Incorporations of diethyl [l -14C]rnalonate by Monascus purpureus Wentii into rubropunctatin (111; R = C5Hll) and monascorubrin (111; R = C7HI5) have shown that the main poly-(3-ketide chain of these metabolites IS assembled from acetate plus malonate in the normal way. However, the p-0x0-lactone systems are derived by condensation of hexanoate and octanoate, respectively, with acetate. Although malonate is utilised in the normal way in the derivation of these fatty acid equivalents, it is not involved in the conversion of these into p-oxodecanoate and p-0x0-octanoate equivalents, respectively. A probable explanation of these results is suggested. Liver pool IKCORPORATION of sodium [1-14C] acetate and [14C]formate into the fungal metabolites sclerotiorin (I),2 rotiorin (11),3 rubropunctatin (111; R = CSH,~),~ and monascin (IV) 3 have shown distributions of label compatible with the patterns (1)-(IV), (a = radioactivity from [1-14C]acetate, = = radioactivity from the C, pool, contributed by [14C]formate), indicating that these compounds are biogenetically derived on polyp-ltetide pathways. Structural analysis suggests that in each of these compounds two chains must be present, the principal one forming the main chromophores and the second one increasing in complexity from 0-acetate (in 1) to an acetoacetyl which has undergone ring closure, giving the p-0x0-lactone system (in 11), and

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The action of the acaricide, chlorodimeform and its metabolite. N-desmethylchlorodimeform, on the activity monoamine oxidase (MAO) from the cattle tick, Boophilus microplus, were studied. Both compounds were found to be potent in vitro and in vivo inhibitors of the enzyme. However the inhibition of MAO does not seem to be related to the toxic action of the acaricide.