Short chain citronellyl esters were synthesized by a new microbial lipase from
Rhizopus
sp strain isolated and lipase produced at UNICAMP, Brazil. Direct esterification
and transesterification reactions have been performed to produce citronellyl
acetate and butyrate in a free-solvent system and with n-hexane in reaction
medium. Reaction mixture for direct esterification and transesterification
was carried out at 45ºC in equimolar concentration of substrates: acid or ester and alcohol. Only
citronellyl butyrate was synthesized by direct esterification with yields from
95 to 100% after 24 hrs. of reaction time, with or without n-hexane. Citronellyl
acetate was synthesized by transesterification with ethyl acetate and cytronellol,
with yield of 58% after 48 hrs. and 48% of conversion for reaction butyl acetate
and cytronellol. The results suggest that the size of the aliphatic chain from
acyl donor was importance to conversion rate. Acids with more than two carbons
showed to be better substrate for
Rhizopus
sp lipase. Transesterification reaction showed different behaviour, ester substrate
with four carbons was better than six carbon for citronellyl acetate synthesis.
