No abstract

The transprotection of N-Fmoc-cysteine containing di- and tripeptides possessing a free SH group to produce the corresponding S-Fm-cysteine di- and tripeptides bearing a free amino group is accomplished efficiently with DBU in dry THF. The N-Fmoc to S-Fm transformation mechanism is discussed. S-Fm-Cysteine di- and tripeptides readily form amide bonds on coupling with N-(Pg-α-aminoacyl)benzotriazoles and N-(Pg-α-dipeptidoyl)benzotriazoles to give larger peptides.

A series of novel scaffolds Thiadiazolyl Piperidine, Thiadiazolyl Piperazine, thiadiazolidine, Thiadiazolyl thiazole and Thiadiazolyl-imidazole-Thione were synthesized from cheap, available and biologically active stearic acid. 2-amino-5-heptadecyl 1,3,4-thiadiazole reacts with chloroacetyl chloride and produced 2-choloro-N-(5-heptadecyl-1,3,4-Thiadiazole-2-yl) acetamide. Which allowed to react with Piperidine, Piperazine, urea and/or Thiourea and Potassium thiocyanate, and the latest scaffolds have been synthesized, respectively, and the structures of these compounds were established by elemental analysis, MS, IR and 1 H-NMR spectral data. The antimicrobial activities of the synthesized compounds were evaluated in-vitro against strains of gram +ve, gram −ve bacteria and fungi. Nonionic surfactant were obtained by addition of different moles of propylene oxide (3,5,7 mole) to the synthesized compounds bearing an active hydrogen. Physico-chemical and surface properties as well as biodegradability of the synthesized non-ionic surfactants were evaluated.