S-[2-[4-(4-amino-5-hydroxy-6-methyloxan-2-yl)oxy-2,5,12-trihydroxy-7-methoxy-6,11-dioxo-3,4-dihydro-1H-tetracen-2-yl]-2-oxoethyl] butanethioate

ethyl 2-butanoylsulfanylacetate

Butyric acid, thio-, S-ester with 1-mercapto-2-butanone

1,1-bis-butyrylmercapto-butane

丁酸