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.
Keywords: Carica papaya latex; plant lipase, biocatalyst; enzymatic
esterification; fatty acid
specificity
