Furanocoumarin with Phytotoxic Activity from the Leaves of Amyris elemifera (Rutaceae)

Kumudini M Meepagala; Amy K Bracken; Frank R Fronczek; Robert D Johnson; David E Wedge; Stephen O Duke

doi:10.1021/acsomega.0c04778

Furanocoumarin with Phytotoxic Activity from the Leaves of Amyris elemifera (Rutaceae)

ACS Omega. 2020 Dec 24;6(1):401-407. doi: 10.1021/acsomega.0c04778. eCollection 2021 Jan 12.

Authors

Kumudini M Meepagala¹, Amy K Bracken^{1

2}, Frank R Fronczek³, Robert D Johnson¹, David E Wedge¹, Stephen O Duke¹

Affiliations

¹ United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research Unit, P.O. Box 1848, University, Mississippi 38677, United States.
² Sally McDonnell Barksdale Honors College, University of Mississippi, University, Mississippi 38677, United States.
³ Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States.

Abstract

Bioassay-guided fractionation of the ethyl acetate extract of Amyris elemifera leaves was carried out to identify phytotoxic and antifungal constituents. A novel phytotoxic furanocoumarin 8-(3-methylbut-2-enyloxy)-marmesin acetate (1) and its deacyl analog 8-(3-methylbut-2-enyloxy)-marmesin (2) were isolated. The X-ray crystal structure determination is reported for the first time for 1. Both 1 and 2 have the S configuration at C-2' based on X-ray crystallographic data. Both these compounds inhibited the growth of the dicot Lactuca sativa (lettuce) and the monocot Agrostis stolonifera with a more pronounced inhibitory effect on the monocots at 330 μM by 1. In Lemna paucicostata Hegelm phytotoxicity bioassay, the IC₅₀ value for 1 was 26 μM, whereas 2 had an IC₅₀ value of 102 μM. Compounds 1 and 2 were weakly antifungal against Colletotrichum fragariae Brooks in TLC bioautography.