9β-Pimarane Diterpenes from the Tuber of Icacina trichantha

MM Onakpa; T Gödecke; M Zhao; BD Santarsiero; AI Uzoma; CT Che

doi:10.1055/s-0033-1348684

Planta Medica, Inhaltsverzeichnis

9β-Pimarane Diterpenes from the Tuber of Icacina trichantha

MM Onakpa ¹, T Gödecke ¹, M Zhao ¹, BD Santarsiero ², AI Uzoma ³, CT Che ¹

¹Department of Medicinal Chemistry and Pharmacognosy, and WHO Collaborating Center for Traditional Medicine, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612
²Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, Chicago, IL 60607
³Department of Veterinary Physiology and Pharmacology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria

Abstract

The tuber of Icacina trichantha Oliv. (Icacinaceae) is a home remedy used to treat constipation, poisoning, malaria and to induce emesis in Nigeria. The antidiabetic potentials of its extracts have been reported. In the present study, four 9β-pimarane (9β-podocarpane) diterpenes were isolated from the tuber extract. The structures were elucidated by means of NMR and HR-MS. The planar structures of 1 and 2 were consistent with those of icacinol and humirianthenolide C, respectively, which have been found in other plant sources, and 3 and 4 are new natural products. The relative stereochemistry of the isolates was determined by NOE experiments; and the stereochemistry of 1 was found to be different from that of icacinol through X-ray diffraction analysis.