Pangelin, an Antimycobacterial Coumarin from Ducrosia anethifolia

The aerial parts of Ducrosia anethifolia afforded the monoterpene glucoside 8-debenzoylpaeoniflorin (1) and the prenylated furanocoumarin pangelin {5-[2′′(R)-hydroxy-3′′-methyl-3′′-butenyloxy]furocoumarin} (2). Their structures were determined by extensive 1- and 2-dimensional NMR studies. Compound 2 demonstrated activity against a panel of fast growing mycobacteria, namely Mycobacterium fortuitum, M. aurum, M. phlei and M. smegmatis and minimum inhibitory concentration (MIC) values ranged from 64 - 128 μg/mL. Whilst compounds 1 and 2 have previously been reported as an antihyperglycaemic component from Paeonia lactiflora, and as a constituent of Angelica pancici, respectively, this is the first report of the full 1H- and 13C-NMR data for these natural products.