Phomoxanthone A was first identified in a screening for antimalarial compounds. It showed strong antibiotic activity against a multidrug-resistant strain of the main causative agent of malaria, the protozoan parasite Plasmodium falciparum. The same study also reported antibiotic activity of PXA against Mycobacterium tuberculosis and against three animal cell lines, two of which were derived from human cancer cells. These findings not only showed that PXA has antibiotic activity against very diverse organisms, but they also sparked further studies that investigated PXA as a potential antibiotic or anti-cancer drug. A later study also reported antibiotic activity for PXA against the alga Chlorella fusca, the fungus Ustilago violacea, and the bacterium Bacillus megaterium. This broad range of activity disqualified it as a specific antibiotic that could be used in the treatment of infectious diseases, however the hope that it could be used as an anti-cancer drug remained. Preliminary results from a study in human cancer cells and non-cancer cells suggested that PXA might be more toxic to the former than to the latter, although results from in vivo studies have not yet been presented.
Aside from a potential medical use, recent findings indicate that PXA might have an application as a research tool in the study of mitochondrial membrane dynamics, particularly non-canonical mitochondrial fission and remodelling of the mitochondrial matrix.