Fig 7. Proposed tailoring steps in the biosynthetic pathway of medermycin.

(S)-DNPA: 4-dihydro-9-hydroxy-1-methyl-10-oxo-3-H-naphtho[2,3-c]pyran-3-acetic acid, as a first chiral intermediate in the pathway of medermycin. NDP-angolosamine: the specific glycosyl moiety formed under the control of seven glycosylating genes indicated in the med gene cluster in Fig. 1B. The conversion from DDHK to DHK could be catalyzed by an oxygenase encoded by med-ORF7 in the med gene cluster [26]. The numbering given is based on the biosynthetic origin of these intermediates.