Pergamon 0031-9422 (95)00152-2 Phytochemistry, Vol. 40, No. 2, pp. 587 591, 1995 Copyright © 1995 Elsevier Science Lid Printed in Great Britain. All rights reserved 0031 9422/95 $9.50 + 0.00 ALKALOIDS FROM LEAVES AND STEM BARK OF ER VATAMIA PEDUNCULARIS MONIQUE ZI~CHES-HANROT,* JEAN-MARC NUZILLARD, BERNARD RICHARD, HUBERT SCHALLER,t HAMID A. HADI,t THIERRY SI~VENET~"and LOUISETTE LE MEN-OLIVIER Facult6 de Pharmacie (U.R.A. au C.N.R.S. N°492), 51, rue Cognacq-Jay, 51096 Reims Cedex, France; l"Institut de Chimie des Substances Naturelles du C.N.R.S., 91198 Gif-sur-Yvette Cedex, France (Received in revised form 4 January 1995) Key Word lndex--Ervatamia peduncularis; Apocynaceae; leaves; stem bark; indole alkaloids; NMR. Abstract---Chemical study of the leaves and stem bark of Ervatamia peduncularis afforded two novel bisindole alkaloids, pedunculine and peduncularidine, together with seven known alkaloids, coronaridine, coronaridine hydroxyindolenine, eglandine, heyneanine, eglandulosine, heyneanine hydroxyindolenine and N(1)-methyl-aspidos- permidine. Structural elucidation of the new alkaloids was based on their spectral data. INTRODUCTION In the framework of our chemical studies on the genus Ervatamia [1-3,1, and of our collaborative research pro- gram between C.N.R.S. and the University of Malaya [41, we report herein our results on the alkaloidal con- tent of Ervatamia peduncularis [5,1. This species is a shrub 2.5 m tall whose roots are used in traditional medicine for the treatment of syphilis and of ulcerations of the nose [6,1. Plant material was collected at Genting Simpah 'Malaysia' and identified by two of the authors (H. S. and H. A. H.). RESULTS AND DISCUSSION The crude alkaloids were extracted and purified using a classical acid-base method. Isolation of alkaloids was performed by means of column chromatography and preparative TLC. Six known alkaloids were obtained from the crude alkaloid mixture (AM) of the stem bark. They are in increasing order of polarity, coronaridine (1) (10% AM), coronaridine hydroxyindolenine (2) (0.3% AM), eglandine (3) (2% AM), heyneanine (4) (44% AM), eglandulosine (5) (0.5% AM) and heyneanine hydroxyin- dolenine (6) (0.5% AM). In the AM of the leaves, we have isolated the known N(1)-methyl aspidospermidine (7) (2% AM) and two new bases for which we propose the trivial names, pedunculine (8) (17.9% AM) and pedun- cularidine (9) (15% AM). Compounds 1-5 and 7 were identified by comparison of their spectra (UV, IR, mass, NMR) and by co-TLC with reference samples. The structure of 6 was elucidated by comparison of its spectral data with those in the literature [7,1. However, *Author to whom correspondence should be addressed. assignments of carbons in the fragment C-9:C-12 differ; they were established by analysis of COSY and HMQC data. Inverting atoms at positions 9 and 12, and 10 and 11 also leads to coherent assignments. Structure 6 was proven by chemical correlation with heyneanine (4); oxi- dation of 4 with H20 2 [8] gave heyneanine hydroxyin- dolenine identical to 6. Isolation of 7 provided an opportunity for completing previous 1H and 13C NMR assignments [9, 10] by means of 2D NMR experiments. Its structure was confirmed by methylation of aspidospermidine [11], which gave a compound identical to 7. The new alkaloids 8 and 9 were obtained as purple amorphous solids and determination of their specific rotations was precluded due to the colour of their solu- tions. These two compounds possess many spectral ana- logies suggesting closely-related structures. Their com- plex UV spectra (2max ca 220, 260, 308, 333 rim) suggest the superimposition of anilinoacrylic and indoline chro- mophores. Their IR spectra display absorptions for a conjugated carbonyl group (v ca 1660 and 1600 cm- 1) and for OH and/or NH (v ca 3350 cm-t). The bisindolic nature of 8 and 9 was deduced from mass and 13C NMR spectra which gave 43 resonances for the two compounds in the latter (Table 2). Furthermore, 1H NMR spectra (Table 1) showed two ethyl side-chains (triplets at 60.8 and 0.75), three methyl singlets between 63.75 and 3.9 corresponding to one methyl ester and two aromatic methoxyl groups. Another methyl singlet at 62.8 is as- cribable to a N-methylgroup. The low-field region of these spectra displays one deshielded NH, at 68.75, the signals of an AMX system (br s: H-9', dd: H- 11' and d: H-12') and one shielded proton singlet at 65.75 in 8 and 5.85 in 9. These data suggest that one indole ring is substituted at C-10' while the other is trisubstituted. 587