13-Hydroxylupanine, esters

Hydroxylupanine 13-Hydroxylupanine esters a-Isolupanine N-Methylangustifoline 17-Oxolupanine... 

G. cinerea thus proves to be a plant of some chemotaxonomic interest, because its major alkaloidal constituents are esters of 13-hydroxylupanine, compounds which are characteristic of the genus Cytisus rather than of Genista. In Cytisus species, for instance, the biosynthetic sequence lupanine, 13-hydroxylupanine, 13-hydroxylupanine esters, is often observed. However, G. cinerea also contains alkaloids characteristic of the Genista genus, e.g. anagyrine and hystrine, although these are only present in very small amounts, and in fact anagyrine was not encountered in the extracts from some samples. ... 

CijHjoNjOj. Mr 260.34, mp. 210 C, (aJc -147.7° (C2H5OH). Tetracyclic quinolizidine alkaloid of the sparteine type with an a-pyridone structure from several genera of the Fabaceae (e. g., Baptisia, Caulophyl-lum, Sophora). In analogy to 13-hydroxylupanine, esters of B. occasionally occur, and generally as the acetates. The 13-epimer epi-baptifoline (mp. 215 C, [o]d 138.9°) is often found together with B. . 

Figure 3.4a. The effect of exposure of plants to light on the composition of lupine alkaloids. Top Artificial light plants were grown in July, the plants exposed 18 hr were additionally illuminated with 4000 lux during the twilight hours, and the plants exposed 12 and 9 hr were covered to shorten the time of exposure. Bottom Natural light plants were planted at month intervals hence, their growth rate was according to their location, Poznan, Poland. The curves represent the concentration of free and esterified alkaloids in the total plant in mg/100 g of plant material (dry weight). The numbers represent the milligram contribution of free alkaloids (ALK) and hydroxylupanine ester fraction (HEF). Formulas lupanine (I) a free alkaloid, and cinnamoyloxylupanine (II) a HEF (Nowacki et ai, 1973). Courtesy of the journal.

Several alkaloids (130-142) were isolated from plants of the genera Cadia, Calpurnia, Sarothamnus, and Genista. They are believed to be ethers and esters of hydroxylupanine derivatives (159-178). Alkaloid esters on hydrolysis gave the respective organic acids and hydroxylupanines. The structures of these alkaloids have been established mainly by spectral methods. 

In addition to sparteine three derivatives of 13-hydroxylupanine were isolated namely, the veratric ester (cineverine), the trimethoxy-benzoic ester (sarodesmine), and the isovanilic ester which is new and named isocinevanine (151, 152). 

Lupinine Group.—Previous investigation of Cadia purpurea (cf. Vol. 7) resulted in the isolation of 13-hydroxylupanine (1) and its derivatives and cadiamine, Ci5H26N203, containing two hydroxy-groups. Structure (4) for the latter alkaloid has now been proposed.5 Esters (5) and (6) have also been obtained from the same... 

The configuration at C-13 was determined by measuring the hydrolysis rate of the azobenzenecarboxylic ester of the alkaloid. This widely occurring alkaloid is 13a-hydroxylupanine that is, the hydroxyl is... 

The branches of this plant served as a source for three different esters of 13-hydroxylupanine (97). They are cinegalleine (3-hydroxy-... 

Ten alkaloids have now been isolated from the branches of Genista cinerea DC. These include six esters of 13-hydroxylupanine, four of which have been previously reported. The two esters recently isolated (from Provengal plants) are cinevanine (10), which is the vanillic acid ester of 13-hydroxylupanine, and 13 benzoyloxylupanine. The former had not previously been isolated from natural sources, but the latter had been found previously in Lupinus angustifolius and L albus. The four remaining alkaloids of Genista cinerea are 13-hydroxylupanine, lupanine, anagyrine, and hystrine (11), a base which was first obtained from G. hystrix Lange. 

In such species as L. albus and L. termis, lupanine oeeurs as ( )-lupanine with melting points of 127—128 ° C and 250-252 ° In L. polyphyllus Lindl., L. angustifolius L., and L. albus L., 17-oxolupanine has also been detected. Hydroxylupanine and their esters occur in Lupinus densiflorus, L. latifolius, Lupinus polycarpus, Lupinus ruber, Lupinus burkei L. rotundiflorus, L. montanus, L. exaltatus, L. mexicanus, L. madrensis and L. polyphyllus ... 

PND was shown to be 10 to 50 times more sensitive than FID (Wink et al. 1982). The other detection method commonly used to obtain further information on the chemical structures was EI-MS. However, even GC-MS data are not always sufficient for the identification of quinolizidine alkaloids, since structural isomers such as tetrahydrorhombifoline and N-methyl-angustifoline were found to have the same retention time and very similar mass spectra but could be distinguished by TLC (thin-layer chromatography) (Balandrin and Kinghorn 1981). From some esters of hydroxylupanine it was not possible to detect the molecular ion (Wink et al. 1982). FD-MS (field desorption) was performed directly on the alkaloid extract to detect the molecular ions of the various bases in the mixture. The identity of the compounds was further confirmed by comparison of their retention indices with the ones of authentic samples. More recently, also CI-MS (isobutane or... 

N-methylalbine), 17-oxolupanine, 13a-hydroxymultiflorine, and different esters of 13-hydroxylupanine such as 13-propyloxylupanine, 13-isobutyryloxylupanine, 13-butyryloxy lupanine, 13-isovaleroyloxylupanine, 13-angeloyloxylupanine,... 

During germination, esterification reactions take place. In L. albus, for example, levels of albine and 13a-hydroxylupanine decreased, whereas lupanine and its ester 13a-tigloyloxylupanine increased [21] the latter one also increased during germination of L. angustifolius. 

Usually leaves have different alkaloid profiles than seeds. Generally the hydrox-ylated alkaloids predominate in seeds, whereas esters of 13-hydroxylupanine,... 

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