Akira Shishido

Cyclolinopeptides B - E, new cyclic peptides from Linum usitatissimum☆

Abstract New cyclic nona and octapeptides, cyclolinopeptides B - E were isolated from the seeds of Linum usitatissimum and their structures were elucidated as cyclo (-Pro-Pro-Phe-Phe-Val-Ile-Met-Leu-Ile-), cyclo (-Pro-Pro-Phe-Phe-Val-Ile-Mso-Leu-Ile-), cyclo (-Pro-Phe-Phe-Trp-Ile-Mso-Leu-Leu-), and cyclo (-Pro-Leu-Phe-Ile-Mso-Leu-Val-Phe-), respectively, by extensive 2D NMR methods and chemical degradations. Cyclolinopeptides B and E showed immunosuppressive activity. New cyclic nona and octapeptides, cyclolinopeptides B - E were isolated from the seeds of Linum usitatissimum and their structures were elucidated as cyclo (-Pro-Pro-Phe-Phe-Val-Ile-Met-Leu-Ile-), cyclo (-Pro-Pro-Phe-Phe-Val-Ile-Mso-Leu-Ile-), cyclo (-Pro-Phe-Phe-Trp-Ile-Mso-:eu-Leu-), and cyclo (-Pro-Leu-Phe-Ile-Mso-Leu-Val-Phe-), respectively, by extensive 2D NMR methods and chemical degradations. Cyclolinopeptides B and E showed immunosuppressive activity.

Cyclolinopeptides F–I, cyclic peptides from linseed

Four cyclic peptides, cyclolinopeptides F-I, were isolated from seeds of Linum usitatissimum. Their structures were elucidated by extensive 2D NMR spectroscopic methods and by chemical degradation. Further, their immunosuppressive activity is examined.

A new immunosuppressive cyclic nonapeptide, cyclolinopeptide B from Linum usitatissimum

Abstract A new cyclic nonapeptide, cyclolinopeptide B: cyclo (-Pro-Pro-Phe-Phe-Val-Ile-Met-Leu-Ile-), has been isolated from the seeds of Linum usitatissimum and its structure was elucidated by extensive 2D NMR methods and chemical degradations. Cyclolinopeptide B showed potent immunosuppressive activity comparable with that of cyclosporin A.

DICHOTOMINS A -E, NEW CYCLIC PEPTIDES FROM STELLARIA DICHOTOMA L. VAR. LANCEOLATA BGE.

Abstract New cyclic penta or hexapeptides, dichotomins A - E [A: cyclo(-Gly-Thr-Phe-Leu-Tyr-Val-); B: cyclo(-Gly-Thr-Phe-Leu-Tyr-Thr-); C: cyclo(-Gly-Thr-Phe-Leu-Tyr-Ala-): D: cyclo(-Gly-Val-Gly-Phe-Tyr-[le-): E: cyclo(-Gly-Tyr-Ala-Phe-Ala-)] . have been isolated from the roots of Stellaria dichotoma L. var. lanceolata Bge. Their structures were elucidated on the basis of extensive 2D NMR, chemical degradation and X-ray crystallographic analysis.

Conformational analysis of cyclolinopeptides A and B

Abstract Three dimensional structures of cyclolinopeptides A (CLA; cPPFFLIILV) and B (CLB; cPPFFVIMLI) isolated from the seeds of Linum usitatissimum were examined by X-ray analysis and distance geometry calculations using nuclear Overhauser effect constraints. Conformation in the solid state of CLA was similar to those in the solution state of CLA and CLB.

Dichotomin A, a new cyclic hexapeptide from Stellaria dichotoma L. var. lanceolata Bge

Abstract A new cyclic hexapeptide, dichotomin A, showing cell growth inhibitory activity, has been isolated from the roots of Stellaria dichotoma L. var. lanceolata Bge. and the structure and solid state conformation were elucidated by extensive 2D NMR, chemical degradation and X-ray analysis.