Sialic acids in fungi: A minireview

The increasing number of reports on the presence of sialic acids in fungi ( N-acetyl, N-glycolyl-and 5,9-N,O-diacetyl neuraminic acids) based on direct and indirect evidence warrants the present review. Formerly suggested as s ialidase-sensitive sources of anionic groups at the cell surface of fungal species grown in chemically defined media (e.g., Fonsecaea pedrosoi), siali c acids have also been found in Sporothrix schenckii, Paracoccidioides bras iliensis, Cryptococcus neoformans and recently, in Candida albicans. Method s used involved adequate hydrolysis and extraction procedures, HTPLC, gas-c hromatography, colorimetry, mass spectroscopy, sialidase-sensitive lectin a nd influenza virus binding. Apart from protecting fungal cells against phag ocytosis (S. schenckii, C. neoformans) and playing a cellular structural ro le (F. pedrosoi), other biological functions of sialic acids are still bein g investigated.