Activity-guided fractionation of the leaves of Macaranga triloba, using an in vitro bioassay based on the inhibition of cyclooxygenase-2, resulted in the isolation of a rotenoid, 4,5-dihydro-5′α-hydroxy-4′α- methoxy-6a,12a-dehydro-α-toxicarol (1), as well as 12 known compounds, (+)-clovan-2β,9α-diol, ferulic acid, 3,7,3′,4′- tetramethylquercetin, 3,7,3′-trimethylquercetin, 3,7-dimethylquercetin, abscisic acid, 1β,6α-dihydroxy-4(15)-eudesmene, 3β-hydroxy-24- ethylcholest-5-en-7-one, loliolide, scopoletin, taraxerol, and 3-epi-taraxerol. The structure of compound 1 was determined using spectroscopic methods. All isolates were evaluated for their potential to inhibit cyclooxygenases-1 and -2 by measuring PGE2 production, and to induce quinone reductase in cultured Hepa 1c1c7 mouse hepatoma cells.
Bibliographical noteFunding Information:
We thank Dr. K. Fagerquist, Mass Spectrometry Facility, Department of Chemistry, University of Minnesota, Minneapolis, MN, and Drs. J. A. (Art) Anderson and Y. Wang, Research Resources Center (RRC), University of Illinois at Chicago (UIC), for the mass spectral data. We are grateful to the RRC, UIC, for providing spectroscopic equipment, and to Dr. R. A. Kleps of the RRC, UIC, for facilitating the running of the 500 MHz NMR instrument. This research was supported by program project P01 CA48112, funded by the National Cancer Institute, NIH, Bethesda, MD.
- 4,5-Dihydro-5′α- hydroxy-4′α-methoxy-6a,12a-dehydro-α-toxicarol
- Cyclooxygenases-1 and -2
- Macaranga triloba
- Quinone reductase