GB1501119A - Folate compounds - Google Patents

Abstract

1501119 Radioactively labelled folate compounds RADIOCHEMICAL CENTRE Ltd 20 Dec 1974 [11 Dec 1973] 32434/77 Divided out of 1501118 Heading C2C The invention comprises compounds of the formula where a dotted line indicates that the bond may be single or double, X is H or CH 3 , m is 0 or 1 (such that the adjacent N atom is trivalent), and either (a) R is where q is 0 or 1, p is 1 or 2, Q is C x H 2x+1 where x is 1 to 6, and when q is 0, n is 1 and Z is H, and when q is 1, n is 1 to 13 and Z is OH, or (b) R is where Z is OH, n is 1, and one Y is H and the other Y is -SeC x H 2x+1 , where x is 1 to 6, or an ester or salt of such acids. They may be obtained by reacting isobutyl chloroformate with a N<SP>10</SP>-protected pteroic acid in the presence of a tertiary amine under anhydrous conditions in dry solvents to give a mixed anhydride which is subsequently reacted with an appropriate Se-75 labelled amines or amino-acids, e.g. selenomethionine, selenoethionine, Se-methyl-selenocysteine, Se-ethylselenocysteine and 2-(methylseleno)-ethylamine. The products are useful in the saturation analysis of folate compounds by competitive radioassay. Se - methyl - L - selenocysteine - Se 75 is prepared by forming a red-brown solution of disodium diselenide containing Se 75, adding sodium #-chloro-L-alanine thereto, purifying the resulting crude selenocysteine-Se 75, and reacting it with methyl iodide in the presence of Na and liquid NH 3 . 2 - (Methylseleno) - ethylamine - Se 75 is prepared by adding methyl iodide to a red-brown solution of disodium diselenide containing Se 75 to give dimethyl diselenide, cleaving this compound with Na to yield sodium methyl selenide and adding thereto 2-bromo-ethylamine hydrobromide.