Quinolizidine alkaloids degradation

Lythraceae Alkaloids.— The rate at which quinolizidine alkaloids of the cryogenine (35) type are synthesized and degraded in Heimia salicifolia has been studied as has their sequence of appearance in growing plants. " The results do not yet add to the preliminary data so far obtained on these alkaloids. ... 

The structure of nupharamine is obviously very close to that of the quinolizidine alkaloids which also occur in Nuphar species (see Chap.38) and, for example, it is possible to degrade the quinazoline, alkaloid nupharidine (71) to (-)-nupharamine via the enamine (72) (R.T. LaLonde et al.,... 

The internal storage capacity is limited by the number of storage cells. Excreted alkaloids which are dissolved in the medium are exposed to catalytic activities in the medium (e.g., peroxidases) and can thus be degraded as was demonstrated for quinolizidine alkaloids in lupine cell cultures (92). A role for peroxidases in product degradation has been recently demonstrated for indole alkaloids produced by suspension cultures of Tabemaemontana. Reduction of peroxidase activity by removal of Ca ions from the medium resulted in the formation of the alkaloid... 

C14H22N2O, Mr 234.34, mp. 80.5-81 °C, [oId -7.5° (+5.2°) (C2H5OH). A tricyclic quinolizidine alkaloid of the sparteine type from 4 genera of the Fabaceae Cytisus, Diplotropis, Lupinus, Ormosia). A. exists as 2 optically active isomers The biosynthesis of A. in plants is assumed to involve ring opening and side chain degradation of lupanine as a precursor Ut. Waterman 8, 197-239. Planta Med. 59, 289 (1993). Pelletier 2, 105-148. 

Ortega-David E, Rodriguez-Stouvenel A. Degradation of quinolizidine alkaloids of lupin by Rhizopus oligosporus. Appl Microbiol Biotechnol 2013 97(11) 4799-810. 

Figure 1.13. Degradation of quinolizidine alkaloids A—general structure. B—end product alkaloids, and C— products derived from alkaloids. The structure of lupine alkaloids four ring— sparteine type three ring—cytisine type two ring— lupinine type laige hollow arrow— most common oxidation and hydroxylation arrows from parallel lines— most common dehydrogenation site.

Halichlorine (789) ([a]o +240.7°, c 0.54, MeOH), isolated from the Japanese sponge Halichondria okadai, is a complex alkaloid possessing a novel spiro-quinolizidine macrolide structure (537). Elucidation of the structure was based on detailed analysis of coupling constants and NOE effects in the NMR spectrum The absolute configuration of the ansa chain was inferred by degradation to the... 

Lythraceae Alkaloids.—Cryogenine (18) has been shown to incorporate [3- " C]-phenylalanine in Heimia salicifolia. Oxidative degradation established the incorporation of labels at the positions shown in (18) the difference in incorporation of the two units may be a function of the stage at which they normally enter the biosynthetic pathway. Although ring d and the whole of its C3 side chain are probably derived from phenylalanine, it is not yet clear whether this precursor supplies three or only one carbon atom of the quinolizidine system. 

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