Alkaloids of Unknown Structure

A number of species of the genus Ochrosia have been investigated, and among the alkaloids already discussed are ellipticine and methoxy-ellipticine from 0. elliptica (Section VII, D). Other alkaloids from this species include elliptinine for which structure CCCLVIII has been 

71) is also very similar (194). Australian and New Guinea species, notably 0. poweri, contain a number of alkaloids (161), including elliptamine, C24H30N2O5, powerine, C21H26N2O4, and poweramine, C23H30N2O4 (161). Elliptamine, the most widespread, is unstable in the form of the free base. It forms an orange-red picrate. Powerine and poweramine may be 5- and 6-methoxy indoles, respectively (161). 

In addition to olivacine and guatambuine (Section VII, C), an unnamed alkaloid, mp 186°-188°, resembling uleine in its color reactions, has been isolated from Aspidosperma australe (147)3. A glycosidic alkaloid, quebrachacidine, C26H28N2O11, has been found in A. quebracho-bianco (195), and its aglycone has been prepared. Several alkaloids have been reported in A. oblongum and A. album (196), notably kromantine, mp 176°, [a]D+ 159° (in chloroform), from the latter species (196a). 

Among the many alkaloids of Rhazya stricta (see Table I), the structure of the alkaloid rhazinine remains to be determined (197). This indolic base, C19H24N2O, contains a primary alcoholic group but, unlike akuammidine (CCCXXII) which accompanies it in the plant, it contains no G-methyl (197). Other alkaloids of the same plant include rhazidine, C20H26N2O3, H20, mp 278-279°, [ x]D — 21° (in ethanol) (199, 200, 62). 

Two unnamed alkaloids, mp 233°-235° (dec.) and 135°-139°, respectively, were isolated from Stemmadenia donnell-smitkii, but no further information is available on these at the time of writing (8). 

Kouminidine was first isolated from G. elegans in 1931 and given the molecular formula C20H26N2O4 (25,59). No structural information has been available. 

The water-soluble alkaloid kounidine (C2,H24N205) was isolated from G. elegans in 1936 (60), but the structure remains unknown. 

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Part 15. Alkaloids of unknown structure and their derivatives ... 

Appendix. Alkaloids of Unknown Structure from Calabash Curare and... 

Other than several alkaloids of unknown structure, the spermidine alkaloid codonocarpine (104) and its /V-methyl derivative (105, alkaloid IV) were isolated from the bark of the Australian Codonocarpus australis (94). 

Gas chromatography of cocaine of plant origin has mainly involved the analysis of the coca plant [77-79]. Identification and quantitation GC methods of minor naturally occurring tropane alkaloids in illicit cocaine samples have also been reviewed [80]. Moore et al. presented an in-depth methodology for the analysis of the coca plant by GC-FID, GC-ECD, and GC-MS for the identification of alkaloids of unknown structure [81]. Recently, Casale et al. [82] have analyzed the seeds from Erythroxylum coca for their alkaloidal content. Several tropane alkaloids were detected and characterized and it appeared that methylecgonidine (MEG) was the primary constituent and not an analytical artifact. 

In study of Corydalis incisa cultivated in North America, Manske reported the presence of five alkaloids, protopine, bicuculline, cory-palmine, and an alkaloid of unknown structure designated as alkaloid F62 17). 

Finally, two toxic, isomeric indole alkaloids of unknown structure have been isolated from a toxigenic fungus identified as Penicillium islandicum Sopp., found on freshly dug green peanuts. ... 

The alkaloids of Sections II-VI and their transformation products are listed in alphabetical order in Tables 5-10. Derivatives have been listed in the order (a) quaternary ammonium salts, (6) A-alkyl derivatives, and (c) 0- and A-acyl derivatives. Alkaloids of unknown structure, listed in Table 11, follow the same order, except that products of reduction are listed after the quaternary salts. Figures enclosed in parentheses designate melting points of polymorphic and/or solvated crystal modifications. 

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