Synthesis, crystal structure of and DFT calculations on bisglycinato-bis[p-(hydroxymethyl)pyridine]nickel(II)

The main aim of this study was to investigate the relationship between mIn tA new Ni(II) complex of bisglycinato-bis[p-(hydroxylmethyl)py-ridine] was synthesized and characterized by elemental analysis, IR, UV–Vis spectroscopy and X-ray single crystal diffraction analysis. The thermal stability of the title complex was also determined. The complex adopts a distorted octahedral geometry and possesses inversion symmetry with the Ni(II) ion as the center of inversion. Density function theory (DFT) calculations of the structure, electronic absorption spectra, electron structure and natural population analysis (NPA) at the B3LYP/LANL2DZ level of theory were performed. The predicted geometric parameters and electronic spectra were compared with the experimental values and they supported each other. The NPA results indicate that the electronic transitions were mainly derived from the contribution of an intra-ligand (IL) transition, a ligand-to-metal charge transfer (LMCT) transition and a d-d transition. The electron structure calculations suggest that the central Ni(II) ion uses its 4s and 3d orbitals to form covalent bonds with coordinated N and O atoms. The calculated bond orders are also consistent with the thermal decomposition results. Based on vibrational analysis, the thermodynamic properties of the title complex were predicted and the correlative equations between these thermodynamic properties and temperature are also reported

3-(4-Fluoro­phen­yl)-1-(4-methoxy­phen­yl)prop-2-en-1-one

The title compound, C16H13FO2, was prepared from 4-methoxy­hypnone and 4-fluoro­benzophenone by Claisen–Schmidt condensation. All the bond lengths and bond angles are in normal ranges. The dihedral angle formed by the two benzene rings is 33.49 (2)°. The crystal packing is stabilized by inter­molecular C—H⋯O hydrogen-bonding inter­actions

Gynostemma pentaphyllum for dyslipidemia: A systematic review of randomized controlled trials

Objective: To evaluate the lipid-lowering effect and safety of Gynostemma pentaphyllum (GP) used alone or as adjunctive therapy for dyslipidemia. Methods: Eight databases and three clinical trial registries were searched until January 2022. Randomized controlled trials (RCTs) assessing the effectiveness of GP for dyslipidemia were included. Trial quality was assessed using the Cochrane Risk of Bias Tool 2.0. Data were analyzed by RevMan 5.4 with effects estimated as risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI). Results: Twenty-two RCTs involving 2,407 dyslipidemia participants were included. Regarding the risk of bias, 14 RCTs had some concerns, seven RCTs were high, and one trial was low. GP was comparable to n-3 fatty acids (RR 0.89, 95% CI 0.62–1.28) and red yeast rice (RR 0.33, 95% CI 0.1–1.12) on normalization of serum lipids. GP plus n-3 fatty acid was superior in normalization of triglycerides (TG) and total cholesterol (TC) than n-3 fatty acids (RR 1.34, 95% CI 1.01–1.77). GP was similar to lipid-lowering agents (statins, fibrates, and n-3 fatty acids) in regulating TG, TC, and high-density lipoprotein cholesterol (HDL-C). GP plus lipid-lowering agents were superior to lipid-lowering agents in TG (MD −0.65 mmol/L, 95% CI −1.03 to −0.28), LDL-C (MD −0.57 mmol/L, 95% CI −1.07 to −0.08), and HDL-C (MD 0.15 mmol/L, 95% CI 0.11–0.20). GP was inferior to red yeast rice in TC (MD 0.64 mmol/L, 95% CI 0.15–1.13), TG (MD 0.43 mmol/L, 95% CI 0.15–0.71), and HDL-C (MD −0.25 mmol/L, 95% CI −0.47 to −0.04). GP had fewer adverse events than lipid-lowering drugs. Conclusion: Very low certainty evidence showed that GP’s effects on TC, TG, and HDL-C were comparable to that of lipid-lowering agents. Low certainty evidence showed that red yeast rice was superior to GP in TC, TG, and HDL-C. Low to moderate certainty evidence showed that the effects of GP plus lipid-lowering agents were superior to that of lipid-lowering agents on TG, LDL-C, and HDL-C. GP use for more than 8 weeks appears safe

Crystal engineered acid–base complexes with 2D and 3D hydrogen bonding systems using p-hydroxybenzoic acid as the building block

p-Hydroxybenzoic acid (p-HOBA) was selected as the building block for self-assembly with five bases, i.e., diethylamine, tert-butylamine, cyclohexylamine, imidazole and piperazine, and generation of the corresponding acid–base complexes 1–5. Crystal structure analyses suggest that proton-transfer from the carboxyl hydrogen to the nitrogen atom of the bases can be observed in 1–4, while only in 5 does a solvent water molecule co-exist with p--HOBA and piperazine. With the presence of O–H···O hydrogen bonds in 1–4, the deprotonated p-hydroxybenzoate anions (p-HOBAA–) are simply connected each other in a head-to-tail motif to form one-dimensional (1D) arrays, which are further extended to distinct two-dimensional (2D) (for 1 and 4) and three-dimensional (3D) (for 2 and 3) networks via N–H···O interactions. While in 5, neutral acid and base are combined pair-wise by O–H···N and N–H···O bonds to form a 1D tape and then the 1D tapes are sequentially combined by water molecules to create a 3D network. Some interlayer or intralayer C–H···O, C–H···p and p×××p interactions help to stabilize the supramolecular buildings. Melting point determination analyses indicate that the five acid–base complexes are not the ordinary superposition of the reactants and they are more stable than the original reactants