Rapid conversion of a homocystine-containing peptide into its corresponding 11CH3-labeled methionine sulfone analogue. PET experiments with H-[S-11CH3]Met(O2)-Glu-His-Phe-D-Lys-Phe-OH
✍ Scribed by W.P.A. Janssen; J.W. van Nispen; J.F.G.A. Jansen; T. Wiegman; A.M.J. Paans; D. de Wied; M.G. Woldring; W. Vaalburg
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- French
- Weight
- 137 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0022-2135
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✦ Synopsis
Conflicting information exists regarding the entry of peripherally administered neuropeptides to the central nervous system to induce central activity.
Recently, the first publication on the synthesis of an "CH, containing neuropeptide, Met-enkephalin, has appeared (1) followed by information on its kinetics in brain, pituitary and plasma of Rhesus monkeys as measured by PET ( 2 ) . The label was in the CH, group of the side-chain of the methionine residue. As precursor molecule the fully protected homocysteine-containing peptide 2-Tyr-Gly-Gly-Phe-Hcy(Bz1 )-OBzl' was prepared. After removal of the protecting groups with sodium in liquid ammonia, 'lCH,I was added and the obtained reaction product was isolated by HPLC. The total reaction time starting with the synthesis of the labeled reagent was 40 min. A similar approach was applied to the synthesis of the ' ' C labeled undecapeptide substance P to give the desired peptide within 45-60 min ( 3 ) .