Streptomyces spiroverticillatus

Tautomycin was obtained from the terrestrial microorganism Streptomyces spiroverticillatus and is chemically characterised as an ester of a carboxylic acid derived fi om a dialkyl maleic anhydride, with a long chain (26-C) polyol containing two cyclic ethers. In a simultaneous study of the best-known natural inhibitory compounds of PP2A, in which the non-radioactive malachite green assay was applied, tautomycin was the least potent compound [144]. This is consistent with the findings reported by Honkanen et al. [129] and other authors. Its primary site of phosphatase inhibition is PPlc, as was reported in a comparative study with okadaic acid and calyculin A [131]. 

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