A new naphthoquinone, 6-methoxy-7-hydroxy-a-dunnione (1), along with four known compounds (2, 4, 10, and 11) were isolated from Sinningia canescens (Mart.) Wiehler tubers, while S. warmingii (Hiern.) Chautems furnished eight known compounds (3-10). The known compounds were identified as 7-hydroxy-