Penicillic acid (PA) is a polyketide mycotoxin produced by several species of Aspergillus and Penicillium species showed antibacterial activity against various plant pathogenic bacteria and can be as a lead molecule for the development of synthetic agrochemicals to control plant bacterial diseases. In addition, PA induces single-strand DNA breaks and inhibits DNA synthesis, demonstrating mutagenic and cytotoxic effects. Penicillic acid irreversibly inhibits GDP-mannose dehydrogenase (DMG), an alginate synthesis enzyme, interrupting the committed step in alginate biosynthesis.

Quisqualic acid is an agonist of (AMPA)-subtype glutamate receptor, GRIA2, and group I metabotropic glutamate receptors. Quisqualic acid has been shown to inhibit human glutamate carboxypeptidase II (GCPII), an enzyme occurs in the central nervous system as well as in human prostate (where it is called prostate-specific membrane antigen; PSMA). Inhibitors of this enzyme as was discovered can provide neuroprotection, but can also be useful for the detection, imaging, and treatment of prostate cancer.