Biotransformation of caryophyllene by Diplodia gossypina

Fermentation of caryophyllene with Diplodia gossypina affords a number of products which are all derived from the 4,5-epoxide. Twelve of these are described here for the first time. The main products are 12-hydroxy-4,5-epoxy-caryophyllene and the corresponding acid. On side reactions additional hydroxylations occurred or the exo-methylene group was also epoxidized and further degraded. Two rearranged compounds were found, one resulting from an epoxide rearrangement leading to an eight-membered ring, the other one being a cyclization product possessing the rare skeleton of the punctatin antibiotics.