Introduction Two plants with antimalarial activity, Ficus fistulosa Reinw. ex Blume (Moraceae) and Rhaphidophora decursiva Schott (Ara- ceae), were collected in the Cuc Phuong National Park (Nho Quan District, Ninh Binh Province, Vietnam) as part of our Inter- national Cooperative Biodiversity Group (ICBG) project [1], [2]. Our initial study of F. fistulosa led to the identification of two new and five known triterpenes, none of which demonstrated antimalarial activity [3]. A continued investigation of the active fraction of F. fistulosa unexpectedly yielded a trichothecene, ver- rucarin L acetate, as the active antimalarial compound. Our pre- vious chemical and biological investigation of R. decursiva led to the isolation of several antimalarial compounds having IC 50 val- ues in the range of 0.35 ± 6.5 mg/mL with the W2 (chloroquine- resistant) and D6 (chloroquine-sensitive) clones of Plasmodium falciparum [4], [5]. However, these levels of activity did not cor- relate proportionally with the activity of a minor fraction (F87), which inhibited the growth of D6 by 99.4% at a concentration of 5 ng/mL. A comparison of the spectral data of verrucarin L acet- ate isolated from F. fistulosa led to the identification of another trichothecene, roridin E, as the primary active antimalarial com- pound in fraction F87 of Raphidophoradecursiva. The current pa- per describes the isolation, identification and biological evalua- tion of these active trichothecenes. Materials and Methods Plant material The initial collection of leaf + stem bark samples of Ficusfistulosa Reinw. ex Blume (Moraceae) and leaf + stem samples of Antimalarial Agents from Plants. III. Trichothecenes from Ficus fistulosa and Rhaphidophora decursiva Hong-Jie Zhang 1 Pamela A. Tamez 1 Zeynep Aydogmus 1 Ghee Teng Tan 1 Yoko Saikawa 2 Kimiko Hashimoto 2 Masaya Nakata 2 Nguyen Van Hung 3 Le Thi Xuan 3 Nguyen Manh Cuong 4 D. Doel Soejarto 1 John M. Pezzuto 1 Harry. H. S. Fong 1 Affiliation 1 Program for Collaborative Research in Pharmaceutical Sciences, m/c 877, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, the University of Illinois at Chicago, Chicago, Illinois, USA 2 Faculty of Science and Technology, Department of Applied Chemistry, Keio University, Kohoku-ku, Yokohama, Japan 3 Institute of Chemistry, National Center for Science and Technology, Nghia Do, Tu Liem, Hanoi, Vietnam 4 Cuc Phuong National Park, Nho Quan District, Ninh Binh Province, Vietnam Correspondence Professor Harry H. S. Fong ´ Program for Collaborative Research in the Pharmaceutical Sciences, M/C 877 ´ College of Pharmacy ´ University of Illinois at Chicago ´ 833 S. Wood St. ´ Chicago, IL 60612 ´ USA ´ E-mail: hfong@uic.edu ´ Fax:+1-312-413-5894 Received April 25, 2002 ´ Accepted July 28, 2002 Bibliography Planta Med 2002; 68: 1088±1091 ´  Georg Thieme Verlag Stuttgart ´ New York ´ ISSN 0032-0943 Abstract Bioassay-directed fractionation of an extract prepared from the dried leaves and stem barks of Ficus fistulosa Reinw. ex Blume (Moraceae) led to the isolation of verrucarin L acetate (1), to- gether with 3a-hydroxyisohop-22(29)-en-24-oic acid, 3b-glu- co-sitosterol, 3,4-dihydro-6,7-dimethoxyisocarbostyril, 3,4,5- trimethoxybenzyl alcohol, a-methyl-3,4,5-trimethoxybenzyl alcohol, indole-3-carboxaldehyde, palmanine, and auranti- amide acetate. Roridin E (2) was identified in a subfraction from the dried leaves and stems of Rhaphidophora decursiva Schott (Araceae). Verrucarin L acetate and roridin E were char- acterized as macrocyclic trichothecene sesquiterpenoids and found to inhibit the growth of Plasmodium falciparum with IC 50 values below 1 ng/ml. Keywords Ficus fistulosa ´ Moraceae ´ Rhaphidophora decursiva ´ Araceae ´ antimalarial activity ´ bioassay-directed fractionation ´ tricho- thecene sesquiterpenoids ´ verrucarin L acetate ´ roridin E Original Paper 1088 Heruntergeladen von: University of Georgia Libraries. Urheberrechtlich geschützt.