Self-decomposition of DL-/methyl-14C/carnitine to labelled β-methylcholine and acetonyltrimethylammonium

✍ Scribed by Heinz Löster; Hermann Seim; Erich Strack

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: French
• Weight: 383 KB
• Volume: 20
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.2580200902

✦ Synopsis

The s e l f -d e c o m p o s i t i o n r a t e o f DL-/methyl-14C/carnitine (32 m C i / mmol) i n t h e c r y s t a l l i n e b e t a i n e f o r m was s t u d i e d . I t was found t o be decomposed t o 39.5 i n 4.5 y e a r s . On t h i s b a s i s a s e l fd e c o m p o s i t i o n c o e f f i c i e n t G = 4.2 was c a l c u l a t e d f o r t h e s o l i d s t a t e . DL-/N-me thyl-14C/13-methylcholine was t h e most i m p o r t a n t l a b e l l e d p r o d u c t o f d e c o m p o s i t i o n (12 x) . /N-methyl-14C/acetonyltrimethylammonium was a l s o p r e s e n t among t h e r a d i o l y t i c p r o d u c t s (2 9 4 . I t was d e t e c t e d as i t s 2,4-dinitrophenylhydrazone b y means o f t h i n -l a y e r c h r o m a t o g r a p h i c s e p a r a t i o n and a u t o r a d i o g r a p h y . Key words : 1 4 C -l a b e l l e d D L -c a r n i t i n e , r a d i o l y s i s , t r i m e t h y lammonium compounds, U -m e t h y l c h o l i n e I n t r o d u c t i o n L ( -) -c a r n i t i n e (L(-)-3-hydroxy-4-N,N1N-trimethylaminobutyrate) i s e s s e n t i a l f o r t h e o x i d a t i o n o f l o n g c h a i n f a t t y a c i d s i n t h e m i t o c h o n d r i a of mammals and humans. Because t h e i m p a i r m e n t o f p h y s i o l o g i c a l L -c a r n i t i n e c o n c e n t r a t i o n l e a d s t o c a r n i t i n e def i c i e n c y syndromes (l), t h e m e t a b o l i s m o f c a r n i t i n e i s b e i n g i n t e n s i v e l y s t u d i e d . To t h i s end, and f o r t h e d e t e c t i o n o f s i x L -c a r n i t i n e -s p e c i f i c enzymes (2), l 4 C -1 a b e l l e d c a r n i t i n e i s 0362-4803/83/091035-11$l.10 0 1983 by John Wiley & S o n s , L t d .