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The binding mechanism between pefloxacin mesylate (PM) and transferrin (Tf) was explored using spectral experiment combined with molecular modeling techniques. The binding parameters and thermodynamic functions of PM-Tf solution system were measured at different temperatures. The effect of PM on molecular conformation of Tf was investigated and the interaction mechanism was also discussed. The results showed that dynamic quenching mechanism occurs with PM binding to Tf. The value of binding distances (r) is low, which indicates the occurrence of energy transfer. The drug had conformational effect on Tf, which resulted in changes of hydrophobic environment of the binding domain in Tf. According to the obtained thermodynamic parameters, the main interaction force between PM and Tf is attributed to hydrophobic bonding. The results of molecular modeling revealed that hydrophobic and hydrogen bonds are main binding forces in the PM-Tf system. These results were in accordance with spectral experiments. The research results have given a better theoretical reference for the study of pharmacological mechanism between protein and quinolone.
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<p><b>OBJECTIVE</b>To study the genetic polymorphism and genetic relationship of different provenances of Leonurus japonicus.</p><p><b>METHOD</b>Genetic relationship in 19 provenances, which came from nationwide origins were measured by using polymerase chain reaction (PCR) with ISSR marker.</p><p><b>RESULT</b>Twenty ISSR primers were selected from 100 ISSR primers and used for ISSR amplification. A total of 164 bands were generated, of which 117 bands were polymorphic bands (the percentage of polymorphic band, PPB = 71.34%). The similarity coefficients were calculated with NTsys 2.10e software and the dendrogram were constructed with UPGMA. Nineteen samples were divided into 3 types using the cluster analysis according to their genetic similarity coefficient.</p><p><b>CONCLUSION</b>Results from the cluster analysis were correlated significantly with the morphological characteristics and geographical location of 19 samples. The data indicate that ISSR technique is useful to determine genetic diversity and genetic relationship among Leonurus provenances, providing a scientific basis for genetic breeding, differentiation and new cultivar selection.</p>
Subject(s)
China , DNA Primers , Genetics , Genetic Markers , Genetic Variation , Leonurus , Classification , Genetics , Phylogeny , Polymorphism, GeneticABSTRACT
Object The formulation of a standard for the quality control of BINGGANKANG GRANULE was studied Methods The presence of Fructus Ligustri Lucidi, Radix Astragahi, Rhizoma Polygoni Cuspidati, Radix Isatidis and Fructus Schisandrae Chinensis were identified by TLC The content of ginsenoside Rg 1, the main active principle in the granule derived from Panax quinquefolius L was assayed by TLCS Results Linearity was found in the range from 2 08～10 40 ?g of ginsenoside Rg 1, the average recovery was 97 64% and RSD=1 74% Conclusion The method was found to be highly sensitive, simple, precise and reproducible and may be used for the quality control of the granule
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Objective:To establish a RP HPLC method to determine the content of icariin in COMPOUND XIANLINGPI INJECTION.Methods:The samples was determined by RP HPLC on an ODS column. UV detection wavelength was at 270 nm. Icariin as an external standard and CH 3OH H 2O(30∶70) as a mobile phase.Results: The average recovery was 98.32%. RSD was 1.48%.Conclusion:The method is simple and accurate. It can be used to control the quality of COMPOUND XIANLINGPI INJECTION.