Scheme 13. The pathways from emodin 1 to the grisandienes (i.e. geodin 19 and trypacidin – 21) and the diphenyl ethers (i.e. pestheic acid 22, RES-1214-1 23 and asterric acid −24). Erdin 20 and demethylasterric acid 75 (in red box) have been isolated from the geodin producer Aspergillus terreus96 and are likely derived from the same biosynthetic pathway.RCDO = ring cleaving dioxygenase. O-met = O-methyltransferase. MCO = multi-copper oxidase.
