Quinoline alkaloids other than Cinchona

Quinoline Alkaloids, Other than Those of Cinchona by H. T. Openshaw 65... 

QUINOLINE ALKALOIDS, OTHER THAN THOSE OF CINCHONA... 

Openshaw HT (1953) Quinoline alkaloids, other than those of Cinchona. In Manske RHF, Holmes HL (eds) The alkaloids, vol III. Academic, New York, pp 65-100... 

The enzyme strictosidine synthase (EC 4.3.3.2) is responsible for the stereospecific coupling of tryptamine and secologanin, yielding strictosidine (Fig. 12). This glucoalkaloid is the precursor for all terpenoid indole and related alkaloids, including among others the Cinchona quinoline alkaloids. Hampp and Zenk (707) isolated and purified this enzyme to homogeneity from a cell suspension culture of R. serpentina. The enzyme could successfully be immobilized on CNBr-activated Sepharose 4B, as was reported for this enzyme isolated from Catharanthus roseus (102,708). It proved to be more stable than the C. roseus enzyme the half-life of the immobilized enzyme was 100 days at a temperature of 37°C. 

Quinine isolated from Cinchona succirubra represents the oldest example of quinoline alkaloids antiparasitic effects, particularly antiplasmodial activity it has been used to treat malaria for more than three centuries. Other quinoline alkaloids such as 2- -propylquinoline, chimanine B, 2-n-pentylquinoline, and 4-methoxy-2-phenylquinoline have been also shown to be effective against strains of parasites causing cutaneous leishmaniasis [189,190] (Fig. 25). 

Quinine and related alkaloids isolated from the bark and other parts of Cinchona plants, such as Cinchona ledgeriana and Cinchona succimbra (Rubia-ceae), can be classified as quinoline alkaloids because these alkaloids also possess a quinoline moiety. However, the biosynthetic origin of the chro-mophore of these alkaloids is tryptophan rather than anthranilic acid. Namely, the quinoline moiety is formed by the oxidative transformation of the indole nucleus during biosynthesis, as described in Section 2.17. 

BQC is derived from quinine, which is a member of the cinchona family of alkaloids. Ammonium salts derived from quinidine, a diastereomer of (1) at the hydroxyl substituent, have been used less frequently in catalysis than BQC. Quini-dinium salts often give rise to products with enantioselectivity opposite to that from (1). Other related compounds, such as those derived from cinchonine and cinchonidine (which lack the methoxy substituent on the quinoline nucleus), have found application in organic synthesis. The cinchona alkaloids, as well as salt derivatives in which the benzyl group bears various substituents, have also been studied. Results from polymer-bound catalysts have not been promising. ... 

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