Lupinus hirsutus

Lupinus luteus L., Lupinus hispanicus L., Lupinus hirsutus L. They have also been found in Anabasis aphyla. In absolute configuration, lupinine is in its (—)-form, which is non-stable thermally, and is easily epimerized to epilupinine, which is a stable (+)- form of lupinine . The melting point of (—)-lupinine is 70-71 °C, of mixed (+ and —)-lupinine 63-64°C, and of (+)-lupinine (synthetic)... 

The new glycosidic alkaloid (- )-(3-methoxy-4-a-L-riiamnosyloxycinnamoyl)-epilupinine was isolated as a 5 1 mixture of (Z)- and ( )-isomers 338 and 339 ([a]o -37.5 , c 0.056, EtOH) from the aerial parts of Lupinus hirsutus 332). In addition to the customary spectroscopic evidence, the structure was corroborated by hydrolysis with 3% aqueous hydrochloric acid to form rhamnose and the known compound. (+ )-(4-hydroxy-3-methoxycinnamoyl)epilupinine (337). The latter was hydrolyzed in its turn with 7% hydrochloric acid to give (+ )-epiIupinine (331). The ( )-isomer 339 ([a]p -80°, c 0.28, EtOH) was subsequently reported as a new alkaloid from aerial parts of L. varius ssp. orientalis similar spectroscopic data were cited, and hydrolysis to L-rhamnose and the corresponding aglycone also supported the structural assignment (525). 

The bicyclic lupine alkaloid, (-)-(3 -methoxy-4 -a-L-rhamnosyloxycinna-moyl)-epilupinine, Fig. (33), was isolated from the aerial parts of Lupinus hirsutus [218]. 

CH,OCOCH=CHOR IS (-)-(tranx -a-L-rhamnOsyloxy- cinnamoyl)epilupinine (R=a-L-Rha) Lupinus hirsutus L. (aerial parts) 13... 

Fig. 9 Acyltransferase-catalyzed formation of the lupin alkaloid esters in Lupinus hirsutus...

Saito K, Suzuki H, Takamatsu S, Murakoshi 1, (1992) Acyltransferases for lupin alkaloids in Lupinus hirsutus. Phytochemistry 32 87-91... 

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