O-Seco-RA-XXIV, a possible precursor of an antitumor peptide RA-XXIV, from Rubia cordifolia L.
摘要:
O-Seco-RA-XXIV, a new cyclic peptide, cyclo-(D-alanyl-L-glutaminyl-N,O-dimethyl-L-tyrosyl-L-alanyl-N-methyl-L-tyrosyl-N-methyl-L-tyrosyl), was isolated from the roots of Rubia cordifolia L. along with RA-XXIV. Its structure and relative stereochemistry were determined by interpretation of the spectroscopic data and X-ray crystallography, and its absolute stereochemistry by the Marfey's amino acid analysis of its acid hydrolysate. Isolation of the two peptides from the same plant source may indicate that O-seco-RA-XXIV is a possible precursor of RA-XXIV and that the formation of the diphenyl ether linkage in the cycloisodityrosine moiety is to be formed after the formation of the cyclohexapeptide chain in this series of peptides. (C) 2012 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.
O-Seco-RA-XXIV, a new cyclic peptide, cyclo-(D-alanyl-L-glutaminyl-N,O-dimethyl-L-tyrosyl-L-alanyl-N-methyl-L-tyrosyl-N-methyl-L-tyrosyl), was isolated from the roots of Rubia cordifolia L. along with RA-XXIV. Its structure and relative stereochemistry were determined by interpretation of the spectroscopic data and X-ray crystallography, and its absolute stereochemistry by the Marfey's amino acid analysis of its acid hydrolysate. Isolation of the two peptides from the same plant source may indicate that O-seco-RA-XXIV is a possible precursor of RA-XXIV and that the formation of the diphenyl ether linkage in the cycloisodityrosine moiety is to be formed after the formation of the cyclohexapeptide chain in this series of peptides. (C) 2012 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.