The r a d i o l y s i s o f O( + ) -c a r n i t i n e b y 6 0 C o -l -r a d i a t i o n was examined t o o b t a i n o p t i c a l l y a c t i v e B -m e t h y l c h o l i n a . I t was f o u n d t h e t t h e r a d i o l y s i s l e a d s t o a number o f trimethylannondum bases b u t t o no o t h e r b e t a i n e s . The a c i d s formed were n o t i n v s s t i g a t e d . The bases produced were s e p a r a t e d b y i o n exchange chromatography. ( + ) -a -M e t h y l c h o l i n e and acetonyltrimethylammonium c o u l d be i d e n t if i e d b y means o f common a n a l y t i c a l methods ( I R , NMR, MS and MA) a p p l i e d t o t h e f r a c t i o n s . The amounts o f methylamines formed b y i r r a d i a t i o n , and d e t e r m i n e d by gas chromatography, were v e r y s m a l l . R a c e m i z a t i o n o f t h e D ( + ) -c a r n i t i n e d i d n o t o c c u r d u r i n g i r r a d i a t i o n , L ( -) -c z r n i t i n e was n o t f o u n d when an e n z y m a t i c a l d e t e r m i n a t i o n method was used. The f a c t t h a t ( + ) -8 -m e t h y l c h o l i n e was formed f r o m D ( + ) -c a r n i t i n e is p h a r m a c o l o g i c a l l y i m p o r t a n t , because acetyl-L(+)-B-methylcholine