Molecular Docking and Biophysical Studies for Antiproliferative Assessment of Synthetic Pyrazolopyrimidinones Tethered with Hydrazide-Hydrazones.

Chemotherapy represents the most applied approach to cancer treatment. Owing to the frequent onset of chemoresistance and tumor relapses, there is an urgent need to discover novel and more effective anticancer drugs. In the search for therapeutic alternatives to treat the cancer disease, a series of hybrid pyrazolo[3,4-d]pyrimidin-4(5H)-ones tethered with hydrazide-hydrazones, 5a–h, was synthesized from condensation reaction of pyrazolopyrimidinone-hydrazide 4 with a series of arylaldehydes in ethanol, in acid catalysis. In vitro assessment of antiproliferative effects against MCF-7 breast cancer cells, unveiled that 5a, 5e, 5g, and 5h were the most effective compounds of the series and exerted their cytotoxic activity through apoptosis induction and G0/G1 phase cell-cycle arrest. To explore their mechanism at a molecular level, 5a, 5e, 5g, and 5h were evaluated for their binding interactions with two well-known anticancer targets, namely the epidermal growth factor receptor (EGFR) and the G-quadruplex DNA structures. Molecular docking simulations highlighted high binding affinity of 5a, 5e, 5g, and 5h towards EGFR. Circular dichroism (CD) experiments suggested 5a as a stabilizer agent of the G-quadruplex from the Kirsten ras (KRAS) oncogene promoter. In the light of these findings, we propose the pyrazolo-pyrimidinone scaffold bearing a hydrazide-hydrazone moiety as a lead skeleton for designing novel anticancer compound

Quantum flux effects on the energy spectra and thermo-magnetic properties in 2D Schrodinger equation with Mobius square potential

A 2D Schrodinger equation with interacting Mobius square potential model is solved using Nikiforov-Uvarov Functional Analysis (NUFA) formalism. The energy spectra and the corresponding wave function for the linearly and exponentially varying quantum magnetic flux are obtained analytically in a closed form. The evaluated energy spectra are used to obtain an expression for the partition functions for the two cases comprises of the linearly and exponentially varying quantum magnetic flux and vis-a-vis is use to evaluate other thermodynamic and magnetic properties for the system. The results are used to study the free energy, mean energy, the entropy, specific heat, magnetization, magnetic susceptibility and the persistent current of the system. The numerical bound state energies are computed.Comment: 39 Pages, 64 figure

Formation and interactions of cold and ultracold molecules: new challenges for interdisciplinary physics

Progress on researches in the field of molecules at cold and ultracold temperatures is reported in this review. It covers extensively the experimental methods to produce, detect and characterize cold and ultracold molecules including association of ultracold atoms, deceleration by external fields and kinematic cooling. Confinement of molecules in different kinds of traps is also discussed. The basic theoretical issues related to the knowledge of the molecular structure, the atom-molecule and molecule-molecule mutual interactions, and to their possible manipulation and control with external fields, are reviewed. A short discussion on the broad area of applications completes the review.Comment: to appear in Reports on Progress in Physic

A novel hepatopancreatic phospholipase A2 from Hexaplex trunculus with digestive and toxic activities.

A marine snail digestive phospholipase A2 (mSDPL) was purified from delipidated hepatopancreas. Unlike known digestive phospholipases A2, which are 14 kDa proteins, the purified mSDPL has a molecular mass of about 30 kDa. It has a specific activity of about 180 U/mg measured at 50 degrees C and pH 8.5 using phosphatidylcholine liposomes as a substrate in the presence of 4 mM NaTDC and 6mM CaCl2. The N-terminal amino-acid of the purified mSDPL does not share any homology with known phospholipases. Moreover, the mSDPL exhibits hemolytic activity in intact erythrocytes and can penetrate phospholipid monolayers at high surface pressure, comparable to snake venom PLA2. These observations suggest that mSDPL could be toxic to mammal cells. However, mSDPL can be classified as a member of a new family of enzymes. It should be situated between the class of toxic phospholipase A2 from venoms and another class of non toxic pancreatic phospholipase A2 from mammals.Persona

Étude des propriétés de conduction électrique des phosphates condensés mixtes éléments monovalents-terres rares : LiDy(PO3_3)4_4, NaNd(PO3_3)4_4, AgLa(PO3_3)4_4, NH4_4DyPO3_3)4_4

Single crystals of LiDy(PO$_3$)$_4$, NaNd(PO$_3$)$_4$, NH$_4$Dy(PO$_3$)$_4$ and AgLa(PO$_3$)$_4$ polyphosphates have been grown using the flux method. A mixture of monovalent carbonate (M$_2$CO$_3$), rare earth oxide (Ln$_2$O$_3$) and phosphoric acid (H$_3$PO$_4$ 85%) was heated at 285°C during a week. Single crystals were obtained and characterized by X-ray diffraction, infrared and Raman spectroscopy. Their investigation was carried out by thermal analysis (ATG/ATD). Their electric conductivity was measured by impedance spectroscopy. The conductivity, $\sigma$, vary between $1{,}5\times10^{-8}~\Omega^{-1}$.cm$^{-1}$ at 300 °C and $2\times10^{-5}~\Omega^{-1}$.cm$^{-1}$ at 500 °C. The activation energies increase from 0,31 for NH$_4$Dy(PO$_3$)$_4$ to 1,26 eV for NaNd(PO$_3$)$_4$. The basic structural units of these phosphates are ribbons (PO$_3$)$_{\rm n}$ formed by corner-sharing of PO$_4$ tetrahedra with variable geometry, which are unfavourable to the ionic conduction. The ionic transport was mainly assured by M$^+$ ions; moreover, the hydrogen bond established in the structure of NH$_4$Dy(PO$_3$)$_4$ and the proton exchange allow to explain the relatively high conductivity of this phosphate. The results are discussed and correlated to the structural properties of these phosphates

Rovibrational cooling of molecules by optical pumping

SUMMARY We demonstrate rotational and vibrational cooling of cesium dimers by optical pumping techniques. We use two laser sources exciting all the populated rovibrational states, except a target state that thus behaves like a dark state where molecules pile up thanks to absorption-spontaneous emission cycles. We are able to accumulate photoassociated cold Cs2 molecules in their absolute ground state (v = 0, J = 0) with up to 40% efficiency. Given its simplicity, the method could be extended to other molecules and molecular beams. It also opens up general perspectives in laser cooling the external degrees of freedom of molecules