Natural products with interesting biological properties and structural diversity have often served as valuable lead drug candidates for the treatment of human diseases. Salacinol, a naturally occurring alpha-glucosidase inhibitor, was shown to be one of the active principles of the aqueous extract of a medicinal plant that has been prescribed traditionally as an Ayurvedic treatment for type II diabetes. Salacinol contains an intriguing zwitterionic sulfonium-sulfate structure that comprises a 1,4-anhydro-4-thio-D-arabinitol core and a polyhydroxylated acyclic chain.
Facile synthesis of de-O-sulfated salacinols (3) was developed by employing the coupling reaction of an epoxide, 1,2-anhydro-3,4-di-O-benzyl-D-erythritol (9) with 2,3,5-tri-O-benzyl-1,4-dideoxy-1,4-epithio-D-arabinitol (10) as the key reaction. The reported structure of a potent alpha-glucosidase inhibitor named neosalacinol (8), isolated recently from Ayurvedic medicine Salacia oblonga, was proved incorrect, and revised to be de-O-sulfated salacinol formate (3c) by comparison of the spectroscopic properties with those of the authentic specimen synthesized.
An approach to controlling blood glucose levels in individuals with type 2 diabetes is to target alpha-amylases and intestinal glucosidases using alpha-glucosidase inhibitors acarbose and miglitol. One of the intestinal glucosidases targeted is the N-terminal catalytic domain of maltase-glucoamylase (ntMGAM), one of the four intestinal glycoside hydrolase 31 enzyme activities responsible for the hydrolysis of terminal starch products into glucose.
A practical HPLC-MS method for the quantitative determination of salacinol (1) and kotalanol (2), potent alpha-glucosidase inhibitors from Salacia species (Hippocrateaceae) as a specific remedy for diabetes in Ayurvedic system, was developed. The optimum conditions of separation and detection of these two constituents were achieved on a Asahipak NH2P-50 column (5 mcirom particle size, 2.0 mm i.d. x 150 mm) with a CH(3)CN-H(2)O mobile phase, associated with MS using electrospray ionization source.
A quantitative analytical method for the highly polar sulfonium pseudo-sugar constituents neosalacinol (3) and neokotalanol (4), another two potent α-glucosidase inhibitors isolated from Ayurvedic traditional medicine Salacia species, was developed by employing an ion pair reagent upon chromatographic separation.
Inhibition of intestinal α-glucosidases and pancreatic α-amylases is an approach to controlling blood glucose and serum insulin levels in individuals with Type II diabetes. The two human intestinal glucosidases are maltase-glucoamylase and sucrase-isomaltase. Each incorporates two family 31 glycoside hydrolases responsible for the final step of starch hydrolysis.
With the aid of an in silico method, α-glucosidase inhibitors with far more potent activities than salacinol (1), a potent natural α-glucosidase inhibitor isolated from an Ayurvedic traditional medicine Salacia reticulata, have been developed.
Ageing changes gut microbiota composition and alters immune system function. Probiotics, prebiotics and synbiotics may improve the health status of elderly individuals by modifying the intestinal environment and the microbiota composition, and by stimulating the immune system. In this work, we studied the effects of synbiotic supplementation on the gut microbiota of healthy elderly volunteers. Fifty-one elders were randomly assigned to consume either a synbiotic dietary supplement or a placebo in addition to their usual diet for a 2-week period.