Convolvulaceae calystegines

N-raethyl group and occur occasionally as minor constituents in plants producing tropane alkaloids [76,77]. A recent survey of the occurrence of calystegines in Solanaceae and Convolvulaceae plants discovered that they are widely distributed in these families [1,2,78-80],... 

Calystegines appear to be vddely distributed in the Convolvulaceae family [78,80]. Eich and coworkers focused on the occurrence of seven calystegines (A3, A5, Bi, B2, B3, B4, Cl) identified by GC-MS analysis with authentic samples as references and analyzed the extracts of 65 Convolvulaceae species from predominantly tropical... 

Calystegine Cx Moms alba (Moraceae) roots Ipomoea batatus (Convolvulaceae) roots opolia japonica (Solanaceae) roots Duboisia leichhardtU (Solanaceae) leaves Lycium chinense (Solanaceae) roots Ipomoea camea (Convolvulaceae) leaves/stems ... 

Both alkaloids have (+) and (-) forms but only the (-) hyoscyamine and (-) scopolamine are active. The biosynthetic pathway of tropane alkaloids, Fig. (1) is not totally understood, especially at the enzymatic level. Edward Leete has pioneered the biosynthetic studies of tropane alkaloid since 1950"s using whole plants and isotope labels [85-86]. The tropane alkaloid hyoscyamine is bioconverted by the enzyme H6H (hyoscyamine 6p-hydroxylase, EC 1.14.11.11) to scopolamine via 6p-hydroxyhyoscyamine. Hyoscyamine is the ester of tropine and (S)-tropic acid. The (S)-tropic acid moiety derives from the amino acid L-phenylalanine, while the bicyclic tropane ring derives from L-omithine primarily or L-arginine via tropinone. Tropinone is stereospecifically reduced to form either, tropine which is incorporated into hyoscyamine, or on the other hand into pseudotropine which proceeds to calystegines, a group of nortropane derivates that were first found in the Convolvulaceae family [87]. 

The only other genus of plants in the Convolvulaceae which has been examined for the presence of calystegines is Ipomoea. Seeds of Weir Vine (Ipomoea sp. Q6 [aff. calobra]) growing in a very limited area of Queensland, Australia were analyzed by GC-MS and shown to contain calystegine B2 (18) and possibly also calystegine C, (21), co-occurring with the potyhydroxyindolizidine alkaloid swainsonine (5). A related species, I. polpha, from the Northern... 

The detection of calystegines in so many genera of the Solanaceae suggests that additional investigation of this plant family could prove fruitful, if only to attempt to define the subfamilies and tribes in which these alkaloids occur. However, caution should be exercised in adopting this approach due to the fact that calystegines also occur in the taxonomically disparate families Convolvulaceae and Moraceae. 

Calystegine A (32)/ Calystegine B2 (33) Calystegia sepium (Convolvulaceae) leaves/roots [47.48] Calystegia japonica (Convolvulaceae) roots [8] Convolvulus arvensis (Convolvulaceae) leaves/roots [47.49] Ipomoea sp. aff. calobra (Convolvulaceae) seeds [38] Atropa belladonna (Solanaceae) leaves/roots [47,48]... 

Unusual pyronotropane tropane alkaloids have been fotmd in the family Proteaceae. Tropine and pseudotropine esters of benzoic acid have been isolated from the family Euphorbiaceae. Novel dithiolane esters, along with tropine esters of acetic, propionic, n-butyric, isobutyric, isovaleric, and benzoic acids have been fotmd in the Rhizophoraceae. Calystegines, as well as a 3-hydroxybenzoate ester, have been fotmd in Brassicaceae. The calystegines have been used as chemotaxonomic markers in the Convolvulaceae family [20]. Tropine esters with methoxy-substituted benzoic acids are also characteristic for the later family. 

Schimming T, Jenett-Siems K, Mann P, Tofem-Reblin B, Milson J, Johnson RW, Deroin T, Austin DF, Eich E (2005) Calystegines as chemotaxonomic markers in the Convolvulaceae. Phytochemistry 66(4) 469-480. doi 10.1016/j.phytochem.2004.12.024 Hartmann T, Witte L, Oprach F, Toppel G (1986) Reinvestigatirai of the alkaloid composition of Atropa belladonna plants, root cultures, and cell suspension cultures. Planta Med 52(05) 390-395. doi 10.1055/s-2007-969194... 

However, at least one group of subclass B type metabolites, namely Tl-type tropane alkaloids as well as calystegines (see Sect. 3.5) represent plesiomotphic characters since both are also metabolites of the Convolvulaceae family. Such metabolites are found throughout the family. Obviously, they are the basis for apomorphic developments. 

Table 3.9 Distribution of the most frequent calystegines in the Convolvulaceae including species found negative data from Schimming et al. (1998, 2005) if not indicated otherwise...

Table 3.9 Distribution of the most frequent calystegines in the Convolvulaceae including species...

Schimming T, Tofern B, Mann P, Richter A, Jenett-Siems K, Drager B, Asano N, Gupta MP, Correa MD, Eich E (1998) Distribution and taxonomic significance of calystegines in the Convolvulaceae. Phytochemistry 49 1989-1995... 

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