In pursuit of effective agents for hepatocellular carcinoma derived from the Artemisia species, this study built upon initial findings that an ethanol (EtOH) extract and ethyl acetate (EtOAc) fraction of the aerial parts of Artemisia dubia Wall. ex Bess. exhibited cytotoxicity against HepG2 cells with inhibitory rates of 57.1% and 84.2% (100 μg·mL^-1), respectively. Guided by bioactivity, fourteen previously unidentified sesquiterpenes, artemdubinoids A-N (1-14), were isolated from the EtOAc fraction. Their structural elucidation was achieved through comprehensive spectroscopic analyses and corroborated by the comparison between the experimental and calculated ECD spectra. Single crystal X-ray diffraction provided definitive structure confirmation for artemdubinoids A, D, F, and H. Artemdubinoids A and B (1-2) represented unique sesquiterpenes featuring a 6/5-fused bicyclic carbon scaffold, and their putative biosynthetic pathways were discussed; artemdubinoid C (3) was a novel guaianolide derivative that might be formed by the [4 + 2] Diels-Alder reaction; artemdubinoids D and E (4-5) were rare 1,10-seco-guaianolides; artemdubinoids F-K (6-11) were chlorine-containing guaianolides. Eleven compounds exhibited cytotoxicity against three human hepatoma cell lines (HepG2, Huh7, and SK-Hep-1) with half-maximal inhibitory concentration (IC₅₀) values spanning 7.5-82.5 μmol·L^-1. Artemdubinoid M (13) exhibited the most active cytotoxicity with IC₅₀ values of 14.5, 7.5 and 8.9 μmol·L^-1 against the HepG2, Huh7, and SK-Hep-1 cell lines, respectively, which were equivalent to the positive control, sorafenib.
Humans ; Artemisia/chemistry* ; Sesquiterpenes/chemistry* ; Cell Line ; Hep G2 Cells ; Crystallography, X-Ray ; Molecular Structure

The present study explored the effect of co-amorphous technology in improving the dissolution rate and stability of silybin based on the puerarin-silybin co-amorphous system prepared by the spray-drying method. Solid-state characterization was carried out by powder X-ray diffraction(PXRD), polarizing microscopy(PLM), Fourier transform infrared spectroscopy(FT-IR), differential scanning calorimetry(DSC), etc. Saturated powder dissolution, intrinsic dissolution rate, moisture absorption, and stability were further investigated. The results showed that puerarin and silybin formed a co-amorphous system at a single glass transition temperature which was higher than that of any crude drug. The intrinsic dissolution rate and supersaturated powder dissolution of silybin in the co-amorphous system were higher than those of the crude drug and amorphous system. The co-amorphous system kept stable for as long as three months under the condition of 40 ℃, 75% relative humidity, which was longer than that of the single amorphous silybin. Therefore, the co-amorphous technology could significantly improve the dissolution and stability of silybin.
Calorimetry, Differential Scanning ; Desiccation ; Drug Compounding/methods* ; Drug Stability ; Silybin ; Solubility ; Spectroscopy, Fourier Transform Infrared ; Technology ; X-Ray Diffraction

A new coronavirus (SARS-CoV-2) has been identified as the etiologic agent for the COVID-19 outbreak. Currently, effective treatment options remain very limited for this disease; therefore, there is an urgent need to identify new anti-COVID-19 agents. In this study, we screened over 6,000 compounds that included approved drugs, drug candidates in clinical trials, and pharmacologically active compounds to identify leads that target the SARS-CoV-2 papain-like protease (PLpro). Together with main protease (M
Antiviral Agents/therapeutic use* ; Binding Sites ; COVID-19/virology* ; Coronavirus Papain-Like Proteases/metabolism* ; Crystallography, X-Ray ; Drug Evaluation, Preclinical ; Drug Repositioning ; High-Throughput Screening Assays/methods* ; Humans ; Imidazoles/therapeutic use* ; Inhibitory Concentration 50 ; Molecular Dynamics Simulation ; Mutagenesis, Site-Directed ; Naphthoquinones/therapeutic use* ; Protease Inhibitors/therapeutic use* ; Protein Structure, Tertiary ; Recombinant Proteins/isolation & purification* ; SARS-CoV-2/isolation & purification*

Nine new compounds, including five natural rarely-occurring 2, 3-dihydro-1H-indene derivatives named diaporindenes E-I (1-5), and four new benzophenone analogues named tenellones J-M (6-9) were isolated from the deep-sea sediment-derived fungus Phomopsis lithocarpus FS508. All the structures for these new compounds were fully characterized on the basis of spectroscopic data, NMR spectra, and ECD calculation and single-crystal X-ray diffraction analysis. The potential anti-tumor activities of compounds 1-9 against four tumor cell lines SF-268, MCF-7, HepG-2, and A549 were evaluated using the SRB method. Compound 7 exhibited cytotoxic activity against the SF-268 cell line with an IC
Antineoplastic Agents/pharmacology* ; Cell Line, Tumor ; Crystallography, X-Ray ; Fungi ; Molecular Structure ; Phomopsis

Pectin methylesterase (PME) is an important pectinase that hydrolyzes methyl esters in pectin to release methanol and reduce the degree of methylation of pectin. At present, it has broad application prospects in food processing, tea beverage, paper making and other production processes. With the in-depth study of PME, the crystal structures with different sources have been reported. Analysis of these resolved crystal structures reveals that PME belongs to the right-hand parallel β-helix structure, and its catalytic residues are two aspartic acids and a glutamine, which play the role of general acid-base, nucleophile and stable intermediate, in the catalytic process. At the same time, the substrate specificity is analyzed to understand the recognition mechanism of the substrate and active sites. This paper systematically reviews these related aspects.
Carboxylic Ester Hydrolases ; chemistry ; metabolism ; Catalytic Domain ; Crystallography ; Pectins ; metabolism ; Protein Structure, Tertiary ; Substrate Specificity

PURPOSE: The aim of this study was to investigate the effect of different numbers of heat treatments applied to superstructure porcelain on optical, thermal, and phase formation properties of zirconia.MATERIALS AND METHODS: Forty zirconia specimens were prepared in the form of rectangular prism. Specimens were divided into four groups (n = 10) according to the number of firing at heating values of porcelain. Color differences and translucency parameter were measured, and X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC) were performed. Data were analyzed with analysis of variance (ANOVA).RESULTS: There were no statistically significant differences in ΔE, TP, L, a, and b value changes of the zirconia specimens as a result of repetitive firing processes (P>.05).CONCLUSION: Although additional firing processes up to 4 increase peak density in thermal analysis, additional firing processes up to 4 times can be applied safely as they do not result in a change in color and phase character of zircon frameworks.
Calorimetry, Differential Scanning ; Dental Porcelain ; Fires ; Heating ; Hot Temperature ; X-Ray Diffraction

PURPOSE: The purpose of this study was to evaluate the effects of various protocols and systems for finishing and polishing monolithic zirconia on surface topography, phase transformation, and bacterial adhesion. MATERIALS AND METHODS: Three hundred monolithic zirconia specimens were fabricated and then treated with three finishing and polishing systems (Jota [JO], Meisinger [ME], and Edenta [ED]) using four surface treatment protocols: coarse finishing alone (C); coarse finishing and medium polishing (CM); coarse finishing and fine polishing (CF); and coarse finishing, medium polishing, and fine polishing (CMF). Surface roughness, crystal phase transformation, and bacterial adhesion were evaluated using atomic force microscopy, X-ray diffraction, and streptococcal biofilm formation assay, respectively. One-way and two-way analysis of variance with Tukey post hoc tests were used to analyze the results (α=.05). RESULTS: In this study, the surface treatment protocols and systems had significant effects on the resulting roughness. The CMF protocol produced the lowest roughness values, followed by CM and CF. Use of the JO system produced the lowest roughness values and the smallest biofilm mass, while the ME system produced the smallest partial transformation ratio. The ED group exhibited the highest roughness values, biofilm mass, and partial transformation ratio. CONCLUSION: Stepwise surface treatment of monolithic zirconia, combined with careful polishing system selection, is essential to obtaining optimal microstructural and biological surface results.
Bacterial Adhesion ; Biofilms ; Clinical Protocols ; Dental Polishing ; Microscopy, Atomic Force ; X-Ray Diffraction

We prepared a polymorphic form of valnemulin hydrogen tartrate (Form I) to overcome the instability and irritating odor of valnemulin hydrochloride that affect its use in the production and application of veterinary drugs. The physicochemical properties of Form I were characterized by scanning electron microscopy, X-ray powder diffraction, infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The results showed the crystal structure and thermal properties of Form I were very different from those of a commercially available form of valnemulin hydrogen tartrate (Form II). Form I and Form II were more stable than valnemulin hydrochloride after storage under irradiation and high humidity conditions, respectively. The solubility of Form I was 2.6 times that of Form II, and Form I was selected for use in pharmaceutical kinetics experiments in vivo. Compared to valnemulin hydrochloride, after oral administration at a dose of 10 mg/kg in pigs, Form I had similar pharmaceutical kinetic behavior but a slightly higher area under the concentration–time curve from time zero to the last measurable concentration. Consequently, Form I should be suitable for the development of simple formulations and be effective in the clinical application of veterinary drugs.
Administration, Oral ; Calorimetry, Differential Scanning ; Humidity ; Hydrogen ; Kinetics ; Microscopy, Electron, Scanning ; Odors ; Pharmacokinetics ; Powder Diffraction ; Solubility ; Spectrum Analysis ; Swine ; Veterinary Drugs

The calcium phosphate coating on various pretreated metals was prepared by soaking in modified simulated body fluid (m-SBF) solution. The coating structure and its surface morphologies were determined by x-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results revealed significant differences in morphology and composition of the calcium phosphate coatings with and without chitosan and NaOH-pretreated commercially pure titanium (cp-Ti) substrate. The calcium phosphates formed on chitosan coated-Ti pretreated with NaOH were ~ 350 nm-sized resulting in strong bonding of the apatite layer with the substrates and a uniform gradient of stress transfer from coating materials to the Ti-substrate. After NaOH pretreatment, the hydroxyl groups bind to Ca²⁺ to attract PO₄³⁻ anions, eventually resulting in a continuous layer of calcium phosphate on chitosan coated-Ti substrate during immersion in m-SBF solution. The chitosan coated-Ti showed hydrophobic surface while NaOH pretreatment resulted in maximum hydrophilicity to the Ti substrate. Due to improved wettability of Ti by NaOH pretreatment before chitosan coating, aggregation of calcium phosphate was prevented and size-controlled composite materials were obtained.
Anions ; Body Fluids ; Calcium Phosphates ; Calcium ; Chitosan ; Clothing ; Hydrophobic and Hydrophilic Interactions ; Immersion ; Metals ; Microscopy, Electron, Scanning ; Spectroscopy, Fourier Transform Infrared ; Titanium ; Wettability ; X-Ray Diffraction

The single-factor test was used to optimize the high-pressure homogenization method to prepare the phenolic extract nanosuspensions(DBNs). The physicochemical properties of the obtained nanosuspensions were characterized and the cumulative release in vitro was evaluated. The results showed that the drug concentration was 0.5 g·L~(-1), the mass concentrations of PVPK30 and SDS were 0.5 and 0.25 g·L~(-1), respectively, the probe ultrasonic time was 5 min, the homogenization pressure was 900 bar, and the number of homogenization was 2 times. The prepared DBNs had an average particle size of(168.80±0.36) nm, polydispersity index(PDI) of 0.09±0.04, stability index(SI) of 0.85, and DBNs were stable for storage within 30 days. Scanning electron microscopy showed that the particle size of the dragon's blood extract was reduced and the uniformity was improved in the obtained nanosuspensions. X-ray diffraction pattern and differential scanning calorimetry showed that the phenolic extract of dragon's blood was still in an amorphous state after being prepared into nanosuspensions. The results of saturated solubility measurement showed that the solubility of DBNs lyophilized powder reached 6.25 g·L~(-1), while the solubility of DB raw powder was only 28.67 mg·L~(-1). The in vitro dissolution experiments showed that DBNs lyophilized powder accumulated in gastrointestinal fluid for 8 h. The release amount was 90%,the cumulative release of the raw powder in the gastrointestinal fluid for 24 h was less than 1%, and the solubility and dissolution rate of the DBNs lyophilized powder were significantly higher than the DB raw powder. The method is simple in process and convenient in operation, and can successfully prepare uniform and stable nanosuspensions to improve its solubility, and provides a research basis for solving the application limitation of dragon's blood extract.
Calorimetry, Differential Scanning ; Nanoparticles ; Particle Size ; Plant Extracts ; chemistry ; Solubility ; Suspensions ; X-Ray Diffraction