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Controlled release formulations of Thiram (Dimethylcarbamothioylsulfanyl-N,N-dimethylcarbamodithioate), a contact fungicide, have been prepared using laboratory synthesized poly(ethylene glycol) (PEG) based functionalized amphiphilic copolymers. The kinetics of thiram from developed controlled release (CR) formulations were studied in comparison with that of the commercially available 75 WS. Release from the commercial formulation was faster than with the developed CR formulations. Maximum amount of thiram was released on 35th day for PEG-2000 4d, 28th day for PEG-1500 4c, 21st day for PEG-1000 4b and 15th day for PEG-600 4a in comparison to commercial formulation (7th day). The diffusion exponent (n) of thiram in water ranged from 0.356 to 0.545 in the tested formulations. The half-release (t(1/2)) values ranged between 14.78 to 22.1 days, and the Period of Optimum Availability (POA) of thiram ranged from 7.79 to 25.15 days. An effort has also been made to identify the suitable polymers that could reduce the seed deterioration during storage and also act as an effective carrier of fungicide thiram. The results demonstrate that the seeds coated with the different formulations deteriorated at a slower pace as manifested in high germination percentage over control. Apart from the fungicidal effect of thiram, the polymers acted as barriers to moisture reducing the rate of seed deterioration and checked the degradation of thiram. The CR formulation 4d, with PEG 2000, was found to be most effective as seed coat.

A 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 5 min 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 = 23.24 mg L−1) was found to be most active against S. rolfsii. But in case of A. solani, compound 3c (ED50 = 29.9 mg 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.

Despite the emergence of novel biotechnological and biological solutions, agrochemicals continue to play an important role in crop protection. Fungicide resistance is becoming a major problem; numerous cases of fungicide resistance have occurred worldwide in the last decade, resulting in the loss of several fungicides. The discovery of new molecules has therefore assumed critical importance in crop protection. In our quest for biologically active molecules, we herein report the synthesis of a series of twenty-one 3-Iodochromone derivatives (4a–4u), in a two-step process by condensation of 2-hydroxyacetophenone derivatives (2a–2u) with N,N-dimethylformamidedimethylacetal yielding enaminones (3a–3u), followed by cyclization with iodine to corresponding 3-iodochromones. Characterization of these compounds was done by IR, 1H NMR, 13C NMR, and LC-HRMS techniques. All synthesized compounds were screened for their fungicidal activity against Sclerotium rolfsii. Among these 6,8-Dichloro-3-iodochromone 4r was found to be most active (ED50 = 8.43 mg L−1). 2D-Quantitative Structural Activity Relationship (2D-QSAR) analysis was also performed by generating three different models viz., Multiple Linear Regression (MLR, Model 1), Principal Component Regression (PCR, Model 2), and Partial Least Squares (PLS, Model 3). Predictive power and statistical significance of these models were assessed with external and internal validation and leave one-out cross-validation was used for verification. In QSAR study, MLR (Model 1) was found to be best having correlation coefficient (r2) 0.943, cross-validated correlation coefficient (q2) 0.911 and r2pred 0.837. It was observed that DeltaEpsilonC, T_2_Cl_6, T_2_F_6, T_T_F_3, and ZCompDipole are the major descriptors which influence the fungicidal activity of 3-Iodochromone derivatives. The physicochemical parameters were estimated by the VLifeMDS 4.6 software. The QSAR study results will be helpful for structure optimization to improve the activity.

Full experimental detail and 1H & 13C NMR, IR and Elemental analysis characterization of all the forty-two compounds (9a-9f, 10a-10f, 11a-11f, 12a-12f, 13a-13f, 14a-14f and 15a-15f) and copies of 1H and 13C NMR spectra of compounds (

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Two novel series (5a–f, 6 and 7a–f, 8) of benzothiazole-appended bis-triazole derivative-based fungicides were prepared and their antifungal activity evaluated against plant pathogen Rhizoctonia solani. It was found that compound 5f is the most potent fungicide.

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