Labelling of ochratoxins with ³H or ¹²⁵I

Abstract

LABELLING OF OCHRATOXINS WITH 3H OR1 2 5 1 D. Schmiedovd, K . V e r e S , B.Cern9 I n s t i t u t e of Nuclear Biology and Radiochemistry, Czechoslovak Academy of S c i e n c e s , Prague J. Ruprich, I n s t i t u t e of Hygiene and Epidemiology, Prague J. N6meEek , I n s t i t u t e of Microbiology , Czechoslovak Academy of S c i e n c e s , Prague SUMMARY C a t a l y t . i c hydrogenation of o c h r a t o x i n A by c a r r i e r -f r e e 5 t r i t i u m was used t o p r e p a r e H-ochratoxin B w i t h a h i g h s p e c i f i c a c t i v i t y . I o d i n a t i o n of o c h r a t o x i n B by c a r r i e r -f r e e N a ' 251 u s i n g t h e c h l o r a m i n e method y i e l d e d ' 251-ochratoxin w i t h a h i g h s p e c i f i c a c t i v i t y . Another 1 2 5 1 -d e r i v a t i v e of o c h r a t o x i n A was p r e p a r e d by i o d i n a t i o n of an o c h r a t o x i n A -L--t y r o s i n e -m e t h y l e s t e r c o n j u g a t e . A l l t h r e e r a d i o a c t i v e p r ep a r a t i o n s w e r e found t o b e u s e f u l f o r radioimmunoassay. K e y words: Ochratoxin A and B , l a b e l l i n g , t r i t i a t i o n , r a d i o i o d i n a t i o n , t y r o s i n e -m e t h y l e s t e r c o n j u g a t e