Alkaloid structures unknown structure

Alkaloids with Unknown Structures Isolated FROM Catharanthus roseus... 

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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