Comparative α-glucosidase and α-amylase inhibition studies of rhodanine–pyrazole conjugates and their simple rhodanine analogues

Rhodanine-benzamides as potential hits for α-amylase enzyme inhibitors and radical (DPPH and ABTS) scavengers

A series of 3-substituted and 3,5-disubstituted rhodanine-based derivatives were synthesized from 3-aminorhodanine and examined for α-amylase inhibitory, DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities in vitro. These derivatives displayed significant α-amylase inhibitory potential with IC50 values of 11.01-56.04 µM in comparison to standard acarbose (IC50 = 9.08 ± 0.07 µM). Especially, compounds 7 (IC50 = 11.01 ± 0.07 µM) and 8 (IC50 = 12.01 ± 0.07 µM) showed highest α-amylase inhibitory activities among the whole series. In addition to α-amylase inhibitory activity, all compounds also demonstrated significant scavenging activities against DPPH and ABTS radicals, with IC50 values ranging from 12.24 to 57.33 and 13.29-59.09 µM, respectively, as compared to the standard ascorbic acid (IC50 = 15.08 ± 0.03 µM for DPPH; IC50 = 16.09 ± 0.17 µM for ABTS). These findings reveal that the nature and position of the substituents on the phenyl ring(s) are crucial for variation in the activities. The structure-activity relationship (SAR) revealed that the compounds bearing an electron-withdrawing group (EWG) at para substitution possessed the highest activity. In kinetic studies, only the km value was changed, with no observed changes in Vmax, indicating a competitive inhibition. Molecular docking studies revealed important interactions between compounds and the α-amylase active pocket. Further advanced research needs to perform on the identified compounds in order to obtain potential antidiabetic agents.

Recent Studies of Nitrogen and Sulfur Containing Heterocyclic Analogues as Novel Antidiabetic Agents: A Review

The prevalence of diabetes mellitus is on the rise, which demands the identification of novel antidiabetic drugs. There is a need for safer and more effective alternatives because the therapy methods now available to manage diabetes have limits. Due to their diverse pharmacological characteristics, heterocyclic molecules with nitrogen and Sulfur atoms have become intriguing candidates in medicinal chemistry. These substances have a wide variety of structures that can be customized to target different pathways associated with diabetes and can affect important biological targets involved in glucose homeostasis. This review provides a thorough summary of the most recent studies on heterocyclic analogues of nitrogen and Sulfur as prospective antidiabetic agents. This review examines the variety of their structural forms, their methods of action, and assesses the results of preclinical and clinical investigations on their effectiveness and safety. Additionally, further optimization and development of innovative antidiabetic medications are highlighted, as well as the difficulties and prospects for the future in utilizing the therapeutic potential of these analogues. This study seeks to stimulate additional investigation and cooperation between researchers and medicinal chemists, promoting improvements in the creation of efficient and secure antidiabetic medicines to fulfill the needs in the management of diabetes.

Recent advances in the synthesis and medicinal perspective of pyrazole-based α-amylase inhibitors as antidiabetic agents

Diabetes is a serious health threat across the globe, claiming millions of lives worldwide. Among the various strategies employed, inhibition of α-amylase is a therapeutic protocol for the management of Type 2 diabetes mellitus. α-Amylase is a crucial enzyme involved in the breakdown of dietary starch into simpler units. However, the clinically used α-amylase inhibitors have various drawbacks. Therefore, design and development of novel α-amylase inhibitors have gained significant attention. The pyrazole motif has been identified as a versatile scaffold in medicinal chemistry, and recent studies have led to the identification of various pyrazole-based α-amylase inhibitors. This review compiles therapeutic implications of pyrazole-appended α-amylase inhibitors; their synthesis, biological activities, structure-activity relationships and molecular docking studies are discussed.

Identification of novel pyrazole containing ɑ-glucosidase inhibitors: insight into pharmacophore, 3D-QSAR, virtual screening, and molecular dynamics study

Pharmacophore modelling, 3 D QSAR modelling, virtual screening, and molecular dynamics study, all-in-one combination were employed successfully design and develop an alpha-glucosidase inhibitor. To explain the structural prerequisites of biologically active components, 3 D-QSAR models were generated using the selected best hypothesis (AARRR) for compounds 55 included in the model C. The selection of 3 D-QSAR models showed that the Gaussian steric characteristic is crucial to alpha glucosidase's inhibitory potential. The alpha-glucosidase inhibitory potency of the compound is enhanced by other components, including Gaussian hydrophobic groups, Gaussian hydrogen bond acceptor or donor groups, Gaussian electrostatic characteristics, and a Gaussian steric feature. An identification of structure-activity relationships can be obtained from the developed 3 D-QSAR, C model, with R2 = 0.77 and SD = 0.02 for training set, and Q2 = 0.66, RMSE 0.02, and Pearson R = 0.81 for testing set, corresponding to elevated predictive ability. Additionally, docking and MM/GBSA experiments on 1146023 showed that it interacts with critical amino acids in the binding site when coupled with acarbose. Further, five compounds that display a high affinity for alpha-glucosidase were found, and these compounds may serve as potent leads for alpha-glucosidase inhibitor development. Biological activity will be tested for these compounds in the future.Communicated by Ramaswamy H. Sarma.

Design, synthesis, and structure-activity studies of new rhodanine derivatives as carbonic anhydrase II, IX inhibitors

Rhodanine and its derivatives are an important class of heterocycles with diverse biological properties, including anticancer, antibacterial, and anti-mycobacterial activities. In the present work, four series of new Rhodanine derivatives were synthesized and evaluated for their inhibitory activity against carbonic anhydrase I, II, IX, and XII isoforms. Interestingly, the tested compounds exhibited good inhibitory activity against the cytosolic isoform human carbonic anhydrase (hCA) II and tumor-associated hCA IX. While the Rhodanine-benzylidene derivatives (3a-l) and Rhodanine-hydrazine derivatives (6a-e) are found to be selective against hCA II, the Rhodanine-N-carboxylate derivatives (8a-d) are found to be highly selective toward hCA IX. The Rhodanine-linked isoxazole and 1,2,4-oxadiazole derivatives (8ba, 8da, and 8db) exhibited inhibitory activity against hCA II and hCA IX. Among the tested compounds, 3b, 3j, 6d, and 8db were found to inhibit hCA II with Ki values of 9.8, 46.4, 7.7, and 4.7 µM, respectively. Furthermore, their mechanism of action is supported by molecular docking studies. Notably, the synthesized Rhodanine derivatives belong to a nonsulfonamide class of carbonic anhydrase inhibitors.

HR-LCMS and evaluation of anti-diabetic activity of Hemidesmus indicus (anantmool): Kinetic study, and molecular modelling approach

This study delved into the exploration of novel antidiabetic medications acquired from natural resources, utilizing the Ayurvedic Rasayana herb Hemidesmus indicus through cutting-edge chemoprofiling and molecular modelling techniques. The methanolic extract of Hemidesmus indicus root exhibited the highest extractive yield (24.70 ± 0.08 %) and contained substantial levels of total phenolic and flavonoid content as 154.15 ± 1.24 mg Gallic Acid Equivalent/g extract and 70.61 ± 0.35 Quercetin Equivalent/g extract respectively. Invitro study revealed the potent inhibitory potential of methanolic extract of the herb against essential carbohydrate hydrolytic enzymes α-amylase (IC₅₀ = 4.19 ± 0.04 mg/ml) and α-glucosidase (IC₅₀ = 5.78 ± 0.10 mg/ml). Further, the enzyme kinetic study demonstrated the competitive mode of inhibition of both enzymes. HR-LCMS analysis identified the major phytoconstituents present in the extracts, including Solanocapsine, Cyclovirobuxine C, Lucidine B, Zygadenine, Aspidospermidine, silychristin, 3beta-3-Hydroxy-18-lupen-21-one, Manglupenone, and 19-Noretiocholanolone. Molecular docking, molecular dynamic simulation, and MM/GBSA analysis have proved stable, rigid, compact, and folded form of complexes during the entire 100 ns simulation, illustrating Zygadenine, Solanocapsine, and Cyclovirobuxine C as the superior inhibitors of α-A protein, while Zygadenine, Plumieride, and Phlegmarine exhibited greater inhibitory behaviour towards α-G protein than the FDA-approved drug acarbose. Collectively, our findings indicate that the Hemidesmus indicus could be a promising source of α-A and α-G inhibitors, potentially serving as a lead in order to develop medications for type-2 diabetes.

Rhodanine derivatives: An insight into the synthetic and medicinal perspectives as antimicrobial and antiviral agents

Rhodanine or 2-Thioxothiazolidin-4-one is a privileged heterocyclic compound offering a wide opportunity for structural modification, lead development, and modification. It is one of the highly decorated scaffolds in the drug discovery process. Rhodanine derivatives possess a plethora of biological activities due to their ability to interact with a diverse range of protein targets, which provide tremendous opportunities to discover new drugs with different modes of action. The most common strategy for developing novel rhodanine derivatives is the introduction of structurally diverse substituents at the C-5 or N-3, or both positions. Since the inception of Epralestat into the market in 1992, the exploration of rhodanine-3-acetic acids has led to the development of novel leads against different biological targets such as MRSA, HHV-6, Mycobacterial tuberculosis, dengue, etc. In the current pandemic era, some rhodanine compounds have been explored against SARS-CoV-2. In recent years, rhodanine and its derivatives have witnessed significant progress in developing new drug leads as potential antimicrobial and antiviral agents. Different synthetic methodologies and recent developments in the medicinal chemistry of rhodanine derivatives, including biological activities, their mechanistic aspects, structure-activity relationships, and in silico findings, have been compiled in the present review. This article will benefit the scientific community and offer perspectives on how these scaffolds as privileged structures might be exploited in the future for rational design and discovery of rhodanine-based bio-active molecules.

New Specific α-Glucosidase Inhibitor Flavonoid from Thymelaea tartonraira Leaves: Structure Elucidation, Biological and Molecular Docking Studies

The phytochemical investigation of Thymelaea tartonraira leaves led to the isolation and characterization of six compounds, including one new flavonoid glycoside identified as hypolaetin 8-O-β-D-galactopyranoside (4) along with five known compounds, daphnoretin (1), triumbelletin (2), genkwanin (3), tiliroside (5) and yuankanin (6). Their structures were established based on spectroscopic methods, such as UV, IR, NMR, and HR-ESI-MS. Triumbelletin (2) and tiliroside (5) were isolated for the first time from T. tartonraira leaves. The antioxidant property of all isolated compounds was tested based on DPPH, FRAP and total antioxidant capacity assays. Compound 4 displayed an antioxidant potency more interesting than vitamin C with an IC₅₀ =15.00±0.50 μg/ml, followed by compound 5. Furthermore, the both compounds 4 and 5 were tested for their α-amylase inhibitory activity in-vitro. Compound 4 displayed higher potency to inhibit α-amylase, with an IC₅₀ =46.49±2.32 μg/ml, than compound 5, with an IC₅₀ =184.2±9.2 μg/ml, while the reference compound acarbose presented the highest potency to inhibit α-amylase with an IC₅₀ =0.44±0.022 μg/ml. Compound 4 displayed a strong inhibitory ability of α-glucosidase activity approximately twice more than the reference compound, acarbose, with IC₅₀ values of 60.00±3.00 and 125.00±6.25 μg/ml, respectively. Thus, compound 4 exhibited a specific inhibitory activity for α-glucosidase. The molecular docking studies have supported our findings and suggested that compound 4 has been involved in various binding interactions within the active site of both enzymes α-amylase and α-glucosidase.

Pyrazole scaffold-based derivatives: A glimpse of α-glucosidase inhibitory activity, SAR, and route of synthesis

The α-glucosidase is a validated target to develop drugs for treating type 2 diabetes mellitus. The existing α-glucosidase inhibitors have certain shortcomings related to side effects and route of synthesis. Accordingly, it is inevitable to develop new chemical templates as α-glucosidase inhibitors. Pyrazole derivatives have a special place in medicinal chemistry because of various biological activities. Recently, pyrazole-based heterocyclic compounds have emerged as a promising scaffold to develop α-glucosidase inhibitors. This study focuses on the recently reported pyrazole-based α-glucosidase inhibitors, including their biological activity (in vivo, in vitro, and in silico), structure-activity relationship, and ways of synthesis. The literature revealed the development of several promising pyrazole-based α-glucosidase inhibitors and new synthetic routes for their preparation. The encouraging α-glucosidase inhibitory results of the pyrazole-based heterocyclic compounds make them an attractive target for further research. The authors also foresee the arrival of the pyrazole-based α-glucosidase inhibitors in clinical practice.

Syntheses, in vitro, and in silico studies of rhodanine-based schiff bases as potential α-amylase inhibitors and radicals (DPPH and ABTS) scavengers

A two-step reaction method was used to synthesize a series of rhodanine-based Schiff bases (2-33) that were characterized using spectroscopic techniques. All compounds were assessed for α-amylase inhibitory and radical scavenging (DPPH and ABTS) activities. In comparison to the standard acarbose (IC₅₀ = 9.08 ± 0.07 µM), all compounds demonstrated good to moderate α-amylase inhibitory activity (IC₅₀ = 10.91 ± 0.08-61.89 ± 0.102 µM). Compounds also demonstrated significantly higher DPPH (IC₅₀ = 10.33 ± 0.02-96.65 ± 0.03 µM) and ABTS (IC₅₀ = 12.01 ± 0.12-97.47 ± 0.13 µM) radical scavenging activities than ascorbic acid (DPPH, IC₅₀ = 15.08 ± 0.03 µM; ABTS, IC₅₀ = 16.09 ± 0.17 µM). The limited structure-activity relationship (SAR) suggests that the position and nature of the substituted groups on the phenyl ring have a vital role in varying inhibitory potential. Among the series, compounds with an electron-withdrawing group at the para position showed the highest potency. Kinetic studies revealed that the compounds followed a competitive mode of inhibition. Molecular docking results are found to agree with experimental findings, showing that compounds reside in the active pocket due to the main rhodanine moiety.

A Review of the Recent Development in the Synthesis and Biological Evaluations of Pyrazole Derivatives

Pyrazoles are five-membered heterocyclic compounds that contain nitrogen. They are an important class of compounds for drug development; thus, they have attracted much attention. In the meantime, pyrazole derivatives have been synthesized as target structures and have demonstrated numerous biological activities such as antituberculosis, antimicrobial, antifungal, and anti-inflammatory. This review summarizes the results of published research on pyrazole derivatives synthesis and biological activities. The published research works on pyrazole derivatives synthesis and biological activities between January 2018 and December 2021 were retrieved from the Scopus database and reviewed accordingly.

Multicomponent reaction for the synthesis of new 1,3,4-thiadiazole-thiazolidine-4-one molecular hybrids as promising antidiabetic agents through α-glucosidase and α-amylase inhibition

A simple and efficient protocol was developed to synthesize a new library of thiazolidine-4-one molecular hybrids (4a-n) via a one-pot multicomponent reaction involving 5-substituted phenyl-1,3,4-thiadiazol-2-amines, substituted benzaldehydes and 2-mercaptoacetic acid. The synthesized compounds were evaluated in vitro for their antidiabetic activities through α-glucosidase and α-amylase inhibition as well as their antioxidant and antimicrobial potentials. Compound 4e exhibited the most promising α-glucosidase and α-amylase inhibition with an IC₅₀ value of 2.59 μM, which is ~1.5- and 14-fold superior as compared to the standard inhibitor acarbose. Structure-activity relationship (SAR) analysis revealed that the nature and position of substituents on the phenyl rings had a significant effect on the inhibitory potency.

The Importance of Rhodanine Scaffold in Medicinal Chemistry: A Comprehensive Overview

After the clinical use of epalrestat that contains a rhodanine ring, in type II diabetes mellitus and diabetic complications, rhodanin-based compounds have become an important class of heterocyclic in the field of medicinal chemistry. Various modifications to the rhodanine ring have led to a broad spectrum of biological activity of these compounds. Synthesis of rhodanine derivatives, depended on advenced throughput scanning hits, frequently causes potent and selective modulators of targeted enzymes or receptors, which apply their pharmacological activities through different mechanisms of action. Rhodanine-based compounds will likely stay a privileged scaffold in drug discovery because of different probability of chemical modifications of the rhodanine ring. We have, therefore reviewed their biological activities and structure activity relationship.

Synthesis of imidazole-pyrazole conjugates bearing aryl spacer and exploring their enzyme inhibition potentials

Developing improved enzyme inhibitors is an effective therapy to counter various diseases. Aiming to build up biologically active templates, a new series of bis-diazoles conjugated with an aryl linker was designed and prepared through a convenient synthetic approach. Synthesized derivatives 6(a-m), having different substitutions at the 2^nd position of the imidazole nucleus, depict the scope of present study. These compounds were characterized through spectroscopic methods and further examined for their in vitro enzyme inhibitory potentials against two selected enzymes: α-glucosidase and lipoxygenase (LOX). Overall, this series was found to be effective against α-glucosidase and moderately active against LOX enzyme. Compound 6k was the most potent α-glucosidase inhibitor with IC₅₀ = 54.25 ± 0.67 µM as compared to reference drug acarbose (IC₅₀ = 375.82 ± 1.76 µM). The docked conformation revealed the involvement of substituent's heteroatoms with amino acid residue Gly280 through hydrogen bonding. The most active LOX inhibitor was 6a with IC₅₀ = 41.75 ± 0.04 µM as compared to standard baicalein (IC₅₀ = 22.4 ± 1.3 µM). Docking model of 6a suggested the strong interaction of imidazole's nitrogen with iron atom of the active pocket of enzyme. Other features like lipophilicity, bulkiness of compounds, pi-pi interactions and/or pi-alkyl interactions also affected the inhibiting potentials of all prepared scaffolds.

Design and synthesis of novel pyrazole-phenyl semicarbazone derivatives as potential α-glucosidase inhibitor: Kinetics and molecular dynamics simulation study

A series of novel pyrazole-phenyl semicarbazone derivatives were designed, synthesized, and screened for in vitro α-glucosidase inhibitory activity. Given the importance of hydrogen bonding in promoting the α-glucosidase inhibitory activity, pharmacophore modification was established. The docking results rationalized the idea of the design. All newly synthesized compounds exhibited excellent in vitro yeast α-glucosidase inhibition (IC₅₀ values in the range of 65.1-695.0 μM) even much more potent than standard drug acarbose (IC₅₀ = 750.0 μM). Among them, compounds 8o displayed the most potent α-glucosidase inhibitory activity (IC₅₀ = 65.1 ± 0.3 μM). Kinetic study of compound 8o revealed that it inhibited α-glucosidase in a competitive mode (Ki = 87.0 μM). Limited SAR suggested that electronic properties of substitutions have little effect on inhibitory potential of compounds. Cytotoxic studies demonstrated that the active compounds (8o, 8k, 8p, 8l, 8i, and 8a) compounds are also non-cytotoxic. The binding modes of the most potent compounds 8o, 8k, 8p, 8l and 8i was studied through in silico docking studies. Molecular dynamic simulations have been performed in order to explain the dynamic behavior and structural changes of the systems by the calculation of the root mean square deviation (RMSD) and root mean square fluctuation (RMSF).

Pyrazole Incorporated New Thiosemicarbazones: Design, Synthesis and Investigation of DPP-4 Inhibitory Effects

Dipeptidyl peptidase-4 (DPP-4) inhibition has been recognized as a promising approach to develop safe and potent antidiabetic agents for the management of type 2 diabetes. In this context, new thiosemicarbazones (2a-o) were prepared efficiently by the reaction of aromatic aldehydes with 4-[4-(1H-pyrazol-1-yl)phenyl]thiosemicarbazide (1), which was obtained via the reaction of 4-(1H-pyrazol-1-yl)phenyl isothiocyanate with hydrazine hydrate. Compounds 2a-o were evaluated for their DPP-4 inhibitory effects based on a convenient fluorescence-based assay. 4-[4-(1H-pyrazol-1-yl)phenyl]-1-(4-bromobenzylidene)thiosemicarbazide (2f) was identified as the most effective DPP-4 inhibitor in this series with an IC₅₀ value of 1.266 ± 0.264 nM when compared with sitagliptin (IC₅₀ = 4.380 ± 0.319 nM). MTT test was carried out to assess the cytotoxic effects of compounds 2a-o on NIH/3T3 mouse embryonic fibroblast (normal) cell line. According to cytotoxicity assay, compound 2f showed cytotoxicity towards NIH/3T3 cell line with an IC₅₀ value higher than 500 µM pointing out its favourable safety profile. Molecular docking studies indicated that compound 2f presented π-π interactions with Arg358 and Tyr666 via pyrazole scaffold and 4-bromophenyl substituent, respectively. Overall, in vitro and in silico studies put emphasis on that compound 2f attracts a great notice as a drug-like DPP-4 inhibitor for further antidiabetic research.

Synthesis of indole-tethered [1,3,4]thiadiazolo and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids as anti-pancreatic cancer agents

New indole-tethered [1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one (8a-j) and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids (9a-e) were synthesized using [4+2] cycloaddition reactions of functionalized 1,3-diazabuta-1,3-dienes with indole-ketenes. All molecular hybrids were structurally characterized by spectroscopic techniques (IR, NMR, and HRMS) and screened for their anti-pancreatic cancer activity in vitro. The [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids (9a-e) showed stronger anti-pancreatic cancer activity than the [1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one hybrids (8a-j) against the PANC-1 cell line. Compound 9d bearing an ortho-chlorophenyl moiety emerged as the most potent anti-pancreatic cancer agent with an IC₅₀ value of 7.7 ± 0.4 µM, much superior to the standard drug Gemcitabine (IC₅₀ > 500 µM). The discovery of these [1,3,4]thiadiazolo and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids elicits their potentials as pursuable candidates for pancreatic cancer chemotherapy.

Antibacterial evaluation and molecular docking studies of pyrazole-thiosemicarbazones and their pyrazole-thiazolidinone conjugates

A library of pyrazole-thiazolidinone conjugates was synthesized using a molecular hybridization approach through a Vilsmeier-Haack reaction. The compounds were tested for anti-microbial activity against two Gram-positive bacteria (Staphylococcus aureus and methicillin-resistant Staphylococcus aureus) and four Gram-negative bacteria (Escherichia coli, Salmonella typhimurium, Klebsiella pneumonia and Pseudomonas aeruginosa). Among the compounds tested, 3-((2,4-dichlorophenyl)-1-(2,4-dinitrophenyl)-1H-pyrazol-yl)methylene)hydrazinecarbothioamide (3a) and 2-((3-(2-chlorophenyl)-1-(2,4 dinitrophenyl)-1H-pyrazol-4-yl)methyleneamino)thiazolidin-4-one (4b) emerged as the most potent anti-microbial compounds with minimum bactericidal concentrations of < 0.2 µM against MRSA and S. aureus. Structure-activity relationship analysis further revealed that the presence of 2,4-dichloro moiety surprisingly influenced the activity of the compounds. Molecular docking studies of the compounds into the crystal structure of topoisomerase II and topoisomerase IV suggest that compounds 3a and 4b preferably interact with the targets through hydrogen bonding.

The green synthesis and molecular docking of novel N-substituted rhodanines as effective inhibitors for carbonic anhydrase and acetylcholinesterase enzymes

Recently, inhibition effects of enzymes such as acetylcholinesterase (AChE) and carbonic anhydrase (CA) has appeared as a promising approach for pharmacological intervention in a variety of disorders such as epilepsy, Alzheimer's disease and obesity. For this purpose, novel N-substituted rhodanine derivatives (RhAs) were synthesized by a green synthetic approach over one-pot reaction. Following synthesis the novel compounds, RhAs derivatives were tested against AChE and cytosolic carbonic anhydrase I, and II (hCAs I, and II) isoforms. As a result of this study, inhibition constant (Ki) were found in the range of 66.35 ± 8.35 to 141.92 ± 12.63 nM for AChE, 43.55 ± 14.20 to 89.44 ± 24.77 nM for hCA I, and 16.97 ± 1.42 to 64.57 ± 13.27 nM for hCA II, respectively. Binding energies were calculated with docking studies as -5.969, -5.981, and -9.121 kcal/mol for hCA I, hCA II, and AChE, respectively.

The easy synthesis of new N-substituted 5-oxindoline-rhodanines and their sensing ability: the recognition of acetate ions in aqueous solution

Recently, there has been increasing interest in developing innovative synthetic strategies for the decoration of rhodanine-cores.