Alkaloids quinoline family

Of all the alkaloid-producing families, one of the most prolific is the Rutaceae (Waterman, 1975). The alkaloids obtained included 1-benzyltetrahydroisoquinoline, simple tryptophan derivatives, imidazoles and, most commonly, quinoline alkaloids originating from anthranilic acid. The Rutaceae was the only family in which the direct use of anthranilic acid in alkaloid production occurs to any extent. 

The Quinoline Family. The amino acid tryptophan is the precursor of the quinoline alkaloids. Far less numerous than the isoquinoline alkaloids, the quinoline family is distinguished by having the famous dmg quinine as a member. Quinine has been used for ages in the treatment of malaria. It is isolated from the bark of the Cinchona tree. Quinine (3.20) has the rare stmctural feature of a bicyclic amine (a derivative of the l-azabicyclo[2.2.2]octane system) as a substituent. 

Quinoline alkaloids from the Rutaceae family (a = L-anthranilic acid) show antimicrobial activity. Moreover, quinoline alkaloids of the Haplophyllum species are known for their powerful biological properties. For example, skim-mianine has sedative, hypothermic and antidiuretic uses. Haplophyllidine is a strong depressant of the CNS. 

The authors have also extensively studied the indoloquinoline families of alkaloids related to cryptolepine (indolo[3,2-fo]quinoline 57), applying direct and long-range... 

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. ... 

Most often naturally occurring quinolin-2-ones are found In the Rutacea and all the alkaloids listed below arise in plants of this family. 

Quinoline alkaloids are biogenetically derived from anthranilic acid and occur mainly in Rutaceous plants (14). These alkaloids were encountered in Sri Lankan plants of the families Annonaceae and Moraceae, in addition to the Rutaceae. 

Plants belonging to the genus Cinchona of the family Rubiaceae are not indigenous to Sri Lanka. Cinchona ledgeriana Moens. was introduced into Sri Lanka with the sole intention of exporting its bark (26,27) to extract the antimalarial quinoline alkaloid quinine (9) and its D-isomer, quinidine,... 

Addendum. A comprehensive review on the occurrence of alkaloids in the Rutaceae family has appeared. The broad spectrum of alkaloid types, including quinolines, furoquinolines, and acridones, may be appreciated from the list of species given in this review. 

The Papaveraceae and Fumariaceae DC. are closely related families. Their relationship as well as their independence are well demonstrated by the external stmcture of the flowers, the various anatomical characteristics of their different organs, and alkaloid content. As in the Papaveraceae, the protoberberines, ben-zophenanthridines, and protopines are chemotaxonomically significant for the Fumariaceae. Characteristic for the Fumariaceae is the presence of spirobenzylis-oquinolines, indenobenzazepines, secophthalideisoquinolines, phthalideiso-quinolines, and cularines. The Fumariaceae also contain quaternary highly polar alkaloids, insoluble in nonpolar solvents (16). 

Demethylation of acid-sensitive aryl methyl ethers, such as 2,4-dimethoxyquinolines, can be accomplished using a trimethylsilyl iodide/DMAP reagent system, where DMAP is used as a Lewis base to prevent protonation of the alkene from the HIby-product. This reaction was utilized to form the quinoline-containing alkaloid natural product, atanine, from the Rutaceae family. 

CkiehonkMiie [(85,9/()-cinchonan-9-ol]. Formula, see quinine. C,9H22N20, Mr 294.40 plates or prisms, mp. 2I0 C, (a][) -110 (C2H5OH) well soluble in alcohol and chloroform. C. is an alkaloid of the Cinchona group ( Cinchona alkaloid), a quinoline alkaloid. C. is isolated from many Cinchona species (C. tucujensis, C. pubescens) and also occurs in Remijia species (Ruhi-aceae) and in some members of the olive family such as Olea europaea (olive tree) and Ligustrum vulgare (common privet). C. is obtained commercially from cinchona bark. 

The second type of quinoline alkaloid, especially found in the Rutaceae family, has a as anthranilic acid. Typical compounds from this group are edulitine, halfordamine, folifidine, folinine, casimiroin, foliosidine, and swietenidine. The p is 3-carboxyquinoline, and the A is graveoline in the case of those alkaloids from Ruta angustifolia. 

Camptothecin is a quinoline alkaloid isolated from the steins of C. acuminata (Cornaceae) [1], and 10-hydroxy camptothecin and 10-methoxy camptothecin were also obtained as minor alkaloids [2]. C. acuminata is an ornamental plant in China. Campthothecin has also been isolated from both the Apocy-naceae and Rubiaceae plant families. 

In the biosynthetic pathway of the alkaloids derived from anthranilic acid, the carbon atom corresponding to the carboxyl carbonyl group is included in the resulting alkaloids, except for those alkaloids with the phen-azine skeleton. The main groups of alkaloids derived from anthranilic acid are classified as quinoline, acridone, and quinazoline alkaloids. These alkaloids are typically isolated from rutaceous plants, except for febrifugine and related alkaloids, which possess the quinazoline skeleton these are isolated from plants of the Saxifragaceae family. 

QUINOLINE ALKALOIDS ISOLATED FROM HIGHER PLANTS OTHER THAN THE RUTACEAE FAMILY... 

As described in Section 9.1, quinoline alkaloids have been mainly isolated from rutaceous plants, and very few such alkaloids have been isolated from plants in other families. 

In addition to the relatively simple anthranilic-derived metabolites mentioned above, several distinctive types of alkaloids are derived from this amino acid. Most of these are associated with the Rutaceae and related families of the Rutales. Among these groups of alkaloids are the quinazoline, pyrroloquinazoline, quinazolinocarboline, quinoline, furoquinoline, and acridone types. 

Quinolone alkaloids are found most commonly in the Rutaceae, but occasionally are encountered in other families. Alkaloids with a quinoline ring structure occur in four of the seven subfamilies of the Rutaceae (Aurantioideae, Flin-dersioideae, Rutoideae, and Toddalioideae) (in addition, a pyranoquinolone, A -methylflindersine, occurs in the Spathelioideae). Quinolone alkaloids are found in the subfamilies Rutoideae, Toddalioideae, and Aurantioideae, but also have been reported from Xylocarpus (Meliaceae). 

---