Propionyl-CoA production through the catabolism of fatty acids is also associated with thioesterifcation. In a study concerning Aspergillus nidulans, it was found that with the inhibition of a methylcitrate synthase gene, mcsA, of the pathway described above, production of distinct polyketides was inhibited as well. Therefore, the utilization of propionyl-CoA through the methylcitrate cycle decreases its concentration, while subsequently increasing the concentration of polyketides. A polyketide is a structure commonly found in fungi that is made of acetyl- and malonyl-CoAs, providing a product with alternating carbonyl groups and methylene groups. Polyketides and polyketide derivatives are often highly structurally complex, and several are highly toxic. This has led to research on limiting polyketide toxicity to crops in agriculture through phytopathogenic fungi.