5-[[2-Amino-5-O-(aminocarbonyl)-2-deoxy-L-xylonoyl]amino]-1,5-dideoxy-1-[3,4-dihydro-5-(hydroxymethyl)-2,4-dioxo-1(2H)-pyrimidinyl]-β-D-allofuranuronic Acid; Duoyangqing; Milpan; Polar; Polar antibiotic; (2S)-2-[[(2S,3S,4S)-2-Amino-5-carbamoyloxy-3,4-dihydroxypentanoyl]amino]-2-[(2R,3S,4R,5R)-3,4-dihydroxy-5-[5-(hydroxymethyl)-2,4-dioxopyrimidin-1-yl]oxolan-2-yl]acetic acid

Polyoxin B is a fungicide used in the protection of crops and pesticides. Polyoxin B is a natural product that is produced by the fungus Polyporus umbellatus. It is a synthetase inhibitor that specifically inhibits the enzyme malic acid synthetase in bacteria and fungi. Polyoxin B has been shown to have antifungal activity in vitro and to inhibit the growth of Cryptococcus neoformans, which may be due to its ability to inhibit terminal residues, such as acetate extract, bacterial strain, and synthase enzyme.