Synthesis of anthraquinone-connected coumarin derivatives via grindstone method and their evaluation of antibacterial, antioxidant, tyrosinase inhibitory activities with molecular docking, and DFT calculation studies.

Anthraquinones and coumarins have excellent pharmacological activities and are an important class of natural plant metabolites with various biological activities. In this study, anthraquinone-9,10-dione and coumarin derivatives were combined to develop a novel anthraquinone-connected coumarin-derivative sequence. The synthesised novel anthraquinone-connected coumarin derivatives (1a-t) were screened for in vitro antibacterial, antioxidant, and tyrosinase inhibitory activities. The antibacterial activities of the synthesised compounds (1a-t) were tested against both gram-positive and gram-negative bacteria. Specifically, compound 1t was more active against E. aerogenes than ciprofloxacin. With regard to antioxidant activity, compound 1o (50.68 % at 100 µg/mL) was highly active compared to the other compounds, whereas it was less active than the standard BHT (76.74 % at 100 µg/mL). In terms of compound 1r (9.31 ± 0.45 µg/mL) was highly active against tyrosinase inhibitory activity compared with kojic acid (10.42 ± 0.98 µg/mL). In the molecular docking study, compound 1r had a higher docking score (-8.8 kcal mol-1) than kojic acid (-1.7 kcal mol-1). DFT calculations were performed to determine the energy gap of highly active compound 1r (ΔE = 0.11) and weakly active compound 1a (ΔE = 0.12). In this study, we found that every molecule displayed significant antibacterial, antioxidant, and tyrosinase inhibitory properties. Based on these reports, compounds 1r and 1t may act as multi-target agents.

Design of 1,4-Dihydropyridine Hybrid Benzamide Derivatives: Synthesis and Evaluation of Analgesic Activity and Their Molecular Docking Studies.

Purpose: This study aims to determine the analgesic activity of 1,4-dihydropyridine hybrid benzamide derivatives. These hybrid derivatives were synthesized, and their analgesic activity was studied. The synthesis method applied was a one-step reaction involving a green chemistry approach. Methods: The compounds were prepared via the amination method with a yield ranging between 82% and 93%. The title compounds were confirmed by means of IR, 1H and 13C NMR, and mass spectral analyses. The pharmacological activity of all the synthesized compounds was evaluated, and the analgesic activities were monitored in vivo (by tail immersion methods), with a digital analgesiometer. The drug response and damage of tail ata concentration of 10 mg/kg were measured by tail-flicking latency. Results: The activity of compound 2c (81.35% activity at 5mg/kg) can be correlated with its salicylamidemoiety (13.99% activity at 5mg/kg), and diclofenac showed comparable activity (79.21% activity at 5mg/kg reference drugs). Compound 2c has a higher potential to inhibit COX proteins compared to diclofenac. The drug-like nature of the molecule 2c corresponds to its ADME properties. Conclusion: In this study, all the synthesized compounds were found to possess significant analgesic activities; particularly, the performance of compound 2c is excellent. Thus, the preparative method described is an apt route for developing novel therapeutic formulations.

Tyrosinase-mediated synthesis of larvicidal active 1,5-diphenyl pent-4-en-1-one derivatives against Culex quinquefasciatus and investigation of their ichthyotoxicity.

1,5-diphenylpent-4-en-1-one derivatives were synthesised using the grindstone method with Cu(II)-tyrosinase used as a catalyst. This method showed a high yield under mild reaction conditions. The synthesised compounds were identified by FTIR, 1H NMR, 13C NMR, mass spectrometry, and elemental analysis. In this study, a total of 17 compounds (1a-1q) were synthesised, and their larvicidal and antifeedant activities were evaluated. Compound 1i (1-(5-oxo-1,5-diphenylpent-1-en-3-yl)-3-(3-phenylallylidene)thiourea) was notably more active (LD50: 28.5 µM) against Culex quinquefasciatus than permethrin(54.6 µM) and temephos(37.9 µM), whereas compound 1i at 100 µM caused 0% mortality in Oreochromis mossambicus within 24 h in an antifeedant screening, with ichthyotoxicity determined as the death ratio (%) at 24 h. Compounds 1a, 1e, 1f, 1j, and 1k were found to be highly toxic, whereas 1i was not toxic in antifeedant screening. Compound 1i was found to possess a high larvicidal activity against C. quinquefasciatus and was non-toxic to non-target aquatic species. Molecular docking studies also supported the finding that 1i is a potent larvicide with higher binding energy than the control (- 10.0 vs. - 7.6 kcal/mol) in the 3OGN protein. Lead molecules are important for their larvicidal properties and application as insecticides.

Green catalyst Cu(II)-enzyme-mediated eco-friendly synthesis of 2-pyrimidinamines as potential larvicides against Culex quinquefasciatus mosquito and toxicity investigation against non-target aquatic species.

Novel one-pot multicomponent synthesis of 2-pyrimidinamine derivatives can be achieved via green chemistry, using Cu(II)-tyrosinase enzyme (Cu-Tyr) as a catalyst. This method offers mild reaction conditions and a high yield of derivatives. We synthesised several compounds in this manner and evaluated their larvicidal, and antifeedant activities. Out of the synthesised derivatives, compound 3, with a median lethal dose (LD50) of 21.43 µg/mL, was highly active against Culex quinquefasciatus, compared to compounds 1a-m and 2, and the control, hydantocidin. Compounds 1j, 1d, and 1e were low active against C. quinquefasciatus with LD50 values of 78.46, 78.59, and 79.54 µg/mL, respectively. In antifeedant screening, compounds 1j, 1l, and 2 generated 100% mortality within 24 h against Oreochromis mossambicus at 100 µg/mL, where toxicity was determined as the ratio of the number of dead and live fingerlings (%) at 24 h. In contrast, compounds 1a-f, 1i, 1m, and 3 were less toxic to O. mossambicus as compared to the control, dibromoisophakellin. Therefore, compound 3 had high larvicidal activity against C. quinquefasciatus and was less toxic to non-target aquatic species. Molecular docking studies also supported the finding that compound 3 was an effective larvicide with more inhibition ability than the control hydantocidin (-9.6 vs. -6.1 kcal/mol).

Larvicidal activity of novel anthraquinone analogues and their molecular docking studies.

To investigate the larvicidal activities of novel anthraquinones (1a-1k) against Culex quinquefasciatus mosquito larvae. Novel anthraquinones (1a-1k) derivatives were synthesis via condensation method. The compounds were confirmed through FT-IR spectroscopy, 1H & 13C NMR spectrum, and mass spectral studies. The larvicidal activity of compound 1c was highly active LD50 20.92 µg/mL against Culex quinquefasciatus compared standard permethrin with LD50 25.49 µg/mL. Molecular docking studies were carried out for compound 1c against Odorant-binding protein of Culex quinquefasciatus. The compound 1c (-9.8 Kcal/mol) was a potent larvicide with more binding energy than control permethrin (-9.7 Kcal/mol). Therefore, compound (1c) may be more significant inhibitors of mosquito larvicidal.

Synthesis of novel coumarin analogues: Investigation of molecular docking interaction of SARS-CoV-2 proteins with natural and synthetic coumarin analogues and their pharmacokinetics studies.

The severe acute respiratory syndrome coronavirus, identified as SARS-CoV-2, initially established in Wuhan, China at the end of 2019, affects respiratory infections known as COVID-19. In an extraordinary manner, COVID-19 is affecting human life and has transformed a global public health issue into a crisis. Natural products are already recognized owing to the massive advantageous window and efficient antioxidant, antiviral immunomodulatory, and anti-inflammatory belongings. Additionally, the object of the present study was to demonstrate the inhibitory potential of the natural products coumarins and its analogues alongside SARS coronavirus. The present work, focuses on the synthesis of new coumarin analogues and characterized by FT-IR, 1H and 13C NMR, elemental analyses, and mass spectra. The recently synthesised compounds were projected conceptual association for COVID-19 protease and also to explore in anticipation if this protein will help target protease inhibitor drugs such as Calanolide A, Cardatolide A, Collinin, Inophyllum A, Mesuol, Isomesuol, Pteryxin, Rutamarin, Seselin and Suksdorin. The natural coumarin analogues docking scores were compared to standard Hydroxychloroquine. While the 3D module of SARS coronavirus main protease was predicted with the SWISS MODEL web server, as well as biochemical interaction tests were performed with the AutoDock Vina tool between the target protein with ligands. This research further showed that all the protease inhibitors accessed the target protein with negative dock energy. Molecular docking studies found that the natural coumarin analogue Inophyllum A showed an exceptional potential for inhibition with a binding energy of -8.4 kcal/mol. The synthetic coumarin analogues 1m and 1p both demonstrated a similar binding energy, inhibition potential of -7.9 kcal / mol as opposed to hydroxychloroquine and co-crystallized ligand alpha-ketoamide with binding energy values of -5.8 and -6.6 kcal / mol. All compounds evaluated were known as drug-like in nature, passing Lipinski's "Law of 5" with 0 violations except for alpha-ketoamide, passing Lipinski's "Rule of 5" with 1 violation (MW > 500). The inhibitor binding in silico research thus offers a structural understanding of COVID-19 and molecular interactions across the known protease inhibitors centred on the findings of the multiple sequence alliance.

Grindstone Chemistry: Design, One-Pot Synthesis, and Promising Anticancer Activity of Spiro[acridine-9,2'-indoline]-1,3,8-trione Derivatives against the MCF-7 Cancer Cell Line.

In this study, the synthesis of one-pot 10-phenyl-3,4,6,7-tetrahydro-1H-spiro [acridine-9,2'-indoline]-1,3,8-trione derivatives was achieved via a four-component cyclocondensation reaction, which was carried out in solvent-free conditions, and using p-toluenesulfonic acid (p-TSA) as a catalyst. The product was confirmed by FT-IR, 1H-NMR, 13C-NMR, mass spectra, and elemental analysis. Furthermore, the anticancer activity was screened for all compounds. Among these compounds, compound 1c was more effective (GI50 0.01 µm) against MCF-7 cancer cell lines than standard and other compounds. Therefore, the objective of this study was achieved with a few promising molecules having been demonstrated to be potential anticancer agents.

In silico molecular docking: Evaluation of coumarin based derivatives against SARS-CoV-2.

BACKGROUND: The unique anthropological coronavirus which has been titled as SARS-CoV-2 was originally arisen in late 2019 in Wuhan, China affecting respiratory infection named as COVID-19. Coronavirus is disturbing human life in an exceptional method and has converted a public health global crisis. Natural products are ahead consideration due to the huge beneficial window and effective anti-inflammatory, immunomodulatory, antioxidant and antiviral possessions. Consequently, the present study was intended to display inhibition ability of natural products coumarins and their analogues against SARS coronavirus. METHODS: The present study, aims to forecast theoretical assembly for the protease of COVID-19 and to discover advance whether this protein may assist as a target for protease inhibitors such as psoralen, bergapten, imperatorin, heraclenin, heraclenol, saxalin, oxepeucedanin, angelicin, toddacoumaquinone, and aesculetin. The docking score of these natural coumarin analogues compared with standard Hydroxychloroquine. Whereas the 3D assembly of main protease of SARS coronavirus was forecast with SWISS MODEL web server, and molecular interaction studies amongst target protein and ligands were done with AutoDock Vina software. RESULTS: The study more exposed that all the inhibitors acquired with negative dock energy against the target protein. Molecular docking investigation displayed that natural coumarin analogue toddacoumaquinone displayed a remarkable inhibition ability with the binding energy of -7.8 kcal/mol than other compounds against main protease of SARS coronavirus in intricate with α-ketoamide (PDB ID: 5N5O). The synthetic coumarin analogue (1 m) also displayed the comparable inhibition ability with a binding energy of -7.1 kcal/mol against main protease of SARS coronavirus in intricate with α-ketoamide. Keeping the overhead results of ADME and toxicity, all tested compounds were recognized as drug-like nature, passing Lipinski's "Rule of 5" with 0 violation except α-ketoamide passes Lipinski's "Rule of 5" with 1 violation MW > 500. The projected constraints are within the assortment of recognized values. CONCLUSIONS: Based upon the results of the manifold sequence alliance, natural and synthetic coumarin binding sites were preserved. The present in silico examination thus, delivers structural awareness about the protease of COVID-19 and molecular relations with some of the recognised protease inhibitors.

Synthesis, Cytotoxic Analysis, and Molecular Docking Studies of Tetrazole Derivatives via N-Mannich Base Condensation as Potential Antimicrobials.

PURPOSE: A new series of tetrazole derivatives, which are renowned antimicrobials possessing a five-membered aromatic heterocyclic group, are synthesized herein and subjected to antimicrobial and cytotoxicity screening. METHODS: The tetrazole derivatives were synthesized via ultrasonication using Mannich base condensation. Structural verification of the products was performed using IR, 1H NMR, and 13C NMR spectroscopy, as well as mass spectroscopic and elemental analyses. The compounds were then screened for antimicrobial and cytotoxic activity against HepG2 (liver), MCF-7 (breast), and HeLa (cervical) cell lines. Inter- and intra-molecular binding interactions were determined using molecular docking studies. The exact binding mode between the most active tetrazole derivatives (ie, 1b, 2a, and 2b) and the proteins (ie, 4OR7, 1AI9, and 4FM9) was established using Autodock Vina 1.1.2 software and compared to the binding mode of the reference compounds (ie, cefazolin, clotrimazole, and fluorouracil). RESULTS: Compound 1b was extremely active against Enterococcus faecalis relative to the positive control cefazolin. Compounds 1b and 1e were active against Candida albicans and Microsporum audouinii compared to the positive control clotrimazole in antifungal screening. The HepG2 (liver) and MCF-7 (breast) cancer cell lines were particularly susceptible to the synthesized compounds. Compared to the control compound fluorouracil, 2a and 2b were extremely active against all three cancer cell lines. Molecular docking studies showed that 2b exhibited higher binding affinity (-7.8 kcal/mol) to the 4OR7 protein than the control cefazolin (-7.2 kcal/mol). CONCLUSION: Generally, 1b, 2a, and 2b exhibited impressive inhibitory capabilities in antibacterial, antifungal, and cytotoxic screenings relative to the reference compounds. The results of the molecular docking studies and both the microbial and anticancer screenings indicate that these novel derivatives could be developed into potential therapeutic agents for medical applications.