Biotechnology Letters 26: 1211–1216, 2004.
© 2004 Kluwer Academic Publishers. Printed in the Netherlands.
Chemo-enzymatic synthesis of N-arachidonoyl glycine
L. Goujard, M.C. Figueroa & P. Villeneuve
UMR IATE, CIRAD-AMIS, Lipotechny Laboratory, TA 40/16, 73 rue JF Breton, 34398 Montpellier cedex 5, France
Author for correspondence (Fax :+33 (0)4 67 61 55 15; E-mail: firstname.lastname@example.org)
Received 22 April 2004; Revisions requested 6 May 2004; Revisions received 24 May 2004; Accepted 24 May 2004
Key words: arachidonic acid, biocatalysis, fatty amide, glycine, lipase
N-Arachidonoyl glycine was synthesized in a chemo-enzymatic process where glycine tert-butyl ester was acylated
by arachidonic acid and the resulted ester was then de-protected to give the ﬁnal product. Among various lipases
tested and chosen for their ability to cleave fatty amides, that from Candida antarctica B gave the best results
resulting in a 39% hydrolysis after 24 h. This enzyme was then used for the reverse N-acylation synthesis and gave
a 75% product formation after 24 h using methyl ester of arachadonic acid as acyl donor and acetonitrile as solvent.
Direct acylation of glycine gave less than 10% yield.
Lipo-amino acids derivatives are molecules result-
ing from the grafting of aliphatic lipophilic chains to
amino acids through a N-acylation reaction. These
compounds are generally obtained by classical chem-
ical catalysis and used for their good surfactants prop-
erties in pharmaceutical and cosmetic formulations
(Sivasamy et al. 2001, Presenz 1996, Takehara 1989).
However, some examples appeared in the literature
where such molecules are obtained by biocatalysis
(Clapes & Infante 2001). Indeed, enzymatic reactions
are attractive owing to their mild reaction conditions,
the limited use of chemicals or solvents and the fact
that side reactions are generally avoided. On the other
hand, chemically catalysed synthesis of lipo-amino
acids generally requires the use of chemical reactants
such as fatty acyl chlorides and further puriﬁcation
steps. Montet et al. (1990) described the lipase cata-
lysed synthesis of N -acyllysines in a solvent free
system. Similarly, N-lauroyl-β-alanine homologues
were obtained in good yields (>80%) by amidation
of ethyl alanine with methyl laurate using Candida
antarctica lipase in organic solvent (Izumi et al. 1997).
Several others methods have been recently pub-
lished. In a chemo-enzymatic process, Valivety et al.
(1997) were able to synthesize various lipo-amino acid
surfactants starting from N-carbobenzyloxy (Cbz)-
amino acids in order to improve the miscibility of the
amino acid derivatives with the aliphatic acyl donor.
It is also worth noting the enzymatic synthesis of N-
amino acids in a glycerol water system using
acylase from pig kidney (Wada et al. 2002). Various
-amino acids were obtained in moderate
yields ranging from 3.3% (phenylalanine) to 35% (ser-
ine) with the exception of
-arginine which gave a
good conversion of 81%.
Recently, particular attention has been shown to-
ward arachidonoyl amino acids derivatives which are
being understood as crucial signalling molecules in
mammals. Indeed, N-arachidonoyl-ethanolamide (or
anandamide) has been recognized as a primary candid-
ate for the role of endogeous cannabinoid substance
activating the same membrane receptors that are tar-
geted by tetrahydrocannabinol (Cadas et al. 1997).
Similarly, N-arachidonoyl glycine has been recently
identiﬁed as a component of bovine and rat brain and
found to possess biological activity in mammals espe-
cially in suppressing tonic inﬂammatory pain (Huang
et al. 2001). Therefore, this molecule can be envisaged
as a good potential candidate for the formulation of po-
tential anti inﬂammatory drugs. To date, its synthesis
has only been described by chemical catalysis requir-
ing three reactions steps and the use of many chemical