Bioactivity and cysteine sulphoxides of some wild Allium species from Central Asia

Abstract

The very diverse genus Allium L. shows a nearly exclusive distribution across the northern hemisphere with a main centre of diversity in Southwest and Central Asia. Rhizomes or bulbs, extracts of those or green parts of several species are intensively used by the native population of Central Asia [1]. Investigations concerning radical scavenger activity and antibiotic activity were focused on the subgenera Allium, Rhizirideum, and Melanocrommyum. Remarkable high scavenger activity (larger than 100%, related to BHT standard) was reported for A. giganteum Regel, A. alaicum Vved. and A. komarowii Lipsky, all belonging to the subgenus Melanocrommyum. But also an extract obtained from A. pskemense B. Fedt., a close relative of common onion (A. cepa L.), exhibited a high radical scavenger activity. Cysteine sulphoxides of investigated species were also analysed and correlated with results for bioactivity testing. These substances might be responsible for radical scavenger activity but also other compounds must be considered. Antibiotic activity was visualized by an inhibition zone surrounding a filter paper soaked with ethyl acetate extracts. Of all tested samples, A. rosenorum was most active despite this species showed rather low (about 0.1%) cysteine sulphoxide content. Extracts of A. aff. cristophii were only active against Streptococcus pyogenes. A. hymenorrhizum Ledeb. was rich in cysteine sulphoxides and showed an antibacterial activity against most of the tested bacteria strains. Also antifungal and antialgal activities were found.