ABSTRACT
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.
Subject(s)
Biomimetic Materials/chemistry , Coordination Complexes/chemistry , Metalloproteins/chemistry , Oxygenases/chemistry , Plant Oils/chemistry , Biomimetic Materials/chemical synthesis , Catalysis , Coordination Complexes/chemical synthesis , Gas Chromatography-Mass Spectrometry , Hot Temperature , Hydrogen Peroxide/chemistry , Kinetics , Osmolar Concentration , Oxidants/chemistry , Oxidation-Reduction , Oxygenases/metabolism , Polycyclic Sesquiterpenes , Sesquiterpenes/analysis , Sesquiterpenes/chemical synthesis , Sesquiterpenes/chemistryABSTRACT
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.
Subject(s)
Citrus/chemistry , Fruit/chemistry , Oils, Volatile/chemistry , Seasons , Brazil , Chromatography, Gas , Gas Chromatography-Mass Spectrometry , StereoisomerismABSTRACT
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