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A high-purity octamethylcyclotetrasiloxane (D4 ) with low metallic impurity was prepared by adding ethanol and a small amount of crown ether by solidification, filtration and distillation. After alkali catalyzed ring opening polymerization and end capping reaction, the low volatile vinyl and methyl terminated methyl vinyl silicone rubber were prepared with tetramethyldivinyldisiloxane and silicone oil as the end capping agents, respectively. The formula of silicone rubber (Shore A hardness 40 and 70) with high tear resistant and elastic resilience were discussed. The results show that the proper formula for silicone rubber with Shore A hardness 40 was that 85 phr of 110 polysiloxane with vinyl mole fraction of 0. 03%, 15 phr of 110 polysiloxane with vinyl mole of 0. 08%, 31 phr of fumed silica with 380 m2 / g, and 5 phr of hydroxyl silicone oil, 0. 1 phr of zinc stearate, and 3 phr of 112 polysiloxane with vinyl mole of 3%. The prepared silicone rubber showed Shore A hardness of 42, tensile strength of 11. 0 MPa, elongation at break of 980%, tear strength of 38 kN/ m, elastic resilience of 74. 8%, volatile of 0. 8%, and the mass fraction of n-hexane extracts of 1. 5%, which was ideal for the production of Foley catheter negative pressure ball. The proper formula for silicone rubber with Shore A hardness 70 was as follows: 55 phr of 110 polysiloxane with vinyl mole of 0. 08%, 42 phr of 110 polysiloxane with vinyl mole of 0. 23%, 3 phr of 112 with vinyl mole of 3%, 42 phr of fumed silica with specific surface area of 380 m2 / g, 8 phr of hydroxyl silicone oil, 5 phr of methoxy silicone oil, 0. 1 phr of zinc stearate, 0. 5 phr of hydrogen containing silicone oil with active hydrogen mass of 0. 5%, and 5 phr of polyvinyl silicone oil. Thus the silicone rubber has Shore A hardness of 70, tensile strength of 8. 1 MPa, telongation at break of 540%, tear strength of 46 kN/ m, elastic resilience of 71. 5%, volatile of 1. 2%, and n-hexane extracts of 1. 6%, which can be used on Foley catheter, throat or drainage tube. [ABSTRACT FROM AUTHOR]

Molecular imprinting technology（MIT） has predetermination, recognition and usability, and has been widely used in chromatographic separation， solid phase extraction, drug analysis, chiral recognition and other fields. In recent years， researchers have introduced macrocyclic compounds into MIT， which not only increases the types of functional monomers， but also effectively improves the specificity of molecularly imprinted polymers and the selectivity of target molecules. In this paper， the research progress and application of macrocyclic compounds such as cyclodextrin， calixarene， pillararene， crown ether, cucurbituril and other supramolecular compounds in MIT in the past ten years are reviewed and its development prospects are prospected. [ABSTRACT FROM AUTHOR]

A ureidopyrimidinone-linked benzo-21-crown-7 host molecule and a secondary ammonium salt molecule were synthesized. A [2] pseudorotaxane dimer could be orthogonally self-assembled from the host and guest molecules by the quadruple hydrogen bonding and host-guest interactions. The results from 'H NMR suggested that the disassembly and reassembly of this [2] pseudorotaxane dimer could be reversibly controlled by addition/removal of K. [ABSTRACT FROM AUTHOR]

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The performance of ordinary calixarene can be improved with introducing of sulfur, nitrogen atom. Treatment of thiacalix[4]arene hydrazides derivative 3 with aryl aldehyde derivatives 4, the novel thacalix[4] crowns derivatives 5 containing amides and schif-base units were syntheszzed in high yields with the weak acid catalyst. The new compounds were characterized by elemental analyses, ESI-MS, ¹H NMR spectra. At the same time, we studied the coordination properties of novel thiacalix [4]arene derivatives 5 and series of alpha amino acids. The results showed that the thiacalixarene crown have an effective coordination ability and selectivity on amino acids. [ABSTRACT FROM AUTHOR]

Drug metabolism research plays an essential role in drug discovery and development. Great efforts have been made domestically to be line with the international standardized research on drug metabolism. In this article, we will review new-generation of tyrosine kinase inhibitors(TKIs), these TKIs include icotinib, apatinib, famitinib, flumatinb, allitinib, fruquintinib, and selatinib, among which icotinib and apatinib have been approved by China food and drug administration(CFDA) to reach the market, while others are in clinical trials. For these TKIs, the structural modified sites are active metabolic centers and CYP3A4 is identified as the primary metabolic enzyme. Considering the active intermediates, the crown ether ring of icotinib is oxidated to open to form an aldehyde; the indolylidene ring of famitinib is oxidated followed by rearrangement to form a quinone- imine; the α, β-unsaturated carbonyl group of allitinib is oxidated to form an epoxide, these intermediates are capable of covalently binding biomolecules and generating toxicity. In addition, human (14)C radioactive trials of most of these TKIs have not been conducted, and the data of drug-drug interactions in clinic are also absent, which indicate our deficiency compared to the international regular approaches in metabolic research.