Mediterranean fruit fly (Ceratitis capitata) is a top horticultural pest, affecting a variety of fruits and increasingly damaging extra-early citrus cultivars. Lambda-cyhalothrin, a commonly used pyrethroid insecticide, is losing effectiveness due to resistance in C. capitata, driven by repeated and sublethal treatments. In this work, we have developed an eco-friendly nanosystem based on mesoporous silica nanoparticles loaded with lambda-cyhalothrin and capped with hydrolysed corn protein that both attracts protein-feeding insects and seals the insecticide inside. This design protects the active ingredient from premature degradation and photolysis and ensures targeted release-triggered by protease enzymes in the fly’s saliva, thereby activating the insecticide only upon ingestion. Field tests on clementine leaves demonstrated sustained insecticidal activity for over four weeks, far longer than conventional pyrethroid sprays, while minimizing off-target exposure and sublethal dosing.

A practical and regioselective method has been developed for 3-halo-2H-chromene synthesis via decarboxylative halogenation. These chromenes are key intermediates in synthesizing isoflavene derivatives and related bioactive compounds, including molecules of interest in agrochemical research. In this study, 3-carboxy-2H-chromenes, prepared from salicylaldehyde-derived cyanochromenes, were subjected to decarboxylative halogenation under mild conditions. Systematic evaluation of halogen sources, bases, solvents, and other reaction parameters revealed that combining tetrabutylammonium tribromide with sodium-containing bases in acetonitrile promotes decarboxylative bromination with high regioselectivity. This method was designed for chromene substrates bearing oxygen-containing functional groups, which are often difficult to synthesize due to competing electrophilic aromatic substitutions. The optimized protocol, demonstrated on gram scale, afforded the corresponding 3-bromo-2H-chromene as the sole isolable species without requiring column chromatography. The resulting 3-bromo-2H-chromene was converted into an isoflavene derivative via Suzuki–Miyaura coupling, accomplishing its first convergent synthesis as well as formal total synthesis of an isoflavan natural product.

Derivatives of 1-heterocyclic 2-methylbenzimidazoles (HMBIs), prepared from previously reported 1-benzyl-2-methylbenzimidazoles, were synthesized to assess their larvicidal activity against the silkworm, Bombyx mori. Among the series, 2-methyl-1-(thiophen-2-yl)-methylbenzimidazole (SGH2) produces a distinctive biological phenotype characterized by growth retardation arising from epidermal abnormalities, together with defects in molting and pupation. To explore the basis of these effects, we examined the potential disruption of endocrine signaling as a causal mechanism. Specifically, we evaluated the binding of SGH2 to lepidopteran hemolymph juvenile hormone (JH)-binding protein (JHBP), an important modulator of insect hormone function, using a fluorescence-based ligand-sensor system that couples JHBP to two reporter fluorophores. SGH2 exhibited binding to JHBP with an EC₅₀ of 2.13±0.34 µM, a potency comparable to that of JH. These findings indicate that HMBI derivatives, such as SGH2, can interfere with JH-mediated developmental processes in Lepidoptera and identify a promising scaffold for the design of novel insect growth regulators aimed at controlling lepidopteran pests.

The environmental fate of dimefluthrin (DIM), 2,3,5,6-tetrafluoro-4-(methoxymethyl)benzyl (1R,3R)-2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropanecarboxylate, was investigated in a water-sediment system in the USA. The study focused on the formation of degradation products and non-extractable residues (NER) using ¹⁴C-DIM labelled either at the benzyl or cyclopropyl carbon. The degradation half-life was calculated to be 15.6 days at 20°C, which is well below the regulatory persistence threshold of 120 days. The primary degradation pathway was hydrolysis of the ester linkage. Other reactions, such as oxidation at various positions, produced several minor metabolites that were subsequently mineralised to CO₂ and/or incorporated into NER. Specifically, in the cyclopropyl-labelled samples, NER exceeded 10% of the applied radioactivity (% AR) with 78–86% of the total NER consisting of non-hazardous biogenic residues (type-III NER) as verified by ¹⁴C-labelled amino acid analysis. Potentially hazardous type-I NER were negligible, accounting for less than 0.5% AR for both labels. These insights into NER formation, particularly regarding the role of microbial activity in the environmental distribution of DIM and its metabolites, indicate minimal environmental risks from such residues.

All eight stereoisomers of aptosimon (9-oxosesamin) were synthesized by employing Evans’ anti- and syn-aldol condensations. Among them, the (7S,7′R,8R,8′S)-aptosimon was more active than (+)- and (−)-sesamin at 1×10⁻⁵ M in promoting lettuce root growth under illumination conditions (44 µmol·m⁻²·s⁻¹). The effect of the 9-oxo group on the promotion of lettuce root growth was not observed from the results of activity experiments of stereoisomers carrying the same stereochemistry as those of (+)- and (−)-sesamin (1). However, the importance of 7S-configurations of aptosimon (9-oxosesamin) stereoisomers for the higher promotion of lettuce root growth was suggested. Based on optical rotation data and NMR analysis of the synthesized stereoisomers, the diacylglycerol acyltransferase inhibitory aptosimon was determined to be (7S,7′S,8S,8′R)-aptosimon and its enantiomer.

Based on the structure of the natural active molecule piperine, a series of novel piperidine-phenylenediamine derivatives were designed and synthesized using a molecular hybridization strategy. The antifeedant activity of all of the compounds against Spodoptera exigua and their cytotoxicity toward Sf9 insect cells were evaluated. The results showed that most of the derivatives exhibited good antifeedant activity, which correlated with their structures. Among them, compound D5 showed the strongest antifeedant activity (EC₅₀=0.184 mg/mL). In the cytotoxicity study, compounds D15 and J1 showed particularly potent antiproliferative effects, with IC₅₀ values of 4.137 µM and 3.726 µM, respectively. Mechanistic studies revealed that both compounds inhibit proliferation by inducing apoptosis and arresting the cell cycle, as evidenced by cell morphology observation, fluorescence staining, and flow cytometry analysis. In summary, the present study provides potential candidates for the development of new environmentally friendly insecticides based on the combination principle.

Scorpion venom contains antimicrobial peptides (AMPs). These AMPs are classified into three families based on peptide length: long-chain (>35 residues), intermediate-chain (20–35 residues), and short-chain (13–19 residues) AMPs. Previously, we identified both short- and intermediate-chain AMPs from the venom of the scorpion Isometrus maculatus. A comparative analysis of their antibacterial activities revealed that short-chain AMPs exhibit relatively weaker activity than intermediate-chain AMPs. A structural comparison indicated that intermediate-chain AMPs possess a longer C-terminal region enriched in basic residues, a feature absent in short-chain AMPs. Removal of this C-terminal basic region from intermediate-chain AMPs resulted in a marked loss of antibacterial activity. Conversely, the addition of basic residues at the C-termini of short-chain AMPs significantly enhanced their activity. These results demonstrate that basic residues in the C-terminal region of scorpion intermediate-chain AMPs are crucial for antibacterial activity.