Secondary Metabolites by Chemical Screening, 23. Waraterpols, New Penicillium Metabolites and Their Derivatives

Substituted phenols can easily be recognized by using the chemical screening method, whereby they are found to be widely spread secondary metabolites of microorganisms. In the culture filtrate of Penicillium sp. (strain FH‐A 6260) new phenols named waraterpols were detected by a striking purple coloration by using anisaldehyde/sulfuric acid. These secondary metabolites (1 to 3 and 6 to 8) exhibit a C15‐carbon skeleton and can be characterized as hydroxylated branched‐chain sesquiterpenoids with a benzoide moiety. The minor compounds were O‐acetyl (2 and 3) and dehydrated derivatives (6 to 8) of the parent compound waraterpol (1), which was shown to be 6‐[2‐hydroxy‐4‐(hydroxymethyl)phenyl]‐2‐methylheptane‐1,6‐diol. Derivatization of 1 resulted in the quinone and hydroquinone compounds 10 and 5 as well as in the cyclic derivatives 11 and 12. The waraterpols exhibit distinct antibacterial and antifungal activities whereas an inhibition of HIV‐1 in a MT‐4 cell assay was found for 11.