Coumarin chalcone fibrates: A new structural class of lipid lowering agents

(2E)-2-(4-ethoxybenzylidene)-3,4-dihydro-2H-naphthalen-1-one single crystal: Synthesis, growth, crystal structure, spectral characterization, biological evaluation and binding interactions with SARS-CoV-2 main protease

A new α-Tetralone based chalcone compound, (2E)-2-(4-ethoxybenzylidene)-3,4-dihydro-2H-naphthalen-1-one (EBDN) has been synthesized by Claisen–Schmidt condensation reaction of α-Tetralone (1) with 4-Ethoxybenzaldehyde (2) in basic medium. Then it was allowed to grow through slow evaporation solution growth technique. The molecular structure of grown EBDN has been systematically characterized by SCXRD, FT-IR, ¹H NMR and ¹³C NMR spectroscopic studies. The micro-hardness, thermal (TGA & DTA) and photoluminence studies of the synthesized EBDN were also examined. The EBDN was screened for its anti-inflammatory, antidiabetic and anti-oxidant activity. It has shown admirable anti-inflammatory and antidiabetic activity. Protein-Ligand interactions of EBDN with SARS-CoV-2 main protease (PDB code: 6yb7) also performed.

Signaling pathways and proteins targeted by antidiabetic chalcones

Chalcones have shown a broad spectrum of biological activities with clinical potential against various diseases. The biological activities are mainly attributed to the presence of α, β-unsaturated carbonyl system, perceived as potential Michael acceptors. In this review, we discussed the antioxidant potential of chalcones and elucidated the mechanisms of pathways and proteins such as carbohydrate digestive enzymes (α-amylase and α-glucosidase), aldose reductase, SGLT-2, and Nrf2 that are targeted by antidiabetic chalcones. In addition to their insulin mimetic potential, we explore the major molecular targets of chalcones and discuss the biochemical and therapeutic implication of modulating these targets. Finally, we dwell on the opulence of the literature and envisage how RNA interference-mediated gene silencing technique and in silico molecular docking could be exploited in the search for novel and more efficacious antidiabetic chalcones.

Hybrids of Coumarin Derivatives as Potent and Multifunctional Bioactive Agents: A Review

BACKGROUND

Coumarins exhibit a plethora of biological activities, e.g. antiinflammatory and anti-tumor. Molecular hybridization technique has been implemented in the design of novel coumarin hybrids with several bioactive groups in order to obtain molecules with better pharmacological activity and improved pharmacokinetic profile.

OBJECTIVE

Therefore, we tried to gather as many as possible biologically active coumarin hybrids referred in the literature till now, to delineate the structural characteristics in relation to the activities and to have a survey that might help the medicinal chemists to design new coumarin hybrids with drug-likeness and varied bioactivities.

RESULTS

The biological activities of the hybrids in most of the cases were found to be different from the biological activities presented by the parent coumarins. The results showed that the hybrid molecules are more potent compared to the standard drugs used in the evaluation experiments.

CONCLUSION

Conjugation of coumarin with varied pharmacophore groups/druglike molecules responsible for different biological activities led to many novel hybrid molecules, with a multitarget behavior and improved pharmacokinetic properties.

Coumarin-based Scaffold as α-glucosidase Inhibitory Activity: Implication for the Development of Potent Antidiabetic Agents

BACKGROUND

Delaying the absorption of glucose through α-glucosidase enzyme inhibition is one of the therapeutic approaches in the management of Type 2 diabetes, which can reduce the incidence of postprandial hyperglycemia. The existence of chronic postprandial hyperglycemia impaired the endogenous antioxidant defense by inducing oxidative stress-induced pancreatic β-cell destruction through uncontrolled generation of free radicals such as ROS, which in turn, leads to various macrovascular and microvascular complications. The currently available α -glucosidase inhibitors, for instance, acarbose, have some side effects such as hypoglycemia at higher doses, liver problems, meteorism, diarrhea, and lactic acidosis. Therefore, there is an urgent need to discover and develop potential α-glucosidase inhibitors.

OBJECTIVE

Based on suchmotifs, researchers are intrigued to search for the best scaffold that displays various biological activities. Among them, coumarin scaffold has attracted great attention. The compound and its derivatives can be isolated from various natural products and/or synthesized for the development of novel α-glucosidase inhibitors.

RESULTS

This study focused on coumarin and its derivatives as well as on their application as potent antidiabetic agents and has also concentrated on the structure-activity relationship.

CONCLUSION

This review describes the applications of coumarin-containing derivatives as α - glucosidase inhibitors based on published reports which will be useful for innovative approaches in the search for novel coumarin-based antidiabetic drugs with less toxicity and more potency.

Chalcones and Flavanones Bearing Hydroxyl and/or Methoxyl Groups: Synthesis and Biological Assessments

Chalcones and flavanones are isomeric structures and also classes of natural products, belonging to the flavonoid family. Moreover, their wide range of biological activities makes them key scaffolds for the synthesis of new and more efficient drugs. In this work, the synthesis of hydroxy and/or methoxychalcones was studied using less common bases, such as sodium hydride (NaH) and lithium bis(trimethylsilyl)amide (LiHMDS), in the aldol condensation. The results show that the use of NaH was more effective for the synthesis of 2′-hydroxychalcone derivatives, while LiHMDS led to the synthesis of polyhydroxylated chalcones in a one-pot process. During this study, it was also possible to establish the conditions that favor their isomerization into flavanones, allowing at the same time the synthesis of hydroxy and/or methoxyflavanones. The chalcones and flavanones obtained were evaluated to disclose their antioxidant, anticholinesterasic, antibacterial and antitumor activities. 2′,4′,4-Trihydroxychalcone was the most active compound in terms of antioxidant, anti-butyrylcholinesterase (IC50 26.55 ± 0.55 μg/mL, similar to control drug donepezil, IC50 28.94 ± 1.76 μg/mL) and antimicrobial activity. 4′,7-Dihydroxyflavanone presented dual inhibition, that is, the ability to inhibit both cholinesterases. 4′-Hydroxy-5,7-dimethoxyflavanone and 2′-hydroxy-4-methoxychalcone were the compounds with the best antitumor activity. The substitution pattern and the biological assay results allowed the establishment of some structure/activity relationships.

Pharmacological and Nutritional Effects of Natural Coumarins and Their Structure-Activity Relationships

Coumarins are fused benzene and pyrone ring systems with a wide spectrum of bioactivities, including antitumor, anti-inflammation, antiviral, and antibacterial effects. In this paper, the current development of coumarin-based drugs is introduced, and their structure-activity relationship is discussed by reviewing the relevant literature published in the past 20 years. Coumarin molecules can be customized by the target site to prevent systemic side effects by virtue of structural modification. The ortho-phenolic hydroxyl on the benzene ring has remarkable antioxidant and antitumor activities. Coumarins with aryl groups at the C-4 position have good activities in anti-HIV, antitumor, anti-inflammation, and analgesia. C-3 phenylcoumarins have strong anti-HIV and antioxidant effects. Tetracycline pyranocoumarins can significantly inhibit HIV; osthol structural analogues have antimicrobial activity. Praeruptorin C and its derivatives play an important role in lowering blood pressure and dilating coronary arteries, and khellactone derivatives have significant inhibitory effects on AIDS, cancer, and cardiovascular diseases. It is concluded that the specific site on the core structure of coumarin exhibits one or more activities due to the electronic or steric effects of the substituents. This review is intended to be conducive to rational design and development of more active and less toxic agents with a coumarin scaffold.

Highly Efficient Synthesis of Chalcones from Poly Carbonyl Aromatic Compounds Using BF3-Et2O via a Regioselective Condensation Reaction

A new, simple, highly efficient method for the synthesis of different types of carbonyl chalcones through a regioselective condensation reaction of appropriate 5-acetyl-2-hydroxybenzaldehyde with various substituted acetophenones and 4-hydroxyisothalaldehyde with various substituted aldehydes using BF3-Et2O as a reagent is described.

Acarbose versus trans-chalcone: comparing the effect of two glycosidase inhibitors on obese mice

OBJECTIVE

Acarbose and trans-chalcone are glucosidase inhibitors whose beneficial effects have been demonstrated in diabetes. The present study aimed at investigating their potential effects in obesity.

MATERIALS AND METHODS

NMRI male mice (n = 48) were subjected to a high fat diet for four weeks, which induced an initial state of obesity. One control group was given normal rodent diet. Obese animals were then switched to normal rodent diet, and divided to four groups (n = 12 in each): untreated, sham (receiving grape seed oil), and experimental groups receiving acarbose and trans-chalcone (12 mg/kg) during eight weeks. Body weight, blood glucose and other biochemical parameters including triglycerides (TG), cholesterol, HDL, AST, and ALT were measured, as well as leptin, adiponectin, TNF-α, and total antioxidant capacity (TAC). Histological studies were performed on adipose cells and liver tissue samples.

RESULTS

All factors were affected in a positive manner by acarbose, save for body weight, blood sugar and leptin levels, on which acarbose effects, although observable, were not statistically significant. Grape seed oil, used as a solvent for trans-chalcone was found to possess significant effect on TG and TAC, and had beneficial effects on other factors including liver enzymes and cholesterol. Trans-chalcone effects were significant on HDL, leptin and ALT. All compounds seemed to be able to affect fat deposition in liver tissue, and decrease the size of adipose tissue cells to some extent.

CONCLUSION

In conclusion, the tested compounds were able to affect lipid accumulation in tissues and influence adipokines, which may result in an enhanced state with regard to inflammation and oxidative stress.

Therapeutic potential of chalcones as cardiovascular agents

Cardiovascular diseases are the leading cause of death affecting 17.3 million people across the globe and are estimated to affect 23.3 million people by year 2030. In recent years, about 7.3 million people died due to coronary heart disease, 9.4 million deaths due to high blood pressure and 6.2 million due to stroke, where obesity and atherosclerotic progression remain the chief pathological factors. The search for newer and better cardiovascular agents is the foremost need to manage cardiac patient population across the world. Several natural and (semi) synthetic chalcones deserve the credit of being potential candidates to inhibit various cardiovascular, hematological and anti-obesity targets like angiotensin converting enzyme (ACE), cholesteryl ester transfer protein (CETP), diacylglycerol acyltransferase (DGAT), acyl-coenzyme A: cholesterol acyltransferase (ACAT), pancreatic lipase (PL), lipoprotein lipase (LPL), calcium (Ca(2+))/potassium (K(+)) channel, COX-1, TXA2 and TXB2. In this review, a comprehensive study of chalcones, their therapeutic targets, structure activity relationships (SARs), mechanisms of actions (MOAs) have been discussed. Chemically diverse chalcone scaffolds, their derivatives including structural manipulation of both aryl rings, replacement with heteroaryl scaffold(s) and hybridization through conjugation with other pharmacologically active scaffold have been highlighted. Chalcones which showed promising activity and have a well-defined MOAs, SARs must be considered as prototype for the design and development of potential anti-hypertensive, anti-anginal, anti-arrhythmic and cardioprotective agents. With the knowledge of these molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective chalcone derivatives as potential cardiovascular agents.

An overview of molecular hybrids in drug discovery

INTRODUCTION

The hybridization of biologically active molecules is a powerful tool for drug discovery used to target a variety of diseases. It offers the prospect of better drugs for the treatment of a number of illnesses including cancer, malaria, tuberculosis and AIDS. Hybrid drugs can provide combination therapies in a single multi-functional agent and, by doing so, be more specific and powerful than conventional classic treatments. This research field is in great expansion and attracts many researchers worldwide.

AREA COVERED

This review covers the main research published between early 2013 to mid-2015 and takes into account several previous reviews on the subject. Its intention is to showcase the most recent advances reported towards the development of molecular hybrids in drug discovery. Particular attention is given to anticancer hybrids throughout the review.

EXPERT OPINION

Current advances show that molecular hybrids of biologically active molecules can lead to powerful therapeutics. Natural products play a key role in this field. It is also believed that toxin hybrids present a great opportunity for future progress and should be further explored. Furthermore, the synthesis of hybrid organometallics should be systematically studied as it can lead to potent drugs. The crucial requirement for growth still remains the efficacy of synthesis. Hence, the development of efficient synthetic methods allowing rapid access to diverse series of hybrids must be further investigated by researchers.

Hybrids of coumarin–indole: design, synthesis and biological evaluation in Triton WR-1339 and high-fat diet induced hyperlipidemic rat models

Lipid lowering activity of novel coumarin–indole hybrids has been demonstrated.

Coumarin–chalcone hybrids: promising agents with diverse pharmacological properties

Coumarin–chalcone hybrid is an interesting template for medicinal chemists to develop therapeutic agents with diverse pharmacological activity.

Chalcone scaffolds as anti-infective agents: structural and molecular target perspectives

In recent years, widespread outbreak of numerous infectious diseases across the globe has created havoc among the population. Particularly, the inhabitants of tropical and sub-tropical regions are mainly affected by these pathogens. Several natural and (semi) synthetic chalcones deserve the credit of being potential anti-infective candidates that inhibit various parasitic, malarial, bacterial, viral, and fungal targets like cruzain-1/2, trypanopain-Tb, trans-sialidase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), fumarate reductase, falcipain-1/2, β-hematin, topoisomerase-II, plasmepsin-II, lactate dehydrogenase, protein kinases (Pfmrk and PfPK5), and sorbitol-induced hemolysis, DEN-1 NS3, H1N1, HIV (Integrase/Protease), protein tyrosine phosphatase A/B (Ptp-A/B), FtsZ, FAS-II, lactate/isocitrate dehydrogenase, NorA efflux pump, DNA gyrase, fatty acid synthase, chitin synthase, and β-(1,3)-glucan synthase. In this review, a comprehensive study (from Jan. 1982 to May 2015) of the structural features of anti-infective chalcones, their mechanism of actions (MOAs) and structure activity relationships (SARs) have been highlighted. With the knowledge of molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective anti-infective agents.

Discovery of 2'-hydroxychalcones as autophagy inducer in A549 lung cancer cells

A series of 2'-hydroxychalcone derivatives was synthesized and the effects of all the compounds on growth of A549 lung cancer cell were investigated. The results showed that all compounds had inhibitory effects on the growth of A549 lung cancer cells and compound possessed the highest growth inhibitory effect and induced autophagy of A549 lung cancer cells.

Chalcones and their therapeutic targets for the management of diabetes: structural and pharmacological perspectives

Diabetes Mellitus (DM) is the fastest growing metabolic disorder affecting about 387 million people across the globe and is estimated to affect 592 million people by year 2030. The search for newer anti-diabetic agents is the foremost need to control the accelerating diabetic population. Several natural and (semi) synthetic chalcones deserve the credit of being potential candidates that act by modulating the therapeutic targets PPAR-γ, DPP-4, α-glucosidase, PTP1B, aldose reductase, and stimulate insulin secretion and tissue sensitivity. In this review, a comprehensive study (from January 1977 to October 2014) of anti-diabetic chalcones, their molecular targets, structure activity relationships (SARs), mechanism of actions (MOAs) and patents have been described. The compounds which showed promising activity and have a well-defined MOAs, SARs must be considered as prototype for the design and development of potential anti-diabetic agents. They should be evaluated critically at all clinical stages to ensure their therapeutic and toxicological profile to meet the demand of diabetics.

Antioxidant properties of several coumarin–chalcone hybrids from theoretical insights

Structural features, antioxidant ability and UV-Vis absorption properties of a series of coumarin–chalcone derivatives have been elucidated by means of density functional theory.

Synthesis and antifilarial activity of chalcone-thiazole derivatives against a human lymphatic filarial parasite, Brugia malayi

Here we report the synthesis of novel chalcone-thiazole compounds and their antifilarial activity. The antifilarial properties of these hybrids were assessed against microfilariae as well as adult worms of Brugia malayi. Among all the synthesized compounds, only two compounds, namely 4g and 4n were identified to be promising in vitro. These active compounds were tested in B. malayi-jird (Meriones unguiculatus) and B. malayi-Mastomys coucha models. Compound 4n showed 100% embryostatic effect and 49% macrofilaricidal in jirds and M. coucha models, respectively. This study provides a new structural clue for the development of novel antifilarial lead molecules.

Antiobesity, antioxidant and cytotoxicity activities of newly synthesized chalcone derivatives and their metal complexes

Four sets of rationally designed chalcones were prepared for evaluation of their antiobesity, antioxidant and cytotoxicity activities. These sets include nine oleoyl chalcones as mimics of oleoyl estrone, three monohydroxy chalcones (chalcone ligands), Schiff base-derived chalcones and four copper as well as zinc complexes. Oleoyl chalcones 4d, 4e and particularly 6a as an isosteric isomer of oleoyl estrone, were as active as Orlistat on weight loss and related metabolic parameters using male SD rats in vivo. Chalcone ligands 10a-c and Schiff base-derived chalcones 11 and 14a,b were weakly antioxidants, while, the copper and zinc complexes 15a-d were good antioxidants with zinc chelates 15b,d being more active than their copper analogues 15a,cin vitro. Compounds 10c and 14a showed good cytotoxicity activities as Doxorubicin against PC3 cancer cell line in vitro, while, the copper complex 15c showed promising activity with IC₅₀ value of 5.95 μM. The estimated IC₅₀ value for Doxorubicin was 8.7 μM. Chalcones 14a,b are bifunctional probes for potential investigations in cancer diagnosis and radiotherapy by complexation with Gd(3+) or metal radioisotopes followed by posttranslation of Shiga toxin B-subunits that target globotriosyl ceramide expressing cancer cells.