Two new compounds and the anti-mycobacterial activity of the constituents from Zanthoxylum leprieurii root bark

The emergence of resistance to the existing TB drugs necessitated a search for new anti-mycobacterial compounds from Z. leprieurii root bark, which is used locally for the treatment of tuberculosis (TB) in Uganda. Two new compounds: (E)-N-isobutyl-3-(4-((3-methylbut-2-en-1-yl)oxy)phenyl)acrylamide (1) and 4-(5,5a,6,8,8a,9-hexahydrofuro[3′,4′:6,7]-naphtha[2,3-d][1,3]dioxol-5-yl)-2-methoxyphenol (2), were isolated from the dichloromethane (DCM) extract. In addition, sixteen known compounds were isolated from the DCM and methanol extracts. The structures of the isolates were elucidated by spectroscopic techniques and subjected to anti-mycobacterial activity testing using the microplate Alamar blue assay (MABA). Five compounds exhibited significant anti-mycobacterial activities against the susceptible (H37Rv) strain and could provide vital templates for developing new and highly effective TB drugs.