Hyoscyamine secondary

Hairy roots are not as readily manipulated by altering culture conditions or pH as are suspension cultures. However, the effect of temperature on growth and hyoscyamine production in transformed root cultures of Datura stramonium has been demonstrated by Hilton and Rhodes [86]. Another way to enhance the secondary metabolite accumulation of hairy roots is the addition of precursors and/or metabolic intermediates to the growth medium. The addition of (R,S)- phenyllactic acid increased significantly the accumulation of hyoscyamine and scopolamine in the hairy root culture of Datura Candida x D. aurea [72]. 

The alkaloids of the tropane group show a series of common chemical characteristics, particularly that of being esters of organic acids combined with bicyclic hydramines. They include Z-hyoscyamine and its isomer atropine, cocaine, scopolamine or hyoscine, and a series of secondary alkaloids. 

Based on the above reports we investigated the possibility of using "hairy root" cultures in studies of secondary metabolism. We focused on the tropane alkaloids, synthesized in the roots of various Solanaoeae genera (Atropa, Datura, Brugmanaia, Hyosayamua, and Duboisia). Hyoscyamine and scopolamine are widely used in narcotic medicine as sedatives and in the treatment of sea sickness. Scopolamine tilso happens to be the best known antidote against nerve gas. 

Tropane alkaloids include some medicinally important secondary plant metabolites as atropine (racemic mixture of 1- and d-hyoscyamine) and scopolamine. This group also includes cocaine, which, since it is a major drug of abuse, is frequently analyzed in forensic science. GC analysis of this class of compounds was first shown to be possible by Lloyd et al. in 1960. 

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...

The first-discovered muscarinic antagonist was atropine which occurs as a secondary metabolite in the roots of the plant Atropa belladonna and other plants of the species Solanaceae. Atropine is an ester of tropine with hydroxy-methylphenylacetic add. The cosmetic use of extracts of belladonna for dilating the pupils to render women more attractive eventually led to its use (mydriatic) in the examination of the cornea in ophthalmology. Atropine is biosynthesised as a single enantiomer (called L-hyoscyamine), but once in solution, it easily racemises due to the carbonyl group situated in the alpha position to the chiral centre (Fig. 16.13). 

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