Isolation of β-asarone, an antibacterial and anthelmintic compound, from Acorus calamus in South Africa

The aromatic rhizomes of Acorus calamus L. are used extensively in traditional medicine worldwide. They reportedly relieve stomach cramps, dysentery and asthma, and are used as anthelmintics, insecticides, tonics and stimulants. Alcoholic rhizome extracts of A. calamus growing in KwaZulu-Natal, South Africa, were previously found to have anthelmintic and antibacterial activity. Using bioassay-guided fractionation, the phenylpropanoid β-asarone was isolated from the rhizome. This compound was shown to possess anthelmintic and antibacterial activity. It has previously been isolated from A. calamus, and a related species, A. gramineus. Different varieties of A. calamus exhibit different levels of β-asarone, with the diploid variety containing none of the compound. Mammalian toxicity and carcinogenicity of asarones has been demonstrated by other researchers, supporting the discouragement of the medicinal use of Acorus calamus by traditional healers in South Africa.