Maeda Hiroaki, Zhu Xia, Suzuki Shiho, Suzuki Kiyoshi, Kitamura Shinichi
Research and Development Division, Daiwa Pharmaceutical Company, Ltd., 1650-88 Okuhara-cho, Ushiku, Ibaraki 300-0551, Japan.
J Agric Food Chem. 2004 Aug 25;52(17):5533-8. doi: 10.1021/jf049617g.
Lactobacillus kefiranofaciens, isolated from kefir grains, produces an extracellular polysaccharide when cultured, not only in PYG10 medium but also in a liquid medium containing a rice hydrolysate that had been previously degraded by treatment with a glucoamylase. The maximum yield of the polysaccharide, using the rice hydrolysate as the medium, was 2.5 g/L after a 7-day culture period at pH 5.0 and 33 degrees C. Compositional analysis, methylation analysis, specific rotation, and (1)H and (13)C NMR spectroscopy revealed that the structures of polysaccharides obtained from these two different culture media are essentially identical. The polysaccharide is composed of a hexasaccharide repeating unit and, thus, is known as kefiran. The weight-average molecular weight and the z-average radius of gyration of a sample, purified from the rice hydrolysate medium, were determined to be 7.6 x 10(5) g/mol and 39.9 nm, respectively, by gel permeation chromatography equipped with a multiangle laser-light-scattering photometer. Changes in blood pressure and serum components were examined in SHRSP/Hos rats, using doses of 100 and 300 mg of kefiran/kg of rat. A suppression in the increase in blood pressure was observed in these rats after 30 days. This activity is discussed in terms of the concentration of serum components of the rat, with emphasis on lipid components such as cholesterols, triglycerides, and free fatty acids.
从开菲尔粒中分离出的开菲尔糖乳杆菌，在培养时不仅能在PYG10培养基中产生胞外多糖，还能在含有经糖化酶处理预先降解的大米水解物的液体培养基中产生。以大米水解物为培养基，在pH 5.0和33℃下培养7天后，多糖的最大产量为2.5 g/L。组成分析、甲基化分析、比旋光度以及（1）H和（13）C核磁共振光谱表明，从这两种不同培养基中获得的多糖结构基本相同。该多糖由一个六糖重复单元组成，因此被称为开菲尔多糖。通过配备多角度激光光散射光度计的凝胶渗透色谱法测定，从大米水解物培养基中纯化得到的样品的重均分子量和z-平均回转半径分别为7.6×10（5）g/mol和39.9 nm。在SHRSP/Hos大鼠中，使用100和300 mg/kg大鼠剂量的开菲尔多糖检测血压和血清成分的变化。30天后，在这些大鼠中观察到血压升高受到抑制。根据大鼠血清成分的浓度，重点是胆固醇、甘油三酯和游离脂肪酸等脂质成分，对这种活性进行了讨论。
