a good pharmacophore nucleus due to its various pharmaceutical applications. Its derivatives have a wide range of biological activities such as antioxidant, analgesic, and antimicrobial including antibacterial, antifungal, antimalarial, anticancer, antiallergic, antihypertensive, anti-inflammatory, and antipsychotic. Indeed, the thiazole scaffold is contained in more than 18 FDA-approved drugs as well as in numerous experimental drugs. Objective: To summarize recent literature on the biological activities of thiazole ring-containing compounds Methods: A literature survey regarding the topics from the year 2015 up to now was carried out. Older publications were not included, since they were previously analyzed in available peer reviews. Results: Nearly 124 research articles were found, critically analyzed, and arranged regarding the synthesis and biological activities of thiazoles derivatives in the last 5 years.     

A Comprehensive Review of Aminochalcones

Chalcones, members of the flavonoid family, display a plethora of interesting biological activities including but not limited to antioxidant, anticancer, antimicrobial, anti-inflammatory, and antiprotozoal activities. The literature cites the synthesis and activity of a range of natural, semisynthetic, and synthetic chalcones. The current review comprehensively covers the literature on amino-substituted chalcones and includes chalcones with amino-groups at various positions on the aromatic rings as well as those with amino-groups containing mono alkylation, dialkylation, alkenylation, acylation, and sulfonylation. The aminochalcones are categorized according to their structure, and the corresponding biological activities are discussed as well. Some compounds showed high potency against cancer cells, microbes, and malaria, whereas others did not. The purpose of this review is to serve as a one-stop location for information on the aminochalcones reported in the literature in recent years.     

Synthetic approaches for BF2-containing adducts of outstanding biological potential. A review

Organic compounds containing the F or B elements in their structures have recently attracted the interest of the chemists and medicinal chemists because their improved biological properties displayed in comparison to their non-fluorinated or non-borinated parent structures. It is widely been documented that curcumine (CUR) have a high biological potential as antioxidant, anti-inflammatory and anticancer agent, among others, but some drawbacks related to its unfavorable bio-physicochemical properties have prevented its applicability as chemotherapeutic drug. Nevertheless, recent studies have shown that the introduction of the BF₂ functionality in its structure (i.e. CUR-BF₂ adducts) and analogues have significantly improved their biological properties, mainly, their anticancer and antibiotic activities.On the other hand, the BF₂-adduct BODIPY (i.e. 4,4-difluoro-4-bora-3a-azonia-4a-aza-s-indacene) and derivatives are widely known by their outstanding photophysical properties displayed. However, recently it have increased the interest in such structures, but this time, for the biological properties that these fluorescent compounds are also shown, as convenient probes for diverse biological targets.Focusing on the above findings, we were interested into compile, in this review article, the literature documented since 2000–2020 exclusively engaged with the synthetic strategies established for the synthesis of curcumine-BF₂ adducts, BODIPY and their related derivatives, in which the biological properties displayed by such structures have been highlighted. Remarkably, the biological activities displayed by the aforementioned BF₂-based compounds are mainly related with cell imaging studies, biomolecules recognition and labels, antibiotic properties and antiproliferative agents, which were conveniently used to organize them in concise Tables and Schemes to facilitate their comparisons, and to underscore the key points of the present review.     

Synthesis and Toxicity Assessments Some Para-methoxy Chalcones Derivatives

Chalcones is a very interesting compounds because it is known to have various of biological activities such as antimicrobial, antifungal, anticancer, antimalarial, antioxidant, antitumor, anti-inflammatory and antidepressant. Moreover, natural and synthetic compounds of chalcones have roles as precursors for other compounds. Therefore, many chalcones become model structures of target compounds by researcher. In this research, methoxy chalcones derivatives have been synthesized using stirrer method and using base catalyst NaOH. The synthesized results obtained are (E)-3-(4-isoprophylphenyl)-1-(4’-methoxyphenyl)prop-2-en-1-one (1), (E)-1-(4’-methoxyphenyl)-3-p-tolylprop-2-en-1-one (2) and (E)-3-(3-bromophenyl)-1-(4’-methoxyphenyl)prop-2-en-1-one (3). The purity of all compounds have been tested using TLC, melting point test, analytical HPLC. Then they are characterized using UV, FTIR, ¹H-NMR and MS spectroscopy. The toxicity assessments of the novel compounds were done by Brine Shrimp Lethality Test (BSLT) method. The all compounds showed very good activity with LC₅₀ value<200 μg/mL.     

Synthesis of pyrano[2,3-c]pyrazoles: A review

One-pot synthesis of pyrano[2,3-c]pyrazole derivatives via two or multicomponent condensation of β-ketoesters, hydrazine monohydrate/phenyl hydrazine, malononitrile, and substituted benzaldehydes is of great interest not only in synthetic chemistry but also in medicinal chemistry because of the tremendous biological activities, such as anticancer, anti-inflammatory, analgesic, antimicrobial, and enzyme inhibitory activities exhibited by pyranopyrazoles. This review provides extensive knowledge on novel synthetic methodologies of biologically active non-spiro/spiro-pyrano[2,3-c]pyrazole derivatives published recently.     

Naturally occurring furofuran lignans: structural diversity and biological activities

Furofuran lignans containing the 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane skeleton, represent one of the major subclasses of the lignan family of natural products. Furofuran lignans feature a wide variety of structures due to different substituents at aryl groups and diverse configurations at furofuran ring. Moreover, they exhibit a wide range of significant biological activities, including antioxidant, anti-inflammatory, cytotoxic, and antimicrobial activities. This review summarizes source, phytochemistry, and biological activities of 137 natural furofuran lignans isolated from 53 species in 41 genera of 27 plant families for the last 20 years, which provides a comprehensive information for further research of these furofuran lignans as potential pharmaceutical agents.     

Biginelli Reaction Mediated Synthesis of Antimicrobial Pyrimidine Derivatives and Their Therapeutic Properties

Antimicrobial resistance was one of the top priorities for global public health before the start of the 2019 coronavirus pandemic (COVID-19). Moreover, in this changing medical landscape due to COVID-19, finding new organic structures with antimicrobial and antiviral properties is a priority in current research. The Biginelli synthesis that mediates the production of pyrimidine compounds has been intensively studied in recent decades, especially due to the therapeutic properties of the resulting compounds, such as calcium channel blockers, anticancer, antiviral, antimicrobial, anti-inflammatory or antioxidant compounds. In this review we aim to review the Biginelli syntheses reported recently in the literature that mediates the synthesis of antimicrobial compounds, the spectrum of their medicinal properties, and the structure–activity relationship in the studied compounds.     

Clove Essential Oil (Syzygium aromaticum L. Myrtaceae): Extraction,Chemical Composition,Food Applications,and Essential Bioactivity for Human Health

Clove (Syzygium aromaticum L. Myrtaceae) is an aromatic plant widely cultivated in tropical and subtropical countries, rich in volatile compounds and antioxidants such as eugenol, β-caryophyllene, and α-humulene. Clove essential oil has received considerable interest due to its wide application in the perfume, cosmetic, health, medical, flavoring, and food industries. Clove essential oil has biological activity relevant to human health, including antimicrobial, antioxidant, and insecticidal activity. The impacts of the extraction method (hydrodistillation, steam distillation, ultrasound-assisted extraction, microwave-assisted extraction, cold pressing, and supercritical fluid extraction) on the concentration of the main volatile compounds in clove essential oil and organic clove extracts are shown. Eugenol is the major compound, accounting for at least 50%. The remaining 10–40% consists of eugenyl acetate, β-caryophyllene, and α-humulene. The main biological activities reported are summarized. Furthermore, the main applications in clove essential oil in the food industry are presented. This review presents new biological applications beneficial for human health, such as anti-inflammatory, analgesic, anesthetic, antinociceptive, and anticancer activity. This review aims to describe the effects of different methods of extracting clove essential oil on its chemical composition and food applications and the biological activities of interest to human health.     

An update on bioactive plant lignans

Lignans are a class of secondary plant metabolites produced by oxidative dimerization of two phenylpropanoid units. Although their molecular backbone consists only of two phenylpropane (C6-C3) units, lignans show an enormous structural diversity. There is a growing interest in lignans and their synthetic derivatives due to applications in cancer chemotherapy and various other pharmacological effects. This review deals with lignans possessing anticancer, antioxidant, antimicrobial, anti-inflammatory and immunosuppressive activities, and comprises the data reported in more than 100 peer-reviewed articles, so as to highlight the recently reported bioactive lignans that could be a first step towards the development of potential new therapeutic agents.     

Pyridine Scaffolds,Phenols and Derivatives of Azo Moiety: Current Therapeutic Perspectives

Synthetic heterocyclic compounds have incredible potential against different diseases; pyridines, phenolic compounds and the derivatives of azo moiety have shown excellent antimicrobial, antiviral, antidiabetic, anti-melanogenic, anti-ulcer, anticancer, anti-mycobacterial, anti-inflammatory, DNA binding and chemosensing activities. In the present review, the above-mentioned activities of the nitrogen-containing heterocyclic compounds (pyridines), hydroxyl (phenols) and azo derivatives are discussed with reference to the minimum inhibitory concentration and structure–activity relationship, which clearly indicate that the presence of nitrogen in the phenyl ring; in addition, the hydroxyl substituent and the incorporation of a diazo group is crucial for the improved efficacies of the compounds in probing different diseases. The comparison was made with the reported drugs and new synthetic derivatives that showed recent therapeutic perspectives made in the last five years.     

Important insights from the antimicrobial activity of Calotropis procera

Calotropis procera (family Apocynaceae) is a valuable medicinal plant as it contains many valuable phytochemicals such as glycosides (mostly cardenolides), flavonoids, triterpenes, alkaloids, steroids, saponins, proteins and enzymes. Multiparous biological activities such as anti-inflammatory, antioxidant, anticancer, wound healing and wideranging antimicrobial activities of C. procera have been well investigated and reported. The main aim of this review was to present the encompassing information regarding antimicrobial activities of C. procera latex, different crude extracts and some isolated compounds which have been tested for antimicrobial property. Comprehensive data extracted from earlier as well as recently published original articles regarding antibacterial, antifungal, anti-protozoal and antiviral properties of C. procera were discussed and summarised in tabular forms. The compiled data comprised of plant parts, geographical origin, type of tested extracts/fractions, test model, used doses, tested microorganisms, obtained results and relevant references. In addition, the isolated antimicrobial pure compounds of C. procera are also discussed in a separate section. The analysis and information presented in this review identified the existing critical knowledge gaps in the research and also explored the future perspectives and further research opportunities of C. procera.     

Synthetic strategies toward the synthesis of polyphenolic natural products: Pauciflorol F and isopaucifloral F: A review

Pauciflorol F and isopaucifloral F are very important polyphenolic natural products and exhibit a variety of biological activities such as antibiotic, anticancer, anti-HIV, antioxidant, antifungal, and anti-inflammatory activities. These important molecules have gained significant attraction of medicinal chemists and several new strategies have been developed toward the synthesis of pauciflorol F and isopaucifloral F. This review article summarizes the major synthetic approaches adopted for the synthesis of these two indanone-based compounds.     

Synthesis and pharmacological properties of chalcones: a review

Chalcones and their analogs have been an area of great interest in recent years. Numerous research papers have been published, and chalcones continue to show promise for new drug investigations. Researchers have explored new approaches for the synthesis of chalcone derivatives, which have revealed an array of pharmacological and biological effects. These chalcone derivatives have shown important antimicrobial, antifungal, anti-mycobacterial, antimalarial, antiviral, anti-inflammatory, antioxidant, antileishmanial anti-tumor, and anticancer properties. This review highlights the synthesis and pharmacological properties of chalcone derivatives.     

Preparative isolation and purification of alkannin/shikonin derivatives from natural products by high-speed counter-current chromatography

Alkannin and shikonin (A/S) and their derivatives have been found in the roots of several Boraginaceous species and are also produced through plant tissue cultures. The chiral compounds A/S are potent pharmaceutical substances with a wide spectrum of biological and pharmacological activities like wound healing, antimicrobial, anti-inflammatory, anticancer and antioxidant activity. High-speed counter-current chromatography (HSCCC) was applied for the first time to the separation, preparative isolation and purification of A/S and their esters from extracts of Alkanna tinctoria roots, as well as commercial samples. The constituents of HSCCC fractions and their purity were determined by high-performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS), since DAD cannot detect oligomeric A/S derivatives that are present in most of the samples containing the respective monomeric derivatives. The purity of HSCCC fractions was compared with the one of fractions isolated by column chromatography (CC) using as stationary phases silica gel and Sephadex LH-20. As shown, the purity of monomeric alkannin/shikonin was greater by HSCCC than CC separation of commercial A/S samples.     

钯催化合成香豆素研究进展

香豆素是一类苯并六元含氧杂环类化合物,具有抗氧化、抗菌、抗炎等多种生理活性,受到人们的广泛关注。近年来不断有香豆素的新合成方法报道,特别是高效的过渡金属钯催化合成反应。本文综述了近20年来钯络合物催化合成香豆素骨架的研究进展,主要包括羰基化反应、炔烃芳基化反应、烯烃芳基化反应和偶联反应,以期为合成新型香豆素提供参考。     

Synthetic transformations and biological screening of benzoxazole derivatives: A review

The presence of benzoxazole moiety in most of the heterocyclic compounds is well reported. The present literature review mainly highlights the novel synthetic transformation and describes the biological potential of most of the heterocyclic compounds by virtue of presence of benzoxazole framework. Most of the researchers have revealed that benzoxazole derivatives exhibit significant antibacterial, anti-inflammatory, antifungal, anticancer, analgesic, antiviral, anti-tubercular, and anthelmintic activities. Benzoxazole moieties also act as tyrosinase inhibitor and cholesterol ester transfer protein inhibitor. This literature review may provide an opportunity to the chemists to design new derivatives of benzoxazole that proved to be the successful agent in view of safety, effectiveness, and efficacy.