전국 각지 토양으로 부터 채취한 토양균을 screening하여 ${alpha}-amylase$를 저해하는 물질을 생성하는 균주인 Streptomyces DMC-72를 선발하였다. 이 균주가 생성하는 저해제를 acetone 침전 및 이온 교환 수지인 Amberlite IRC-50, Amberlite CG-50과 SP-Sephadex C-25를 이용하여 분리하였다. 이 물질은 ${alpha}-amylase$ 뿐만아니라 다른 amylase와 기타 효소에 대해서도 억제작용을 나타내었다. 이 물질은 기질인 soluble starch의 가수분해에 대해서 non-competitive하게 저해작용을 보이주고 있으며 열 및 넓은 범위의 pH에서 안정한 물질이었다. 이 물질은 anthrone 시험과 IR spectrum에 의해서 oligosaccharide계 화합물임을 알 수 있었다.
Of 450 strains isolated from the soil microbes collected in various locations in Korea, a strain had a strong inhibitory activity against bacterial ${alpha}-amylase$ and was named strain DMC-72 of the genus Streptomyces. The amylase inhibitory metabolite produced by this strain was purified by means of acetone precipitation, adsorption on Amberlite IRC-50 and SP-Sephadex C-25. The inhibitor was found to be a derivative of oligosaccharides by spectral and chemical data. The inhibitor was stable at the pH range of $1{sim}13$ and at $100^{circ}C$ for half an hour, also inhibited other amylases such as salivary ${alpha}-amylase$, pancreatic ${alpha}-amylase$, fungal ${alpha}-amylase$ and glucoamylase. However, it showed no inhibitory activity against ${alpha}-glucosidase$, ${eta}-glucosidase$, dextranase, and ${eta}-amylase$. The kinetic studies of the inhibitor showed that its inhibitory effects on starch hydrolysis by ${alpha}-amylase$ were noncompetitive.
