sp. et al. 2005). Today it really is accepted that is made up of 13 carefully related understory shrubs or little tree varieties (Peters et al. 2005 which occur also in the damp TOK-001 forests from the Amazon Basin and the low elevations of mountainous regions of Peru Ecuador Colombia Venezuela and Brazil (7 varieties) and Panama (1 varieties) (Peters et al. 2005 (Maguire & Weaver 1975) researched herein is wide-spread in wet exotic forests from the central and eastern area of the Amazon Basin and northwestern SOUTH USA and from French Guyana and Suriname in the north to central elements of the condition of Amazonas (AM) in Brazil towards the western and south [see map in Peters et al. (2005)]. – Ethnobotanical and ethnopharmacological publications have described the traditional uses of spp as antimalarials and febrifuges in The Guyanas Brazil Colombia and Peru (Milliken 1997). However in many Brazilian (Carvalho & Krettli 1991 Brand?o et al. 1992 Milliken 1997 Mors et al. 2000 Krettli et al. 2001) Colombian (Schultes & Raffauf 1990) and Peruvian (Milliken 1997) studies the plants collected are incorrectly identified as the type species of the genus Aubl. – We became interested in studying the local herb based on earlier reports by the Dr Antoniana Krettli group (Oswaldo Cruz Foundation state of Minas Gerais Brazil) in which the water extract of roots of a sp. exhibited significant in vivo activity in a mouse model of malaria. spp are rare sparsely populated plants in the Amazon forests. We initially conducted studies TOK-001 TOK-001 around the propagation of this herb from stem cuttings (Silva et al. 2006). Pio Corrêa (1926) reported that extracts were toxic. Polar extracts of were not toxic to in the brine shrimp assay (Quignard et al. 2003). In another study extracts of at 500 μg/mL exhibited moderate toxicity (7-64% lethality) to larvae of (Pohlit et al. 2004 Also extracts of were highly active inhibitors of the growth of cancer tumour cell lines (Pohlit et al. 2007). Antimalarial plants such as are potential sources of drug leads against spp (Andrade-Neto et al. 2007 Schmidt et al. 2012a b). Recently we isolated the tetra-oxygenated xanthone decussatin (1) and a rare seco-iridoid monoterpene aglycone djalonenol (amplexine) (2) from ( Pohlit et al. 2012). In the present work the in vitro and in vivo Plxnc1 antiplasmodial activity and cytoxicity of the extracts fractions and chemical components of the leaves and roots of the central Amazonian herb were investigated. Spectroscopic characterisation of the isolates 1 and 2 is also presented. MATERIALS AND METHODS – All solvents used for extraction partitioning and chromatography were fractionally distilled prior to use. Solvents for NMR were purchased from Sigma-Aldrich (St. Louis USA). – Medium pressure liquid chromatography (MPLC) was performed using a Büchi System with Pump model 688 Gradient Former model 687 ultraviolet visible spectroscopy and fraction collector model 684 and a normal phase column with 40-63 μm particle size. 1 H-NMR 13 C-NMR DEPT 135 1 H- 1 H COSY and HMQC spectra were acquired on a Bruker DPX 300 (300 MHz) in CDCl 3 /TMS or (CD 3) 2 CO/TMS. FT-IR spectra had been acquired on the Bomem model M 102 spectrometer. Electronic ionization-gas chromatography-mass spectrometry (EI-GC-MS) was performed on the Hewlett-Packard Horsepower 5890 series gas chromatograph combined to mass detector Horsepower 5971 working at an ionization energy of 70 eV. – Seed materials were gathered in Sept and Oct TOK-001 2000 in Country wide Institute for Amazonian Research’s (INPA) Campina and Adolpho Ducke Forest Reserves which can be found in better Ma-naus AM. Voucher specimens had been deposited on the INPA Herbarium beneath the accessions 208104 (collector AM Pohlit) and 205948 (collector AM Pohlit). Id from the seed examples as Maguire and Weaver (Gentianaceae) was corroborated by LS (co-author of today’s paper). Root base and mature leaves were dried in the tone and surface to great powders separately. – Dried out powdered root base were regularly extracted within a Soxhlet equipment with methanol (3 × 6 h). The.