Spermidine, chemical structure

There is no uniform classification for the A. In the literature divisions according to origin (examples Aconitum, Amaryllidaceae, Aspidosperma, cactus, Catharanthus, Cephalotaxus, Cinchona, coca, Corydalis, curare, Dendrobates, ergot, Erythrina, Iboga, Lycopodium, Maytenus, opium, Rauvol-fia, Senecio, Strychnos, tobacco, Vinca alkaloids, salamander, Solanum, Veratrum steroid alkaloids) in addition to divisions according to chemical structure (examples aporphine, benzylisoquinoline, bis-benzylisoquinoline, berberine, carboline, diterpene, inudazole, indole, indolizidine, isoquinoline, lupinane, macrocyclic, morphine, peptide, / -phenyl-ethylamine, piperidine, purine, pyridine, pyrrolidine, pyrrolizidine, quinoline, quinolizidine, quinucli-dine, spermine, spermidine, steroid, terpene, tro-pane, tropolone alkaloids) are used. 

Figure 9.2. Metabolism of pyrrolizidine alkaloids (PAs) in Senecio vernalis. The substrates for alkaloid biosynthesis, putrescine and spermidine, are derived from primary metabolism. Homospermidine, synthesized by homospermidine synthase (HSS), is the first pathway specific intermediate. It is exclusively incorporated into the necine base moiety of senecionine A-oxide, the backbone structure of all PAs found in this Senecio species. During allocation from the roots as site of synthesis to the shoots, it is chemically modified to provide the species specific PA-pattem.

The structure elucidation of 34 was based, in principle, on two facts color reactions and hydrolysis. Compound 34 does not react with ninhydrin (therefore, no primary amino group is present) but it does react with l-fluoro-2,4-dinitrobenzene. By exact determination of the absorption ratio E35O/E390 after the reaction with the latter reagent, Tait concluded that 34 contains a secondary amino group (50). Hydrolysis (6 N HC1, 110°C, 24 hr) of the so-called compound II afforded 2,3-dihydroxybenzoic acid and spermidine (50). The presence of two 2,3-dihydroxybenzoyl residues in 34 was demonstrated by its enzymatic (50) and chemical synthesis (51-54). 

The key alkaloid of the dihydroperiphylline group is periphylline (138), on which intensive chemical and spectroscopic analysis was performed. Essential to the structure determination was the detection of spermidine in an alkali melt of tetrahydroperiphylline (139), prepared by catalytic hydrogenation of periphylline (138). Alkali hydrolysis of 138 yielded ( -cin-... 

Verbascenine (205) has been isolated from the aerial parts of Verbascum species (140). Its structure elucidation was based on chemical degradation reactions as well as careful analysis of spectral data (140). In addition to spermidine, spermine was isolated from a KOH melt reaction and identified as its tetraacetyl derivative. The two cinnamic acid residues were identified by spectroscopic methods. A C=C double bond was found in only one of these units. The other cinnamic acid residue is part of a / -aminodihydrocin-namide. Therefore, verbascenine must be cyclic. The number of possible structures was reduced to two (205 and 206) on the basis of the formation of certain derivatives and their spectroscopic properties. Structure 205 is preferred for verbascenine because of the mass spectral behavior of its... 

Codonocarpine (C26H3i05Ng mp 187°) is a new alkaloid structurally-related to lunarine. Hydrolysis generated spermidine, [H2N(CH2)3NH-(CH2)4NH2]. Spectral analysis indicated that its structure is 42 and chemical degradation was consistent therewith. Hydrolysis of the tetrahydro derivative of the 0-methyl derivative gave an acid whose properties were consistent with structure 43 (52). 

Figure 3. Line- and space-filling structures of the polyamines putrescine, spermidine and spermine. With a little imagination, it is possible to envisage how the essentially linear paraquat molecule might fit into a transport system that has evolved to convey these chemicals into lung cells.

Details concerning the structural elucidation of homaline (57) and the related alkaloids hopromine, hoprominol, and hopromalinol, isolated from Homalium pornyense, have been published. The related spermidine alkaloid periphyllene (58) has been recently isolated from the leaves of Peripterygia marginata. Its structure and absolute stereochemistry were determined by spectral and chemical-degradation studies. 

Figure 19.9 Structures of small-molecule cat- Chemical Society.) (b) Titanium oxide solids alysts and SEM micrographs, (a) Silica obtained formed with spermidine. (Reprinted with per-with cysteamine. (Reprinted with permission mission from Ref. [166]. Copyright 2007, Amer-from Ref. [152]. Copyright 2005, American lean Chemical Society.)...

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