Bemisia tabaci (Hemiptera: Aleyrodidae) biotype B is one of the most limiting pests of tomato crops in the world. Tomato yield is currently dependent on the use of pesticides, which are problematic to farmers, consumers and the environment. A promising alternative to reduce the harmful effects caused by the indiscriminated use of synthetic insecticides is the use of insecticides of botanical origin. This study aimed to evaluate the effect of 3% (w/v) aqueous extracts from different structures of thirteen botanical species on the behavior of B. tabaci biotype B adults, as well as insecticidal activity of such aqueous extracts on B. tabaci eggs, nymphs, and adults infesting tomato plants. A distilled water solution was used as a negative control, and thiamethoxam insecticide (18 g/100 L of water) as a positive control. Leaf extract of Toona ciliata was observed to have the most efficient inhibitory effect in tests of extracts on whitefly behavior. Furthermore, the use of leaf extract of Toona ciliata led to the most drastic reduction in the number of adults and eggs on tomato leaflets. Leaf extract of Piper aduncum led to the greatest observed ovicidal effect (78.00% of non-hatched nymphs); however it was not effective against nymphs and adults. The leaf extracts of Trichilia pallida, Trichilia casaretti, and Toona ciliata showed the highest control indexes (67.9, 60.3, and 55.1%, respectively). For adults mortality, T. pallida was the most effective (72.8%). Our results indicate that application of extracts of T. pallida, T. ciliata, and T. casaretti are promising strategies to manage B. tabaci biotype B on tomato.
Aim: Geraniol and linalool are major constituents of the essential oils of medicinal plants. Materials & methods: Antifungal activity of geraniol and linalool were evaluated against five Candida species. The genotoxicity of these compounds was evaluated by the cytokinesis-block micronucleus test, and the embryotoxic assays use zebrafish model. Results: Geraniol and linalool inhibited Candida growth, but geraniol was more effective. The geraniol at concentration of 800 μg/ml and the linalool at concentration of 125 μg/ml significantly increased chromosome damage. Geraniol was more toxic to zebrafish embryo than linalool: LC50 values were 31.3 and 193.3 μg/ml, respectively. Conclusion: Geraniol and linalool have anticandidal activity, but they also exert genotoxic and embryotoxic effects at the highest tested concentrations.
Two Novel Plumeran Indole Alkaloids Isolated from Aspidosperma cylindrocarpon (Apocynaceae) -[isolation, structure determination and antimalarial activity]. -(GUIMARAES*, H. A.; VIEIRA, I. J. C.; BRAZ-FILHO, R.; CROTTI, A. E. M.; DOS S. ALMEIDA, V.; DE PAULA, R. C.; Helv. Chim. Acta 96 (2013) 9, 1793-1800, http://dx.doi.org/10.1002/hlca.201200522 ; Lab. Cienc. Quim., Cent. Cienc. Tecnol., Univ. Estadual Norte Fluminense, Campos, 28013 Rio de Janeiro, Brazil; Eng.) -M. Paetzel 07-228
Background: Dental caries is a major public health concern that affects the populations of many countries worldwide. In this paper, we screened twenty-four plant-derived extracts for their antimicrobial activity against a representative panel of cariogenic bacteria.
Methods:The leaves of each species were dried, powdered and sequentially extracted with n-hexane, dichloromethane and methanol under Sonication for 5 min. The minimum inhibitory concentration (MIC) values of the resulting extracts were determined by using the broth micro dilution method in 96-well micro plates. Chlorhexidine was used as positive control. The chemical composition of the most active extract was determined by gas chromatography -mass spectrometry (GC-MS).
Results:The n-hexane extract of P. neochilus (PN-Hex) afforded the lowest MIC values against S. mitis (MIC = 31.2μg/mL), S. mutans (MIC = 31.2μg/mL), S. sanguinis (MIC = 31.2μg/mL), S. salivarus (MIC = 62.5μg/mL), S. sobrinus (MIC = 62.5μg/mL), E. faecalis (MIC = 62.5μg/mL) and L. casei (MIC = 250μg/mL). GC-MS analysis of this extract revealed that spathulenol (46.1 %), trans-caryophyllene (19.0 %), caryophyllene oxide (10.7 %) and germacrene D (7.8 %) were the major constituents in PN-Hex.
Conclusion:The n-hexane extract of P. neochilus (PN-Hex) displays promising antimicrobial activity against some cariogenic bacteria. Our results suggest that this extract might be promising for the development of new oral care products.
Material and methods
Plant material and extractionSpecimens of thirteen species (Table 1) were collected in May 2010 at ¨Sítio 13 de Maio¨ (20°26'S 47°27'W 977m), localized near the city of Franca, State of São Paulo, Brazil and identified by Prof. Dr. Milton Groppo.
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