Serratamic acid

Not only are simple carbohydrate esters found in Nature, but fatty acyl derivatives of amino acids have also been reported. These include serratamic acid [V-(D-3-hydroxydecanoyl)-L-serine], siolipin A and siolipin B. The latter is the ornithine analogue of siolipin A ... 

A strain of Serratia resembling S. indica was isolated from coconuts and grown on a synthetic medium. An alkaline extract of the bacterial mass was prepared. After acidification, serratamic acid was obtained in the form of crystals m.p. 138°C (dec.), Md — 10° (ethanol) (6). 

Acid hydrolysis of serratamic acid gave a nitrogen-free acid, C10H20O3J and a water soluble component identical with L-serine. The acid, m.p. 47°C, [ajo —19° (chloroform), was identified as 3(d)-hydroxydecanoic acid. As serratamic acid exhibits amide bands in its infrared spectrum (1649, 1632, 1549 cm" ) and contains a primary hydroxyl group, structure (1), N-(3D-hydroxydecanoyl)-L-serine, was proposed (6) (Scheme 1). This structure was confirmed by synthesis from 3d-hydroxydecanoic acid and L-serine methyl ester (7). 

From an extract of S. marcescens with methylene chloride a neutral compound, M.W. 515, was isolated by fractional crystallization. Mild alkaline hydrolysis of this compound gave serratamic acid as the only product. The neutral compound, called serratamolide, of m.p. 159-160 °C and optical rotation [a] + 4.8° (ethanol), C26H46N2O8, was therefore a dimer of serratamic acid. Among three possible structures, structure (2) (Scheme 1) was suggested since hydrogenolysis of the dibromo derivative... 

A careful study of the acetone extracts of S, marcescens showed that serratamolide was the only lipidic bound form of serine and that serratamic acid was an artefact of alkaline extractions (77). 

Cartwright, N.J. Serratamic acid, a Derivative of L-Serine Produced by Organisms of the Serratia group. Biochem. J. 60, 238 (1955). 

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