Chaetomium cochlioides

FIGURE 15.131 Biotransformation of (-)-P-caryophyllene (451) by Pseudomonas ceuciviae, Diplodia gossypina, and Chaetomium cochlioides. 

A preliminary experiment was carried out in Chaetomium cochlioides to study the potential of [ " C, 0]acetate in the investigation of the origin of oxygen atoms. This fungus produces orsellinic acid (17), a typical tetraketide, which is derived from one molecule of acetyl-CoA and three molecules of malonyl-CoA without oxidation or reduction. The incorporation of into... 

Other important epoxides are postulated in the biosyntheses of pheromones derived from epoxide intermediates like the insect pheromone a-(—)-(75, 2/ ,45, 5/ )-multistriatin [6]. Here again the enantioselectivity of the epoxidation is essential for the biological activity of the compounds. The fungus Chaetomium cochlioides rearranges enantiospecif-ically the epoxide 13 of a fatty acid precursor 12 to a branched aldehyde 14 (Fig. 4), an epoxide rearrangement step also reported from other pathways. This intermediate aldehyde is reduced to the alcohol 15 and gives, after another epoxidation step, the tetrahydrofiiran derivative 17 found as a secondary metabolite in a number of Chaetomium spp. [7]. 

Figure 10 Epoxidation of caryophyllene and rearrangement of the 4,5-epoxide by Chaetomium cochlioides.

---