Inhibition of Amino Acid Decarboxylase Activity of Enterobacter aerogenes by Active Components in Spices.

The water and ethanol extracts of several commercially available spices were examined for their inhibitory action on the decarboxylase activity of a crude extract of Enterobacter aerogenes . The water extracts had a negligible effect on histidine decarboxylase activity, except for water extract of cloves which reduced the activity by about 40%. However, the ethanol extracts had a rather higher inhibitory action upon histidine, lysine, and ornithine decarboxylases. Of the spices used, cloves, cinnamon, sage, nutmeg, and allspice were very effective in inhibiting the decarboxylases. Among the components of those spices, cinnamaldehyde and eugenol were found to be effective inhibitors.