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Synthesis of the new immunostimulating agent pidotimod (3‐L‐pyroglutamyl‐L‐thiazolidine‐4‐carboxylic acid) labelled with 14 C‐ and 35 S‐isotopes
Author(s) -
Ferraboschi Patrizia,
Grisenti Paride,
Santaniello Enzo,
Giachetti Claudio,
Zanolo Giovanni,
Signorelli Giovanni,
Coppi Germano
Publication year - 1992
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580311203
Subject(s) - chemistry , thiazolidine , pyroglutamic acid , carboxylic acid , chemical synthesis , hydrochloride , hydrolysis , medicinal chemistry , stereochemistry , organic chemistry , in vitro , amino acid , biochemistry
3‐L‐Pyroglutamyl‐L‐thiazolidine‐4‐carboxylic acid (Pidotimod), a new immunostimulating agent, has been prepared labelled with 14 C and 35 isotopes starting from L‐[U‐ 14 C]‐glutamic acid 5 and L‐[ 35 S]‐cysteine hydrochloride 6 , respectively. In the first synthesis, L‐[U‐ 14 C]‐ 5 is converted into L‐[U‐ 14 C]‐pyroglutamic acid 2 , which was reacted with ethyl L‐thiazolidine‐4‐carboxylate 3 to afford the ester 4 , in turn hydrolyzed to [ 14 C]‐Pidotimod 1 . In the second synthesis, L‐[ 35 S]‐ 6 reacted with formaldehyde to give L‐[ 35 S]‐thiazolidine‐4‐carboxylic acid 7 , which was coupled with the activated ester of pyroglutamic acid, compound 8 , to afford [ 35 S]‐Pidotimod 1 . The total activity of [ 14 C]‐Pidotimod was 1.2 mCi (specific activity 5.52 mCi/mmol) and that of [ 35 S]‐Pidotimod was 1.0 mCi (specific activity 9.43 mCi/mmol).