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 4,4a,5,6,7-hexahydro-3-hydroxy-6-(1',2'-dihydroxy-1'-methylethyl)-4-methyl-2(3H)-naphthalenone, N-trans-p-coumaroyl tyramine and N-trans-feruloyl tyramine. Three of the compounds are novel.