Quinoline, —Alkaloids

Quinoline alkaloids Quinoline Chloroquinine Cinchonidine Quinine Quinidine... 

L-tyrosine Tyrosine-derived alkaloids Indole alkaloids Quinoline alkaloids /3-carboline alkaloids Pyrroloindole alkaloids Ergot alkaloids Iboga alkaloids Corynanthe alkaloids Aspidosperma alkaloids Protoalkaloids Terpenoid indole alkaloids True alkaloids... 

The major analytes in this category are the alicyclic compounds (alkaloids and terpenes) heterocyclic compounds (barbiturates, benzodiazapams, indole alkaloids, quinolines, nucleic acids, and nucleotides) aminoacids and peptides oligopeptides and proteins (globular, nucleo-, and lipo-) saccharides and polysaccharides and condensation products of saccharides with all the other analytes, e.g., glucuronides and gly-coproteins. Thus far, most analyses have been done on solid and solution forms of the drug substances. A few illustrations are reported in which CD was used in the direct analysis of biological extracts. 

Pinidine and Coniine Nicotiana Alkaloids yV-Methylpelletierine Lycopodium Alkaloids Lyduraceae Alkaloids Pyrrolizidine Group Tropane and Pyrrolidine Alkaloids Quinoline and Acridme Alkaloids Benzodiazepine Alkaloids Tylophora Alkaloids Cactus Alkaloids Ephedrine... 

Anthranilic acid Anthranilic acid-derived alkaloids Tme alkaloids Quinazoline alkaloids Quinoline alkaloids Acridine alkaloids... 

In the biosynthesis of the furoquinoline alkaloids, in order to form the five-membered ring, a ring closure procedure must occur and, as the biosynthetic precursor of these alkaloids, quinoline alkaloids with an epoxide moiety were considered [6]. Namely, in the biosynthesis of dictamnine, it was considered that the ring closure occurred on an unidentified precursor with an epoxide moiety to form platydesmine, which was converted into myrtopsine and finally dictamnine. Thus, quinoline alkaloids with an epoxide moiety in the side chain were considered to be important biosynthetic precursors of both the quinoline alkaloids with a C5 unit at the C-3 position, such as orixine and related alkaloids, and the furoquinoline alkaloids. Such biosynthetic precursors with an epoxide moiety were not isolated previously, probably because they might spontaneously cyclize. Finally, 2 R-preorixine, with an epoxide moiety in the side chain, and considered to be the direct biosynthetic precursor of orixine, was isolated from the... 

Distribution of Pyrroloquinazoline Alkaloids Biological Activity Quinazolinocarboline Alkaloids Quinoline, Furoquinoline, Acridone, and 4-Quinoline Alkaloids... 

Interesting correlation between distribution of the strictosidine synthase activity and alkaloid content in the 6-month C. ledgeriana plants was found by Aerts et al. The enzyme was active in the top of stems, in young leaflets, and in the roots, and these parts also contained the highest concentration of the alkaloids. Quinoline alkaloids were accumulated in the roots, whereas cinchophyllines in aerial part of plants [218]. Similarly high activity of strictosidine synthase in the germinating Cinchona seeds and cell cultures has been reported [219]. Four isoforms of strictosidine synthase have been isolated and purified from the suspension culture of C. robusta [220]. 

Other classes of alkaloids, which exhibit fluorescence, include the quinoline and isoquinoline alkaloids. Quinoline is weakly fluorescent. The anti-malarial drug quinine includes a methoxy substituent on the 6 position of the quinoline moiety and fluoresces very intensely. Quinine, in sulfuric acid solution, is often used as a standard in fluorescence spectroscopy for determining a quantum yield. Its fluorescent properties are sensitive to pH. At pH 2 it has an excitation maximum of 347 nm with fluorescence at 448 nm. At pH 7 the peaks shift to absorb at 331 nm and emit at 382 nm. In hydrochloric acid solution, absorption is unaffected but fluorescence intensity is quenched greatly by the halide anions. 

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