Tetracyclic lupine alkaloid

Fig. (34). Structures of the tetracyclic lupine alkaloids (-)-6a-hydroxylupanine [219], 4a-hydroxy-13 P-methoxy lupanine, 3P,4a-dihydroxy-13 P-methoxy lupanine and...

Three new tetracyclic lupine alkaloids were isolated from Lupinus species and characterised (-)-13p-hydroxymultiflorine was isolated from seeds of L. varius, and (+)-2P-hydroxyaphylline and (+)-13a-hydroxyaphyllidine from seeds ofZ,. hartwegii. Fig. (37) [225]. 

The biogenetic pathway to lupine alkaloids from piperidylquinolizidine could not be demonstrated in spite of the ready chemical conversion of such bases to close relatives of the tetracyclic lupine alkaloids (36). 

The most common group of alkaloids possessing a quinolizidine nucleus is that of the lupine alkaloids which can simply be classified as bicyclic (lupinine/epilupinine type), tricyclic (cytisine type) or tetracyclic, (sparteine/lupanine or matrine type). Fig. (23). This grouping is made according to structure complexity and without considering biosynthesis, as the detailed biosynthetic pathways are still not completely understood. 

Ten of the 45 alkaloids that were gas chromatographed by Lloyd et al. in 19611 on a 2-3 % SE-30 on Chromosorb W column were lupine alkaloids. The bicyclic lupinine and the tricyclic sparteine, a-isosparteine and 13-hydroxysparteine were chromatographed at at column temperature of 160°C, the tricyclic cytisine, methylcytisine, methylcytisine-N-oxide and the tetracyclic lupanine, 13-hydroxylupanine and matrine at 204°C.The retention times of the alkaloids are listed in Table 7.1. 

Simple bicyclic compounds form a rather small subset of the lupine (or lupin) alkaloids, the overwhelming majority of which have tricyclic or tetracyclic structures based on the quinolizidine motif. These alkaloids are characteristic metabolites of the Papilionoideae, a sub-family of the Leguminosae (Fabaceae), although representative examples have also been isolated from several other plant families. The simple lupine quinolizidines were surveyed in Volume 28 of this treatise (7), while later reviews in Volumes 31 (5) and 47 (9) comprehensively covered all classes of lupine alkaloids, including those containing indolizidine components. Much relevant material is also to be found in the review on the biosynthesis of pyrrolizidine and... 

These tetracyclic and tricyclic quinolizidine alkaloids are commonly known as lupine alkaloids. The simple bicyclic alkaloids such as lupinine are produced from two lysine units via cadaverine. Tricyclic alkaloids such as cytisine are considered to be formed from tetracyclic alkaloids through anagyrine-type alkaloids (Fig. 5.2.7). 

Lupins produce both tetracyclic (e.g., lupanine) and bicyclic quinolizidine alkaloids (i.e., lupinine), which typically accumulate as esters of tiglic acid, p-coumaric... 

Sparteine is an alkaloid obtained from lupin beans with antiarrhythmic and oxytocic properties. It has a tetracyclic aliphatic structure with two tertiary alicyclic nitrogens. Since sparteine does not contain a chromophore, it cannot be detected with UV or FL. Therefore, Moncrieff (1990) developed a method of detecting sparteine, and its dehydro metabolites, in urine with... 

Sparteine 115 and lupanine 116, containing a tetracyclic bis-quinolizidine ring system, are alkaloids of the legumes (Fabaceae) species of lupin (Gems Lupinus) and broom (genus Cytisus, Sarothamnus, Genista). Sparteine 115 has been used in the management of cardiac arrhythmias [61]. 

Lupins produce both tetracyclic (e.g. lupanine) and bicyclic quinolizidine alkaloids (i.e. lupinine) (Figure 4.15), which typically accumulate as esters of tiglic acid, p-coumaric acid, acetic acid and ferulic acid (Suzuki et al. 1996). The biological significance of these esters is not clear. Quinolizidine alkaloid esters are mainly distributed in the genera... 

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