Characteristics open type, secondary

Fig. 3.18 Chemotaxonomy and phylogeny of the Solanaceae. The provisional phylogenetic tree of Fig. 2.2 is shown here again though without terms for the clades in order to have a clear structure in favour of metabolite symbols. Plotted on the tree is the occurrence of three dominant and characteristic classes of secondary metabolites of the Solanaceae family with two subclasses in one case (I) Tropane alkaloids (two subclasses), (11) steroidal alkaloids/glycoalkaloids, (III) with-anoUdes/withasteroids. These metabolites are indicated by the following symbols. Co-occurrence of different classes (rather rare) is also indicated, i.e., by two corresponding symbols. Filled square tropane alkaloids of the structural types T5, T6, and T7-A - T7-B (very poisonous ester alkaloids with a tropic acid residue, e.g., hyoscyamine/atropine, scopolamine and their derivatives). Taxa highlighted by dt filled square may also show co-occurrence with tropane alkaloids of the following subclass according to Table 3.1 however, this is not highlighted in such cases. Open square tropane alkaloids of the structural types T1 - T4, T7-C, and T7-D (ester alkaloids of...

Potentiometric sensing based on type 3 derivatives of a-, P-, and y-cyclodextrins has been reported.We have been interested in the type 1 cyclodextrin derivatives developed by Tagaki, e.g., host 41. This type of cyclodextrin derivative is characteristic in that the primary hydroxyl groups at the C-6 positions are exhaustively substituted with long alkyl chains. At the surface of an oiganic membrane, this structural feature allows the secondary hydroxyl side (wider open end of the cavity) to face the aqueous solution to accommodate a guest molecule. The interfacial receptor functions of these cyclodextrin hosts have been confirmed mainly by rt-A isotherm studies. 

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