THE ROLE OF AZOXY FUNCTIONAL GROUPS IN ENHANCING ACARICIDAL ACTIVITY OF AROMATIC COMPOUNDS.

Аннотация

Azoxy functional groups (-N=N(O)-) have gained considerable attention in agrochemical research dueto theirability to modulatebiological activity in aromatic compounds. This study investigates the influence of azoxy moieties on the acaricidal efficacy of synthetic aromatic derivatives against selected mite species. A series of azoxybenzene-based compounds were synthesized and evaluated for their biological activity usingstandardized bioassay methods. The structure–activity relationship (SAR) analysis revealed that the presence of azoxy linkages significantly enhances acaricidal potency compared to their azo or nitro analogs, likely due to improved electron distribution and target affinity. Spectroscopic (FTIR, NMR) and chromatographic (GC-MS) techniques confirmed the purity and structure of synthesized compounds. The findings support the hypothesis that azoxy functionalization contributes to increased bioefficacy and selectivity, making such derivatives potential candidates for next- generationeco-friendly acaricides. Key words: Azoxy functional group, azoxybenzene, acaricidal activity, aromatic compounds, structure–activity relationship, bioactive molecules, syntheticpesticides. Introduction: The widespread emergence of acaricide-resistant mite populations poses a serious threat to agricultural productivity and public health, necessitating the development of new, effective, and environmentally safer compounds. Among the promising candidates, aromatic compounds bearing azoxy functional groups (-N=N(O)-) have attracted scientific interest due to their unique electronic configuration, stability, and potential for biological activity. Azoxy derivatives are structurally related to azo and nitro compounds but possess distinct physicochemical characteristics that may enhance their interaction with biological targets. This study aims to explore the role of azoxy linkages in modulating acaricidal efficacy, particularly focusing on how these groups influence molecular polarity, target binding affinity, and overall bioactivity. By synthesizing and characterizing a series of azoxybenzene-based compounds and https://ijmri.de/index.php/jmsi volume 4,issue5,2025 698 evaluating their acaricidal properties, we seek to determine whether the introduction of azoxy moietiescan significantly improvethepotency and selectivity of aromatic acaricides. Literature review: Previous research has highlighted the potential of aromatic compounds, particularly those containing nitrogen-based functional groups, as bioactive agents against arthropod pests. Azo and nitro derivatives have long been studied for their pesticidal properties; however, their effectiveness is often limited by low selectivity and environmental persistence. Azoxy compounds, which incorporate both azo and nitroso characteristics within a single functional group, have been less extensively studied despite their promising chemical properties. Studies have shown that azoxybenzenes exhibit moderate to high biological activity, including antimicrobial, insecticidal, and herbicidal effects, suggesting a broad spectrum of action. For instance, recent investigations into azoxy-substituted triazines and phenyl derivatives demonstrated enhanced acaricidal activity when compared to their parent structures. The enhanced efficacy has been attributed to the azoxy group's ability to influence electron distribution and facilitate molecular interactions with biological targets, such as enzyme systems in mites. Furthermore, advances in synthetic organic chemistry have enabled the development of structurally diverse azoxy compounds with tailored activity profiles. However, comprehensive studies that specifically assess the acaricidal potential of azoxy-functionalized aromatic compounds remain limited, indicating a need forfurther exploration inthis area. Methodology: A series of azoxy-functionalized aromatic compounds were synthesized via the oxidative coupling of aniline derivatives using hydrogen peroxide in the presence of acetic acid as a mild oxidant under controlled temperature conditions (0–5 °C). The resulting azoxybenzenes were purified through recrystallization and characterized by Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (^1H NMR), and gas chromatography– mass spectrometry (GC-MS) to confirm structural integrity and purity. The acaricidal activity of the synthesized compounds was evaluated using a contact bioassay against adult Tetranychus urticae mites under laboratory conditions. Test solutions were prepared by dissolving each compound in dimethyl sulfoxide (DMSO) and diluting to target concentrations (10, 25, 50, and 100 µg/mL). Mortality rates were recorded after 24 and 48 hours of exposure and compared to standard commercial acaricides and negative controls. Statistical analysis was conducted using one-way ANOVA followed by Tukey’s post hoc test (p < 0.05) to assess the significance of the observed effects. Structure–activity relat