Solanidane alkaloids structure

The structural features of the solanum alkaloids are based on two primary skeletal configurations solanidane, with or without glycoside functionalities, as featured by the toxic and teratogenic steroidal alkaloids a-chaconine and a-solanine with the indolizidine type E-F ring (Figure 2.7a) and the spirosolane... 

In other studies, solanidane-induced teratogenicity was proposed to depend upon C-22 configuration, c/Fig, (10), and the teratogenicity of epimeric solanidanes was suggested to correlate with the direction in which the unshared pair of electrons on the nitrogen atom projects relative to the steroidal plane [S2]. Earlier structure - terata relations of plant steroidal alkaloids have been summarized [S3]. 

Appendix) is graphically emphasized in Fig. (11) with values of the relative teratogenic potency of individual steroidal alkaloids from Table 2 placed adjacent to their structural type. The variance in values for the jervanes, solanidanes, and spirosolanes primarily reflects the level of saturation at C-5, C-6 e.g., 100 vs. 40 for jervanes, 32 vs. 9 for solanidanes, and 6 vs. 4 for spirosolanes. In each instance the higher value... 

The most significant chemical progress in the last 10 years is the finding that in addition to the long known alkaloids with spirosolane and solanidane skeleton there are a number of new ones which represent novel types of structure (II, IV, V). Extensive investigations have progressed further to establish the complete stereochemistry of the alkaloids as well as to confirm these statements by a number of new partial and total syntheses. 

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