title: [Syntheses of human little gastrin-I and its leucine-15, norleucine-15 and methoxinine-15 analogs].
abstract: Human little gastrin-I is known to exhibit a high tendency to air-oxidation of its methionine-15 residue to the corresponding S-oxide derivative, with concomitant loss of biological activity. Since its leucine-15 analog, even if fully biologically active, differs significantly from the parent hormone in the immunological properties, the norleucine-15 and methoxinine-15 analogues were synthetized. For the required comparative analyses new syntheses of human little gastrin-I and of its leucine-15 analog were additionally elaborated. Upon an optimized condensation of the fragments, followed by the deprotection step, partition chromatography as well as preparative high-performance liquid chromatography led to the desired gastrins in satisfactory yields and high degree of purity as judged by the expected and known side products.
mesh_terms: D000595:Amino Acid Sequence; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D005755:Gastrins / Q000138:chemical synthesis*; D006714:Homoserine / Q000031:analogs & derivatives; D006728:Hormones / Q000138:chemical synthesis*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy
chemical_list: D005755:Gastrins; D006728:Hormones; C037856:gastrin heptadecapeptide, Leu(15)-; C037855:methoxine; C013550:gastrin 17; D006714:Homoserine; C037857:gastrin heptadecapeptide, Nle(15)-; C037858:gastrin heptadecapeptide, methoxine(15)-
vernacular_title: Zur Synthese von Human-Little-Gastrin-I und dessen Leucin-15-, Norleucin-15- und Methoxinin-15-Analoga.