The method for preparation of the rhinacanthins-rich R. nasutus (RRn) extract has been previously described (Panichayupakaranant et al. 2009) In a recent study it was shown that the RRn extract possessed antifungal activity against Trichophytonrubrum, T.mentagrophytes and Microsporum gypseum with the potency equal to that of rhinacanthin-C, the most antifungal active constituent of R. nasutus leaf extract.