The Biosynthesis of 6-Methylsalicylic Acid

• Published in: The Journal of biological chemistry 1967-04, Vol.242 (8), p.1880-1886
• Main Author: Light, Robley J.
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)96083-7

Two strains of Penicillium patulum have been isolated from cultures of NRRL 2159A. One produces 6-methylsalicyclic acid (MSA) very soon after transfer of mycelium from a germinating medium to Czapek-Dox medium and is designated an early MSA strain. In the other, 6-methylsalicyclic acid production begins only after 24 to 36 hours on Czapek-Dox medium, and it is designated a late MSA strain. Cell-free extracts of the early MSA strain incorporate about 3 mµmoles of 1,3- 14 C-malonylcoenzyme A per mg of protein into 6-methylsalicylic acid in a 10-min incubation. This activity is only a small fraction of the synthetic capacity in vivo of the mycelium but is about 7-fold higher than the maximum activity found in the late MSA strain extracts and is higher than activities reported for other crude preparations. Chemical degradation of the product after recrystallization with carrier shows that one-third of the radioactivity is in the carboxyl group, which is consistent with an acetyl polymalonyl biosynthetic mechanism.