Ultrasonic and free-radical degradation of mannan from Candida albicans.

Abstract Mannan from pathogenic Candida albicans serotype A was degraded by means of ultrasound and/or OH generated in situ by Fenton reaction. The kinetics of degradation was monitored by HPLC analysis and the weight-average molecular weights ( M w ) and index of polydispersity (PDI) were compared. A well-defined low-molecular-weight mannan (∼30 kDa) with narrowed PDI of 1.8 was obtained after 120 min of ultrasonication. Similar or even lower M w (up to 16 kDa) was achieved upon free-radical exposure depending on Fe 2+ concentration used; however, this was accompanied by overall broadening of PDI and distinct changes in polymer structure as indicated by NMR analysis.