Hensel A, Schmidgall J, Kreis W
Institut für Botanik und Pharmazeutische Biologie, Friedrich-Alexander-Universität Erlangen, Germany.
Planta Med. 1997 Oct;63(5):441-5. doi: 10.1055/s-2006-957730.
Extracellular polysaccharides (ECP) were isolated in yields of up to 4 mg/ml from the culture media of suspension-cultured cells from Digitalis lanata Ehrh. ECP content was increasing continuously over the first ten days of cultivation and then stayed constant until day 20. ECP were fractionated by ion-exchange chromatography into two neutral and one acidic fractions. Further fractionation was achieved by gel-permeation chromatography (GPC). One neutral fraction was separated into two distinct fractions with average molecular weights of 160 and 70 kDa, respectively. The second neutral fraction was hetero-disperse in GPC with average molecular masses of 112, 32, and 8 kDa. Polysaccharides of all neutral fractions consisted of glucose, xylose, galactose, and arabinose. Methylation analysis indicated these fractions to contain xyloglucans besides minor amounts of highly branched arabinogalactans. Xyloglucans were, using endo-beta-(1-->4)glucanase, fragmented into subunits which were identified mainly as tri- and pentasaccharides. The acidic fraction eluated as a single peak during gel-permeation chromatography with an average molecular weight of 56 kDa. Analysis of carbohydrate composition and linkage analysis indicated that this polysaccharide is an acidic arabinogalactan. 2,6-Dideoxysugars, the typical carbohydrate components of cardiac glycosides in Digitalis lanata, were not detected in ECP.
从毛花洋地黄悬浮培养细胞的培养基中分离出细胞外多糖（ECP），产量高达4毫克/毫升。在培养的前十天，ECP含量持续增加，然后在第20天之前保持恒定。通过离子交换色谱法将ECP分离为两个中性组分和一个酸性组分。通过凝胶渗透色谱法（GPC）进行进一步分离。一个中性组分被分离为两个不同的组分，平均分子量分别为160 kDa和70 kDa。第二个中性组分在GPC中是多分散的，平均分子量为112 kDa、32 kDa和8 kDa。所有中性组分的多糖均由葡萄糖、木糖、半乳糖和阿拉伯糖组成。甲基化分析表明，除少量高度分支的阿拉伯半乳聚糖外，这些组分还含有木葡聚糖。使用内切β-(1→4)葡聚糖酶将木葡聚糖片段化为亚基，这些亚基主要被鉴定为三糖和五糖。酸性组分在凝胶渗透色谱中以单峰洗脱，平均分子量为56 kDa。碳水化合物组成分析和连接分析表明，这种多糖是一种酸性阿拉伯半乳聚糖。在ECP中未检测到2,6-二脱氧糖，即毛花洋地黄中强心苷的典型碳水化合物成分。
