Solanidanes

The third and fourth isomerides, viz., the two aZZosolanidanols, were prepared from solanidone (A Solatubenone of Roehelmeyer A -solaniden-3-one), already deseribed (p. 663), by hydrogenation with platinised Raney niekel in an alkaline medium. The reaetion produet yielded aZZosolanidan-3(a)-ol and aZZosolanidan-3(jS)-ol. R probably also ineluded the two solanidanols sinee the unerystallisable residue on epimerisation by sodium in boiling xylene followed by preeipitation with digitonin, yielded some solanidan - 3( j8 )-ol. 

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... 

Figure 14.3 Potato glycoalkaloids. (a) is tomatine, a spirosolane and (b) solanine, a solanidane.

Potato GAs usually belong to one of two structural types, either solanidanes or spirosolanes (Figure 14.3). Solanine and chaconine, both solanidanes, often comprise upwards of 90% of the total GA complement of domesticated potatoes, with chaconine often more abundant than solanine (Griffiths et al., 1997 Sotelo and Serrano, 2000). 

The first naturally occurring 3/S-amino-solanidane alkaloid, solanogantine (C27H46N2O), has been isolated from S. giganteum 27 This non-crystalline base was... 

Solasodlns (spirosolane-type) Solanidine (solanidane-type)... 

Analogies with the above reactions have been pointed out (1), namely, with the internal acylations of dihydrocorynantheine (3) and solanidan-3-on-18-oic acid (4). 

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... 

Table 3. The Embryolethality and Teratogenicity of Jervanes, Spirosolanes, and Solanidanes... 

Tomatine is tomatidine-3/3-lycotetrose. The lycotetrose moiety has a galactose attached to the 3-hydroxyl-group of tomatidine that is substituted on its 4-hydroxyl by a glucose. This glucose is further substituted at its 2-hydroxyl by another glucose and at its 4-hydroxyl by a xylose. Structures for muldamine and 225,25R- solanidanes (representing solanidanes both saturated and unsaturated at C-S, C-6) are shown below. 

Properties. Demissine, C5oH s02 N, melts at 305-308° when recrystallized from methanol or ethanol [a]n — 20° (pyridine). Acid hydrolysis yields one mole each of D-xylose and D-galactose and two of D-glucose as well as demissidine, C27H<(ON which proved to be solanidan-3/3-ol (31). 

NOMENCLATUBE. The relationships in the steroids which find many counterparts in numerous solanidine derivatives suggest a rational nomenclature based on that of the steroids. The oxygen-free saturated compound V serves as the basic skeleton and is termed solanidane. This terminology will be used here, adopting the latest principles of steroid nomenclature (63). Instead of the earlier terms cis-, trans-, and alio-, the letters a, and J will be used to indicate configuration in the same way that they are used in the steroid group. 

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