Quinidine Quinine

The cinchona alkaloids of practical importance are quinine, quinidine, cinchonine and cinchonidine, but, in addition, over twenty others have been isolated from cinchona and cuprea species. Their names and formulae are as follows ... 

Quinine, quinidine, quinicine, epfquinine, e fquinidine, A-quinine.. ... 

Fig. 3 Structiu-es of Cinchona alkaloids (quinine, quinidine, cinchonidine, and cinchonine) transformed into their corresponding 1-N-oxide derivatives [34]...

Further evidence for the formation of intermediate compounds in catalytic reactions is afforded by the observation (a) that optically active camphor is formed from optically inactive (racemic) camphor carboxylic acid in the presence of the d- or /-forms of quinine, quinidine or nicotine and (6) that optically active bases, e.g., quinidine, catalyze the synthesis of optically active mandelonitrile from benzaldehyde and hydrocyanic acid.10 These results hardly admit of any other interpretation than the intermittent production of a catalyst-reactant compound. 

FIGURE 1.1 Chemistry and stereochemistry of the native cinchona alkaloids quinine, quinidine, cmchonidme, and cinchonine as well as their corresponding C9-epimeric compounds. 

N-acylated and N-oxycarbonylated a-amino acids Quinine, quinidine, epiquinine and epiquinindine tcrt-butylcarbamate Methanol—O.IM 204 ammonium acetate, pH 6.0 (80 20)... 

Mepivacine, bupivacine, doxapram, quinine, quinidine, atenolol, metoprolol, propranolol, pethidine, methadone (5)-N-(3,5-dinitro-benzoyl) tyrosine Acetonitrile—ammo 208 nium acetate (60 40)... 

Quinine/Quinidine-Based Catalysts (e.g., Cinchona Alkaloids). 265... 

Antimalarial drugs are designed to prevent or treat malaria. Antimalarial drugs currently used for treatment for prophylaxis are mefloquine, primaquine, chloroquine, pyrimethamine, amodiaquin, quinine/quinidine, chloroguanide. 

Drugs that may interact with rifabutin include the following Anticoagulants, azole antifungal agents, benzodiazepines, beta blockers, buspirone, corticosteroids, cyclosporine, delavirdine, doxycycline, hydantoins, indinavir, rifamycins, losartan, macrolide antibiotics, methadone, morphine, nelfinavir, quinine, quinidine, theophylline, aminophylline, tricyclic antidepressants, and zolpidem. 

The use of compounds with activated methylene protons (doubly activated) enables the use of a mild base during the Neber reaction to 277-azirines. Using ketoxime 4-toluenesulfonates of 3-oxocarboxylic esters 539 as starting materials and a catalytic quantity of chiral tertiary base for the reaction, moderate to high enantioselectivity (44-82% ee) was achieved (equation 240). This asymmetric conversion was observed for the three pairs of Cinchona alkaloids (Cinchonine/Cinchonidine, Quinine/Quinidine and Dihydro-quinine/Dihydroquinidine). When the pseudoenantiomers of the alkaloid bases were used, opposite enantioselectivity was observed in the reaction. This fact shows that the absolute configuration of the predominant azirine can be controlled by base selection. 

Quinoline alkaloids Quinoline Chloroquinine Cinchonidine Quinine Quinidine... 

Figure 44. Diagram of the quinine, quinidine and cinchonine synthesis pathway.

This structural group of indole alkaloids covers simple indole alkaloids (e.g., tryptamine, serotonin, psilocin and psilocybin), /3-carboline alkaloids (e.g., harmine), terpenoid indole (e.g., ajmalicine, catharanthine and tabersonine), quinoline alkaloids (e.g., quinine, quinidine and cinchonidine), pyrroloindole... 

This group of alkaloids has two structurally different a. The a of alkaloids found in the genus Cinchona (Ruhiaceae), such as quinine, quinidine, cinchonidine and cinchonine, is L-tryptophan. The j8 is tryptamine and the

[Pg.114]

Quinidine is an alkaloid obtained from various species of Cinchona or its hybrids, from Remijia pedunculata, or from quinine. Quinidine is the dextrorotatory isomer of quinine. 

Mefloquine is effective in treating most falciparum malaria. The drug is not appropriate for treating individuals with severe or complicated malaria, since quinine, quinidine, and artemisinins are more rapidly active, and since drug resistance is less likely with those agents. The combination of artesunate plus mefloquine showed excellent antimalarial efficacy in regions of Southeast Asia with some resistance to mefloquine, and this regimen is now one of the combination therapies recommended by the WHO for the treatment of uncomplicated falciparum malaria (Table 52-4). Artesunate-mefloquine is the first-line therapy for uncomplicated malaria in a number of countries in Asia and South America. 

Clindamycin (see Chapter 44) is slowly active against erythrocytic schizonts and can be used after treatment courses of quinine, quinidine, or artesunate in those for whom doxycycline is not recommended, such as children and pregnant women. Azithromycin (see Chapter 44) also has antimalarial activity and is now under study as an alternative chemoprophylactic drug. Antimalarial activity of fluoroquinolones has been demonstrated, but efficacy for the therapy or chemoprophylaxis of malaria has been suboptimal. 

Most of the alkaloids are chiral molecules having many chiral centers. Therefore, these molecules have been used to prepare effective and successful CSPs. Cinchona alkaloids (i.e., quinine, quinidine, epiquinine, epiquinindine, cinchonine, and cinchonidine), which differ in their absolute configuration and alkyl side chains, have been used as the starting materials for the preparation of CSPs... 

Some of the most remarkable examples of terpenoid indole alkaloid modifications are to be found in the genus Cinchona (Rubiaceae), in the alkaloids quinine, quinidine, cinchonidine,... 

Alkaloids containing quinoline as the principal nucleus include anemonine from Anemone tha-lietroides, galipine from Angostura bark (Galipea officinalis), and the cinchona alkaloids, quinine, quinidine, cinchonine, and cinchonidine (Figure 11.8). 

Quinine, quinidine, cinchonine, and cinchonidine have similar actions. Dilute solutions cause direct depression with prolonged refractory phase. Concentrated solutions produce rigor. 

The I3C NMR spectra of quinine, quinidine, dihydroquinine, dihydro-quinidine, and their A -oxides, (2) cinchonidine, 9-epiquinine, 9-epiquinidine, and dihydro-9-epiquinidine (189) have been described. Some of the assignment problems are illustrated with reference to cinchonidine [297] and quinidine [298]. Assignment of the C(2) and... 

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