Hydrophobic substituents increase the potency of salacinol, a potent α-glucosidase inhibitor from Ayurvedic traditional medicine 'Salacia'.

Using an in silico method, seven analogs bearing hydrophobic substituents (8a: Me, 8b: Et, 8c: n-Pent, 8d: n-Hept, 8e: n-Tridec, 8f: isoBu and 8g: neoPent) at the 3'-O-position in salacinol (1), a highly potent natural α-glucosidase inhibitor from Ayurvedic traditional medicine 'Salacia', were designed and synthesized. In order to verify the computational SAR assessments, their α-glucosidase inhibitory activities were evaluated in vitro. All analogs (8a-8g) exhibited an equal or considerably higher level of inhibitory activity against rat small intestinal α-glucosidases compared with the original sulfonate (1), and were as potent as or higher in potency than the clinically used anti-diabetics, voglibose, acarbose or miglitol.

Highly Diastereoselective Route to α-Glucosidase Inhibitors, Neosalacinol and Neoponkoranol.

A facile and highly diastereoselective route to potent natural α-glucosidase inhibitors, i.e., neosalacinol (4) and neoponkoranol (6), isolated from the traditional Ayurvedic medicine "Salacia" was developed by intramolecular cyclization of appropriately substituted sulfides (9 and 12).

Role of the side chain stereochemistry in the α-glucosidase inhibitory activity of kotalanol, a potent natural α-glucosidase inhibitor.

Synthesis and evaluation of four diastereomers (9a, 9b, 9c and 9d) of kotalanol, a potent α-glucosidase inhibitor isolated from an Ayurvedic medicinal plant Salacia species, are described. Stereo-inversion at C-3' and C-4' of kotalanol (2) caused significant decrease of the inhibitory activities against maltase and sucrase, whereas inhibitory activity against isomaltase sustained, thus resulted in exerting selectivity against isomaltase.

A novel C-C bond formation at the 5-position of uridine derivatives.

We have developed a novel C-C bond formation at the 5-position of uridine derivatives using intramolecular base-catalyzed Baylis-Hillman type reaction.