Other Related Alkaloids

The stereochemistry of the normal-type oxazolidine ring in veatchine, atisine, and other related alkaloids was ill-defined in the literature (25),... 

Senecioneae Tribe.—A new dihydropyrrolizinone alkaloid has been isolated from Jacmaia incana (Sw.) B. Nord. by Bohlmann and co-workers.30 The structure (44) for this alkaloid was deduced from 14 n.m.r. and mass-spectral data. The 7/ -configuration was assumed after comparison of the rotation of (44) with those of other related alkaloids. Previously isolated dihydropyrrolizinone alkaloids have all contained macrocyclic rings, as in senaetnine (45). Senaetnine was present in Odontocline hollickii (Britt, ex Greenm.) B. Nord.30... 

This report embodies the work published on the isolation, structure determination, and synthesis of Erythrina, Cocculus, Cephalotaxus, and other related alkaloids. 

A fluorimetric method for the determination of atropine and other related alkaloids has been described (99). The method is based on the formation of fluorescent complex between atropine and eosine To a solution of atropine in chloroform (9 ml) 0.1% eosine solution is added (1 ml). The mixture is shaken thoroughly and the fluorescence intensity at 556 nm (excitation at 365 nm) is measured after 10 minutes. Beer s law is obeyed with 1 to 5 pg of atropine per ml the coefficient of variation is 2.6%. 

The one and only morphinandienone, (+)-milonine (8,14-Dihydromorphinandienone) (54), was isolated from the dried leaves of Cissampelos sympodialis, a plant used in medicine in northeastern Brazil [50]. Blasko and Cordell reviewed morphinandienone, homomorphinandienone, and other related alkaloids with respect to isolation, structure, elucidation, spectroscopy, and synthesis [94],... 

The approximately 100 alkaloids of this series occur in the family Amaryllidaceae. This family is considered closely related to the Liliaceae and some taxonomists (e.g., Cron-quist, 1981) have merged the two into one large family. The alkaloids of the Amaryllidaceae are similar to colchicine and other related alkaloids of the Liliaceae in that both phenylalanine and tyrosine are involved in their synthesis. All Amaryllidaceae alkaloids, however, are derived from a single intermediate, norbelladine (4). The three major structural types are found at times in individuals of the same species. 

Some alkaloids of ergot possess potent vasoconstricting abilities these were largely responsible for one of the effects of ergotism called St. Anthony s Fire, a gangrenous condition of the extremities which often resulted in loss of limbs. Other related alkaloids produced delirium and hallucinations, and, in more severe cases, convulsions. 

Fig. 5.2.1. The biogenetic route to cocaine and other related alkaloids...

The general biogenetic route of cocaine and other related alkaloids is shown in Fig. 5.2.1. The fundamental skeleton is formed by the combination of lysine-ornithine derived pyrrolidine and the three- or four-carbon moiety of ace-tate-malonate origin. The acyl part of scopolamine has been demonstrated to be formed from phenylalanine through deamination and skeletal rearrangement (63). 

The aerial part of Zanthoxylum inerme was divided into bark and wood. From the bark, more than 0.07% of nitidine was isolated together with other related alkaloids. By contrast, none of these alkaloids were found in the wood, and 4-methoxy-l-methyl-2-quinoline was the only nitrogeneous compound occurring together with several coumarins and lignans. These results are shown in Table 5.2.2 (75). Nitidine has been shown to have cytotoxic and antitumor activities. 

Emetine and other related alkaloids are biosynthesized from dopamine and secologanin of mevalonate origin through a glycosidic intermediate, desacetylipe-coside (Fig. 5.2.14) (6). Alkaloids having biogenetic importance, such as protoemetine, have also been found in the same plant (7). 

A set of 60 cDNAs were isolated by subtractive hybridization of Nicotiana tabacum roots before and after removal of the flowers and young leaves, a process known as topping [32], Topping is known to increase the amount of nicotine and other related alkaloids in the plant. A number of the subtracted cDNAs that were unique to the topped plants corresponded to known alkaloid biosynthetic enzymes. The functions of additional cDNAs observed in the subtracted library were not clear and remain under investigation. Further study of these new clones may provide insights into alkaloid natural product biosynthesis in N. tabacum. 

All the available evidence suggests that plants make alkaloids to deter predators. Some, like the tobacco alkaloids are strongly toxic to insects. Nicotine, anabasine and other related alkaloids are produced in the roots of the tobacco plant and translocated to the leaves. Nicotine is certainly toxic to most insects. Formerly, a crude preparation of nicotine was used commercially as an insecticide, but the tobacco hornworm (Manduca sexto) (Plate 15) has adapted itself so that its larvae feed only on tobacco... 

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