A unique water soluble formulation of β-asarone from sweet flag ( Acorus calamus L.) and its in vitro activity against some fungal plant pathogens

An antifungal substance β-asarone was isolated from ethyl acetate extract of Acorus calamus L. As β-asarone is lipophilic, it was made into water soluble formulation by encapsulating into beta methyl cyclodextrin (BMCD). At β-asarone concentration of 30 ppm, this formulation completely inhibited mycelial growth of major plant pathogenic fungi,Phytophthora capsici, which was isolated from infected black pepper (Piper nigrum L.) leaf and identified by internal transcribed spacer polymerase chain reaction (ITS PCR) and sequencing. Further, this formulation completely inhibited the germination of zoospore and complete cessation of zoospore motility was observed within a minute.   Key words: Acorus calamus L., β-asarone, beta methyl cyclodextrin (BMCD),Phytophthora, internal transcribed spacer polymerase chain reaction (ITS PCR), zoospore.