Abstract
Antimicrobial activity of trans-4-methylthio-3-butenyl isothiocyanate (TMBI) from Raphanus sativus L. cv. “Aokubi-Miyashige Daikon” was examined using Escherichia coli, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus oryzae. Isothiocyanate content of the sample used for the antimicrobial assay was determined in the form of thiourea derivative.
trans-4-Methylthio-3-butenyl thiourea (TMBT) was prepared from “Aokubi-Miyashige Daikon. ” Ethyl, allyl, butyl, or phenyl thiourea was prepared from each commercial isothiocyanate. Standard curves of these thioureas were made using modified Grote reagent.
Inhibitory effect of TMBI to microbial growth was detected and the value for minimum inhibitory concentration (MIC) was 2.14mM. However, TMBT did not prevent the growth of microorganisms. Moreover, antimicrobial activity of ethyl, allyl, butyl, or phenyl isothiocyanate was assayed and each value for MIC was obtained.
From these results, it was concluded that TMBI, prepared from “Aokubi-Miyashige Daikon, ” was the highest in antimicrobial activity among 5 kinds of isothiocyanates examined.
