Abstract The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a globally significant agricultural pest capable of devastating cereal crops and other economically important plants. The present study investigates the in vitro inhibitory effects of copper(II) sulfate (CuSO₄), ethylenediaminetetraacetic acid (EDTA), and sodium chloride (NaCl) on key carbohydrate-digesting enzymes in the fourth instar of S. frugiperda, with a particular emphasis on invertase. Enzyme activity profiling revealed that invertase dominates carbohydrate metabolism in adults, while trehalase and amylase are more active in larvae. CuSO₄ exhibited the strongest inhibition, completely suppressing invertase, trehalase, and amylase activity at 0.5 M (P < 0.01), with significant dose-dependent suppression evident even at 0.01 M. EDTA exerted significant but less potent inhibition, reducing enzyme activities by approximately 24–38% at 0.5 M (P < 0.01). NaCl showed negligible inhibitory effects across all tested concentrations (0.1–2.0 M; P > 0.05 at ≤ 0.1 M for amylase). Notably, CuSO₄ inhibition was rapid, requiring less than two minutes to achieve near-complete suppression at 25 °C, and was significantly influenced by temperature. The strong inhibitory effect of CuSO₄ suggests that it disrupts key metabolic pathways in S. frugiperda, likely through protein denaturation and metal ion interference. These findings highlight the potential of CuSO₄ as a biochemical disruptor that could be further explored as a novel pest control strategy. Future research should focus on in vivo assessments of CuSO₄ toxicity, its interactions with insect physiological processes, and its potential integration into sustainable pest management programs.
Abstract Background The predatory mite Neoseiulus californicus (McGregor) is extensively used in biological control programs, yet quantitative comparisons of its efficacy against different pest species remain limited. This study systematically quantified and compared the functional and numerical responses of N. californicus to two economically significant pests: the two-spotted spider mite, Tetranychus urticae Koch and western flower thrips, Frankliniella occidentalis (Pergande), across egg and first-instar larvae under controlled laboratory conditions. Results N. californicus exhibited a Type II functional response to all prey stages (R² = 0.955–0.994). Attack rates were 1.2–1.7 times higher for T. urticae (0.72–0.76 day⁻¹) than F. occidentalis (0.45–0.59 day⁻¹). The most pronounced difference was handling time: 7.6–9.3× times shorter for spider mites (3.7–3.9 min.) than thrips (29.5–34.7 min.), resulting in maximum predation rates of 370–385 vs. 41–49 prey day⁻¹. At operational densities (15–30 prey/arena), predation efficiency was 72.4% for spider mites vs. 53.5% for thrips. Oviposition rates were 1.39× times higher on T. urticae (2.50 ± 0.27 eggs female⁻¹ day⁻¹) than F. occidentalis (1.80 ± 0.22 eggs/ female/ day). An integrated performance index was 2.89× times higher for spider mites, with optimal predator deployment densities at 18.7 and 22.3 prey per arena for T. urticae and F. occidentalis, respectively. Conclusion N. californicus demonstrates greater predatory and reproductive performance against T. urticae compared to F. occidentalis, driven by more efficient prey handling and enhanced reproductive output under laboratory conditions. These results suggest predator: prey ratios of 1:6–1:10 as a theoretical baseline for spider mite management. These ratios represent a theoretical starting point for hypothesis generation; field validation is required before operational application. For thrips control, N. californicus should be integrated with complementary approaches. These laboratory-derived parameters provide a quantitative foundation for designing future field studies and informing the development of release strategies.
Naphthyridine derivatives have emerged as privileged scaffolds with diverse pharmacological activities, particularly in anticancer and antiviral drug discovery. In this study, a series of naphthyridine-based derivatives (1-10b) was designed, synthesized, and structurally characterized using IR, 1H/13C NMR, and mass spectrometry, and evaluated as dual-function antiproliferative and anti-fowlpox virus agents supported by integrated computational analyses. The synthesized compounds were screened for in vitro antiproliferative activity against HeLa, HCT-116, and MCF-7 cancer cell lines, as well as normal WI-38 lung fibroblasts. Several derivatives exhibited potent cytotoxic activity with enhanced selectivity toward cancer cells. Compound 5b showed the highest activity against HeLa cells, compound 1 was most effective against HCT-116 cells, while compounds 7 and 8 displayed remarkable activity against MCF-7 cells, with compound 7 surpassing doxorubicin and compound 8 demonstrating excellent selectivity toward normal cells. Mechanistic investigations revealed that compounds 7 and 8 acted as dual topoisomerase I/IIβ inhibitors, inducing G2/M cell cycle arrest and intrinsic apoptosis associated with caspase-9 activation and downregulation of topoisomerase II protein expression. Selected derivatives were further evaluated for antiviral activity against fowlpox virus using in ovo and in vivo SPF embryonated chicken egg models, where compounds 2 and 9a exhibited the highest therapeutic indices, comparable to ribavirin, and compound 9a markedly suppressed viral replication and titers in vivo. ADMET profiling, molecular docking, molecular dynamics simulations, and DFT calculations supported the experimental findings and identified compound 10a as the most favorable theoretical candidate. Overall, this integrated experimental-computational approach establishes naphthyridine derivatives as a rationally designed multifunctional chemotype for simultaneous anticancer and antiviral drug development.
Strawberries are highly perishable fruits due to moisture loss, intense metabolic activity, and microbial contamination, leading to rapid quality deterioration during storage. In this study, mango seed extract (MSE), a natural antioxidant source, was loaded with chitosan (CS) and carboxymethyl chitosan (CCS) nanoparticles to develop edible coatings for postharvest quality enhancement. Nanoparticles were characterized by dynamic light scattering (DLS) to determine particle size and zeta potential, revealing stable formulations with average sizes of 68.1 nm (CS LM) and 91.3 nm (CCS LM). Antioxidant capacity was assessed using ABTS and DPPH radical scavenging assays, where CCS LM exhibited superior activity (> 92%, p < 0.05) compared to free MSE and CS LM. Antimicrobial properties were evaluated by microbial inhibition tests against Staphylococcus aureus, Escherichia coli, and Candida albicans, showing significant inhibition rates at 800 µg/mL. Storage performance was assessed over 21 days at 2 °C by monitoring weight loss, firmness, color preservation, pH, titratable acidity, and microbial counts. Results demonstrated that CCS LM-coated strawberries had minimal weight loss (5.7%, p < 0.05), retained firmness, and showed reduced bacterial (1.2 log₁₀ CFU/g) and fungal counts (1.3 log₁₀ CFU/g) compared to uncoated fruits. These findings suggest that MSE-loaded CCS nanoparticles, through their antioxidant and antimicrobial functions, offer a promising sustainable strategy to improve the postharvest quality and storage performance of strawberries.
This study reports the synthesis and bioevaluation of ten novel pyranothiazolopyrimidine derivatives. Their insecticidal efficacy against Aphis gossypii (Glover, 1887) revealed compounds 3 and 10 as lead candidates, exhibiting toxicity comparable to the commercial standard acetamiprid insecticide. Notably, these compounds demonstrated a markedly safer ecotoxicological profile toward the earthworms (Aporrectodea caliginosa), with LC50 values orders of magnitude higher than acetamiprid over 5- and 10-day exposures. Application also induced measurable changes in soil chemistry. These findings identify compounds 3 and 10 as promising insecticidal agents that combine potent aphid toxicity with significantly reduced nontarget risk, highlighting their potential for further development.
