It is known that 1-deoxynojirimycin ( 1) is contained in the leaves and roots of Morus sp. The modified purification procedures of 1 from leaves of Morus bombycis led to the isolation of many polyhydroxylated alkaloids. These include 1, N-methyl-1-deoxynojirimycin ( 2), 2- O-α- d-galactopyranosyl-1-deoxynojirimycin ( 3), fagomine ( 4), 1,4-dideoxy-1,4-imino- d-arabinitol ( 5), 1,4-dideoxy-1,4-imino-(2- O-βB- d-glucopyranosyl)- d-arabinitol ( 6), and 1α,2β,3α,4β-tetrahydroxy- nor-tropane ( 7), designated nortropanoline. The isolation of 2 is the first report of its natural occurrence. Compounds 3 and 6 are the first naturally occurring glycosides of 1 and 5, respectively. Natural alkaloidal glycosidase inhibitors are classified into five structural types: namely polyhydroxylated piperidines, pyrrolidines, pyrrolines, indolizidines, and pyrrolizidines. Nortropanoline is a novel tropane alkaloid and a new type of polyhydroxylated alkaloid.
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