Antitubercular Natural Products: Berberine from the Roots of Commercial <i>Hydrastis </i><i>c</i><i>anadensis </i>Powder. Isolation of Inactive 8-Oxotetrahydrothalifendine, Canadine, β-Hydrastine, and Two New Quinic Acid Esters, Hycandinic Acid Esters-1 and -2

Abstract

Berberine (4) is responsible for the activity of an extract of a commercial root sample of Hydrastis canadensis against multiply drug resistant Mycobacterium tuberculosis. Two new quinic acid feruloyl esters, compounds 2 and 3, have been isolated from the same source along with canadine (1c), 8-oxotetrahydrothalifendine (1), and beta-hydrastine (5). These were found to be inactive. The structures of the new compounds were elucidated from spectral (1H, 13C, HMQC, HMBC, and H-H COSY) and chemical evidences.