Two new puriniums, heteromines D (4) and E (5), and three new pyrimidines, heteromines F (6), G (7), and H (8), were isolated from the aerial parts of Heterostemma brownii Hay. Their structures were determined as 7,9-dimethyl-2-(N,N-dimethylamino)guaninium chloride, 7,9-dimethyl-2-(N-methylamino)guaninium chloride, 6-methoxy-4-(N-methylamino)-2-(N,N-dimethylamino)-5- (N-methylformamido)pyrimidine, 6-methoxy-2,4-bis(N-methylamino)-5-(N-methylformamido)pyrimidine, and 2-amino-6-methoxy-4-(N-methylamino)-5-(N-methylformamido)-pyrimidi ne, respectively.