Caution in the use of 2-iminothiolane (Traut's reagent) as a cross-linking agent for peptides. The formation of N-peptidyl-2-iminothiolanes with bombesin (BN) antagonist (D-Trp(6),Leu(13)-psi[CH(2)NH]-Phe(14))BN(6-14) and D-Trp-Gln-Trp-NH(2).

During a study aimed at generating a bispecific molecule between BN antagonist (D-Trp(6),Leu(13)-psi[CH(2)NH]-Phe(14))BN(6-14) (Antag1) and mAb22 (anti-FcgammaRI), we attempted to cross-link the two molecules by introducing a thiol group into Antag1 via 2-iminothiolane (2-IT, Traut's reagent). We found that reaction of Antag1 with 2-IT, when observed using HPLC, affords two products, but that the later eluting peptide is rapidly transformed into the earlier eluting peptide. To understand what was occurring we synthesized a model peptide, D-Trp-Gln-Trp-NH(2) (TP1), the N-terminal tripeptide of Antag1.

Bioadhesive peptides as potential anticancer drug carriers: activation via isopeptide deblocking by proteases.

Background: Bioadhesive peptides are potentially useful as anticancer drug carriers, if the bioadhesivity becomes active only at the tumor site. We propose that this function can be achieved by the prodrug strategy using proteases in tumors.

Materials And Methods: A laminin fragment peptide, Ac-AASIKVAVSADR-NH2 (5), and its derivatives, Ac-AASIK(L) VAVSADR-NH2 (6), Ac-AASIDpm(NH2)VAVSADR-NH2 (7) and Ac-AASIDpm(L)(NH2)VAVSADR-NH2 (8), were synthesized and tested for their bioadhesive activity with 6 cancer cell lines.

[Crystal modifications of 3-cyan-6-methyl-5-(pyrid-4-yl)-1,2-dihydropyrid-2-one (milrinone)].

The preparation and characterisation of crystalline alpha-, beta- and gamma modifications of 3-cyan-6-methyl-5-(4-pyrid-4-yl)-1,2-dihydropyrid-2-on e are described. The thermic transformation of alpha- and beta-modification into gamma-modification was proved by thermogravimetric analysis (t.g.