myxochelin A

Myxochelin A is a microbial metabolite that has been found in A. disciformis and has diverse biological activities. It is active against Gram-positive bacteria, including B. cereus, S. aureus, and M. luteus, but not Gram-negative bacteria or fungi in an agar diffusion assay when used at a concentration of 80 μg/disc. Myxochelin A inhibits 5-lipoxygenase (5-LO) activity with an IC₅₀ value of 1.9 μM for the recombinant human enzyme. It is cytotoxic to 26-L5 colon cancer cells when used at a concentration of 3 μg/ml.

Myxochelin A is a potent inhibitor of human 5-lipoxygenase (5-LO). Studies show that Myxochelin A is a natural product that may possess potent antitumor activity at non-cytotoxic concentrations.