Chemical synthesis of labelled intermediates in cyanogenic glucoside biosynthesis

✍ Scribed by Birger Lindberg Møller

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: French
• Weight: 372 KB
• Volume: 14
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.2580140504

✦ Synopsis

Abstract

Chemical syntheses of [UL‐ ^14^C]‐labelled N‐hydroxytyrosine, p‐hydroxyphenylpyruvic acid oxime, p‐hydroxyphenylacetaldoxime, and p‐hydroxyphenylacetonitrile in high yields from L‐[UL‐^14^ C]‐tyrosine are described. These syntheses involve initial conversion of L‐tyrosine to p‐hydroxyphenylpyruvic acid, which then is allowed to react with hydroxylamine to form p‐hydroxypheny lpyruvic acid oxime. N‐Hydroxytyrosine is obtained from the latter by reduction with sodium cyanoborohydride, and is oxidatively decar‐boxylated to p‐hydroxyphenylacetaldoxime by treatment with ammonia. Finally, p‐hydroxyphenylacetonitrile is obtained by dehydration of the aldoxime with thionylchloride. All synthesized compounds were identified by combined GLC/MS of their trimethylsilyl derivatives. The commercial availability of several specifically labelled ^14^C, ^2^H, and ^3^H tyrosines and of ^2^H and ^3^H sodium cyanoborohydride makes the method equally useful for synthesis of various specifically labelled compounds.