ANTIMICROBIAL ACTIVITIES OF SULFUR COMPOUNDS DERIVED FROM S-ALK (EN) YL-L-CYSTEINE SULFOXIDES IN ALLIUM AND BRASSICA

Abstract

Allium and Brassica vegetables have long been known for their antimicrobial activity against various microorganisms, including Gram-positive and Gram-negative bacteria and fungi. Most microorganisms tested were sensitive to extracts of the Allium and Brassica vegetables and the degree of sensitivity varied depending on the strain under study and test conditions. Among the vegetables, garlic showed the most potent activity, followed by onion. Brassica, including cabbage, showed the least potent activity. The principal antimicrobial compounds of Allium and Brassica have been elucidated as allicin (S-allyl-L-propenethiosulfinate) and methyl methanethiosulfinate, respectively. Both compounds belong to the same chemical group, thiosulfinate, generated from S-allyl and S-methyl derivatives of L-cysteine sulfoxide, respectively, existing in Allium and Brassica as major non-protein sulfur-containing amino acids. There have been only few applications of garlic as a natural food preservative, in spite of numerous studies on antimicrobial activity of the vegetables. Relative instability of the antimicrobial compounds and the strong odor of their mother plants seem to limit the use of them as a practical food preservative.

Keywords:

• Antimicrobial activity
• S-Alk(en)yl-L-cysteine sulfoxide
• Garlic
• Cabbage
• Allium
• Brassica

ACKNOWLEDGMENT

This work was supported by the Brain Korea 21 Project.