Further studies of a new vitamin E analogue more active than α-tocopherol in the rat curative myopathy bioassay

AbstractThe bioactivities of the acetates of 2R,4'R,8'R- and 25,4'R,8'R-2,4,6,7-tetramethyl-2-(4',8',12'-trimethyltridecyl)-5-hydroxy-3,4-dihydrobenzofuran (RRR- and SRR-1-Ac) have been measured in the rat curative myopathy bioassay and compared with the RRR and SRR stereoisomers of α-tocopheryl acetate (RRR- and SRR-2-Ac). Each stereoisomer of 1 is only slightly more active than the corresponding stereoisomer of 2(RRR-1-Ac/RRR-2-Ac = 110; SRR-1-Ac/SRR-2-Ac = 1.16). This finding contrasts with our earlier finding [(1986) FEBS Lett. 205, 117 120], confirmed in the present study, that all-rac-1-Ac is 1.5-1.9 as active as all-rac-2-Ac. We suggest that the stereochemistry (S vs R) at the 4' and 8' tail carbons is of less biological importance in 1 than in 2