白及（Bletilla striata (Thunb.) reichb. f.）的SOD同工酶只有一条较宽的谱带，确认为Ｃｕ·Ｚｎ－ＳＯＤ。其块茎ＳＯＤ总活性和比活性都高，且含有丰富的白及胶；经丙酮分级沉淀，Sephadex G100凝胶过滤和ＤＥＡＥ－纤维素柱层析分离纯化，获得对ＣＮ^-敏感的淡兰色Ｃｕ·Ｚｎ-ＳOＤ粉末。在凝胶电泳染色图谱上，纯化后的酶与粗酶液的ＳＯＤ区带相对应，且其酶活性染色带与蛋白染色带位置对应，表明已纯化到均一程度。该酶分子量约３３ＫＤ，亚基分子量约为１６．４ＫＤ；紫外光区的吸收峰在２６４．６ｎｍ，等电聚焦电泳呈现一条蛋白区带，ｐＨ值在４．３５左右；该酶在ｐＨ６．０～１０．０，温度在５０℃范围内具稳定性。纯化后的酶为４５６３．２ｕ／ｍｇ·蛋白，纯化了５１倍，活力回收为２２．３％。上述酶没有过氧化氢酶活性。提取过程中还得到高质量的副产品白及胶。

The isozyme of SOD in Bletilla striata (Thunb.) reichb. f. has only a single broad band which identified as Cu·Zn-SOD. Both the total and relative activities of SOD in the tuber are higher , and rich of Bletilla glue. After gradient precipitate, Sephadex G100 gel filtration and DEAE-cellulose column chromatographic isolation and purification,a light-blue and CN^--sensitive powder of Cu·Zn-SOD was obtained. On gel-electrophoresis chromatogram, the dividing zone of the purified enzyme is correspond with the crude extracts, moreover, the stained band of the purified enzymic activity identifies with that of enzyme protein, it demonstrated that this enzyme might be purified to a homologuous form. The M.W. of the enzyme is about 33 KD, the subunit is correspond with the crude extracts ,moreover, the stained band of this enzyme activity identifies with that of enzymic protein, it demonstrated that this enzyme might might be purified to a homologuous form. The M.W. of the enzyme is about 33KD, the subunit is 16.4 KD. The peak of U.V. absorption band is 264.6 nm, and shows single band on isofocus electrophoresis, it’s isoelectric point is about pH 4.35. The enzyme is stable under the condition of pH6.0～10.0 and 50℃. The purified enzyme is 4563.3 unit per mg protein, so that it is purified by 51 fold, the rate of recovery of activity is 22.3%.The enzyme does not express the activity of catalase. A by-product, high quality Bletilla glue was also obtained from extractive process.