Rolf Geiger

Synthesis and biological evaluation of 4-alanine-luteinizing hormone-releasing hormone ([Ala4] LH-RH)

Abstract Synthesis of [Ala 4 ] LH-RH as well as its chemical, physical and biological properties are described. This analogue exhibits only 5% of the activity of LH-RH decapeptide. This demonstrates that the hydroxyl group of serine 4 is not absolutely essential for LH-RH activity. Although serine may be one of the groups necessary for a strong combined functional effect, it is more likely that its role is concerned with binding to the receptors.

Amine Protecting Groups

Publisher Summary This chapter provides an overview of amine protecting groups. A main guideline for principles concerning the selection of protecting group is the cleavage condition to which a given peptides proved to be sufficiently stable. Because of the stability of a great number of peptides and proteins against acidolysis in aqueous or anhydrous medium, much attention has been devoted to acid-labile protecting groups of the urethane type. Thus, highly differentiated acid lability becomes the most frequently employed principle of cleavage, complemented by hydrogenation and, more recently, by β-elimination. The favorable properties of the 9-fluorenylmethyloxycarbonyl group led to a novel strategy to use this residue for Nα protection and tert-butyl-type groups for side-chain protection in solid-phase synthesis.

Synthese eines Triacontatripeptids der Sequenz 31-63 des Schweine-Proinsulins

The synthesis of the sequence 31 — 63 of the porcine proinsulin connecting the B- and A-chain is described.

[Synthesis of an insulin-like growth factor I hybrid insulin (author's transl)].

Stepwise Edman degradation of the insulin B chain is achieved after reversible protection of the amino groups in A1 and B29 with the acid-stable methylsulfonylethyloxycarbonyl residue. Condensation of the protected N-terminal tetrapeptide of insulin-like growth factor I with the degraded insulin yields an hybrid insulin whose synthesis and biological properties are discussed.