(±)-Zanthonitidine A, a Pair of Enantiomeric Furoquinoline Alkaloids from Zanthoxylum nitidum with Antibacterial Activity

A pair of new enantiomeric furoquinoline alkaloids, (±)-zanthonitidine A ( 1 ), together with nine known ones ( 2 – 10 ) were isolated from the radix of Zanthoxylum nitidum . Their chemical structures were elucidated based on the extensive spectroscopic analysis. The racemic mixture of 1 was separated by chiral column chromatography, and the absolute configurations of (+)- 1 and (−)- 1 were determined by the comparison of experimental and calculated electronic circular dichroism spectra. Antibacterial activities of compounds 1 – 9 were evaluated, and compounds (+)- 1 , (−)- 1 , 3 , 7 and 8 showed antibacterial activities against Bacillus subtilis , Enterococcus faecalis or Staphylococcus aureus . Graphical Abstract