| Abstract: | Two kinds of dehydropeptide analogs of enkephalin containing a ΔTyr unit at the N-terminus have been synthesized by coupling Boc-ΔTyr-(Cl2Bzl)-OH with amino acid amides and tetrapeptide esters using the water soluble carbodiimide-HOBt method. Pentapeptides consisting of ΔTyr1, and ΔPhe4 or ΔLeu5 were also prepared. Ultraviolet difference spectroscopy was important in the characterization of the dehydro moieties, ΔTyr, ΔPhe and ΔLeu. Attempts to liberate ΔTyr1-enkephalins have been unsuccessful because of the instability of an N-terminal ΔTyr residue having p-phenolic group in the side chain. |
