Lupanines

Feeding experiments utilizing C-, N-, and H-labeled cadaverine (44) and lysine (24) in l upinus augustifolius a source of the lupine alkaloids (—)-sparteine (50, R = H,H) and (+)-lupanine (50, R = O), have been reported which lend dramatic credence to the entire biosynthetic sequence for these and the related compounds discussed above (41). That is, the derivation of these bases is in concert with the expected cyclization from the favored aH-trans stereoisomer of the trimer expected on self-condensation of the 1-dehydropiperidine (45). 

C. stenopetalus belong to group (c) and contain up to 0-4 per cent, of alkaloids mainly cytisine and methylcytisine with traces of anagyrine in some specimens of the second species. C. monspes-sulanus also belongs to group (c) and contains 0-9 per cent, of alkaloids chiefly methylcytisine with some cytisine and a new alkaloid monspessulanine (p. 146), probably of the lupanine group. (1946). 

L. laxus Rydb. Sparteine, d-lupanine, trilupine (p. 132) and fourth... 

The oxidation of lupanine has been investigated by a number of w orkers. Beckel noted that d-lupaniiie formed a perbromide, which on treatment with alcohol yielded cthoxylupanine dihydrobromide, C12H23ON2. OC2H5,2HBr (colourless needles, m.p. 227-8°, [a]7° — 129-4°), from which a number of interesting substances were obtained in yields too small for characterisation. 

The first complete formula (I) suggested for lupanine was that of Thoms and Bergerhoff, based mainly on the formation of 2-ethylpyridine when lupanine was distilled with zinc dust, which seemed to indicate a similarity between tropane and lupanine. 

In 1931 Winterfeld and Kneuer, as a result of their observation that jS-lupinane can be obtained from lupanine, and the formation of 2-methyl-pyrrolidine by the oxidation of sparteine, combined these two features in a partial formula (II) for lupanine, which could be developed in various ways depending on the mode of attachment of the methylpyrrolidine residue. In view, however, of Ing s demonstration of the relationship of anagyrine, CJ5H20ON2, to Z-lupanine, CJ5H24ON2, and d-sparteine, C15H28N2, it was elearly neeessary to consider formul for lupanine derivable from the two alternati-ves, which Ing had proposed for anagyrine and which are shown below as (III) and (IV) with the formul for lupanine derived from them (V) by Ing and (VI) by Clemo and Raper. Sparteine would be represented by (V) or (VI) with the change CO CH2. 

Couch has suggested that dilupine and trilupine see below) are near relatives of lupanine. 

The lupinane group has not attracted chemists as a primary material for modification in the hope of developing substances of possible therapeutic interest. Liberalli found lupanine was inactive in avian malaria and Clemo and Swan state that this is also the case for ll-(e-diethylamino- -pentyl)aminolupinane. Lupinine -aminobenzoate has been investigated in Russia and shown to possess marked local anaesthetic action. ... 

Lupanine, Sparteine, Anagyrine, Cytisine, Matrine and Associated Bases. . . . . . . -. ... 

The reaction of 2-(a-pyridyl)alkylmalonic acid with J -piperideine leading to formation of 3-((x-pyridyl)quinolizidine-l-carboxylic acid on decarboxylation, has been used by Van Tamelen and Foltz (316) for the syntheis of the alkaloid lupanine (Scheme 20). A very elegant synthesis of matrine has been accomplished by Bohlmann et al. (317). 

Alkaloids, e.g. lupanine, angustifoline, sparteine, lupinine, hydroxylupanine 130°C, 17-35 h Induced blue fluorescence (Xf, = 400 nm), detection limits 10 ng. [6]... 

Alkaloids, e.g. lupanine, angustifoline, sparteine, lupinine, hydroxylupanine... 

Kirch et al. (1995) examined individual plants collected in Corsica, Elba, Sardinia, Liguria, and Provence for alkaloids and observed four groups, one characterized by sparteine [119] (see Fig. 2.34 for structures 119-124), one characterized by lupanine-based alkaloids [120 and 121], one that had a very low level of alkaloid production, and one that lacked sparteine and lupanine-based compounds, but did accumulate other alkaloids such as anagyrine [122], ammodendrine [123], and compounds based on cytisine [124], their outlier group. The distribution of these four chemotypes is presented in Table 2.10. 

Spar = Sparteine type Lupa = Lupanine type Lows = Low alkaloid content Others = Other alkaloid types. 

Lopez et al. reported the isolation of three quinolizidine alkaloids such as lupanine (30), 13-a-hydroxylupanine (31), and 17-oxo-lupanine (32) from Lupinus perennis Wild, (family Fabaceae) all these three isolates were found to have potent activity in enhancing glucose-induced insulin release from isolated rat islet cells in a glucose concentration-dependent manner. While the synthetic compound 2-thionosparteine... 

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