1.Peel strength and interfacial characterization of maxillofacial silicone elastomers bonded to titanium.
Artopoulou II1, Chambers MS2, Zinelis S3, Eliades G3. Dent Mater. 2016 Apr 22. pii: S0109-5641(16)30018-5. doi: 10.1016/j.dental.2016.03.024. [Epub ahead of print]
OBJECTIVES: To investigate the effect of three adhesive primers on the morphology, chemistry and peel bond strength of two maxillofacial silicone elastomers with commercially pure titanium (cpTi).
2.Passive membrane permeability of macrocycles can be controlled by exocyclic amide bonds.
Hickey JL, Zaretsky S, St Denis MA, Kumar Chakka S, Morshed MM, Scully CC, Roughton AL, Yudin AK. J Med Chem. 2016 Apr 27. [Epub ahead of print]
We have developed a strategy to synthesize passively permeable peptidomimetic macrocycles. The cyclization chemistry centers on using aziridine aldehydes in a multicomponent reaction with peptides and isocyanides. The linker region in the resulting product contains an exocyclic amide positioned α to the peptide backbone, an arrangement that is not found among natural amino acids. This amide provides structural rigidity within the cyclic peptidomimetic and promotes the creation of a stabilizing intramolecular hydrogen bonding network. This exocyclic control element also contributes to the increased membrane permeability exhibited by multicomponent-derived macrocycles with respect to their homodetic counterparts. The exocyclic control element is employed along with a strategic placement of N-methyl and D-amino acids to produce passively permeable peptides, which contain multiple polar residues. This strategy should be applicable in the pursuit of synthesizing therapeutically relevant macrocycles.
3.The cytotoxic and tyrosine kinase inhibitory properties of C21 steroids and iridoids from the tubers of Alocasia cucullata.
Peng W1,2, Liang S3, Hu J3, Chen Z1,2, Zheng X4. J Nat Med. 2016 Apr 27. [Epub ahead of print]
Ten steroids and iridoids were isolated from the tubers of Alocasia cucullata (Lour.) G. Don. Among them, alocasgenin A (1) and alocasgenoside B-C (2-3) were new compounds and the aglycone of compound 1, obtained from the acid hydrolysis of 1, was named alocasgenol (1a). Also, for the first time, tenacigenin B (4), 17β-tenacigenin-B (5), 3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-tenacigenin C (6), marsdenoside A-B (7-8) and tenacigenoside A-B (9-10) were isolated from the genus Alocasia. The chemical structures were elucidated by the extensive analysis of spectral data and compared with the literature. By evaluation of the cytotoxic and tyrosine kinase inhibition, compounds 1-10, 1a and compound 2 showed significant growth inhibition against two tumour cell lines, MGC-803 and HT-29, while compounds 1, 1a, 3, 6 and 8 presented moderate inhibition. Furthermore, compound 2 had the inhibitory property against the enzyme activity biochemically.
4.Dual-template magnetic molecularly imprinted particles with multi-hollow structure for the detection of dicofol and chlorpyrifos-methyl.
Yang T1,2, Feng S1, Lu Y2, Yin C2, Wang J1. J Sep Sci. 2016 Apr 27. doi: 10.1002/jssc.201600258. [Epub ahead of print]
In this work, a novel dual-template magnetic molecularly imprinted polymer particle for dicofol and chlorpyrifos-methyl was prepared through oil-in-water emulsifier-free emulsion technology. The resulting magnetic particles were characterized with electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. It was found that as-prepared particles were well-shaped spherical, with multi-hollow structures and in a size around 125 μm. Meanwhile it showed a good magnetic sensitivity. The results testified that multi-hollow magnetic molecularly imprinted polymers possessed excellent recognition capacity and fast kinetic binding behavior to the objective molecules. The maximum binding amounts towards dicofol and chlorpyrifos-methyl were 31.46 and 25.23 mg/g, respectively. The feasibility of the use of the particles as a solid-phase extraction sorbent was evaluated. Satisfactory recoveries ranging from 90.62-111.47 and 91.