Specificity of Carica papaya Latex as Biocatalyst in the Esterification of Fatty Acids with 1-Butanol

Papaya ( Carica papaya ) latex, reportedly known to have good lipolytic activity, has been evaluated as biocatalyst in the esterification of various fatty acids with 1-butanol in the presence of myristic acid as the reference standard. C. papaya latex strongly discriminates against fatty acids having a cis -4 unsaturation, e.g. all - cis -4,7,10,13,16,19-docosahexaenoic acid, cis -6 unsaturation, e.g. petroselinic ( cis -6-octadecenoic), γ-linolenic ( all - cis -6,9,12-octadecatrienoic), and stearidonic ( all - cis -6,9,12,15-octadecatetraenoic) acids, and cis -8 unsaturation, e.g. dihomo-γ-linolenic ( all - cis -8,11,14-eicosatrienoic) acid. Fatty acids having cis -5 unsaturation, e.g. all - cis -5,8,11,14,17-eicosapentaenoic acid, and those having a cis -9 unsaturation, e.g. oleic ( cis -9-octadecenoic) and α-linolenic ( all - cis -9,12,15-octadecatrienoic) acids are very well accepted as substrates. Fatty acids having hydroxy groups, e.g. ricinoleic (12-hydroxy- cis -9-octadecenoic) acid and 12-hydroxystearic acid, epoxy groups, e.g. trans -9,10-epoxystearic acid, and cyclopentenyl groups, e.g. hydnocarpic [(11-(2‘-cyclopentenyl)undecanoic] acid and chaulmoogric [13-(2‘-cyclopentenyl)tridecanoic] acid are also well accepted as substrates. The observed substrate specificities are similar to those reported for lipase preparations from microorganisms, animals, and plants.