In the treatment of Type II (noninsulin-dependent) diabetes, management of blood glucose levels is critical. One strategy is to delay digestion of ingested carbohydrates, thereby lowering postprandial blood glucose concentration [1]. This can be achieved by inhibiting the activity of pancreatic a-amylase, which mediates the hydrolysis of complex starches to oligosaccharides, and ⁄ or membrane-bound intestinal a-glucosidases, which hydrolyze these oligosaccharides to glucose in the small intestine [1]. Carbohydrate analogues, such as acarbose (1) and miglitol (2) (Fig. 1 Inhibitors targeting pancreatic a-amylase and intestinal a-glucosidases delay glucose production following digestion and are currently used in the treatment of Type II diabetes. Maltase-glucoamylase (MGA), a family 31 glycoside hydrolase, is an a-glucosidase anchored in the membrane of small intestinal epithelial cells responsible for the final step of mammalian starch digestion leading to the release of glucose. This paper reports the production and purification of active human recombinant MGA amino terminal catalytic domain (MGAnt) from two different eukaryotic cell culture systems. MGAnt overexpressed in Drosophila cells was of quality and quantity suitable for kinetic and inhibition studies as well as future structural studies. Inhibition of MGAnt was tested with a group of prospective a-glucosidase inhibitors modeled after salacinol, a naturally occurring a-glucosidase inhibitor, and acarbose, a currently prescribed antidiabetic agent. Four synthetic inhibitors that bind and inhibit MGAnt activity better than acarbose, and at comparable levels to salacinol, were found. The inhibitors are derivatives of salacinol that contain either a selenium atom in place of sulfur in the five-membered ring, or a longer polyhydroxylated, sulfated chain than salacinol. Six-membered ring derivatives of salacinol and compounds modeled after miglitol were much less effective as MGAnt inhibitors. These results provide information on the inhibitory profile of MGAnt that will guide the development of new compounds having antidiabetic activity.Abbreviations HPA, human pancreatic a-amylase; MGA, maltase glucoamylase; MGAnt, maltase glucoamylase N-terminal catalytic domain; pNP, paranitrophenyl; SIM, sucrase isomaltase.