Two metabolites of the fungus Periconia macrospinosa are shown to be 5-chloro-3.4-dihydro-8-hydroxy-6-methoxy-3-methylisocoumarin (Ia) and methyl 2-allyl-3,5-dichloro-1,4-dihydroxycyclopent-2-enoate (11). Related compounds had previously been isolated from SDorormia affinis.
Antibiotic 1233A is shown to be I 2-hydroxy-l3-hydroxymethyl-3.5,7-trimethyltetradeca-2,4-dienedioic acid 12,14-lactone (1 a). A second metabolite, 1233B, is believed to be one of the C -I 2 epimers of the parent acid (5a).WHEN grown on Czapek-Dox medium, the unidentified fungus ACC 1233, believed to be a CephaZos$orium sp., produces an antibiotic carboxylic acid, 1233A, for which we suggest the structure (la).l Antibiotic 1233A is the first p-lactone to have been isolated from a fungus; the only other natural products known to contain a p-lactone system appear t o be anisatin and neoanisatin, toxic sesquiterpenes from the seeds of Illicium anisatma L.2Antibiotic 12338, C,,H,O,, forms a methyl ester (lb) and an acetate (lc). Its n.m,r. (see Table ) and u . v . ~ (Imx. 267 nm) spectra suggest the presence of the system CMe:CHCMe:CH-CO,H , and this part structure was confirmed by hydrogenation to a tetrahydroderivative (2) with the expected properties, and by ozonolysis to the methyl ketone (3a), pyruvaldehyde, and p-formylcrotonic acid (4) , the last two being isolated
Me MeMe 13 12
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