A L K A L O I D S OF A c o n i t u m m o n t i c o l a

V. E . N e z h e v e n k o , M. S. Y u n u s o v , a n d S. Y u . Y u n u s o v

UDC 547.944/945

F r o m the roots of Aconitum mont icola (Kuyandysai, Dzhungarian Ala-Tau), which has not previously been investigated, we have isolated songorine, norsongorine, bases with mp 146-151°C (acetone) and with mp 155-160°C (acetone), and also a new alkaloid with rap 208-210°C (ace tone-methanol ) with the composit ion C2sHalNOy, tool. wt. 467 (mass spec t romet r ica l ly ) which we have called acomonine(I).

The base (I) contains an ethyl, four methoxy, and th ree hydroxyl groups. The acetylat ion of (I) with acet ic anhydride in pyridine gave a monoacetate (II) with rap 76-78°C (acetone), mol wt. 509. With p- to luene-

KBr sulfonyl chloride, acomonine gave anhydroacomonine 0II) with mp 129-132°C (acetone), IR spectrum: v max 3040 cm -1 (= CH); NMR spectrum: 5.82 ppm (1_ H, multiplet) and 5.32 ppm (1 H, doublet, J = 1 0 Hz); toOl. wt. 449. Substance 0]I) was hydrogenated by Adams method to deoxyacomonine (IV), tool wt. 451. Per iodate oxidation of anhydroacomonine led to secodemethanolanhydroacomonine (V) with mp 155-1580C (hexane- acetone); tool. wt. 415. Consequently, in acomonine one hydroxy group is secondary and two a re t e r t i a ry and they fo rm an a -g lyco l sys tem.

The resu l t s of a compar i son of the empir ica l and expanded formulas of acomonine show that its skele- ton consists of six rings. The IR spec t rum of (V) shows the absorpt ion bands of an c~,~-unsaturated ketone in a s i x - m e m b e r e d ring and of a ketone in a f i ve -membered ring at 1655 and 1735 cm -1, respect ively , and in the UV spec t rum there is a maximum at 232 nm (log ~ 3.87). The mass spec t rum of (V) is ve ry close to the spec t rum of demethylenesecodemethanoldeoxydelcor ine [1, 2]. These facts show that the base (I) con- tains the lycoctonine skeleton in which the d i t e r t i a ry o~-glycol sys tem is located at C 7 and C 8 and one meth- oxy group at C15.

The p re sence in the alkaloid of a skeleton consist ing of 19 carbon atoms and of one ethyl group, and \ \

the absence of p r i m a r y OH, NH, N-- CH3, a n d 7 c - oH3 groups shows that the ethyl group (NMR spectrum:

1.13 ppm, 3 H, triplet) is at tached to the ni trogen atom, and there is a methoxymethyl group at C a. In the mass spec t ra of alkaloids of the lycoctonine type, the maximum peak is, as a rule, fo rmed by the splitting off of the substituent f r om posit ion I [3, 4]. In the mass spec t rum of acomonine, the maximum is the peak of the M - 1 5 ion, as in the spec t rum of deoxycondelphine [3]. When (I) was t reated with KMnO 4 in aqueous acetone solution, anhydrooxyacomonine (VI) was formed, with mp 204-206°C (acetone), tool. wt. 465, the IR spec t rum of which showed absorpt ion bands at 900 and 1000 cm -1, which a re cha rac t e r i s t i c for internal eth- e r s of a - ca rb ino lamines [5]. Substance (VI) was reduced by sodium te t rahydrobora te to the initial base. Under the same conditions of oxidation, deoxyacomonine gave an oxo der ivat ive (VII), tool. wt. 465, with a lac tam carbonyl in a s i x -membered ring (v mK-Ba~ 1630 era-l). The mass spec t ra of acomonine [M--15 (100%), M--17 (43%)], its anhydraoxy der ivat ive [M-15 (100%)], and its monoacetate (II) [M-59 (100%)] and the facts given above pe rmi t the second hydroxy group to be located at C a. This is confirmed by the NMR spec t rum of (IlI) and also by the nature of the splitting of the signal of the hydroxy group of the geminal proton in the NMR spec t rum of (II) (4.7 ppm, 1 H, quadruplet, JAX=7 Hz, JBX--- 10 Hz).

The NMR spec t rum of acomonine has the signal of the geminal proton to the Cl0 methoxy group (3.6 ppm, 1 H, triplet, J ~ 5 Hz), showing the absence of substituents at C 9 and Cli [6].

On the basis of the above facts , the following par t ia l s t ruc tu re is proposed for acomonine:

Order of the Red Banner of Labor Insti tute of the Chemis t ry of Plant Substances of the Academy of Sciences of the Uzbek SSR. Trans la ted f rom Khimiya Pr i rodnykh Soedinenfi, No. 3, pp. 409-410, May-June, 1974. Original a r t ic le submitted September 14, 1973.

© 1975 Plenum Publishing Corporation, 227 ICest 17th Street, New York, N. Y. 10011. No part o f this publication may be reproduced, stored in a retn'eval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission o f the publisher. A copy o f this article is available from the publisher for $15.00.

416

~ OCH l

f, >" , \ '" , t " , ~ oci+ r

• ~ ~-OCHa',Ox

Work on determining the s t ruc tu re of acomonine is continuing.

1. 2.

3. 4. 5. 6.

L I T E R A T U R E C I T E D

A. S. NarzuUaev, M. S. Yunusov, and S. Yu. Yunusov, Khim. Pr i rodn. Soedin., 497 (1973). A. S. Narzullaev, M. S. Yunusov, and S. Yu. Yunusov, Khim.-Pr i rodn. Soedin., 412 (1974) [in this issue, p. 420]. M. S. Yunusov, Ya. V. Rashkes, V. A. Tel 'nov, and S. Yu. Yunusov, Khim. Pr i rodn. Soedin., 515 (1969). M. S. Yunusov, Ya. V. Rashkes, and S. Yu. Yur~sov, Khim. Pr i rodn. Soedin., 86 (1972}. R. Anet, D. Clayton, and L. Marion, Can. J. Chem., 35, 397 (1957). M. S. Yunusov and S. Yu. Yunusov, Khim. Pr i rodn. Soedin., 335 (1970).

417