Planta Med 2014; 80 - PD109
DOI: 10.1055/s-0034-1382530

Bioactive pimarane diterpenes from Icacina trichantha

MM Onakpa 1, 2, M Zhao 1, T Gödecke 1, WL Chen 1, SM Swanson 1, AI Uzoma 2, CT Che 1
  • 1Department of Medicinal Chemistry and Pharmacognosy, and WHO Collaborating Center for Traditional Medicine, University of Illinois at Chicago, Chicago, IL60612, USA
  • 2Department of Veterinary Physiology and Pharmacology, University of Nigeria, Nsukka, Nigeria

Further to our previous report on the isolation and X-ray crystallographic structures of two 9βH-pimaranes (icacinol 2 and humirianthol 3) from the tubers of the African medicinal plant Icacina trichantha, compounds 1, 4 and 5 were obtained. Compound 1 was elucidated to be a new 17-hydroxyl derivative of icacinol. The absolute configuration was established by comparison with 2. Compounds 4 and 5 are 17-nor-9βH-pimaranes, identified to be humirianthenolide C and icacenone, respectively. All isolates displayed cytotoxic activity in the human melanoma MDA-MB-435 cells (IC50= 0.66 – 6.44µM), while 2, 3, and 4 also exhibited cytotoxicity in the human colon cancer HT-29 cells (IC50= 3.00 – 4.94µM).

Fig. 1