The C-1' epimers of the sesquiterpenoids 2-(1',2'-dihydroxy-1'-methylethyl)-6,10-dimethylspiro[4,5]dec-6,9-dien-8-one and 2-(1',2'-dihydroxy-1'-methylethyl)-6,10-dimethyl-9-hydroxyspiro[4,5]dec-6-en-8-one were isolated from potato tubers infected with Phoma foveata and Fusarium spp., in addition to