ANTICOCCIDIAL ACTIVITY OF NOVEL SEMI-SYNTHETIC ANALOGUES OF DEOXYFRENOLICIN AND FRENOLICIN Β (PART II)

Semi-synthetic C-3a and C-4 substituted analogues of the naphthopyranquinones, frenolicin Β 1, and deoxyfrenolicin 2, have been produced and their biological activity as anticoccidial agents investigated in vivo. INTRODUCTION In a previous paper, we described the synthesis and in vivo anticoccidial activities of some semi-synthetic analogues of the naphthopyranquinone, frenolicin Β 1 in which modifications had been carried out in the benzofused ring of the naphthoquinone. Apart from phenolic pro-drugs derived from 1 these modifications led to less potent anticoccidial agents. It has previously been reported that deoxyfrenolicin 2 is virtually devoid of in vivo anticoccidial activity. In this paper we describe the synthesis and anticoccidial activity of some analogues of 1 and 2 in which modifications have been made at the C-4 and C-3a positions. U.K.