RESUMEN
The wood protective action of citrus wax, a waste from the citrus industry that is a mixture of citrus fruit epicuticular waxes and essential oils, was evaluated against the termite Cryptotermes brevis Walker (Isoptera: Kalotermitidae). The antifeedant index (AI) of the total wax and fractions was calculated. The total citrus wax exhibited an AI50 value of 24.69 mg/cm³, the wax after hydrodistillation showed the strongest antifeedant property (AI50 11.68 mg/cm³). Fractionation of the wax and gas chromatography-mass spectrometric analysis allowed the identification of coumarins and furancoumarins as the active compounds. These results suggest the potential use of these industrial residues as a natural approach to termite control.
Asunto(s)
Citrus , Conducta Alimentaria/efectos de los fármacos , Isópteros/efectos de los fármacos , Aceites Volátiles/farmacología , Ceras/farmacología , Animales , Ceras/químicaRESUMEN
BACKGROUND: This paper reports the catalytic oxidation of the concentrated orange oil phase using the complexes [Fe(III)(BMPP)Cl(micro-O)Fe(III)Cl(3)], [Cu(II)(BTMEA)(2)Cl]Cl and [Co(II)(BMPP)]Cl(2) biomimetic to methane monooxygenase enzyme as catalysts and hydrogen peroxide as oxidant. RESULTS: The reaction products of oil oxidation, mainly nootkatone, were identified by gas chromatography/mass spectrometry. A screening of catalysts was performed through a full 2(3) experimental design, varying the temperature from 30 to 70 degrees C, the catalyst concentration from 7.0 x 10(-4) to 1.5 x 10(-3) mol L(-1) and the oxidant/substrate molar ratio from 1:1 to 3:1. The results of reaction kinetics employing the most promising catalysts showed that conversions to nootkatone of up to 8% were achieved after 16 h at 70 degrees C. CONCLUSION: The results obtained in this study in terms of nootkatone production should be considered encouraging, since a real, industrially collected, raw material, instead of pure valencene, was employed in the reaction experiments, with a final content about ten times that present in the original concentrated oil.
Asunto(s)
Materiales Biomiméticos/química , Complejos de Coordinación/química , Metaloproteínas/química , Oxigenasas/química , Aceites de Plantas/química , Materiales Biomiméticos/síntesis química , Catálisis , Complejos de Coordinación/síntesis química , Cromatografía de Gases y Espectrometría de Masas , Calor , Peróxido de Hidrógeno/química , Cinética , Concentración Osmolar , Oxidantes/química , Oxidación-Reducción , Oxigenasas/metabolismo , Sesquiterpenos Policíclicos , Sesquiterpenos/análisis , Sesquiterpenos/síntesis química , Sesquiterpenos/químicaRESUMEN
Cold-pressing and hydrodistilled peel oils of two Brazilian mandarin cultivars, commonly called Cai and Montenegrina (Citrus deliciosa Tenore), were obtained from fruits collected on mandarin trees submitted to the same pedoclimatic and cultural conditions. Their chemical composition and seasonal variation of the main volatile constituents were investigated by capillary GC and GC-MS, and the results were submitted to statistical analysis. To better characterize the oils, the enantiomeric distribution ratio of seven components (alpha-pinene, sabinene, beta-pinene, limonene, linalool, terpinen-4-ol, and alpha-terpineol) was determined by multidimensional gas chromatography (MDGC). The similarities found between both C. deliciosa cultivars are strong evidence for the hypothesis that Montenegrina originated from Cai as previously reported from agronomic studies.
Asunto(s)
Citrus/química , Frutas/química , Aceites Volátiles/química , Estaciones del Año , Brasil , Cromatografía de Gases , Cromatografía de Gases y Espectrometría de Masas , EstereoisomerismoRESUMEN
Os óleos essenciais de duas variedades da árvore canforeira (Cinnamomum camphora Nees & Eberm, Lauracea), conhecidas como Hon-Sho e Ho-Sho cultivadas em canteiros experimentais no sul do Brasil foram estudados. Os óleos essenciais foram obtidos das folhas e ramos de plantas jovens por hidrodestilaçäo. A identificaçäo dos componentes foi feita por GC, GC/MS e índices de retençäo nas fases metil silicone e carbowax. Os principais componentes foram linalol no Ho-Sho e cânfora no Hon-Sho