Oxasilacyclopropane. Isolation and characterization

A crystalline oxasilacyclopropane was isolatedby the reaction of photochemically induced dimesitylsilylene with 1,1,3,3-tetramethyl-2-indanone, and the exact structure of the oxasilacyclopropane was confirmed by X-ray crystal analysis.     

抗重金属真菌的分离及特性研究

从四川省彭州市龙门山镇铜尾矿土壤中分离得到了三株高抗重金属铜离子的真菌.本文对其中一株具有较好重金属抗性的菌株Y2进行了研究,根据形态学特征和18S rDNA序列分析将其鉴定为青霉菌属.在PDA培养基上,Y2菌株能够耐300mmol/LCu2+,限制Y2菌株生长的其它金属盐的最小浓度(mmol/L)依次为:Zn2+,600;Cd2+,<20;Cr3+,<3;Ni2+,<20;Pb2+,<50.在含3种金属盐混合物的PDA中的Y2菌株生长的正交实验结果表明:金属盐之间存在显著的毒性协同效应,不仅与盐的种类也与组成盐之间的浓度相关;Y2菌株具有一定的抗三种金属盐混合物的能力.原子吸收测定Y2菌株对重金属污染土壤的处理,结果表明菌株Y2对土壤中铜有一定吸附作用.     

Purification and characterization of dioscin-alpha-L-rhamnosidase from pig liver

Dioscin-alpha-L-rhamnosidase was isolated, purified and partially characterized from pig liver. The maximum activity was reached at pH 7, 42 degrees C, 24 h, and 2% of substrate concentration. Fe3+ and Cu2+ inhibited the enzyme; the ion Ca2+ activated it. Mg2+ was an inhibitor at 100 mM, but it was an activator at 200 mM. Zn2+ could be a weak activator of the enzyme. The molecular weight of dioscin-alpha-L-rhamnosidase was about 47 kDa as determined by the method of SDS-polyacrylamide gel electrophoresis.     

Isolation and characterization of the polysaccharide ofSophora japonica fruit

Simferopol' State University, and Kursk State Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 748-749, September-October, 1995. Original article submitted March 10, 1995.     

Permeability of ionized salicylate derivatives through guinea pig dorsal skin

pH-dependency of skin permeability to salicylic acid was examined in excised guinea pig dorsal skin. Permeation followed the pH-partition theory at acidic pH. However, above pH 5.0 the observed permeability coefficients were larger than the estimated values obtained from the ratio of the undissociated forms. These findings are quite different from those obtained using the same drug and a silicone rubber membrane, in which permeability coefficients were consistent with the pH-partition theory. The findings suggested that permeation of salicylate as anions occurred at a neutral skin pH. The permeability coefficient of the ionized form was estimated to be about 1.6% of the nonionized form. We also examined the skin permeability of salicylate and its five 5-substituents and two 3-substituents at pH 7.4. We investigated the relationship between their permeability coefficients and the physico-chemical properties of the substituents. Multi regression analysis on the permeability coefficients showed a parabolic relationship between the values of the hydrophobic parameter (pi) and the logarithms of the permeability coefficients. These findings suggested that the ionic permeation pathway of salicylate derivatives is controlled by hydrophobic as well as hydrophilic properties.     

Isolation and characterization of thiosalicylic acid selenotrisulfide

Thiosalicylic acid selenotrisulfide(SeT) was prepared by the reaction of thiosalicylic acid and selenious acid in methanol. The precipitated SeT was partially purified by an extensive washing with methanol and pure SeT was isolated by preparative high-performance liquid chromatography (HPLC) using a reverse phase column. The HPLC method was useful both in the analysis and the isolation of SeT.     

Isolation and characterization of a zein polypeptide

Scientific Research Institute of Biology, Dnepropetrovsk State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 612–613, July–August, 1988.