146142-94-1Relevant articles and documents
Monatin and its stereoisomers: Chemoenzymatic synthesis and taste properties
Bassoli, Angela,Borgonovo, Gigliola,Busnelli, Gilberto,Morini, Gabriella,Drew, Michael G. B.
, p. 1652 - 1658 (2005)
The sweet natural compound monatin 1 has two stereogenic centres and the (2S,4S) absolute configuration has been attributed to the natural isomer. We obtained all four stereoisomers as pure compounds by a six-step synthetic sequence. The stereogenic centre at C-4 was introduced stereoselectively by a regio- and enantiospecific enzymatic hydrolysis of the racemic ethyl dicarboxylate 4 using a protease from Aspergillus oryzae. The absolute configuration of the intermediate products was assigned by X-ray diffraction of chiral derivatives. The stereogenic centre at C-2 was introduced non-specifically, and the resulting diastereomeric mixtures were separated by RP-HPLC. The absolute configurations of the final products were established by comparing retention times on a chiral HPLC column with those of known samples. The four stereoisomers were submitted to tasting trials and three of them, particularly the (2R,4R) isomer, were found to be intensely sweet. A sample of natural monatin analysed under the same conditions is shown to contain all the four stereoisomers. The relative stereoisomeric content in the plant, as well as the possible isomerisation of the chiral centres during extraction and manipulation of monatin samples, are important points that need to be clarified by extensive analysis of the natural extracts. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
Scale-up of a chemo-biocatalytic route to (2 R,4 R)- and (2 S,4 S)-monatin
Rousseau, Amanda L.,Buddoo, Subash R.,Gordon, Gregory E. R.,Beemadu, Sharon,Kupi, B. Godfrey,Lepuru, M. Jerry,Maumela, Munaka C.,Parsoo, Arvesh,Sibiya, Duncan M.,Brady, Dean
, p. 249 - 257 (2011/10/02)
Monatin, a natural sweetener, refers to a collection of four isomers of 2-((1H-indol-3-yl)methyl)-4-amino-2-hydroxypentanedioic acid. A chemo-biocatalytic approach to kilogram quantities of enantiopure 2S,4S-monatin and 2R,4R-monatin from indole is described. Key steps in the process include a (2 + 3) cycloaddition reaction followed by nickel-catalysed reduction to construct the monatin backbone, and a highly selective enzyme resolution of the 2S,4S- and 2R,4R-monatin diastereomeric pair to afford each enantiomer in 99% ee.
PRODUCTION OF MONATIN STEREOISOMERS
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Page/Page column 17, (2009/05/29)
Methods and materials for the production of the high intensity sweetener, monatin, in stereoisomerically-pure or stereoisomerically-enriched form are disclosed. For example, methods using stereoisoselective hydrolysis and separation of a monatin-derived lactone ester are disclosed.
