Sorghum is a cereal grain grown on a global scale for its diverse utility as an alternative energy resource, food for livestock and people, and for its ability to survive and flourish in harsh conditions. One of the factors contributing to the adaptability of sorghum to harsh environment is an allelochemical compound called sorgoleone. Sorgoleone is released as exudate from the roots of the sorghum plant and it inhibits photosynthesis in germinating seedlings. Sorgoleone is strongly hydrophobic, so it is sorbed and persists in the soil and persists in the soil which causes soil sickness and diminishes growth of other neighboring plants, while also reducing soil nitrification. Sorgoleone suppresses growth for many plants, but is most commonly active on small-seeded plants including Abutilon theophrasti, Datura stramonium, Amaranthus retroflexus, Setaria viridis, Digitaria sanguinalis, and Echinochloa crusgalli . Sorgoleone biosynthesis was discovered using retrobiosynthetic NMR analysis of sorghum root exudate. The polyketide synthase involved in sorgoleone synthesis is in a different cellular compartment than the fatty acid synthase. The sorghum root hairs have all the necessary components to synthesize sorgoleone, and do create exudate droplets that are approximately 50% sorgeleone by weight. The exudate droplets may accumulate to 20 micrograms in size per miligram of dry root weight in laboratory conditions. This inhibition may be necessary to avoid autotoxicity, as the chemical structure for sorgoleone (Fig. ) is analogous to ubiquinone, a ubiquitous electron carrier in bacterial photosynthesis and mitochondria. Crucially, sorgoleone closely mimics intermediates in the ubiquinone biosynthesis pathway, replacing a methyl group with a hydroxyl group when compared with demethoxyquinone, the substrate for Coq7 in yeast, UbiF in E. coli, and potentially homologs of At1g24340 in plants. Thus, sorgoleone may inhibit ubiquinone biosynthesis, or directly inhibit photosynthetic or mitochondrial proteins by mimicking ubiquinone or potentially plastoquinone directly. Regardless, photosynthetic activity in the presence of sorgoleone is diminished, as is mitochondrial function, providing a competitive ad- Figure : Chemical structures of sorgoleone and it precursors selected for the current permeability study, together with the last steps of the biosynthesis pathway, adapted from. The putative synthesis pathway begins from 5-pentadecatrienyl resorcinol, which is converted by o-methyltransferase to 5-pentadecatrienyl resorcinol-3-methyl ether to dihydrosorgoleone via a undetermined P450 enzyme, before autooxidizing to sorgoleone. The chemical structure for sorgoleone is very similar to that of quinones used as electron carriers within the light reactions of photosynthesis.