RESUMEN
A method for preparation of carboxy-protected amino acid conjugates of glycyrrhizinic acid with the use of N-hydroxybenzotriazole, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and methyl esters of L-amino acids (phenylalanine, tyrosine, leucine, isoleucine, and methionine) in 85-90% yield was developed. The structure of the prepared compounds was confirmed by IR and 13C NMR spectra.
RESUMEN
Synthesis of amino acid conjugates of glycyrrhizic acid with the use of N-hydroxyphthalimide, N,N'-dicyclohexylcarbodiimide, and tert-butyl esters of L-amino acids (valine, isoleucine, phenylalanine, and methionine) was performed followed by deprotection with trifluoroacetic acid. The target amino acid conjugates were isolated by column chromatography on silica gel in 40-45% yield. The structure of the prepared compounds was confirmed by IR and 13C NMR spectroscopy.