The composition of visnadin

THE COMPOSITION V. I. OF VISNADIN Sheichenko and UDC 577.15/17 V. V. Vandyshev Visnadin was obtained in the f o r m of a c i c u l a r c y r s t a l s with mp 85-87°C (from p e t r o l e u m ether; Kofler block); its IR s p e c t r u m was identical with that given by Kuznetsova [1l. In an examination of its NMR s p e c t r u m , a f o r m of the signal f r o m the proton at C4" which is unusual f o r the s p e c t r a of a c y l c o u m a r i n s of the khellactone group can be seen (Fig. 1). The s m a l l e r splitting of this signal cannot be due to the s p i n - s p i n coupling of H4* with the other protons of the m o l e c u l e , since the components of the q u a r t e t have v e r y diff e r e n t intensities, in spite of the l a r g e c h e m i c a l shifts between the signals. This f o r m of the q u a r t e t has p e r m i t t e d the a s s u m p t i o n that the s u b s t a n c e contains a n o t h e r c o u m a r i n as an i m p u r i t y to which a doublet of l o w e r intensity c o r r e s p o n d s . The s i m i l a r c h r o m a t o g r a p h i c b e h a v i o r s of visnadin and d i h y d r o s a m i d i n [2] and the fact that they a r e both p r e s e n t in the raw m a t e r i a l [2, 3] indicated that this i m p u r i t y could be dihydrosamidin. In actual fact, the addition of d i h y d r o s a m i d i n to visnadin in a ratio of 1 : 1 led to an i n c r e a s e in the intensity of the signal f r o m the Ca* proton of dihydrosamidin, and all the o t h e r signals of t h e s e s u b s t a n c e s in the a r o m a t i c region of the s p e c t r u m coincided. A calculation of the intensities of the two doublets f r o m the Ca* proton in the s p e c t r u m of visnadin showed that it contained 20% of d i h y d r o s a m i d i n . The f u r t h e r purification of the visnadin by r e c r y s t a l l i z a t i o n did not give a p u r e product. The amount of dihydrosamidin p r e s e n t shows that the a c i c u l a r c r y s t a l s of visnadin [2-6] probably c o n s i s t of four m o l e c u l e s of visnadin and one m o l e c u l e of dihydrosamidin which, apparently, f o r m a c r y s t a l lattice. The difficulty of obtaining visnadin in the p u r e s t a t e is p r o b a b l y connected with this phenomenon. it, ~1 H5 H6 U,,4'" H3 1o 9 8 7 6 1"3' 5 l~,umL 4 3 2 i o ppm Fig. 1. NMR s p e c t r u m of visnadin (CCla, 100 MHz). LITERATURE 1. 2. 3. 4. 5. 6. G. G. E. H. A. F. CITED A. Kuznetsova, Natural C o u m a r i n s and F u r o c o u m a r i n s [in Russina], L e n i n g r a d (1967). K. Nikonov and V. V. Vandyshev, Khim. Prirodn. Soedin., 5, 118 (1969). Smith, N. Hosansky, W. G. B y w a t e r , and E. T a m e l e n , J. A m e r . Chem. Soc., 7__99,No. 13, 3534 (1957). D. Schroeder, W. Bencze, and O. Halpern, Chem. B e r . , 92, 2338 (1959). Mustafa, N. A. Starkovsky, and T. I. Salama, J. Org. Chem., 2__66,No. 3 8 9 0 (1961). G. Baddar, S. F a r i d , and N. A. Starkovsky, J. C h e m . Soc., 4522 (1963). All-Union S c i e n t i f i c - R e s e a r c h Institute of Medicinal Plants. T r a n s l a t e d f r o m Khimiya Prirodnykh Soedinenii, No. 3, pp. 368-369, May:June, 1971. Original a r t i c l e submitted J a n u a r y 29, 1971. © 1973 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoeve~ without permission of the publisher. A copy of this article is available from the publisher for $15.00. 343  (...truncated)