Synthesis of cyclopeptides from plants, fungi and sea animals

Abstract

A very flexible synthesis of non proteinogenic amino acids and an effective ring closure method for formation of macrolactams were elaborated. These methods are prerequisite for economical synthesis of cyclopeptides . The total syntheses of several cyclopeptides which had been isolated from plants, fungi and lower sea animals are described.

New Perspectives in the Chemistry and Biochemistry of the Tunichromes and Related Compounds

“…Recently, Pm-1 and Pm-2 from the P. mammillata tunichrome family were synthesized in our laboratory . As for the An tunichromes, the method of U. Schmidt et al to prepare dehydroamino acids by Horner−Emmons−Wittig condensation was employed. − Fully protected l -TOPA was produced following asymmetric hydrogenation using a Wilkinson-type homogenous catalyst (enantiomeric excess 97%). This is in contrast to the An synthetic strategy where the racemate was synthesized .…”

Stereoselective Modification of a Cyclopentapeptide via an α-(Ethylthio)glycine Residue

“…Several naturally occurring − and synthetic − cyclopeptides exhibit important biological activities. To optimize these properties, e.g.…”

Design and development of pyrolyser to extract medicinal oil from the stem of Ziziphus jujuba

“…The presence of long chain acids and a few cyclic compounds are believed to be due to the thermal degradation of various cyclopeptide alkaloids which are reported to be present in the stem barks of Z. jujuba. By comparing the methods followed by Schmidt [35] for the synthesis of cyclopeptide alkaloids, the mechanism of thermal degradation of these cyclopedite alkaloids could be the ring opening followed by the disintergration of the aromatic ring leaving a long chain compound. The long chain compound could be carboxylic acid, ester, amine or ketone while the aromatic compound is a substituted phenolic with substituted functional groups.…”