Kagari Fujita

An efficient and stereoselective synthesis of platelet-activating factors and the enantiomers from D- and L- tartaric acids

Abstract Acetyl glyceryl ether phosphorylcholines, platelet-activating factors ( 1 and 2 ), were efficiently synthesized in a stereochemically unambiguous manner starting from D- and L- tartaric acids as the chiral synthons.

Linear peptide ETA antagonists: rational design and practical derivatization of N-terminal amino- and imino-carbonylated tripeptide derivatives☆

Abstract Novel linear tripeptides possessing high endothelin antagonist activity were derived from endothelin antagonistic cyclic pentapeptides represented by BQ-123. The N-terminal urea moiety of the linear tripeptide derivatives was essential to show the strong antagonist activity. An easy method to prepare these peptides by treatment of the corresponding N-phenoxycarbonylated tripeptide esters with primary or secondary amines is described.

Practical synthesis of a cyclic pentapeptide in solution: large-scale preparation of a representative ETA-selective antagonist, BQ-123Na

Abstract A 100-g scale preparation of a representative endothelin-A receptor (ET A ) selective antagonist, BQ-123Na (a sodium salt of BQ-123), is described. Application of a methyl ester as the side chain carboxy-protecting group for the d -Asp residue made it possible to use a benzyl ester as a carboxy-protecting group for the C-terminal Leu throughout the synthesis.