6-methylsalicylic acid decarboxylase; part of the gene cluster that mediates the biosynthesis of arthrosporols, metabolites that possess a novel hybrid carbon skeleton consisting of a polyketide-derived epoxycyclohexenol combined with a terpenoid-derived monocyclic sesquiterpenol substructure. Arthrosporols B and C are two dehydration derivatives of arthrosporol A. All of the arthrosporols shared the same epoxycyclohexenol moiety, and the difference among them only occurred in the monocyclic sesquiterpenol substructure (PubMed:26422178, PubMed:27723963). The pathway begins with the biosynthesis of 6-methylsalicylic acid (6-MSA), the first precursor of the polyketide-derived epoxycyclohexenol in arthrosporols, by the polyketide synthase (PKS) AOL_s00215g283 via condensation of 1 acetate and 3 malonate units. AOL_s00215g283 performs a series of programmed reactions including Claisen condensation, dehydration, reduction, and cyclization to yield 6-MSA (PubMed:26422178). The 6-methylsalicylic acid decarboxylase AOL_s00215g281 then catalyzes the decarboxylation of 6-methylsalicylic acid to yield m-cresol (PubMed:27723963). The arthrosporols precursor m-cresol might be a versatile precursor for other pathways (PubMed:27723963). The cytochrome P450 monooxygenase AOL_s00215g282 then acts as a m-cresol hydrolase that converts m-cresol to arthrosporols, in combination with other arthrosporols cluster's enzymes such as the cytochrome P450 AOL_s00215g280 (PubMed:27723963, PubMed:28475838). 6-methylsalicylate + H(+) = 3-methylphenol + CO2 Secondary metabolite biosynthesis. Monomer. Abolishes the production of arthrosporol A and accumulates 6-methylsalicylic acid (PubMed:27723963). Leads to altered growth rates and the development of much more fluffy aerial hypha (PubMed:27723963). Belongs to the metallo-dependent hydrolases superfamily. ACMSD family.