Fitoterapia. 2014 Aug 27;
Authors: Radwan MM, Tabanca N, Wedge DE, Tarawneh AH, Cutler SJ
The antifungal activity of twenty-two common spices were evaluated against plant pathogens using direct-bioautography coupled Colletotrichum bioassays. Turmeric, nutmeg, ginger, clove, oregano, cinnamon, anise, fennel, basil, black cumin, and black pepper showed antifungal activity against the plant pathogens Colletotrichum acutatum, C. fragariae, and C. gloesporioides. Among the active extracts, turmeric and nutmeg were the most active and were chosen for further investigation. The bioassay-guided fractionation led to the isolation of three compounds from turmeric (1-3) and three compounds from nutmeg (4-6). Their chemical structures were elucidated by spectroscopic analysis including HR-MS, 1D, and 2D NMR as curcumin (1), demethoxycurcumin (2) and bisdemethoxy-curcumin (3), erythro-(7R,8R)-Δ(8`)-4,7-dihydroxy-3,3`,5`-trimethoxy-8-O-4`-neolignan (4), erythro-(7R,8R)-Δ8`-7-acetoxy-3,4,3`,5`-tetra-methoxy-8-O-4`-neolignan (5), and 5-hydroxy-eugenol (6). The isolated compounds were subsequently evaluated using a 96-well microbioassay against plant pathogens. At 30μM, compounds 2 and 3 possessed the most antifungal activity against Phomopsis obscurans and P. viticola, respectively.
PMID: 25173461 [PubMed – as supplied by publisher]