Aromatic plant distillation produces residues rich in phenolic compounds known to be bioactive. In this context, residues from the hydrodistillation of Mentha piperita L., Cymbopogon citratus Stapf, and Eucalyptus cam...Aromatic plant distillation produces residues rich in phenolic compounds known to be bioactive. In this context, residues from the hydrodistillation of Mentha piperita L., Cymbopogon citratus Stapf, and Eucalyptus camaldulensis Dehnh were chemically and biologically analyzed. The ethanol percentages (70%, 50%, and 30%) were evaluated by determining antioxidant activity using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, total phenolic content, and total flavonoid content. Antifungal activity was evaluated “in vitro” against Fusarium oxysporum, Alternaria alternata, Trametes versicolor, and Coniophora puteana using the diffusion method in malt-agar medium. Antitermite activity was also assessed against Reticulitermes flavipes using the most active extract with low ethanol concentrations (50% and 30%). The optimum ethanol concentration to extract phenolic compounds is 70% for TFC and 30% for TPC, and the antioxidant activity was 0.45 ± 0.01 mg/mL (IC50). The most active extracts were the ethanolic ones, particularly for Eucalyptus camaldulensis, presenting 100% inhibition against the mycelial growth of Coniophora puteana and Alternaria alternata at 1 mg/mL and 0.5 mg/mL, respectively. For antitermite activity, EE50 was the most effective, with a 24% termite survival rate and a degraded food supply surface of 28%. These data suggest the potential use of hydrodistillation residues for biopesticide development.展开更多
Chemical-treated soil or physical barriers have been the most commonly used approach for termite management. We hypothesized that a barrier of soil incorporated with oven-dried Lantana camara L. tissues could prevent ...Chemical-treated soil or physical barriers have been the most commonly used approach for termite management. We hypothesized that a barrier of soil incorporated with oven-dried Lantana camara L. tissues could prevent termite infestation. We first examined the antitermitic effects of the dried tissues from two cultivars （＇Mozelle＇ and ＇New Gold＇） on the subterranean termite, Reticulitermes virginicus （Banks） （Isoptera： Rhinotermitidae）. Results show that all of the tissues of Mozelle had greater antitermic activity than corresponding tissues of New Gold, and leaves had greater termiticidal effects than flowers and stems. When termites were exposed to the test materials in a no-choice bioassay, the 24-day test resulted in a significant reduction of survival （52.5%-88.6%）, running speed （18.2%-37.3%）, live weight （21.8%-53.5%） and body water content （33.2%-56.2%） compared to the control. The consumption of leaves and flowers was exiguous. When used as 25% tissue mulch-barrier, the oven-dried lantana tissues decreased termite tunneling and wood consumption and increased termite mortality. The decreased survival, vigor, and low consumption indicate a toxic and anti-feeding property of the materials tested. The results therefore support our hypothesis that the dried lantana tissues possess antitermitic activities.展开更多
文摘Aromatic plant distillation produces residues rich in phenolic compounds known to be bioactive. In this context, residues from the hydrodistillation of Mentha piperita L., Cymbopogon citratus Stapf, and Eucalyptus camaldulensis Dehnh were chemically and biologically analyzed. The ethanol percentages (70%, 50%, and 30%) were evaluated by determining antioxidant activity using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, total phenolic content, and total flavonoid content. Antifungal activity was evaluated “in vitro” against Fusarium oxysporum, Alternaria alternata, Trametes versicolor, and Coniophora puteana using the diffusion method in malt-agar medium. Antitermite activity was also assessed against Reticulitermes flavipes using the most active extract with low ethanol concentrations (50% and 30%). The optimum ethanol concentration to extract phenolic compounds is 70% for TFC and 30% for TPC, and the antioxidant activity was 0.45 ± 0.01 mg/mL (IC50). The most active extracts were the ethanolic ones, particularly for Eucalyptus camaldulensis, presenting 100% inhibition against the mycelial growth of Coniophora puteana and Alternaria alternata at 1 mg/mL and 0.5 mg/mL, respectively. For antitermite activity, EE50 was the most effective, with a 24% termite survival rate and a degraded food supply surface of 28%. These data suggest the potential use of hydrodistillation residues for biopesticide development.
文摘Chemical-treated soil or physical barriers have been the most commonly used approach for termite management. We hypothesized that a barrier of soil incorporated with oven-dried Lantana camara L. tissues could prevent termite infestation. We first examined the antitermitic effects of the dried tissues from two cultivars （＇Mozelle＇ and ＇New Gold＇） on the subterranean termite, Reticulitermes virginicus （Banks） （Isoptera： Rhinotermitidae）. Results show that all of the tissues of Mozelle had greater antitermic activity than corresponding tissues of New Gold, and leaves had greater termiticidal effects than flowers and stems. When termites were exposed to the test materials in a no-choice bioassay, the 24-day test resulted in a significant reduction of survival （52.5%-88.6%）, running speed （18.2%-37.3%）, live weight （21.8%-53.5%） and body water content （33.2%-56.2%） compared to the control. The consumption of leaves and flowers was exiguous. When used as 25% tissue mulch-barrier, the oven-dried lantana tissues decreased termite tunneling and wood consumption and increased termite mortality. The decreased survival, vigor, and low consumption indicate a toxic and anti-feeding property of the materials tested. The results therefore support our hypothesis that the dried lantana tissues possess antitermitic activities.
