P1 Space Group Research Articles

Identification, Characterization, and Preliminary X-ray Diffraction Analysis of a Novel Esterase (ScEst) from Staphylococcus chromogenes

Ester prodrugs can develop novel antibiotics and have potential therapeutic applications against multiple drug-resistant bacteria. The antimicrobial activity of these prodrugs is activated after being cleaved by the esterases produced by the pathogen. Here, novel esterase ScEst originating from Staphylococcus chromogenes NCTC10530, which causes dairy cow mastitis, was identified, characterized, and analyzed using X-ray crystallography. The gene encoding ScEst was cloned into the pVFT1S vector and overexpressed in E. coli. The recombinant ScEst protein was obtained by affinity and size-exclusion purification. ScEst showed substrate preference for the short chain length of acyl derivatives. It was crystallized in an optimized solution composed of 0.25 M ammonium citrate tribasic (pH 7.0) and 20% PEG 3350 at 296 K. A total of 360 X-ray diffraction images were collected at a 1.66 Å resolution. ScEst crystal belongs to the space group of P212121 with the unit cell parameters of a = 50.23 Å, b = 68.69 Å, c = 71.15 Å, and α = β = γ = 90°. Structure refinement after molecular replacement is under progress. Further biochemical studies will elucidate the hydrolysis mechanism of ScEst. Overall, this study is the first to report the functional characterization of an esterase from Staphylococcus chromogenes, which is potentially useful in elaborating its hydrolysis mechanism.

Supramolecular Assemblies and Reversible De‐/ Rehydration in One‐Dimensional Dimethyltin Carboxylates

AbstractThe study presents the synthesis and structural aspects of a new family of dimethyltin carboxylates, [(Me2Sn)2(btec)(bipy)(H2O)] ⋅ 4H2O (1), [Me2Sn(btec)0.5(bipy)]2 ⋅ H2O (2), [Me2Sn(btec)0.5(bipy)] ⋅ 3H2O ⋅ 0.5bipy (3) and [Me2Sn(btec)0.5(phen)] (4) derived from 1,2,4,5‐benzenetetracarboxylic acid (H4btec). The structure in each case adopts a one‐dimensional motif featuring ditin macrocycles with 2,2'‐bipyridine (bipy) or 1,10‐phenanthroline (phen) acting as the chelating ligand. For 1, the lattice water molecules in association with the framework form infinite T4(0)A(1) water chains. The organic hydrate, bipy ⋅ 6H2O in 3 adopts a layered structure comprising T4(2)6(2) water tapes and trans‐bipy. Dehydration of 2 to 2 a results in crystal structure transformation from centrosymmetric P21/c (in 2) to chiral P212121 space group and reveals conformational changes in the ditin macrocycles from chair to boat form. The reversibility of this transformation has been supported by TGA, PXRD, and single‐crystal X‐ray studies.

Designing a Redox Noninnocent Phenalenyl-Based Copper(II) Complex: An Autotandem Catalyst for the Selective Oxidation of Polycyclic Aromatic Hydrocarbons (PAHs).

A square-planar [CuIIL] complex 1, based on the redox-active phenalenyl unit LH2 = 9,9′-(ethane-1,2-diylbis(azanediyl))bis(1H-phenalen-1-one), is prepared and structurally characterized by single-crystal X-ray diffraction analysis. Complex 1 crystallizes at room temperature with the P1 space group. The molecular structure of 1 reveals the presence of intriguing C–H···Cu intermolecular anagostic interactions of the order ∼2.7715 Å. Utilizing the presence of anagostic interactions and the free nonbonding molecular orbitals (NBMOs) of the closed-shell phenalenyl unit in 1, the oxidation reactions of some industrially important polycyclic aromatic hydrocarbons (PAHs) in the presence of the [CuIIL] complex under very mild conditions have been reported. The direct conversion of anthracene-9-carbaldehyde to 9,10-anthraquinone in one step concludes that the catalyst shows dual activity in the chemical transformations. This also includes the first report of a “single-step” catalytic transformation of pyrene-1-carbaldehyde to the synthetically difficult pyren-4-ol, a precursor for the synthesis of several novel fluorescent probes for cell imaging.

Potent Anticancer Activities of Beauvericin Against KB Cells In Vitro by Inhibiting the Expression of ACAT1 and Exploring Binding Affinity.

Beauvericin (BEA), a cyclic hexadepsipeptide mycotoxin, is a potent inhibitor of the acyl-CoA: cholesterol acyltransferase enzyme 1 (ACAT1), involved in multiple tumor-correlated pathways. However, the binding mechanisms between BEA and ACAT1 were not elucidated. BEA was purified from a mangrove entophytic Fusarium sp. KL11. Single-crystal X-ray diffraction was used to determine the structure of BEA. Wound healing assays of BEA against KB cell line and MDA-MB-231 cell line were evaluated. Inhibitory potency of BEA against ACAT1 was determined by ELISA assays. Molecular docking was carried out to illuminate the bonding mechanism between BEA and ACAT1. The structure of BEA was confirmed by X-ray diffraction, indicating a monoclinic crystal system with P21 space group (α = 90°, β = 92.2216(9)°, γ= 90°). BEA displayed migration-inhibitory activities against KB cells and MDA-MB-231 cells In Vitro. ELISA assays revealed that the protein expression level of ACAT1 in KB cells was significantly decreased after BEA treatment (P ＜0.05). Molecular docking demonstrated that BEA formed hydrogen bond with His425 and pi-pi staking with Tyr429 in ACAT1. BEA sufficiently inhibited the proliferation and migration of KB cells and MDA-MB-231 cells by downregulating ACAT1 expression. In addition, BEA potentially possessed a strong binding affinity with ACAT1. BEA may serve as a potential lead compound for the development of a new ACAT1-targeted anticancer drug.

Crystal and molecular structure of V-amylose complexed with butan-1-ol

Chain-folded lamellar V-amylose single crystals were prepared by adding butan-1-ol to hot dilute aqueous solutions of native amylose. The base-plane electron and X-ray diffraction patterns recorded from hydrated specimens agreed with a P212121 space group and an orthorhombic unit cell. A molecular model resulting from an exhaustive search of helix position and restrained structure refinement against diffraction data was proposed. The unit cell contains 4 antiparallel left-handed 6-fold amylose single helices with 1 butan-1-ol molecule located inside each of the helical cavities. In addition, 4 butan-1-ol and 20 water molecules are distributed in the 4 interstitial spaces. The amylose helices form rows along the b-axis that are alternatively shifted by ±b/8 with respect to one another, which validates the geometrical model proposed by Helbert and Chanzy in 1994.

Vibrational spectroscopy, electrical, and thermal properties of [N (CH3)4][N(C2H5)4]CoCl4 compound

Abstract[N (CH3)4][N(C2H5)4]CoCl4 new hybrid compound was synthesized by slow evaporation at room temperature. The X‐ray powder diffraction indicates that this material has an orthorhombic structure with P212121 space group. Two endothermic peaks at T1 = 293 K and T2 = 387 K are observed by differential scanning calorimetric. The real and imaginary parts of the permittivity as function of temperature shows the ferroelectric phase below T = 288 K. The Nyquist diagrams are simulated based on the equivalent circuit chosen by the Z‐View‐software and show the contribution of the grain and electrodes effect. Raman spectroscopy study at room temperature confirms the composition of the synthesized compound. Furthermore, the ferroelectric–paraelectric phase transition T1 is demonstrated by temperature‐dependent Raman spectroscopic studies.

Design, synthesis, characterization and evaluation of 1,3,5-triazine-benzimidazole hybrids as multifunctional acetylcholinesterases inhibitors

A series of hybrids of benzimidazole and 1,3,5-triazine were designed and synthesized and evaluated as multi-target agents for the treatment of Alzheimer's disease. 24 compounds were designed, synthesized and identified by NMR, IR, HRMS and single-crystal X-ray diffraction studies. The compound 6c had the crystal system of orthorhombic and the space group of P212121. The cholinesterase inhibitory activity of synthesized compounds was measured using colorimetric Ellman's method. Most 1,3,5-triazine-benzimidazole hybrids showed potent acetylcholinesterase-inhibition activities and weak butyrylcholinesterase inhibitory activities. Compound 9f possessed the best acetylcholinesterase inhibitory activity with the IC50 of 0.044 µM, which is better than donepezil (0.052 µM). Molecular docking and molecular dynamics simulations demonstrated that there is a stable interaction between compound 9f and acetylcholinesterase. Simultaneously, experiments have also proved that compound 9f has good metal chelating properties. ADMET in silico prediction results suggest the compound can pass through the blood-brain barrier well and have good drug similarity. So, compound 9f could be a multi-target agent for the treatment of Alzheimer's disease.

X-ray crystal structure, NMR, DFT investigations, pharmaco-kinetic, and toxicity of sarcotrocheliol: A pyrane-based cemranoids of marine origin

One of a recently discovered marine origin cembranoids has been studied experimentally and theoretically to obtain its thorough structural, electronic, spectroscopic, and biochemical activity. The exact molecular structure of sarcotrocheliol (C 20 H 34 O 2 ) 1 has been determined for the first time using a single crystal X-ray diffraction analysis. Crystallography shows that the molecule is crystalline as an orthorhombic, space group of P2 1 2 1 2 1 , with a = 9.20(4) Å, b = 10.80(4) Å, c = 19.99(9) Å. 1 H, 13 C and DEPT-135 NMR measurements of sarcotrocheliol 1 have been measured in four different deuterated solvents: CDCl 3 , CD 3 CN, MeOH- d 4 and DMSO- d 6 . Theoretical calculations have been performed to find the main structural and electronic properties of the compound and matched with the experimental properties. The density functional theory (DFT) method at B3LYP/6-311++G(d,p) level of theory has been used for all computed properties. Vibrational frequencies have been determined using DFT calculations and compared with the experimental values. Computed chemical shifts in the NMR have been determined by the GIAO method. The correlation coefficients between the calculated and experimental NMR chemical shifts have been found to be 0.92 and 0.998 for 1 H and 13 C NMR, respectively. Physicochemical parameters of the compound versus reference drugs have been done. The isolated compound meets the main criteria of the employed rules indicating a drug-like character. The molecular docking studies have been performed for the compound toward the breast and prostate cancers.

Preparation and characterization of a new chiral metal-organic framework with spiranes

Herein we report the first homochiral IRMOF structure with chiral carbocyclic spirolinkers, basic Zn-(R)-spiro[3.3]heptane-2,6-dicarboxylate, named WIG-5. First, (R)-spiro[3.3]heptane-2,6-dicarboxylic acid was prepared involving a HPLC separation on chiral stationary phase, then further transformed into homochiral WIG-5 by the solvothermal reaction with zinc nitrate hexahydrate in dimethyl formamide (DMF). WIG-5 crystallizes in the P212121 space group and is built of two interpenetrated networks with pcu underlying network topology. The tetranuclear secondary building units (SBUs) of WIG-5 are coordinated to two DMF molecules and six (R)-spiro[3.3]heptane-2,6-dicarboxylic acid linkers, that results in the formation of a homochiral distorted MOF-5-like structure. Extensive characterization by single crystal X-ray diffraction, powder X-ray diffraction, polarized light microscopy, infrared microspectroscopy, solid-state vibrational circular dichroism spectroscopy and thermogravimetry/mass spectroscopy has been performed on the new material. Birefringence of large WIG-5 single crystals enables potential optical applications.

Synthesis of green phosphor SrAl2O4: Eu2+, Dy3+: Rietveld refinement and optical properties

Strontium aluminate (SrAl2O4), SrAl2O4: Eu2+ and SrAl2O4: Eu2+/Dy3+ phosphors were prepared by solution combustion method. The XRD patterns of the sample were analysed using Rietveld refinement. The analysis confirmed the multiphase structure consisting of hexagonal (P63 space group) and monoclinic (P121 space group) phases. The refinement χ2 values in the range of 2.1–2.8. The crystal structure model was generated based on the refined data. The refined unit cell volume show increment after Eu and Dy doping. The estimated crystallite size is approximately 19 nm and slightly increase after calcination. The emission spectra of the Eu2+ doped SrAl2O4 sample shows a broad emission band with a peak around 500 nm, corresponding to 4f6 5d1 –4f7 transition. With additional Dy3+ doping, the emission peak shifted towards 522 nm, which emitted green light as illustrated by the CIE diagram. The synthesized compounds were also characterized by FTIR and UV-vis for their chemical bonding and energy band gap respectively.

Pd and octahedra do not get along: Square planar [PdS4] units in non-centrosymmetric La6PdSi2S14

Non-linear optical (NLO) materials require a balance of high second-harmonic generation (SHG) signal and laser damage threshold (LDT), as well as phase matchable behavior. Herein, we report a new member of the (RE)6(TM)x(Tt)2Q14 family of compounds, La6PdSi2S14, which, unlike all other reported TM analogues crystallizing in hexagonal P63 space group, crystallizes in the non-centrosymmetric monoclinic P21 space group. The crystal structure contains chains of edge-sharing distorted square planar [PdS4] units. The square-planar coordination of Pd in La6PdSi2S14 exhibits remarkable NLO properties with high SHG (3.7 × AgGaS2) and LDT (3 × AgGaS2) values as well as phase matchability. This shows the promise of novel materials with distorted structural motifs for enhanced NLO properties. Upon formation of bimetallic chiral sulfides containing both Cu and Pd, Cu occupies the opposite faces of the octahedra forming [CuS3] units while Pd can be stabilized in the center of PdS6 octahedra in the hexagonal P63 crystal structure of La6Pd0.5CuSi2S14. This suggests that it is possible to form mixed metal systems which could further enhance NLO properties by incorporation of additional structural distortions.

Investigation of ferroelectric phase transitions in TlZnPO4 stuffed tridymite compound

This study elucidates both structural and physical behaviors of Thallium–Zinc Orthophosphate (TlZnPO4) compound via solid-state reaction. Advanced analytical techniques were performed to study the microstructure and investigate the existence of phase transitions in this material. Raman and impedance spectroscopy were studied to understand the behavior of the studied material and to determine its vibrational and electrical properties. At room temperature, the XRPD analysis confirmed that the synthesized material could be satisfactorily indexed using a P21 space group of the monoclinic unit cell. DSC analysis reveals the existence of two reversible phase transitions at T1 ​= ​546/498 ​K and T2 ​= ​646/600 ​K (Heating/Cooling). The first combine both order-disorder and displacive mechanism, while the second is displacive. SEM analysis reveals that the grains size is in the micrometric scale. Raman, as well as impedance spectroscopy analysis, proved the existence of two phase transitions. These transitions arise from the rotation of both ZnOn (n = 4, 5) and PO4 in the opposite direction. This rotation provokes a change in coordination of Zn atoms from ZnO5 to ZnO4, achieving higher symmetry. The electrical study confirmed the existence of a non-Debye type relaxation attributed to the grain contribution. The dielectric study proved that the observed phase transitions are ferroelectric.

An organic plastic ferroelectric with high Curie point.

Plastic ferroelectrics, featuring large entropy changes in phase transitions, hold great potential application for solid-state refrigeration due to the electrocaloric effect. Although conventional ceramic ferroelectrics (e.g., BaTiO3 and KNbO3) have been widely investigated in the fields of electrocaloric material and catalysis, organic plastic ferroelectrics with a high Curie point (Tc) are rarely reported but are of great importance for the sake of environmental protection. Here, we reported an organic plastic ferroelectric, (−)-camphanic acid, which crystallizes in the P21 space group, chiral polar 2 (C2) point group, at room temperature. It undergoes plastic paraelectric-to-ferroelectric phase transition with the Aizu notation of 23F2 and high Tc of 414 K, showing large entropy gain (ΔSt = 48.2 J K−1 mol−1). More importantly, the rectangular polarization–electric field (P–E) hysteresis loop was recorded on the thin film samples with a large saturated polarization (Ps) of 5.2 μC cm−2. The plastic phase transition is responsible for its multiaxial ferroelectric feature. This work highlights the discovery of organic multiaxial ferroelectrics driven by the motive of combining chirality and plastic phase transition, which will extensively promote the practical application of such unique functional materials.

Investigation of optical and electrical properties of the semiconducting α-KZnPO4 compound.

We used the solid state method to synthesize the α-KZnPO4 compound. The X-ray diffraction pattern revealed that the sample represents a single hexagonal phase with a P63 space group. The chemical composition of the compound was examined by energy dispersive spectroscopy. The optical absorption measurement confirmed the semiconductor nature of the compound with a band gap around 4.52 eV. Furthermore, the electrical properties of the material were analyzed by means of the impedance spectroscopy, in a frequency range from 100 Hz to 1 MHz and a temperature range from 583 K to 673 K. The dependency of s(T) on temperature showed that the overlapping large polaron tunneling model is the mechanism responsible for AC conduction in the compound. A correlation between the crystal structure and the ionic conductivity was established and discussed. Finally, the temperature variation of M′′ peak showed a thermally activated relaxation process and a temperature-dependent stretching exponent β parameter.

Structural, vibrational, thermal, and optical properties of L-threonine crystals containing Ce3+ ions

In this study, L-threonine (L-Thr) crystal containing Ce3+ (L-ThrCe) impurity was grown through the slow solvent evaporation method. The structural data obtained by X-ray diffraction and Rietveld's refinement revealed that the L-ThrCe crystal crystallizes in the orthorhombic structure with P212121-space group and that the Ce3+ ions probably occupy interstitial spaces within the crystal, promoting a slight expansion on the crystal unit cell volume and a slight strain increase. Fourier-transform infrared and Raman spectroscopy showed that the Ce3+ ion slightly affects the crystalline lattice. Thermal analyses indicated that the L-ThrCe crystal has stability from 300 K up to 483 K. In addition, the L-ThrCe sample showed three bands into the UV-Vis region (240, 253, and 299 nm) characteristic of Ce3+ ions due to the 4f-5d transition. From photoluminescence, it was possible to observe emission broadband with a maximum around 350 nm when excited at 255 nm, corresponding to 2D → 2F7/2, 2F5/2 transitions of the Ce3+ ion. The present study demonstrated that the L-ThrCe crystal has light emission in the ultraviolet region, and it expands the range of potential materials for optical applications.

Single crystal-to-single crystal transformation - from two distinct to three distinct spin crossover centers in 2D coordination polymer [Fe(bbtr)3](CF3SO3)2.

1,4-Di(1,2,3-triazol-1-yl)butane (bbtr) forms a two-dimensional (2D) coordination polymer (1) in a reaction with iron(II) triflate. In the crystal lattice there are two crystallographically unique iron(II) ions surrounded octahedrally by a 1,2,3-triazole ring coordinated through nitrogen atoms N3. Single crystal X-ray diffraction studies revealed that spin crossover for each crystallographically independent iron(II) ion proceeds at a different temperature (T1/2(Fe1) = 201 K; T1/2(Fe2) = 216 K), while the magnetic measurements showed that there is one step, complete thermally induced spin crossover (T1/2 = 205 K). Complex 1 undergoes, with time, single crystal-to-single crystal transformation (SCSC) to the converted system (1c) from the R3̄ to the P63 space group, accompanied by significant changes in the lattice parameter c (a shortening of approximately one-third) and consequently unit cell volume. Structural transformation is associated with rebuilding of the polymeric layer as well as the anion network, which is reflected in the results of Mössbauer studies. In the polymorphic system (1c) there are three crystallographically independent iron(II) ions. The temperature dependence results for magnetic susceptibility indicated complete, one-step spin crossover very similar to that of 1; however, single-crystal X-ray diffraction studies of 1c revealed that spin crossover for each crystallographically independent iron(II) ion occurs in a different manner, revealing three elementary stages (T1/2(Fe1) = 200 K; T1/2(Fe2) = 212 K, T1/2(Fe3) = 214 K).

Partial congener substitution induced centrosymmetric to noncentrosymmetric structural transformation and nonlinear optical properties of PbSnSiS4

The PbxSn2−xSiS4 series from 0 ≤ x ≤ 2 were investigated to study the influence of partial congener cationic substitution on structure and properties. While the centrosymmetric (CS) compounds Pb2SiS4 and Sn2SiS4 crystallizing in the centrosymmetric (CS) P21/c space group have been reported previously, the partial congener cationic substitution induced CS to noncentrosymmetric (NCS) structural transformation in this system and the formed NCS substitution variant PbSnSiS4 are introduced here for the first time. PbSnSiS4 crystallizes in P21 space group with the cell parameters a = 6.4334(8) Å; b = 6.6912(8) Å, c = 8.5037(10) Å, β = 108.576(4) °, Z = 2. The title compound shows a strong second harmonic generation (SHG) response (~ 1.1 × AgGaS2), high laser induced damage threshold (LIDT) (~3 × AgGaS2), and wide IR transparent region from 0.58 to 16.85 µm (down to zero). What’s more, PbSnSiS4 exhibits good crystal growth habits, and millimeter-scale single crystals (~ 2 × 2 × 1 mm3) were obtained in a spontaneous crystallization way. The theoretical calculations indicate that the optical band gaps decrease with increasing Sn content from Pb2SiS4 (1.94 eV), PbSnSiS4 (1.82 eV), to Sn2SiS4 (1.69 eV). The results give an insight into the exploration of new NCS compounds with the congener cationic substitution strategy.

Single‐Bonded Cubic AsN from High‐Pressure and High‐Temperature Chemical Reactivity of Arsenic and Nitrogen

AbstractChemical reactivity between As and N2, leading to the synthesis of crystalline arsenic nitride, is here reported under high pressure and high temperature conditions generated by laser heating in a diamond anvil cell. Single‐crystal synchrotron X‐ray diffraction at different pressures between 30 and 40 GPa provides evidence for the synthesis of a covalent compound of AsN stoichiometry, crystallizing in a cubic P213 space group, in which each of the two elements is single‐bonded to three atoms of the other and hosts an electron lone pair, in a tetrahedral anisotropic coordination. The identification of characteristic structural motifs highlights the key role played by the directional repulsive interactions between non‐bonding electron lone pairs in the formation of the AsN structure. Additional data indicate the existence of AsN at room temperature from 9.8 up to 50 GPa. Implications concern fundamental aspects of pnictogens chemistry and the synthesis of innovative advanced materials.

X-ray powder diffraction data for rivaroxaban, C19H18ClN3O5S

X-ray powder diffraction data, unit-cell parameters, and space group for rivaroxaban, C19H18ClN3O5S, are reported [a = 9.010(3) Å, b = 10.986(6) Å, c = 11.230(1) Å, α = 63.439(5)°, β = 74.355(4)°, γ = 78.133(3)°, unit-cell volume V = 952.87 Å3, Z = 2, ρcal = 1.519 g cm−3, and space group P1]. All measured lines were indexed and are consistent with the P1 space group. No detectable impurities were observed.

Ba2B13O19(OH)5·5H2O: A promising nonlinear optical material with a unique 2[B13O19(OH)5]∞ two-dimensional layer

A case of hydrous borate with the formula of Ba2B13O19(OH)5·5H2O was synthesized by the traditional hydrothermal method. It crystallizes in the chiral P1 space group and has a unique two-dimensional 2[B13O19(OH)5]∞ layer that is constructed by the hydrogen involved [B13O22(OH)5] fundamental building blocks (FBBs). The Ba atoms and H2O molecules are filled in the three-dimensional pore constructed by the 2[B13O19(OH)5]∞ layer. Interestingly, Ba2B13O19(OH)5·5H2O is the first case of hydrous borates that has the above rare [B13O22(OH)5] FBB and 2[B13O19(OH)5]∞ layer, which enriching the structural chemistry of borate system. The diffuse reflection spectrum result shows that the ultraviolet (UV) cutoff edge of Ba2B13O19(OH)5·5H2O is below 200 nm. Its second harmonic generation (SHG) response is approximately 1.0 times that of potassium dihydrogen phosphate at the 1064 nm fundamental wavelength and it is also phase-matchable. Both results indicate that the title compound is a nonlinear optical crystal for UV spectral region. Theoretical simulation calculation shows that the occupied VE states are mainly contributed by the O-2p orbitals, and therefore [B13O22(OH)5] groups are the main sources of SHG effects.