title: Solid phase synthesis of porcine LH-releasing hormone with hydrogen chloride in formic acid as the deblocking reagent.
abstract: The decapeptide corresponding to the amino acid sequence of porcine luteinizing hormone-releasing hormone (LH-RH) which involves 1 mol of tryptophan was synthesized via solid phase synthesis with two different deblocking procedures which used hydrogen chloride in formic acid and hydrogen chloride in acetic acid containing 1% 2-mercaptoethanol. After some fundamental studies on the former reagent with respect to deblocking efficiency toward the Boc group, 0.5 M hydrogen chloride (a 10-fold molar excess with respect to the N-terminal Boc group) in formic acid was used in the present synthesis. The two synthetic products exhibited the same chemical and biological properties as an authentic LH-RH. Hydrogen chloride in formic acid has proved effective without a scavenger although loss of peptide from the resin occurred to a somewhat greater extent than that with hydrogen chloride in acetic acid. A derivative of the synthetic LH-RH formylated at the indole nitrogen had a greatly diminished biological activity, indicating that the intact indole side chain is essential for the activity.
mesh_terms: D000085:Acetates; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005260:Female; D005561:Formates; D007987:Gonadotropin-Releasing Hormone / Q000138:chemical synthesis* / Q000494:pharmacology; D006851:Hydrochloric Acid; D010060:Ovulation / Q000187:drug effects; D010455:Peptides / Q000032:analysis / Q000138:chemical synthesis* / Q000494:pharmacology; D051381:Rats; D013552:Swine
chemical_list: D000085:Acetates; D000596:Amino Acids; D005561:Formates; D010455:Peptides; D007987:Gonadotropin-Releasing Hormone; D006851:Hydrochloric Acid