In vitro inhibition of glycogen-degrading enzymes and glycosidases by six-membered sugar mimics and their evaluation in cell cultures.

We investigated in vitro inhibition of mammalian carbohydrate-degrading enzymes by six-membered sugar mimics and their evaluation in cell cultures. 1-Deoxynojirimycin (DNJ) showed no significant inhibition toward glycogen phosphorylase (GP) but was a potent inhibitor of another glycogen-degrading enzyme, amylo-1,6-glucosidase (1,6-GL), with an IC(50) value of 0.16 microM.

Effect of five-membered sugar mimics on mammalian glycogen-degrading enzymes and various glucosidases.

We investigated inhibitory activities of five-membered sugar mimics toward glycogen-degrading enzymes and a variety of glucosidases. 1,4-Dideoxy-1,4-imino-D-arabinitol (D-AB1) is known to be a potent inhibitor of glycogen phosphorylase. However, the structural modification of D-AB1, such as its enantiomerization, epimerization at C-2 and/or C-3, introduction of a substituent to C-1, and replacement of the ring nitrogen by sulfur, markedly lowered or abolished its inhibition toward the enzyme.

Isolation of glycosidase-inhibiting hyacinthacines and related alkaloids from Scilla socialis.

An examination of the bulbs of Scilla socialis has resulted in the isolation of 11 hyacinthacines, two pyrrolidines, and three piperidines. The structures of the new alkaloids were elucidated by spectroscopic methods as beta-1-C-ethyldeoxymannojirimycin (5), hyacinthacines B7 (10), C2 (11), C3 (12), C4 (13), and C5 (14), and alpha-5-C-(3-hydroxybutyl)hyacinthacine A2 (15). Although, beta-l-homofuconojirimycin (3) and alpha-7-deoxyhomonojirimycin (alpha-7-deoxy-HNJ, 4) are previously known alkaloids, this is the first report of their occurrence in the plant family Hyacinthaceae.