산약 점액성분의 정제와 함량분석에 관한 연구

Abstract

산약 (Dioscoreae Rhizoma)의 수용성 점액물질(mucilage)은 Polysaccharide와 Protein으로 구성되어 있는 proteoglycan으로 알려져 왔다. 본 연구에서는 종래의 mucilage 정제법인 에탄올 침전법과는 다른 새로운 방법으로 mucilage 정제를 실시하고자 하였으며, 산약의 mucilage에 대한 정량법을 확립하고, 산약의 가공에 따른 mucilage 함량변화를 알아보았다. 시료산약은 재배품종으로서 시판되고 있는 두 가지 형태의 마 (곤봉형 마, 杖형 마)를 사용하였고, 각각의 생품과 증건품을 가지고 실험하였다. 산약의 물 추출액을 투석한 추, Bio-gel P-100과 Sephadex G-150을 사용하여 겔 여과한 결과, polysaccharide 부분과 Protein 부분이 서로 분리되어 나타나는 것으로 보아, 산약의 mucilage 에는 Protein이 함유되어 있지 않음을 확인할 수 있었다. 한편, mucilage 정량 방법으로는 산약의 mucilage성분이 alcian blue 와 결합체를 형성하여 침전하는 것을 이용하였는데, 반응시의 pH 가 정량에 큰 영향을 주어 pH 7.5 근처에서 최대의 반응성을 나타내며 정량성도 높았다. Mucilage 의 양은 alcian blue 의 흡광도가 1.0일 때를 1 unit로 하였으며, mucilage 함량은 가열처리시와 투석 후에 두 가지 시료 산약이 모두 현저히 감소하였다. 또한 Ostwald viscometer를 사용하여 산약 mucilage의 점도를 측정한 결과, 두 가지 시료산약의 점도는 증건품이 각각의 생품보다 상당히 낮게 나타났다.;It has been known that the plant mucilages are mainly composed of polysaccharide, and the animal mucopolysaccharides are proteoglycans. However, the mucilage of the rhizome of Dioscorea batatas Decaisne has been reported to be a proteoglycan composed of partially acetylated mannan and protein containing small amounts of phosphorus in a ratio of approximately 1.0:2.2. Thus, we attempted to further characterized the mucilage of the yam. For the purpose, we chosed the two types of the yams, club-like (Type Ⅰ) and cane-like (Type Ⅱ) yams, and their steamed/dried yams as materials. Before and after dialysis of the water extracts of the fresh and processed yams, gel filtration chromatograms were compared each other in terms of the elution profiles of polysaccharide and protein. The former was monitored by hexose and uronic acid analysis, and the letter by UV-absorption and Lowry method. In the profiles of the water extarct from the fresh club-like yam on a Bio-gel P-100 column, two protein and two polysaccharide peaks were observed around a void volume, but they were partially overlapped. However, gel filtration of the overlapped fraction on a Sephadex G-150 yeilded the complete separation profiles. Furthermore, gel filtration of the water extract from the processed club-like yam on the Bio-gel P-100 column gave only one polysaccharide peak around the void volume with no protein peak. Similar results were obtained in the fresh and processed cane-like yam. These results revealed that the mucilage of yam was only composed of polysaccharide. Studies on the sugar composition of the mucilage will be still waited. Next, we assessed some properties of the mucilage in the dialyzed water extracts of yams under three kinds of criteria as following:1) a complex-forming capacity between mucilage and aician blue, 2) mannose contents in the mucilage, 3) viscosity. As a results, the complex-forming capacities of the two types of fresh yams were closely similar, but the mannose content and viscosity of the Type Ⅰ (club-like) yam were lower about 40% than those of the Type Ⅱ (cane-like) yam. The process of the two types of fresh yams by steaming and drying greatly lowered the complex-forming capacity and viscosity, but raised the mannose contents in the Type Ⅰ and Ⅱ yams by 290 and 22%, respectively.