Biological tropane alkaloids

Tropane alkaloids have a tropane (C4N skeleton -f) nucleus. Structurally, these alkaloids synthesize as postcursors of pyrrolines (Figure 57). a, /3,

tropane alkaloids (e.g., atropine, hyoscyamine, cocaine, tropinone, tropine, littorine and cuscohy-grine) have a strong biological activity, especially as neurotransmitters. 

Current methods for tropane alkaloids analysis have been well covered in the literature. An excellent comprehensive review written by B. Drager [45] appeared in 2002, describing the analysis of tropane and related alkaloids in plant material. Sample preparation procedures were reviewed, as well as the analytical methods used for performing the separation and detection of tropane alkaloids, such as gas chromatography (GC), liquid chromatography (LC), and capillary electrophoresis (CE). Therefore, this chapter will not describe in detail these well-known analytical methods but discuss some recently developed applications for the analysis of tropane alkaloids in plant material and biological matrices. 

The isolation of atropine, scopolamine, and cocaine occurred long before the development of modern analytical techniques. Gas chromatography was the first instrumental technique available in the field of separation science and thus it is not surprising that these alkaloids were firstly analyzed by GC despite their low volatility. With the advent of capillary columns and the proliferation of various sample introduction and detection methods, GC has evolved as the dominant analytical technique for screening, identification, and quantitation of tropane alkaloids of plant origin as well as in biological fluids. The state-of-the-art of GC analysis of tropane alkaloids has been the subject of two comprehensive reviews [45,58]. We shall therefore mainly focus on publications which have appeared since 2002. 

Analysis of tropane alkaloids in biological fluids has been developed mostly for cocaine and metabolites. Indeed, it is well recognized that cocaine remains one of the most widely consumed drugs of abuse worldwide. Generally, reversed phase liquid chromatography coupled with UV-VIS detection is employed for these analyses. 

Tropane alkaloids are an important class of natural products possessing different and interesting pharmacological activities. Hyoscyamine (atropine in the racemate form), scopolamine, and cocaine are the major representatives of this class. They are commonly found in plant materials, mainly in genera belonging to three families Solanaceae, Erythroxylaceae, and Convolvulaceae. The importance of these compounds requires that there are accurate analytical methods for their determination in plants and in biological matrices. This chapter describes the state-of-the-art of analytical procedures (extraction and analysis) for analyzing tropane alkaloids. 

Analyses of tropane alkaloids are mainly carried out by GC and HPLC and to a lesser extent by CE. This review describes recent applications developed for the analysis of this class of compounds in plant materials and biological matrices. Of course, mass spectrometry is generally used as the detection technique because of its high sensitivity and selectivity, but other techniques such as UV, fluorescence, flame ionization detection, nuclear magnetic resonance, among others have also been investigated. Finally, desorption electrospray ionization mass spectrometry is reported as a new interesting detection technique for the rapid analysis of samples without any sample preparation. 

Biologic Background Isoquinoline Alkaloids Terpenoid Indole Alkaloids Tropane Alkaloids Purine Alkaloids... 

This Chapter is designed to review the chemistry and biological activity of the calystegines, which at the present time are rarely found to occur in association with the correspondingly substituted tropane alkaloids. However, new sources of calystegines are rapidly bong discovered and die occurrence of additional polyhydroxy tropane alkaloids cannot be excluded. 

SE-30 (5 %) and Carbowax 20 m (1 %) as stationary phases on Chromosorb 60-80 mesh, acid washed. A solid injector was employed to prevent contamination of the column by non-volatile compounds present in the extracts of the biological material investigated. Satisfactory separation of the tropane alkaloids mentioned was obtained at temperatures above 210°C on the SE-30 column. 

Evans WC. Tropane alkaloids of the Solanaceae. In Hawkes JG, Lester RN, Skelding AD, editors, The Biology and Taxonomy of the Solanaceae. London Academic Press 1979. p 241-254. 

Biological Activity of Tropane Alkaloids Distribution of Tropane Alkaloids Piperidine Alkaloids Alkaloids from Piper Species Piperine Alkaloids Involving Condensation with Acetate/Malonate Sedum Alkaloids Lobelia Alkaloids Lycopodium Alkaloids Piperidine Alkaloids in Insects Polyketide-Derived Alkaloids Coniine... 

Many years of research in our laboratory [24, 30, 89, 90, 114] on the impact of artificial pol3 ploidy on the biosynthesis of tropane alkaloids from diploid- and tetraploid-transformed root cultures of D. stramonium L. have revealed that induced polyploidy makes it possible to obtain higher yields of target metabolites as well as to achieve biosynthesis of new biologically active substances that are normally not synthesized in the intact plants (Table 7.3). The comparative analysis of the alkaloid profile of diploid and tetraploid intact D. stramonium L. plants and transformed roots derived from them (Table 7.3) established 39 alkaloids, 33 of which were identified. 

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