ARS | Publication request: Echinopsacetylenes A and B, new thiophenes from Echinops transiliensis

Submitted to: Organic Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 15, 2011
Publication Date: November 8, 2011
Citation: Nakano, H., Cantrell, C.L., Mamonov, L.K., Osbrink, W.L., Ross, S. 2011. Echinopsacetylenes A and B, new thiophenes from Echinops transiliensis. Organic Letters. 13(23):6228-6231.

Interpretive Summary: Many Echinops and Tagetes species have been investigated resulting in the isolation of many bioactive thiophenes. In our continuing study of the thiophenes from Echinops species, we isolated two new compounds from Echinops transiliensis. Echinopsacetylene A is the first natural product possessing an alpha-terthienyl moiety covalently linked with another thiophene moiety, which is essentially a new carbon skeleton. Echinopsacetylene B is the first natural thiophene conjugated with a fatty acid moiety. One of the compounds, echinopsacetylene A, showed toxicity against the Formosoan subterranean termite (Coptotermes formosanus

Technical Abstract: Two new polyacetylene thiophenes, echinopsacetylenes A and B (1 and 2), were isolated from the root of Echinops transiliensis. The structures of 1 and 2 were elucidated on the basis of spectroscopic analyses and chemical transformations. Echinopsacetylene A (1) is the first natural product possessing an '-terthienyl moiety covalently linked with another thiophene moiety. Echinopsacetylene B (2) is the first natural thiophene conjugated with a fatty acid moiety. Echinopsacetylene A (1) showed toxicity against the Formosoan subterranean termite (Coptotermes formosanus).