Novel indazolylchromones: synthesis, fungicidal evaluation, molecular docking and aquatic toxicity prediction

Fungal diseases cause substantial loss to agricultural crops, affecting both quantities and quality. Although several methods are used for preventing disease incidence, fungicides remain crucial for higher yields and better quality. But in the past, the efficacy of several fungicides has decreased due to increased cases of fungicide resistant. In our pursuit of new effective fungicides, we synthesised a series of twenty 2-Indazol-1-yl-chromen-4-one derivatives (6a- 6t). The characterization of synthesized compounds was performed by several spectroscopic methods including Infrared, Nuclear Magnetic Resonance (1H and 13C) and HRMS. Out of 20 synthesised compounds, 19 (6b- 6t) were found to be novel. All synthesised indazolylchromones showed very good antifungal activity against Sclerotium rolfsii and Fusarium oxysporum. Among the tested compounds, 6t and 6f exhibited very good fungicidal activity against S. rolfsii with an ED50 of 10.10 mg L-1 and 16.18 mg L-1, respectively. In case of Fusarium oxysporum compound 6f displayed good’ activity with an ED50 value of 27.82 mg L-1. Molecular docking study was done to predict the binding sites of most active compounds, 6t and 6f with Cytochrome P450 14alpha -sterol demethylase (CYP51) enzyme using molsoft software. The acute toxicity predictions the of synthesized compounds for fish (LC50,96 Hr), daphnid (LC50, 48 Hr) and green algae (EC50, 96Hr) and the chronic toxicity predictions (ChV) were assessed using Ecological Structure Activity Relationship (ECOSAR) model. As per ECOSAR prediction, all the chemicals are inside AD and not missing predictions

Amphiphilic polymer based nanoformulations of mancozeb for management of early blight in tomato

Not AvailableControlled release (CR) nanoformulations of Mancozeb (Manganese-zinc double salt of N, N-bisdithiocarbamic acid), a protective fungicide, have been developed using poly (ethylene glycols) (PEGs) based functionalized amphiphilic copolymers and evaluated for the management of early blight in tomato. During the field experiment, it was observed that number of infected leaflets/plants were less in developed formulation treated plants as compared to commercial products. Number of infected leaflets per plant was 2.40–4.60 and the number of fruits per plant were 6.40–9.00 at 50 mg L−1, whereas at 100 mg L−1, the corresponding numbers were 2.10-4.10 and 6.30-9.10 respectively. These formulations can be used to optimize the release of Mancozeb to achieve disease control for the desired period depending upon the matrix of the polymer used. Importantly, sufficient amount of active ingredient remains available for a reasonable period of time after application leading to reduced number of applications of pesticide.Not Availabl

Lipase-Catalyzed Solvent-Free Amidation of Phenolic Acids

<div><p></p><p>A series of N-alkyl-substituted amides, based on various phenolic acids, have been synthesized by the condensation of equimolar amounts of phenolic acids with different alkyl amines in the presence of Candida antarctica lipase at 60–90 °C in 16–20 h. The reactions were carried out in a solvent-free system without the use of any activating agents. All the products were obtained in appreciable amounts and the yields for different compounds varied between 75.6% and 83.5%. The synthesized compounds were characterized using spectroscopy techniques, namely infrared and NMR (¹H and ¹³C).</p></div

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Not AvailableA new microwave method (MM) has been developed for the synthesis of a series of 16 substituted ferrocenyl chalcones using acetylferrocene (1) with different aldehydes (2a-2p) and comparing it with conventional method (CM). The synthesized compounds were characterized by various spectroscopic techniques viz IR, HR-MS, 1H NMR, and 13C NMR. The time required for completion of reaction in MM varied from 1 to 5min as compared to CM which required 10–40 h. All the synthesized compounds were screened for antifungal activity against Sclerotium rolfsii and Alternaria solani. In vitro fungicidal activity revealed that compound 3o (ED50 = 23.24mg L−1) was found to be most active against S. rolfsii. But in case of A. solani, compound 3c (ED50 = 29.9mg L−1) showed highest activity. The nematicidal activity revealed that the compound 3b was more potent with LC50 values of 10.67, 7.30, and 4.55 ppm at 24, 48, and 72 h, respectively. 2D-Quantitative Structural Activity Relationship (2D-QSAR) analysis of these ferrocenyl chalcones was carried out by developing three different models namely Partial Least Squares (PLS, Model 1), Multiple Linear Regression (MLR, Model 2) and Principal Component Regression (PCR, Model 3). Statistical significance and predictive ability of these models were assessed by internal and external validation and also verified by leave one-out cross-validation. QSAR study revealed that MLR for S. rolfsii (r2 = 0.999, q2 = 0.996), PLS for A. solani (r2 = 0.934, q2 = 0.749) and PCR for M. incognita (r2 = 0.878, q2 = 0.772) were the best model. The physico-chemical parameters were calculated using VLife MDS 4.6 software. QSAR study could be employed for structure optimization to achieve better activity.Not Availabl

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Not AvailableThe present study reports, bioefficacy evaluation of effective compounds against Meloidogyne incognita and Sclerotium rolfsii in pot cultured tomato. The identified five most effective compounds, i.e. (2E)-1-(4-Methylphenyl)-3-ferrocenyl-prop-2-en-1-one (6g), (2E)-1-(4-Methoxyphenyl)-3-ferrocenyl-prop-2-en-1-one (6h), (2E)-1-(3-Bromophenyl)-3-ferrocenyl-prop-2-en-1-one (6j), (2E)-1-(2,4-Dichlorophenyl)-3-ferrocenyl-prop-2-en-1-one (6k) and (2E)-1-(3,5-Dichloro-2-hydroxyphenyl)-3-ferrocenyl-prop-2-en-1-one (6p) along with Carbofuran 3G as positive control were tested at 20, 40 and 80 ppm by soil drenching and root dipping methods. The study revealed that all plant growth parameters were positively influenced by these compounds. The presence of an electron releasing group positively influenced the efficacy, and the activity was highest in compounds 6g and 6h at 80 ppm. Based on in vitro results against S. rolfsii, (2E)-1-Ferrocenyl-3-(4-bromophenyl)-prop-2-en-1-one (3b), (2E)-1-Ferrocenyl-3-(2,6-dichlorophenyl)-prop-2-en-1-one (3o) and (2E)-1-(5-Chloro-2-hydroxyphenyl)-3-ferrocenyl-prop-2-en-1-one (6o) along with Tebuconazole 25.9% EC and Hexaconazole 5% SC as positive control were evaluated. The shoot length was found to be highest (24.50 cm) in plants treated with 3b followed by 3o and 6o at 1000 ppm. The percent disease incidence was significantly decreased as compared to control. The percent disease incidence was found to be minimum in plants treated with 3b at 1000 ppm. However, root dipping was not as effective as soil drenching. Therefore, ferrocenyl chalcone derivatives proved to be of great fungicidal and nematicidal potential opening new opportunities for expanding their effectiveness as new pest control agents.Not Availabl

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Not AvailableBiopesticides are considered to be safe, target specific, biodegradable and eco-friendly. These, especially Azadirachta indica A. Juss. (neem) based biopesticides, are mainly used as emulsified concentrate (EC). There is growing interest in nano emulsions based on phytochemical mixtures due to their better efficacy compared to conventional biopesticides. A. indica seed oil and Cymbopogon nardus (L.) Rendle (Citronella) oil are known to have pest control properties. However, their utilization is often restricted due to relatively low water solubility. This drawback can be overcome by encapsulating oils in oil-in-water (O/W) emulsions or nano emulsions using low or high energy methods. In this study, various nano emulsions of crude neem and citronella oils with surfactants were developed and characterised by Dynamic Light Scattering (DLS) and Transmission Electron Microscope (TEM). Composition of various ingredients of nano emulsions was standardised. TEM study showed the spherical shape of neem and citronella oil nano emulsions. The average size of droplets of neem nano emulsion (NNE) with different percentage of citronella oil ranged from 11.23 ± 3.86 nm to 17.80 ± 4.52 nm while that of citronella nano emulsion (CNE) with different percentage of neem oil ranged from 8.12 ± 2.80 nm to 12.04 ± 3.74 nm. It was found that increase in surfactant ratio to neem oil or citronella oil decreases the size of droplets in nano emulsions. Further, in vitro antifungal study of against Rhizoctonia solani and Sclerotium rolfsii was carried out by poisoned food technique. Results showed that neem nano emulsion 10 (NNE10) and citronella nano emulsion 10 (CNE10) were most active against R. solani (ED50 13.67 mg L−1 and 25.64 mg L−1) and S. rolfsii (ED50 14.71 mg L−1 and 20.88 mg L−1). The standardization of the composition and development of citronella essential oil and neem oil based nano emulsions and their antifungal activity against these two fungi has been reported for the first time.Not Availabl

DataSheet2_Green synthesis, structure–activity relationships, in silico molecular docking, and antifungal activities of novel prenylated chalcones.docx

A series of 16 novel prenylated chalcones (5A-5P) was synthesized by microwave-assisted green synthesis using 5-prenyloxy-2-hydroxyacetophenone and different benzaldehydes. Comparisons were also performed between the microwave and conventional methods in terms of the reaction times and yields of all compounds, where the reaction times in the microwave and conventional methods were 1–4 min and 12–48 h, respectively. The synthesized compounds were characterized using different spectroscopic techniques, including IR, 1H-NMR, 13C-NMR, and LC-HRMS. The antifungal activities of all compounds were evaluated against Sclerotium rolfsii and Fusarium oxysporum under in vitro conditions and were additionally supported by structure–activity relationship (SAR) and molecular docking studies. Out of the 16 compounds screened, 2’-hydroxy-4-benzyloxy-5’-O-prenylchalcone (5P) showed the highest activity against both S. rolfsii and F. oxysporum, with ED50 of 25.02 and 31.87 mg/L, respectively. The molecular docking studies of the prenylated chalcones within the active sites of the EF1α and RPB2 gene sequences and FoCut5a sequence as the respective receptors for S. rolfsii and F. oxysporum revealed the importance of the compounds, where the binding energies of the docked molecules ranged from −38.3538 to −26.6837 kcal/mol for S. rolfsii and −43.400 to −23.839 kcal/mol for F. oxysporum. Additional docking parameters showed that these compounds formed stable complexes with the protein molecules.</p

DataSheet1_Green synthesis, structure–activity relationships, in silico molecular docking, and antifungal activities of novel prenylated chalcones.PDF

A series of 16 novel prenylated chalcones (5A-5P) was synthesized by microwave-assisted green synthesis using 5-prenyloxy-2-hydroxyacetophenone and different benzaldehydes. Comparisons were also performed between the microwave and conventional methods in terms of the reaction times and yields of all compounds, where the reaction times in the microwave and conventional methods were 1–4 min and 12–48 h, respectively. The synthesized compounds were characterized using different spectroscopic techniques, including IR, 1H-NMR, 13C-NMR, and LC-HRMS. The antifungal activities of all compounds were evaluated against Sclerotium rolfsii and Fusarium oxysporum under in vitro conditions and were additionally supported by structure–activity relationship (SAR) and molecular docking studies. Out of the 16 compounds screened, 2’-hydroxy-4-benzyloxy-5’-O-prenylchalcone (5P) showed the highest activity against both S. rolfsii and F. oxysporum, with ED50 of 25.02 and 31.87 mg/L, respectively. The molecular docking studies of the prenylated chalcones within the active sites of the EF1α and RPB2 gene sequences and FoCut5a sequence as the respective receptors for S. rolfsii and F. oxysporum revealed the importance of the compounds, where the binding energies of the docked molecules ranged from −38.3538 to −26.6837 kcal/mol for S. rolfsii and −43.400 to −23.839 kcal/mol for F. oxysporum. Additional docking parameters showed that these compounds formed stable complexes with the protein molecules.</p