[1] The acid is a cellobiose lipid produced by the corn smut fungus Ustilago maydis under conditions of nitrogen starvation.
[3][4] The name comes from Latin ustus which means burnt and refers to the scorched appearance of the smut fungi.
They can be used in pharmaceutical, cosmetic, and food applications and are known for their strong fungicidal activity on many species.
Similar compounds are the extracellular cellobiose lipids of the yeasts Cryptococcus humicola and Trichosporon porosum : 2,3,4-O-triacetyl-beta-D-glucopyranosyl-(1→4)-6-O-acetyl-beta-D-glucopyranosyl -(1→16)-2,16-dihydroxyhexadecanoic acid.
These compounds inhibit the growth of quite a number of various species of yeast and fungi, including Candida albicans and Cryptococcus (Filobasidiella) neoformans.