Biotransformation of n-hexadecane by cell suspension cultures of Cinchona robusta and Dioscorea composita

This manuscript evaluates the phytotoxicity and biotransformation of n-hexa decane as well as peroxidase activity and cytochrome P450 concentration in microsomes for cell suspension cultures of Cinchona robusta and Dioscorea c omposita. Phytotoxicity was evaluated based on viability and growth. Cell c ultures were exposed to a 2 and 4% (v/v) dose of n-hexadecane. The biotrans formation of n-hexadecane was determined based on labeled recovery in polar , nonpolar, and cell residue fractions after cell culture extraction during exponential cell growth phase and stationary phase. Differences were obser ved in accumulation of label during cell growth phase and stationary phase for the cells of the two plants. Differences also were observed between pha ses for label in polar and nonpolar fractions. Thin-layer chromatography de termined labeled intermediates and some were identified. The activity of pe roxidase and concentration of cytochrome P450 was lower in C. robusta than in controls and greater in D. composita than in controls. In vitro biotrans formation was not successful.