synthesis of aureobasidin b analogs and their antifungal activity against candida albicans

Aureobasidins (abs) are a class of cyclodepsipeptides with interesting antifungal properties but they are difficult to synthesize. this study aimed to synthesize analogs of aureobasidin b (abb) by a combination of solid- and solution-phase synthesis and to investigate their antifungal properties. the linear peptides were synthesized on 2-chlorotrityl chloride resin with fmoc strategy and a range of coupling reagents including hatu/hoat, hbtu/hobt, and btc/sym-collidine. the cyclization step was undertaken in the solution phase. four cyclic nonapeptides (np1-np4) and ten cyclic heptapeptides (hp1-hp2, hp4-hp11) were successfully synthesized and characterized. the analogs np1, np4, hp1, and hp2 demonstrated moderate antifungal activity against candida albicans.