Original scientific paper

Crystal and Molecular Structure of 3B-Hydroxy-14,15B-epoxy- 5'B,14B-card-20,22-enolide (Digirezigenin)

Alajos Kalman ; Central Research Institute for Chemistry, Hungarian Academy of Sciences, Budapest - 114, POB. 17, H-1525, Hungary
Gyula Argay ; Central Research Institute for Chemistry, Hungarian Academy of Sciences, Budapest - 114, POB. 17, H-1525, Hungary
Bela Ribar ; Institute of Physics, Faculty of Sciences, Ilije Djuriciea 4, 21000 Novi Sad, Yugoslavia
Sote Vladimirov ; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, 11000 Beograd Yugoslavia
Dobrila Živanov-Štakic ; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, 11000 Beograd Yugoslavia

Abstract

The title compound C23H3204 and its methyl-suberate ester
were discovered in Ch'an Su, the dried venom of the Chinese
toad. Its crystals are orthorhombic, space group P21212i, and quasi-
isostructural with those of the related compound digitoxigenin
(C23H340 4) . The structure was solved by direct methods and refined
by least squares technique to a conventional R index of 0.059 for
2271 unique diffractometer observations. The presence of the rigid
14, 15~-epoxy ring alters considerably the shape of ring D (17E)
relative to that in digitoxigenin (14E). However, it has little effect
upon the general features of the 14-iso-aethiocholane skeleton and
the conformation of the y-lactone ring. The amount of rotation
about the C(l 7)-C(20) bond is hardly changed while the distance
between the position of the carbonyl O relative to digitoxigenin
is only 33.2 pm. The conformation of the title compound is also
compared with that of a bufa-20, 22-dienolide (cinobufagin) which
also possesses a 14, 15~-oxirane ring.

Keywords

Hrčak ID:

194122

URI

https://hrcak.srce.hr/194122

Publication date:

20.10.1984.

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