Search

Zika virus (ZIKV), belonging to the family of flaviviruses, is an emerging mosquito-borne pathogen causing microcephaly and other congenital abnormalities in newborns as well as various neurologic pathologies in adults. The climate change and the lifestyle of current societies, involving global mobility, result in a rapid broadening of ZIKV geographic distribution. There are no vaccines or drugs available to protect against or cure the diseases caused by that virus. Our in vitro studies have demonstrated that sodium polyanethole sulfonate (PASNa), a degradable polymer used in various biomedical applications, acts as an efficient ZIKV inhibitor, both in animal and human cells. The mechanistic studies indicated that PASNa bound to the ZIKV particles thus hindering their attachment to the host cells and also interfered in the late steps of viral replication. PASNa is characterized by very low cytotoxicity and its antiviral activity can be achieved at a concentration much lower than that at which its anticoagulant activity has to be considered. Isothermal titration calorimetry (ITC) studies have shown that the interaction of PASNa with human serum albumin (HSA), the most abundant blood protein, is the endothermic, entropydriven process resulting in the formation of stoichiometric (1:1) PASNa-HSA complexes with a hydrodynamic diameter of 8.8 ± 0.8 nm and zeta potential (ζ) equal to -21.3 mV. The analysis of CD spectra indicated that PASNa did not significantly affect the HSA secondary structure on binding to that protein. [ABSTRACT FROM AUTHOR]

In view of the ever-growing demand for efficient triplet photosensitizers and photoactive components of various optoelectronic devices, we herein report the synthesis and properties of hexaiodo-subphthalocyanines (I 6 SubPcs). The improved five-step route to 4,5-diiodophthalonitrile, which serves as precursor for the synthesis of the I 6 SubPcs, is reported. The improved synthesis merely required one chromatographic separation to afford the high-purity target product. Highly desirable photophysical and photochemical properties were induced in the I 6 SubPcs due to the presence of six heavy iodine atoms. In particular, high values of the singlet-oxygen quantum yields (Φ Δ ) ranging from 0.83 to 0.9 were measured. The I 6 SubPcs investigated proved to be phosphorescent at 77 K in 2-MeTHF with emission band maxima (λ P ) located at λ=957 and 970 nm. The excited-triplet-state energies (E T ) were estimated to be approximately 1.30 eV, whereas the triplet lifetimes (τ T ) were found to be 27.7 and 30.1 μs. The CV/DPV measurements indicated that both I 6 SubPcs exhibited one irreversible oxidation and one quasi-reversible reduction. The spectroelectrochemical measurements pointed to a relative stability and reversibility of the electrochemically formed anion radical, that is, I 6 SubPc .- , and an instability of the species formed upon one-electron oxidation, that is, I 6 SubPc .+ . Estimation of E HOMO gave a value of approximately -5.8 eV whereas E LUMO was found to be located at around -3.8 eV., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Perfluorophthalocyanines incorporating three-valent metals, namely In(Cl), Ga(Cl), and Al(Cl), have been synthesized and characterized. Thermogravimetric analysis revealed that these compounds exhibit outstanding thermal stability and a tendency to sublime at a temperature exceeding around 350 °C without thermal decomposition. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to probe the frontier orbital energy levels of these compounds in THF solution. All three compounds undergo three quasi-reversible reductions with the first one leading to the formation of an anion radical, namely MPc(-.) , as confirmed by spectroelectrochemistry. The compounds studied were intrinsically resistive to oxidation, which indicates that they are very good electron acceptors (n-type materials). The HOMO-LUMO energy gaps (Eg ) of the three compounds determined by UV/Vis spectroscopy were relatively unaffected by the three-valent metals incorporated into the phthalocyanine macrocycle. Similarly, the energies of the HOMO (EHOMO ) and LUMO (ELUMO ) orbitals remained virtually unaffected by the three-valent metals in the perfluorophthalocyanine. Importantly, all the perfluorophthalocyanines studied possess LUMO levels between -4.76 and -4.85 eV, which makes their reduced forms resistant to electron trapping by O2 and H2 O. This property opens up the possibility for the fabrication of electronic devices operating under ambient conditions. All three compounds demonstrated very good photostability as solid thin films., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)