Design and synthesis of novel (Z)-5-((1,3-diphenyl-1H-pyrazol-4-yl)methylene)-3-((1-substituted phenyl-1H-1,2,3-triazol-4-yl)methyl)thiazolidine-2,4-diones: a potential cytotoxic scaffolds and their molecular modeling studies

In an effort to discover potential cytotoxic agents, a series of novel (Z)-5-((1,3-diphenyl-1H-pyrazol-4-yl)methylene)-3-((1-substituted phenyl-1H-1,2,3-triazol-4-yl)methyl)thiazolidine-2,4-dione derivatives (8a–n) were designed and synthesized in various steps with acceptable reaction procedures with quantitative yields and characterized by ¹H NMR, ¹³C NMR, IR, HRMS and ESI–MS spectra. These newly synthesized novel derivatives were screened for their in vitro cell viability/cytotoxic studies against human breast cancer cell line (MCF-7) with various concentrations of 0.625 µM, 1.25 µM, 2.5 µM, 5 µM and 10 µM, respectively. The biological interpretation assay outcome was demonstrated in terms of cell viability percentage reduction and IC₅₀ values against standard reference drug cisplatin. Based on these results, most of the derivatives exhibited promising cytotoxic activity. Among them, particularly compounds 8j (R₁?=?OMe and R₃?=?NO₂) and 8e (R₃?=?CF₃) demonstrate remarkable cytotoxic activity with IC₅₀ values 0.426 µM?±?0.455 and 0.608 µM?±?0.408, which are even better than the standard drug cisplatin 0.636 µM?±?0.458 and compounds 8m (R₂?=?OMe and R₃?=?OMe) and 8c (R₃?=?OMe) exhibited closely equivalent IC₅₀ values to the standard drug with IC₅₀ values 0.95 µM?±?0.32 and 0.976 µM?±?0.313 and rest of the compounds exhibits moderate cytotoxic activity. Moreover, molecular modeling studies and ADME calculations of the novel synthesized derivatives are in adequate consent with the pharmacological screening results.

     

Novel tacrine-based acetylcholinesterase inhibitors as potential agents for the treatment of Alzheimer’s disease: Quinolotacrine hybrids

A new series of quinolotacrine hybrids including cyclopenta- and cyclohexa-quinolotacrine derivatives were designed, synthesized, and assessed as anti-cholinesterase (ChE) agents. The designed derivatives indicated higher inhibitory effect on the acetylcholinesterase (AChE) with IC₅₀ values of 0.285–100 µM compared to butyrylcholinesterase (BChE) with IC₅₀ values of?>?100 µM. Of these compounds, cyclohexa-quinolotacrine hybrids displayed a little better anti-AChE activity than cyclopenta-quinolotacrine hybrids. Compound 8-amino-7-(3-hydroxyphenyl)-5,7,9,10,11,12-hexahydro-6H-pyrano[2,3-b:5,6-c'] diquinolin-6-one (6m) including 3-hydroxyphenyl and cyclohexane ring moieties exhibited the best AChE inhibitory activity with IC₅₀ value of 0.285 µM. The kinetic and molecular docking studies indicated that compound 6m occupied both the catalytic anionic site (CAS) and peripheral anionic site (PAS) of AChE as a mixed inhibitor. Using neuroprotective assay against H₂O₂-induced cell death in PC12 cells, the compound 6h illustrated significant protection among the assessed compounds. In silico ADME studies estimated good drug-likeness for the designed compounds. As a result, these quinolotacrine hybrids can be very encouraging AChE inhibitors to treat Alzheimer’s disease.

Graphic abstract

A novel series of quinolotacrine hybrids were designed, synthesized, and evaluated against AChE and BChE enzymes as potential agents for the treatment of AD. The hybrids showed good to significant inhibitory activity against AChE (0.285–100 μM) compared to butyrylcholinesterase (BChE) with IC₅₀ values of?>?100 μM. Among them, compound 8-amino-7-(3-hydroxyphenyl)-5,7,9,10,11,12-hexahydro-6H-pyrano[2,3-b:5,6-c′] diquinolin-6-one (6 m) bearing 3-hydroxyphenyl moiety and cyclohexane ring exhibited the highest anti-AChE activity with IC₅₀ value of 0.285 μM. The kinetic and molecular docking studies illustrated that compound 6 m is a mixed inhibitor and binds to both the catalytic anionic site (CAS) and peripheral anionic site (PAS) of AChE.

     

Synthesis and biological evaluation of benzomorpholine derivatives as novel EZH2 inhibitors for anti-non-small cell lung cancer activity

The histone lysine methyltransferase EZH2 has been reported to play important roles in cancer aggressiveness, metastasis and poor prognosis. In this study, a series of benzomorpholine derivatives were synthesized and biologically evaluated as EZH2 inhibitors. The target compounds were obtained in good yields from 3-amino-5-bromo-2-hydroxybenzoic acid via cyclization, Suzuki coupling and amidation as the key steps. A preliminary optimization study led to the discovery of several potent novel EZH2 inhibitors (6b, 6c, 6x and 6y). Moreover, 6y inhibited the A549 and NCI-H1975 cell lines (IC₅₀?=?1.1 µM and 1.1 µM, respectively). Further studies indicated that 6y can reduce EZH2 expression in intact cells and cause cell arrest in the G2/M phase.

     

Mechanistic Insights into the Inhibition of Endo-β 1,4 Xyloglucan Hydrolase by a Classical Aspartic Protease Inhibitor

This is the first report of inactivation of xyloglucanase from Thermomonospora sp by pepstatin A, a specific inhibitor towards aspartic proteases. The steady state kinetics revealed a reversible, competitive, two-step inhibition mechanism with IC ₅₀ and K _i values of 3.5?±?0.5 μM and 1.25?±?0.5 μM respectively. The rate constants determined for the isomerization of EI to EI^* and the dissociation of EI* were 14.5?±?1.5?×?10^?5?s^?1 and 2.85?±?1.2?×?10^?8?s^?1 respectively, whereas the overall inhibition constant K _i ^* was 27?±?1 nM. The conformational changes induced upon inhibitor binding to xyloglucanase were monitored by fluorescence analysis and the rate constants derived were in agreement with the kinetic data. The abolished isoindole fluorescence of o-phthalaldehyde (OPTA)-labeled xyloglucanase and far UV analysis suggested that pepstatin binds to the active site of the enzyme. Our results revealed that the inactivation of xyloglucanase is due to the interference in the electronic microenvironment and disruption of the hydrogen-bonding network between the essential histidine and other residues involved in catalysis.     

P–V–T equation of state of rhodium oxyhydroxide

A high pressure X-ray diffraction study of RhOOH was carried out up to 17.44?GPa to investigate the compression behavior of an oxyhydroxide with an InOOH-related structure. A fit to the third-order Birch–Murnaghan equation of state gave K₀?=?208?±?6?GPa, and K′?=?9.4?±?1.3. The temperature derivative of the bulk modulus was found to be ?K/?T?=??0.06?±?0.02?GPa K^?1. The refined parameters for volume thermal expansion were α₀?=?2.7?±?0.3?×?10^?5 K^?1; α₁?=?1.7?±?1.1?×?10^?8 K^?2 in the polynomial form (α(T)?=?α_0?+?α₁(T?300)). Our results show that RhOOH is very incompressible, and has a higher bulk modulus than other InOOH-structured oxyhydroxides (e.g. δ-AlOOH, ε-FeOOH, and γ-MnOOH).     

Breath water-based doubly labelled water method for the noninvasive determination of CO2 production and energy expenditure in mice

ABSTRACT

We explored a novel doubly labelled water (DLW) method based on breath water (BW-DLW) in mice to determine whole body CO₂ production and energy expenditure noninvasively. The BW-DLW method was compared to the DLW based on blood plasma. Mice (n?=?11, 43.5?±?4.6?g body mass (BM)) were administered orally a single bolus of doubly labelled water (1.2?g H₂¹⁸O kg BM^?1 and 0.4?g ²H₂O kg BM^?1, 99 atom% (AP) ¹⁸O or ²H). To sample breath water, the mice were placed into a respiration vessel. The exhaled water vapour was condensed in a cold-trap. The isotope enrichments of breath water were compared with plasma samples. The ²H/¹H and ¹⁸O/¹⁶O isotope ratios were measured by means of isotope ratio mass spectrometry. The CO₂ production (RCO₂) was calculated from the ²H and ¹⁸O enrichments in breath water and plasma over 5 days. The isotope enrichments of breath water vs. plasma were correlated (R²?=?0.89 for ²H and 0.95 for ¹⁸O) linearly. The RCO₂ determined based on breath water and plasma was not different (113.2?±?12.7 vs. 111.4?±?11.0?mmol?d^–1), respectively. In conclusion, the novel BW-DLW method is appropriate to obtain reliable estimates of RCO₂ avoiding blood sampling.     

Effect of NH4I and I2 concentration on agar gel polymer electrolyte properties for a dye-sensitized solar cell

Gel polymer electrolytes were prepared using agar polymer host, NH₄I, and I₂ salts. The sample of agar paste with 1.0 M of NH₄I and 0.2 μM of I₂ exhibits the highest conductivity and lowest viscosity values at room temperature of (2.64?±?0.19)?×?10^?3?S?cm^?1 and 1.17?±?0.29 Pa?s, respectively. All of the gel polymer electrolytes display Arrhenian behavior, and the optimum agar paste gave the lowest activation energy of 0.25 eV. It also had a good physical appearance compared with the other samples. This gel polymer electrolyte had a good potential and was applicable to a role as electrolyte in ITO-ZnO (N719 dye)/agar paste?+?1.0 M NH₄I?+?0.2 μM I₂/Au-Pd-ITO dye-sensitized solar cell.     

Sensitive voltammetric determination of cysteamine using promazine hydrochloride as a mediator and modified multi-wall carbon nanotubes carbon paste electrodes

This paper presents a sensitive electrochemical method for the determination of cysteamine (CA) using promazine hydrochloride-modified multi-wall carbon nanotubes carbon paste electrode (PrH/MWCNTs CPE). Because of the good electrochemical activity of MWCNTs and the acceptable performance of promazine hydrochloride (PrH) as an electrocatalytic mediator, the modified electrode significantly enhanced the sensitivity for the detection of CA in comparison to the bare carbon paste electrode (CPE). All chemical parameters such as pH of solution, concentration of PrH and kinetic parameters of the system were investigated. Linear sweep voltammetric (LSV) method was used to follow the electrocatalytic effect of CA on the current–potential response of PrH. Under optimum conditions, the obtained net peak current ?I _p(I _sample???I _blank) was linear with CA concentrations in two dynamic ranges of 2.0–346.5 μmol l^?1 (?I _p?=?(0.0195?±?0.0043)C _CA?+?(0.7648?±?0.0397) (r ²?=?0.9948)) and 346.5–1,912.5 μmol l^?1 (?I _p?=?(0.0100?±?0.0026)C _CA?+?(3.8981?±?0.0828) (r ²?=?0.9911)) with a detection limit of 0.8 μmol l^?1. Finally, the PrH/MWCNTs CPE was successfully applied for the determination of CA in urine and drug samples with satisfactory results.     

Room temperature phosphorescence lifetime and quantum yield of erythrosine B and rose bengal in aerobic alkaline aqueous solution

The room-temperature phosphorescence behavior of erythrosine B (ER) and rose bengal (RB) in aerobic aqueous solution at pH 10 (10^?4 M NaOH) is investigated. The samples were excited with sliced second harmonic pulses of a Q-switched Nd:glass laser. A gated photomultiplier tube was used for instantaneous fluorescence signal discrimination and a digital oscilloscope was used for signal recording. For phosphorescence lifetime measurement the oscilloscope response time was adjusted to appropriate time resolution and sensitivity by the ohmic input resistance. In the case of phosphorescence quantum yield determination the gated photomultiplier – oscilloscope arrangement was operated in integration mode using 10 MΩ input resistance. Phosphorescence quantum yield calibration was achieved with erythrosine B and rose bengal doped starch films of known quantum yields. The determined phosphorescence lifetimes (quantum yields) of ER and RB in 0.1 mM NaOH are τ_P=1.92±0.1 μs (?_P=(1.5±0.3)×10^?5) and 2.40±0.1 μs ((5.7±0.9)×10^?5), respectively. The results are discussed in terms of triplet state deactivation by dissolved molecular oxygen.     

Preparation and comparative structural properties of porous SnO2 microrods and submicrorods

A facile two-step approach has been used for the synthesis of porous SnO₂ rods: the initial room-temperature precipitation of precursor SnC₂O₄ and its subsequent thermal decomposition at 550 °C. Both the as-obtained porous SnO₂ microrods (length ～10.0?±?3.5 μm, diameter ～1.1?±?0.4 μm) and submicrorods (length ～5.8?±?1.9 μm, diameter ～0.4?±?0.1 μm) are the crystalline mixtures of major tetragonal and minor orthorhombic crystal phases, showing a tetragonal fraction of 84.7 and 87.0 %, respectively. When applied as a lithium-ion battery anode, the porous submicrorods (specific surface area ～13.6 m² g^?1) can deliver an initial discharge capacity of 1,730.7 mAh g^?1 with a high coulombic efficiency of 61.6 % and show the 50th discharge capacity of 662.8 mAh g^?1 at 160 mA g^?1 within a narrow potential range of 10.0 mV to 2.0 V. Similarly, even the anode of porous microrods (specific surface area ～11.8 m² g^?1) can still exhibit an initial discharge capacity of 1,661.1 mAh g^?1 at 160 mA g^?1 with a coulombic efficiency of 60.9 %. Regardless of the polymorphic nature, the acquired porosity may only alleviate the huge volume change of anodes for the first cycle; thus, the structural parameters of average size and specific surface area can be feasibly associated with the enhanced lithium storage capability. Anyway, these indicate a facile oxalate precursor method for the controlling synthesis and high performance of rodlike SnO₂ for lithium-ion batteries.     

Conformational fluctuations in a green fluorescent protein-like Akane family protein: a high-pressure fluorescence study at 0.1–700 MPa

ABSTRACT

We have investigated conformational fluctuations in a new green fluorescent protein(GFP)-like protein rb-Akane found in a red-brown-colored octocoral, Scleronephthya gracillima (Kuekenthal)), with high pressure fluorescence spectroscopy at 0.1–700?MPa. Besides the green fluorescence at 510?nm, two red fluorescence peaks are observed at 590 and 629?nm, the relative intensity of which varies reversibly with pressure. The phenomenon is interpreted as representing the cis–trans isomerization of the chromophore accompanied by the conformational transition between two sub-states of the red fluorescence form of rb-Akane. The two sub-states are separated only marginally in free energy (ΔG⁰?=?1.9?±?0.4?kJ?mol^?1), but significantly in partial molar volume (ΔV⁰?=??19.8?±?1.4?ml?mol^?1) at 0.1?MPa (pH 7.5, 25°C). Above 500?MPa, the fluorescence at λ_max 629?nm undergoes another reversible change with pressure, showing the onset of unfolding.     

Design,Synthesis, Photophysical Properties,Biological Estimation and Molecular Docking Studies of Novel Schiff Base Derivatives as Potential Urease Inhibitors

A quinoline functionalized two novel fluorescent Schiff bases, N-(quinolin-2-ylmethylene) anthracen-1-amine (SB1) and 2-(quinolin-2-ylmethyleneamino) benzene thiol (SB2) were synthesized and confirmed by using ¹H NMR, IR and GC-MS techniques. The spectroscopic properties were examined by absorption spectroscopy and fluorescence spectroscopy. The absorption and fluorescence spectra of the probes (SB1 and SB2) were measured in a variety of solvents. Both the compounds were tested for urease inhibitory activity. The synthesized compound SB2 proved to be the most effective screening for enzyme inhibitory activity with IC₅₀?=?0.111 μM than SB1 (IC₅₀?=?0.287 μM). Molecular docking studies were performed to delineate the binding affinity and conformational positions of chemical compounds within the active region of the target protein. In-vitro analysis depicts the potency of SB1 in free radical scavenging as compared to the reference drug vitamin C.     

Ultrasonic preparation of tetraoxalyl ethylenediamine melamine resin-coated multiwalled carbon nanotubes for trace Ni(II) sensing

Under an aid of ultrasonic, tetraoxalyl ethylenediamine melamine resin-coated multiwalled carbon nanotubes were prepared for Ni(II) sensing in aqueous solution. The processes involved the fabrication of tetraoxalyl ethylenediamine melamine resin by one pot way, the coating of tetraoxalyl ethylenediamine melamine resin at multiwalled carbon nanotubes (MWCNTs), and the determination of Ni(II). The present materials were carefully examined by Fourier transform infrared spectroscopy, field emission scanning electron microscope, and electrochemistry techniques. A great deal of amorphous microsphere could be observed for tetraoxalyl ethylenediamine melamine resin with an average diameter of 1.2 μm, and MTE could evenly adhere at the surface of MWCNTs by the ultrasonic. Tetraoxalyl ethylenediamine melamine resin-coated multiwalled carbon nanotube-modified paraffin-impregnated graphite electrode was successfully used for the determination of Ni(II) by differential pulse adsorptive anodic stripping voltammetry. The current responses (?0.3 V) were linearly increased depending on the concentration from 1?×?10^?11 to 3?×?10^?10 M (i (μA)?=?11.1?+?7.9 c (1?×?10^?12 M); R?=?0.9901, 3σ?=?7?×?10^?12 M).     

ESR and optical study of Cu2+-doped bis-(5,5′-diethylbarbiturato)bis picoline Zn(II)

ESR studies were conducted on Cu²⁺-doped bis-(5,5′-diethylbarbiturato)bis picoline Zn(II). Two Cu²⁺ lattice sites, Cu²⁺(I) and Cu²⁺(II), were identified. These sites exhibit two sets of four hyperfine lines in all directions. The g factor and hyperfine splitting were calculated from ESR absorption spectra: g_x ?=?2.0201?±?0.002, g_y ?=?2.0900?±?0.002, g_z ?=?2.1634?±?0.002, A_x ?=?(30?±?2)?×?10^?4?cm^?1, A_y ?=?(40?±?2)?×?10^?4?cm^?1 and A_z ?=?(154?±?2)?×?10^?4?cm^?1. It was found that Cu²⁺ enters the lattice substitutionally. The ground-state wavefunction of the Cu²⁺ ion in this lattice was determined from the spin Hamiltonian constants obtained from the ESR studies. With the help of an optical absorption study, the nature of the bonding in the complex is also discussed.     

Preformulation and formulation development of a bioactive nitroaromatic compound

The N-(butanoyloxyethyl)-4-(chloromethyl)-3-nitrobenzamide (BNB) is a nitroaromatic derivative with significant antitumor activity. Preformulation, forced degradation (distilled water, acid and base hydrolysis, oxidation, and light), and formulation studies were performed to investigate the chemical behavior of the molecule, the physicochemical properties, and the impact of formulation variables. Pharmacokinetic properties for BNB were estimated in silico. Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) containing BNB were developed by a hot melt homogenization method for parenteral administration. Degradation studies demonstrated that this compound is sensitive to hydrolysis. BNB was predicted to have a favorable absorption, distribution, metabolism, and excretion profile. The nanocarriers developed were characterized for particle size (PS?=?61 to 85 nm), polydispersity index (PI?<?0.3), zeta potential (ZP?=???22 to ??34 mV), and encapsulation efficiency (EE?=?66 to 90%) and remained stable for 30 days of storage. These studies indicated that BNB (inhibitory concentration (IC₅₀) 21.8 μM) and BNB-loaded NLC (IC₅₀ 33.7 μM) showed moderate cytotoxicity against breast cancer cell line. Blank formulations did not induce cytotoxicity and BNB-loaded SLN was able to potentiate the action of BNB (lC₅₀ 12.4 μM). BNB is a promising antitumor agent and it is possible to modulate its activity based on the particle size of the formulation.     

Interaction of Folic Acid with Mn2+ Doped CdTe/ZnS Quantum Dots: In Situ Detection of Folic Acid

To utilize the nanomaterials as an effective carrier for the drug delivery applications, it is important to study the interaction between nanomaterials and drug or biomolecules. In this study GSH functionalized Mn²⁺-doped CdTe/ZnS QDs has been utilized as a model nanomaterial due to its high luminescence property. Folic acid (FA) gradually quenches the FL of GSH functionalized Mn²⁺???doped CdTe/ZnS QDs. The Stern-Volmer quenching constant (K_sv), binding constant (K_s) and effective quenching constant (Ka) for the FA-QDs system is calculated to be 1.32?×?10⁵ M^?1, 1.92?×?10⁵ and 0.27?×?10⁵ M^?1, respectively under optimized condition (Temp. 300 K, pH 8.0, incubation time 40 min.). The effects of temperature, pH, and incubation time on FA-QDs system have also been studied. Statistical analysis of the quenched FL intensity versus FA concentration revealed a linear range from 1?×?10^?7 to 5.0?×?10^?5 for FA detection. The LOD of the current nano-sensor for FA was calculated to be 0.2 μM. The effect of common interfering metal ions and other relevant biomolecules on the detection of FA (12.0 μM) have also been investigated. L-cysteine and glutathione displayed moderate effect on FA detection. Similarly, the common metal ions (Na⁺, K⁺, Ca²⁺ and Mg²⁺) produced minute interference while Zn²⁺ Cu²⁺ and Fe³⁺ exert moderate interference. Toxic metal ions (Hg²⁺ and Pb²⁺) produced severe interferences in FA detection.

Graphical abstract

GSH-Mn²⁺ CdTe/ZnS QDs based Fluorescence Nanosensor for Folic acid

     

The 13C bicarbonate method: an inverse end product method for measuring CO2 production and energy expenditure

We reconsider the principle of the ¹³C bicarbonate (NaH¹³CO₃) method (¹³C-BM) for the determination of the CO₂ production to obtain an estimate of energy expenditure (EE). Its mathematical concept based on a three-compartmental model is related to the [¹⁵N]glycine end product method. The CO₂ production calculated by the ¹³C-BM, R_aCO₂(¹³C) is compared to the result from the indirect calorimetry, RCO₂(IC). In an interspecies comparison (dog, goat, horse, cattle, children, adult human; body mass ranging from 15 to 350?kg, resting and fasting conditions) we found an excellent correlation between the results of ¹³C-BM and IC with RCO₂(IC)?=?0.703?×?R_aCO₂(¹³C), (R²?=?0.99). The slope of this correlation corresponds to the fractional ¹³C recovery (RF(¹³C)) of ¹³C in breath CO₂ after administration of NaH¹³CO₃. Significant increase in RF(¹³C) was found in physically active dogs (0.95?±?0.14; n?=?5) vs. resting dogs (0.71?±?0.10, n?=?17; p?=?.015). The ¹³C recovery in young bulls was greater in blood CO₂ (0.81?±?0.05) vs. breath CO₂ (0.73?±?0.05, n?=?12, p?<?.001) and in ponies with oral (0.76?±?0.03, n?=?8) vs. intravenous administration of NaH¹³CO₃ (0.69?±?0.07; n?=?8; p?=?.026). We suggest considering the ¹³C-BM as a ‘stand-alone’ method to provide information on the total CO₂ production as an index of EE.     

Electrochemical and catalytic investigations of epinephrine,acetaminophen and folic acid at the surface of titanium dioxide nanoparticle-modified carbon paste electrode

In the present paper, the use of a carbon paste electrode modified with 1-(4-(1, 3-dithiolan-2-yl)-6, 7-dihydroxy-2-methyl-6, 7-dihydrobenzofuran-3-yl)ethanone (DDE) and TiO₂ nanoparticles prepared by a simple and rapid method was described. The modified electrode showed excellent properties for electrocatalytic oxidization of epinephrine (EP), acetaminophen (AC) and folic acid (FA). The apparent charge transfer rate constant, k _s?=?1.14 s^?1, and transfer coefficient, α?=?0.54, for electron transfer between the modifier and carbon paste electrode were calculated. It has been found that under optimum condition (pH?=?7.0) in cyclic voltammetry, the oxidation of EP occurs at a potential about 280 mV less positive than that of an unmodified carbon paste electrode. The values of transfer coefficients (α?=?0.46), catalytic rate constant (k?=?1.2?×?10⁴ M^?1 s^?1) and diffusion coefficient (D?=?2.70?×?10^?5 cm² s^?1) were calculated for EP. Differential pulse voltammetry (DPV) exhibited two linear dynamic ranges of 0.5 to 50.0 μM and 50.0 to 1,000 μM for EP. This modified electrode is quite effective not only for the detection of EP, AC and FA but also for the simultaneous determination of these species in a mixture. The limit of detection for EP, AC and FA is 0.10, 1.80 and 2.36 μM, respectively.     

Single-crystal elasticity of the rhodochrosite at high pressure by Brillouin scattering spectroscopy

ABSTRACT

The sound velocity properties of single-crystal rhodochrosite (MnCO₃) were determined up to 9.7?GPa at ambient temperature by Brillouin scattering spectroscopy. Six elastic constants were calculated by a genetic algorithm method using the Christoffel's equations at each pressure. The elastic constants increased linearly as a function of pressure and its pressure derivatives ?Cij/?P for C₁₁, C₃₃, C₄₄, C₁₂, C₁₃, C₁₄ were 5.86 (±0.36), 3.82 (±0.44), 2.06 (±0.39), 5.07 (±0.27), 5.34 (±0.44), 1.52 (±0.24), respectively. Based on the derived elastic constants of rhodochrosite, the aggregate adiabatic bulk and shear moduli (K_s and G) were calculated using the Voigt-Reuss-Hill averages and the linear fitting coefficients (?K_s/?P)_T and (?G/?P)_T were 5.05(±0.26) and 0.73(±0.05), respectively. The aggregate V_p of rhodochrosite increased clearly as a function of pressure and its pressure derivative ?V_p/?P was 7.99(±0.53)?×?10^?2?km/(s?GPa), while the aggregate V_s increased slowly and ?V_s/?P was only 1.19(±0.12)?×?10^?2?km/(s?GPa). The anisotropy factor for As of rhodochrosite increased from ～40% at 0.8?GPa to ～48% at 9.7?GPa, while A_p decreased from ～19% to ～16% at the corresponding pressure.     

Synthesis and Studies of Fluorescein Based Derivatives for their Optical Properties,Urease Inhibition and Molecular Docking

Herein, we design and synthesized new fluorescein based derivatives by insitu formation of fluorescein ester and further treated with corresponding hydrazide and amine to yield respective compounds i.e. FB1, FB2, FB3 and FB4. The spectral purity and characterization was done by using IR, NMR and Mass spectroscopies. The synthesized derivatives were examined for their photophysical properties by using variety of organic solvents and results were discussed in details. The structural diversity of synthesized compounds motivate us to evaluate these compounds for urease inhibition. The compound FB3 (IC₅₀?=?0.0456 μM) shows 100 fold more active against Jack bean urease than standard drug thiourea (IC₅₀?=?4.7455 μM). Other synthesized compounds showed potent activity. Free radical percentage scavenging assay further supported the capacity of compounds to urease inhibition. While, molecular docking simulations helps to examine the molecular interactions of active compounds FB1, FB2, FB3 and FB4 within the binding site of urease enzyme.