${eta}$-Glucan 분획을 제거한 신령버섯 균사체 액체 배양액(${eta}$-glucan-free HEAB)으로부터 새로운 형태의 ${alpha}$-glucosidase 활성저해 소재를 개발하였다. ${eta}$-Glucan-free HEAB를 용매분획하여 10 mg/ml 농도에서 ${alpha}$-glucosidase 저해활성을 측정한 결과 EA분획이 가장 강한 활성(61.6% 저해)을 나타내었고, 경구혈당강하제인 acarbose (5 mg/ml; 39.5% 저해) 보다 강하였다. EA분획을 더 분획하여 ${alpha}$-glucosidase 저해활성이 80.4%인 분획을 얻었다. 이 분획에는 ${alpha}$-glucosidase 저해 활성을 갖는 daidzin 및 genistin과 같은 isoflavone과 isoflavone의 sugar conjugate된 물질이 함유되어 있었다. 따라서 ${alpha}$-glucosidase 저해 활성을 나타내는 ${eta}$-glucan-free HEAB나 EA분획물은 인체의 혈당을 조절할 수 있는 소재로 활용될 수 있을 것이다.
Natural anti-diabetic semipurified ethyl acetate fraction was isolated from the submerged-liquid culture of Agaricus blaze Murill (AB) in a medium containing soybean flakes. Hot-water extract of AB (HEAB) was prepared by extraction at $121^{circ}C$ for 60 min, followed by filtering through a filter presser filled with diatomate. The ${eta}$-glucan-free HEAB, which was a supernatant fraction from HEAB by precipitation in an 80% ethanol solution, was fractionated into hexane, chloroform, ethyl acetate, and butanol fractions. The inhibition of the ${alpha}$-glucosidase activity by fractions was 59.0, 17.0, 61.6, and 37.9%, respectively, suggesting that ethyl acetate fraction was the most active. A subfraction having a strong ${alpha}$-glucosidase inhibitory activity (80.4%) was isolated from the ethyl acetate fraction. This subfraction contained isoflavones (genistin and daidzin) and their conjugates with sugars as potent inhibiters of ${alpha}$-glucosidase activity. These results suggest that the ethyl acetate fraction or HEAB containing isoflavones and their sugars conjugates could be useful sources for controlling blood sugar levels in humans.
