Alexa castanospermine from

This compound exhibits the same relationship to (3-D-fructofuranose as 1-deoxy-nojirimcin does to D-glucopyranose. In 1979, a polyhydroxyindolizidine alkaloid was isolated from the poisonous fruit of Castanospermum australe, a handsome Australian indigenous tree, and coined castanospermine (8) after its source.28 A compound subsequently isolated from the seeds of this plant was the pyrrolizidine australine (9),29 also found in Alexa leiopetala,30 along with other compounds. These discoveries increasingly supported the hypothesis that imino sugars and their structural relatives might be a fairly common family of natural products, and their widespread... 

Castanospermine, isolated from the seeds of Castanospermum australe and from dried pods of Alexa leiopetala [6], is another polyhydroxylated indolizidine v th a potent, competitive and reversible inhibitory effect on several glycosidases. For this reason it has been largely used as a glycosidase identifier and as an auxiliary in the purification of glycosidases and mannosidases [120-125]. Castanospermine was also used in two other... 

Castanospermine (239) was originally isolated from seeds of the Australian legume Castanospermum australe (the Moreton Bay chestnut), and later from plants of the South American genus Alexa, which is also a member of the Leguminosae. Two minor diastereomers of ( + )-239, viz. (+ )-6-epicastanospermine (240) and (+ )-6,7-diepicastanospermine (241), were subsequently isolated from C. australe. Castanospermine owes its status as one of the most widely-investigated... 

Castanospermines (+)-Castanospermine [(lS,65, 7i, 87 ,8a7 )-l,6,7,8-tetrah-ydroxyindolizidine, 1] was isolated from the seeds of the Australian legume Cas-tanospermum australe and the dried pod of Alexa leiopetala The analogues (+)-... 

Alternatively, the diastereomeric mixture of aldol adducts undergoes lithium aluminum hydride reduction, primary alcohol silylation, and chromatographic separation to afford 291. Subsequent Mitsunobu inversion at C-3 to furnish the j -alcohol 292 followed by a depro-tective sequence and ring closure provides (+ )-castanospermine (293). This poly-hydroxylated indolizidine alkaloid isolated from Castanospermum australe and Alexa leipetala is a potent inhibitor of various a- and j8-glucosidases [98] (Scheme 68). 

Castanospermine was isolated from seeds of the Australian tree Castanospermum australe 20) and from the South American genus Alexa 21), Castanospermine is a potent inhibitor of a and P-glucosidase. 6-Epicastanospermine, an inhibitor of amylglycosidase, has been found in seeds of C. australe 22), 7-Deoxy-6-epicastanospermine was also found in seeds of C, australe 23). This compound showed a weak inhibitory effect (Figure 3). 

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