title: Anti-mycobacterial diynes from the Canadian medicinal plant Aralia nudicaulis.
abstract: BACKGROUND
  Aralia nudicaulis, or wild sarsaparilla, is used as a traditional medicinal plant for the treatment of various illnesses by many of the Canadian First Nations. Iroquois and Algonquin First Nations of Eastern Canada use a tea prepared from dried Aralia nudicaulis rhizome as a cough medicine and for the treatment of tuberculosis. Previous investigations of aqueous extracts of Aralia nudicaulis rhizomes have shown it to possess antimycobacterial activity.
  
  
  OBJECTIVE
  To isolate and identify antimycobacterial constituents from Aralia nudicaulis rhizomes.
  
  
  METHODS
  Methanolic extracts of Aralia nudicaulis rhizomes were subjected to bioassay guided fractionation using the microplate resazurin assay (MRA) to assess inhibitory activity against Mycobacterium tuberculosis strain H37Ra. The antimycobacterial constituents were identified by NMR, MS and polarimetry.
  
  
  RESULTS
  Two C17 polyacetylenes with significant antimycobacterial activity were isolated from the Aralia nudicaulis rhizome extract. The polyacetylenes were identified as (3R)-falcarinol and (3R, 9R, 10S)-panaxydol. Falcarinol and panaxydol displayed MICs of 25.6μM and 36.0μM and IC(50)s of 15.3μM and 23.5μM against Mycobacterium tuberculosis H37Ra.
  
  
  CONCLUSIONS
  Falcarinol and panaxydol were identified as the principal constituents responsible for the antimycobacterial activity of Aralia nudicaulis rhizomes validating an ethnopharmacological use of this plant by the Canadian First Nations.
authors.affiliation: Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5.
authors.forename: Haoxin
authors.initials: H
authors.lastname: Li
authors.forename: Taryn
authors.initials: T
authors.lastname: O'Neill
authors.forename: Duncan
authors.initials: D
authors.lastname: Webster
authors.forename: John A
authors.initials: JA
authors.lastname: Johnson
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Gray
mesh_terms: D000995:Antitubercular Agents / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D027983:Aralia / Q000737:chemistry*; D002170:Canada; D053280:Diynes / Q000302:isolation & purification / Q000494:pharmacology*; D005233:Fatty Alcohols / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D007198:Indians, North American; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D027343:Rhizome; D014376:Tuberculosis / Q000188:drug therapy*
chemical_list: D000995:Antitubercular Agents; D053280:Diynes; D005233:Fatty Alcohols; D010936:Plant Extracts; C018541:falcarinol; C055778:panaxydol