Nortropane alkaloids isolation

Morusimic acid B was first isolated together with five new unknown nortropane alkaloids and five other new amino acids by Kusano et al. in 2002 from the ripened fruits of the white Mulberry tree (Moms alba L, Moracae). Several compounds isolated from Moms alba show glycosidase inhibitory properties. 

Glycosidase-inhibiting alkaloids from plants are classified into five structural classes polyhydroxylated pyrrolidines, piperidines, indolizidines, pyrrolizidines, and nortropanes. Furthermore, they also occur as the glycosides. This review describes recent studies on isolation, characterization, glycosidase inhibitory activity, and therapeutic application of the sugar-mimicking alkaloids from plants. 

Through these methods, 26 calystegines, calystegine-like nortropanes, and calystegine glycosides were isolated to date (Table II). The isolation methods for polyhydroxy alkaloids appear laborious and tedious. However, alternative... 

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