Solanidine structure

Solangustidine solangustine, 671 Solanidine, 661, 662, 671, 708, 712, 713 dehydrogenation products, 663 heterocyclic residue, 665 proximate derivatives, 664 structure, 665, 667 Solanine, 661... 

In commercial potatoes (Solanum tuberosum) there are two major glycoalkaloids, a-chaconine and a-solanine, both trisaccharides of the common aglycone solanidine. These two compounds comprise about 95% of the glycoalkaloids in potato tubers. Their hydrolysis products, the p and 7 forms and solanidine, may also be present in relatively insignificant concentrations. The structures of these glycoalkaloids and their hydrolysis products are presented in Figure 6.1. 

Fig. 7 Structure of the glykoalkaloids solanine and chaconine (aglycone solanidine). 

Solanidine and hapepunine have been isolated from Fritillaria verticillata, together with two new alkaloids, baimonidine (33a) and isoverticine (33b). The structures indicated were assigned mainly on the basis of the H and 13C n.m.r. spectra of the new alkaloids and were confirmed by the preparation of these alkaloids from verticinone (33c) by standard methods.70 The 13C n.m.r. spectra of a number of other cevanine derivatives have been reported.70 Fritillarine and a new alkaloid, C27H4303N, have been isolated from F. karelinii.71... 

Bulbs of F. camtschatcensis yielded solanidine (36a) together with traces of hapepunine (34a), veralkamine, an unidentified dihydroxy-spirosolane, and a new aglycon, i.e. camtschatcanidine (36b).54 The structure assigned to camtschat-canidine was deduced from the spectroscopic data, and in particular by comparison of its 13C n.m.r. spectrum with that of solanidine. The structure and stereochemistry proposed were proven by the reduction (by LiAlH4) of the O-acetyl-O-tosyl derivative (36c) of camtschatcanidine to yield solanidine. 

Structures of the steroidal alkaloids whose relative teratogenic potencies are listed in Table 2 and whose embryolethality and teratogenicity is recorded in Table 3 are provided as follows jervine (1), cyclopamine (2), tomatidine (4), and solasodine (6) are listed in the text. Structures for 22/ , 255-solanidine, a-solanine, and ct-chaconine are provided in Fig. (10). In solanidine-N-oxide, the electron pair on the nitrogen atom of solanidine in Fig. (10) is replaced by an oxygen atom. Dihydrosolanidine refers to solanidine with a reduced C-5, C-6 linkage. Dihydrojervine refers to the jervine structure (1) with the C-12, C-13 bond saturated and tetrahydrojervine has both C-5, C-6 and C-12, C-13 linkages saturated. Dihydrosolasodine is shown as structure 6 having C-5, C-6 saturated. 

The elucidation of the structure of solanidine as IV (21, 39) followed the degradative work and was confirmed by a partial synthesis. 

DEHYDROGENATION. The definite determination of the skeletal structure of solanidine, and particularly that portion of the molecule which carries the nitrogen, was accomplished by dehydrogenation with selenium and identification of the products. Early attempts in this direction led to phenanthrene, chrysene, and pyridine (23) presumably because of too drastic conditions. Under so called normal conditions, that is tempera-... 

XXIII) solanidine yields the same product (42, 56) as well as 2-ethyl-5-methylpyridine (XXIV) (20, 21, 39). These fragments rendered it possible to arrive at the correct skeletal structure and to suggest formula IV for solanidine. 

STRUCTURE AND REACTIONS. Solasodine, C27H43O2N, is a weaker base than solanidine and has pKb 6.30 (11). One of the oxygen atoms is present as a secondary hydroxyl in position 3 8 as shown by the formation of a sparingly soluble digitonide and by the reactions to be described later. The function of the second oxygen was more difficult to determine. Since the alkaloid reacted as though it had two active hydrogens... 

Extraction of Fritillaria camtschatcensis, a known source of solanidine, has yielded tomatidenol (34), solasodine (16a), and a new alkaloid hapepunine, C2sH47N02. Hapepunine was assigned the N-methyl 22,26-epiminocholestane structure (35 a) on the basis of spectroscopic studies similar to those described above for teinemine. This structure proposal was proved by the partial synthesis of hapepunine from tomatidenol (34) via the desmethyl derivative (35b). Hapepunine (35 a) is the first natural 16j8-hydroxy-22,26-epiminochoIestane derivative. ... 

Alkaloids such as solanidine and tomatidine are related to diosgenin in terms of structure. These cholesterol-derived metabolites usually occur as the 3-(7-glycosides (e.g., sola-nine and tomatine) (Mann, 1987) (see Chapter 36). 

Rubijervina 12a-hydroxysolanidine solanid-5-ene-3p,12a-diol, a Veratrum alkaloid of the jervera-trum type. M, 413.65, m. p. 242"C, [ajp -h 19 (ethanol). It occurs in hellebore (Veratrum album, V. nigrum and V. viride) and differs structurally from solanidine (see a-Solanine) by the presence of a 12a-hydroxyl group. Rubisco see Ribulose huphosphate carboxylase. 

The alkaloids of the solanidine group share a hexacyclic framework derived from epiminocholestane as a common structural feature with the N-atom... 

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