Catalytic oxidation of concentrated orange oil phase by synthetic metallic complexes biomimetic to MMO enzyme

BACKGROUND: This paper reports the catalytic oxidation of the concentrated orange oil phase using the complexes [Fe III (BMPP)Cl(µ‐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 °C, the catalyst concentration from 7.0 × 10 −4 to 1.5 × 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 °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. Copyright © 2010 Society of Chemical Industry