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Coffee leaf rust (CLR), caused by Hemileia vastatrix, poses a significant threat to global coffee production, resulting in substantial economic losses. This study explores the effectiveness of triazole derivatives synthesized from glycerol in controlling CLR in conilon coffee (Coffea canephora). In vitro assays evaluated the inhibitory effect of triazole derivatives (4a–4q) at concentrations of 10, 25, 50, 75 and 100 ppm on H. vastatrix urediniospore germination, followed by greenhouse experiments to assess their preventive and curative potential. Preventive and curative sprayings of the four most efficient triazoles were conducted on seedlings inoculated with H. vastatrix at concentrations ranging from 0 to 400 ppm, evaluating severity, sporulation, incubation and latent periods. Triazole derivatives 4b, 4d, 4f and 4o effectively suppressed H. vastatrix urediniospore germination, achieving reductions between 9.9% and 78.8%. In greenhouse trials, these compounds demonstrated preventive efficacy by prolonging incubation and latent periods, reducing sporulation and mitigating rust severity, with triazole 4f exhibiting the highest efficiency. Furthermore, the derivatives showed effectiveness in curative treatments, particularly triazole 4f. Physiological analyses indicated no significant alterations in coffee plant metabolism, suggesting the safety of these compounds for agricultural use. Molecular docking studies elucidated their mechanism of action, suggesting their potential as antifungal agents by interacting with the HvCYP51 enzyme involved in ergosterol biosynthesis. Overall, the study underscores the promising efficacy of glycerol‐derived triazole derivatives in managing CLR, providing sustainable solutions for disease control in agriculture. [ABSTRACT FROM AUTHOR]

Commercial synthetic acaricides have selected resistant populations of Rhipicephalus microplus, and generate residues in the environment or in milk/cattle products. In this study, aqueous extracts (AE) from Melia azedarach (Maz), Allium sativum, Capsicum chinense, Nicotiana tabacum (Nta) and Dysphania ambrosioides were evaluated for the bioactivity against the cattle tick. The treatment using Nta or Maz AE resulted in the lowest egg hatching rate (34.0 ± 11% and 25.0 ± 19%), and in the values of reproduction inhibition ranging from 89.0% to 85.3%. Phytochemical screening associated to RP-HPLC/DAD analysis suggested the presence of alkaloids for Nta and gallic acid derivatives and catechins, for Maz. Such results highlighted that the use of Nta and Maz AE can be a promising source of bioactive compounds for the control of infections caused by the cattle tick. [ABSTRACT FROM AUTHOR]

Dysphania ambrosioides (L.) Mosyakin & Clemants, known as santa maria herb, is a medicinal plant used on pest control and to treat parasitic diseases. Due to its potential for pest control, the aim of this work was to determine the chemical composition of D. ambrosioides essential oil and evaluate its molluscicidal effect on Biomphalaria tenagophila, which is an intermediate host for the Schistosoma mansoni trematode, that is responsible for causing human schistosomiasis. The essential oil extracted from its leaves showed 87% of (Z)-ascaridole and 100% of mortality against B. tenagophila at 10 ppm after 24 h of experiment. LC50 and LC90 values were, respectively, 2.40 (1.90-2.99) ppm and 8.75 (6.39-14.12) ppm. D. ambrosioides essential oil proved to be a promising natural molluscicide against schistosomiasis when compared with commercial products. [ABSTRACT FROM AUTHOR]

The synthesis of a series of 1,2,3-triazoles using glycerol as starting material is described. The key step in the preparation of these triazolic derivatives is the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), also known as click reaction, between 4-(azidomethyl)-2,2-dimethyl-1,3-dioxolane (3) and different terminal alkynes. The eight prepared derivatives were evaluated with regard to their fungicide, phytotoxic and cytotoxic activities. The fungicidal activity was assessed in vitro against Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. It was found that the compounds 1-(1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-1H-1,2,3-triazol-4-yl)-cyclo-hexanol (4g) and 2-(1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-1H-1,2,3-triazol-4-yl)propan-2-ol (4h) demonstrated high efficiency in controlling C. gloeosporioides when compared to the commercial fungicide tebuconazole. The triazoles did not present any phytotoxic effect when evaluated against Lactuca sativa. However, five derivatives were mitodepressive, inducing cell death detected by the presence of condensed nuclei and acted as aneugenic agents in the cell cycle of L. sativa. It is believed that glycerol derivatives bearing 1,2,3-triazole functionalities may represent a promising scaffold to be explored for the development of new agents to control C. gloeosporioides. [ABSTRACT FROM AUTHOR]

Essential oils, volatile compounds obtained from plants, provide an alternative approach for controlling agricultural pests due to problems with conventional chemical products, such as insect resistance, environmental issues and human health concerns. This work aimed to extract essential oil from Eucalyptus citriodora to assess its chemical composition and insecticidal activity against the green peach aphid (Myzus persicae) and thrips (Frankliniella schultzei). The essential oil was obtained by hydrodistillation using the Clevenger apparatus and analyzed by gas chromatography with a flame ionization detector and mass spectrometry (GC-FID and GC-MS). A Potter tower was used to spray the insects with the essential oil solutions. The major components found in E. citriodora essential oil were citronellal (29.31%), geraniol (27.63%), β-citronellol (14.88%) and d-cadinene (6.32%). Mortality of M. persicae and F. schultzei nymphs were 85.5% and 34.8%, respectively, using essential oil at 1% (w v-1). Estimated values of LC50 (0.40% w v-1) and LC90 (1.15% w v-1) for M. persicae evidences the potential use of E. citriodora essential oil in controlling this pest. [ABSTRACT FROM AUTHOR]