The inhibitory activities of a water extract of Sanghwang mushroom(Phellinus linteusau)(SWE) against α-glucosidases were evaluated in this study. Inhibiting these enzymes involved in the absorption of disaccharides significantly decreases the postprandial increase in blood glucose level after a mixed carbohydrate diet. Oxygen radical absorbance capacity and 1, 1-diphenyl-2-picryl hydrazyl scavenging activities of the SWE were evaluated to investigate the antioxidant activity of the SWE associated with complications of long-term diabetes. Furthermore, the postprandial blood glucose lowering effect of SWE was compared to a known type 2 diabetes drug(Acarbose®) in a Sprague-Dawley rat model. SWE significantly reduced the blood glucose increase after sucrose loading. These results suggest that SWE, which has high α-glucosidase inhibitory activity and high antioxidant activities, has the potential to contribute to a useful dietary strategy for controlling postprandial hyperglycemia.

In order to confirm the presence of putative glucoamylase gene in Tricholoma matsutake genome, the genomic DNA was prepared from T. matsutake NBRC30773 strain and was used as template to clone the glucoamylases gene (TmGlu1). We obtained the nucleotide sequence of TmGlu1 and its franking region. The coding region (from ATG to stop codon) is 2,186 bp. The locations of exons and introns were determined from the nucleotide sequences of 3’- and 5’-RACE PCR and RT- PCR products. On the other hand, to investigate the relationship between composition of medium and glucoamylase expression, we checked the expression level of glucoamylase gene by realtime reverse transcription PCR and measurement of glucoamylase enzyme activity. It was found that enzyme activity of glucoamylase was very low in different medium. Expression of glucoamylases gene appeared to not be affected by different carbon source.