The novel fungal pigment, neocercosporin (I), C29H26O10, mp 237°, was isolated together with cercosporin (II) from Cercosporina Kikuchii nov. var. (MITTS-1 strain) as reddish violet orthorhombic crystals. The structure of I was elucidated as 5, 8-dihydroxy-2, 11-dimethoxy-1, 12-(2-hydroxypropyl)-6, 7-methylenedioxyperylene-3, 10-quinone. II was photosensitive and isomerized to isocercosporin (III) but I was stable and was not photosensitive.
