Research progress on the structure and function of the type IX secretion system of Porphyromonas gingivalis / 口腔疾病防治

@#The Porphyromonas gingivalis type IX secretion system (T9SS) is a recently discovered protein secretion system that is widely distributed in Bacillus cereus. The T9SS is structurally complex and powerful. More than 20 T9SS components have been verified, and more than 30 virulence factors can be secreted by Porphyromonas gingivalis alone, which contributes significant to the pathogenicity of Porphyromonas gingivalis. T9SS is a large protein complex spanning the inner cell membrane, periplasm, and outer cell membrane. Through the structural and functional connections among its components, it forms a sophisticated functional complex that includes power provision, energy transduction, inner and outer membrane translocation, outer membrane modification, and regulatory systems to recognize, translocate, shear, and modify cargo proteins and translocate bacterial intracellular cargo proteins to the cell surface. In recent years, with advancements in X-ray diffraction and in situ cryoelectron microscopy, the exploration of T9SS has evolved from the functional study of single components to the in situ structural study of multiprotein complexes. Still, the structural resolution of the protein still has shortcomings such as low resolution and an inability to capture dynamic functional structures. Future research directions should focus more on exploring how T9SS interacts and functions with cargo proteins. In this paper, we review the research progress on Porphyromonas gingivalis T9SS on X-ray diffraction and cryoelectron microscopy structure resolution in order to gain a deeper understanding of the transport mechanism of T9SS.

Preformulation screening of lipids using solubility parameter concept in conjunction with experimental research to develop ceftriaxone loaded nanostructured lipid carriers

Abstract Development of ceftriaxone loaded nanostructured lipid carriers to increase permeability of ceftriaxone across uninflamed meninges after parenteral administration. Lipids were selected by theoretical and experimental techniques and optimization of NLCs done by response surface methodology using Box-Behnken design. The Δδt for glyceryl monostearate and Capryol90 were 4.39 and 2.92 respectively. The drug had maximum solubility of 0.175% (w/w) in glycerol monostearate and 2.56g of Capryol90 dissolved 10mg of drug. The binary mixture consisted of glyceryl monostearate and Capryol90 in a ratio of 70:30. The optimized NLCs particle size was 130.54nm, polydispersity index 0.28, % entrapment efficiency 44.32%, zeta potential -29.05mV, and % drug loading 8.10%. In vitro permeability of ceftriaxone loaded NLCs was 5.06x10-6 cm/s; evidently, the NLCs pervaded through uninflamed meninges, which, was further confirmed from in vivo biodistribution studies. The ratio of drug concentration between brain and plasma for ceftriaxone loaded NLCs was 0.29 and that for ceftriaxone solution was 0.02. With 44.32% entrapment of the drug in NLCs the biodistribution of ceftriaxone was enhanced 7.9 times compared with that of ceftriaxone solution. DSC and XRD studies revealed formation of imperfect crystalline NLCs. NLCs improved permeability of ceftriaxone through uninflamed meninges resulting in better management of CNS infections.

Analysis of Polarizing Microscopic Characteristics and X-ray Diffraction Fingerprint of Mineral Medicine Maifanitum / 中国实验方剂学杂志

ObjectiveTo analyze the polarized light microscopic characteristics， the composition of physical phases and their relative contents of Maifanitum from different origins， and to establish the Fourier characteristic fingerprint of Maifanitum powder crystals by X-ray diffraction（XRD）. MethodA total of 26 batches of Maifanitum samples were selected， and the microscopic characteristics of the sample powders and grinding flakes were observed by polarized light microscopy under single polarized light and orthogonal polarized light， and the main phase compositions and their relative contents were analyzed by powder crystal XRD technique， and the XRD Fourier characteristic fingerprint of Maifanitum was established. The incident light source of XRD was Cu target Kβ radiation， the light tube voltage and light tube current were 40 kV and 40 mA， respectively， the divergence slit was 1°， the scattering slit was 1°， the receiving slit was 0.2 mm， the scanning speed was 5°·min-1 with continuous scanning and scanning range of 5-90°（2θ）， and the step length was 0.02°. ResultThe polarized light micrographs of powders and grinding flakes of Maifanitum were obtained， and the main phases were plagioclase， potassium feldspar and quartz， and a few samples also contained illite， pyrite， iron dolomite， calcite， iron amphibole and chlorite， etc. The relative total content of feldspar phases was 61.9%-82.4%， and the relative content of quartz was 12.6%-33.6%. The XRD Fourier fingerprint analysis method of Maifanitum with 13 common peaks as the characteristic fingerprint information was established， and the similarity calculated by the mean correlation coefficient method was 0.920 9-0.997 7， the similarity calculated by the mean angle cosine method was 0.940 5-0.998 4， the similarity calculated by the median correlation coefficient method was 0.921 1-0.997 5， and the similarity calculated by the median angle cosine method was 0.947 5-0.998 2. ConclusionThe polarized light microscopic identification characteristics of Maifanitum are mainly plagioclase， quartz and potassium feldspar， and the technique of powder crystal XRD Fourier fingerprint analysis can be used for the identification of Maifanitum.

Study on alkaloid constituents of Stephania tetrandra S. Moore / 药学学报

Fifteen alkaloid compounds were isolated from the 70% aqueous alcohol extract of Stephania tetrandra S. Moore by silica gel, reversed phase silica gel, Sephadex LH-20 column chromatography and semi-preparative high performance liquid chromatography. They were identified as tetrandraside A (1), (Z)-N-formyl-nornuciferin (2), (E)-N-formyl-nornuciferin (3), salutaridine (4), salutaridine N-oxide (5), (E)-3-(4-hydroxy-3-methoxyphenyl)-N-[2-(4-hydroxy-3-methoxyphenyl)ethyl]-2 propenamide (6), dauriporphine (7), sinomenine (8), liriodenine (9), α-magnoflorine (10), (1S)-4'-β-glucosylcoclaurine (11), tetrandrine (12), fangchinoline (13), tetrandrine 2'-β-oxide (14), and tetrandrine 2'-α-oxide (15), respectively, by MS, NMR and single crystal diffraction. Among them, compound 1 is a new alkaloid glycoside. Compounds 2-11 were obtained from this plant for the first time. These compounds showed obvious cytotoxic activity against drug-resistant lung cancer cell line H1299, and compound 9 had the best activity, with an IC50 of 5.38 μmol·L-1.

Establishment of a cocrystal characterization method for sacubitril valsartan sodium / 药学学报

Sacubitril valsartan sodium (LCZ696) is an ionic cocrystal drug. The purpose of this study was to explore the cocrystal features of LC696 by establishing a variety of characterization methods, and thus provide basic research data for effective quality control. The cocrystal characteristics of LCZ696 and its tablets were identified by applying analytical means including powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FTIR), Raman spectra (RM), differential scanning calorimetry (DSC) and solid-state nuclear magnetic resonance spectroscopy (ssNMR). The crystalline water and hygroscopicity of LCZ696 were analyzed by thermogravimetric analysis (TGA), dynamic vapor sorption (DVS), hygroscopicity test and Karl Fischer reaction method. The results show that PXRD, FTIR, DSC and ssNMR can effectively distinguish the features of LCZ696 cocrystal, sacubitril monomer, valsartan monomer, and sacubitril-valsartan (1∶1) mixture. RM can be used as a supplementary approach. Combined with the analysis by TGA, DVS, hygroscopicity test and Karl Fischer reaction method results, LCZ696 contains 2.5 crystalline water molecules and is very hygroscopic; we recommend that LCZ696 be stored in an environment with a relative humidity below 60%. By characterizing the crystal features we can establish quality control measure and evaluate the stability of the drug tablets. This study provides data in support for the establishment of the LCZ696 quality standard.

Pharmaceutical polymorphism of a 5´-O-oxalatoyl prodrug of zidovudine (azidothymidine)

The importance of polymorphism in pharmaceuticals makes its study relevant. The aim of this study was to investigatethe solid-state forms in which 3´-azido-2´, 3´-dideoxi-5´-O-oxalatoyl-thymidinic acid (AZT-Ac), a zidovudine (AZT)prodrug with improved pharmacokinetic properties, may exist. Samples were prepared using different crystallizationconditions and characterized using powder X-ray diffraction, solid-state nuclear magnetic resonance, differentialscanning calorimetry, thermogravimetry, and hot-stage microscopy. Pharmaceutical relevant properties such assolid-state stability and intrinsic dissolution rate (IDR) at 37°C in simulated gastric fluid (SGF) were also evaluated.AZT-Ac was found to able to exist as a crystalline polymorph (AZT-Ac-C) and an amorphous phase (AZT-Ac-A),which were thoroughly characterized. At 40°C/75% relative humidity (RH), AZT-Ac-A, in part, devitrified toAZT-Ac-C and partially hydrolyzed to AZT after 7 and 14 days of storage, respectively. AZT-Ac-C was physicallystable at 40°C/75% RH but partly hydrolyzed to AZT after 14 days of storage. In SGF, AZT-Ac-C exhibited a linearID profile and provided an ID rate of 0.494 mg/min/cm2, whereas AZT-Ac-A exhibited a nonlinear profile. Therefore,the crystalline form demonstrated the advantages over the amorphous one in terms of solid-state stability and IDR, butthe approaches to enhance its stability should be considered for further formulation of this prodrug.

Evaluation of Chromium and Manganese levels in sports supplements using graphite furnace atomic absorption spectrometry / Avaliação do teor de Cromo e Manganês em suplementos esportivos por meio de espectrometria de absorção atômica em forno de grafite

ABSTRACT Objective In this paper, we studied three different types of ordinary sports supplements containing whey protein: whey protein-based ones, hypercaloric ones, and protein bars. Methods A sample preparation procedure was studied employing microwave-assisted wet digestion in order to determine the Chromium and Manganese levels by graphite furnace atomic absorption spectrometry. Results The developed methods have presented good accuracy (recoveries in the range of 90% to 109%) and precision (Relative standard deviation <8%). Although an adequate detectability was obtained (50ng g-1 for Manganese and 65ng g-1 for Chromium), the sample preparation method was also adequate to inductively coupled plasma mass spectrometry analysis. The method was applied to 26 commercial samples, in which the Chromium concentrations were in the range between 0.22 and 1.0μg g-1 and the Manganese concentrations varied from 2.0 to 37μg g-1. Conclusion The results obtained by atomic absorption for both analytes were in agreement with those obtained by mass spectrometry. In addition, some samples presented concentrations of Chromium above the recommended daily intake and, as a result, we used the X-ray powder diffraction technique as an analytical tool to evaluate the oxidation state of Chromium in such samples.

RESUMO Objetivo Neste trabalho, foram estudados diferentes tipos de suplementos esportivos contendo proteína de soro de leite, conhecidos como: whey protein, hipercalóricos e barras de proteína. Métodos Um procedimento de preparo de amostras foi estudado com o emprego de digestão úmida assistida por micro-ondas, a fim de determinar os teores de cromo e manganês por espectrometria de absorção atômica em forno de grafite. Resultados Os métodos adotados apresentaram boa exatidão (recuperações na faixa de 90 a 109%) e precisão (Desvio padrão relativo <8%). Embora tenha sido obtida uma capacidade de detecção adequada de 50ng g-1 para o manganês e de 65ng g-1 para o cromo, o método de preparo da amostra também se revelou adequado para a utilização em análises por espectrometria de massas com plasma indutivamente acoplado. O método foi aplicado a 26 amostras comerciais, cujas concentrações de cromo variaram entre 0,22 e 1,0μg g-1, e de manganês entre 2,0 e 37μg g-1. Conclusão Os resultados obtidos por absorção atômica, para ambos os analitos, mostraram-se de acordo com aqueles obtidos por espectrometria de massas. Além disso, algumas amostras apresentaram concentrações de cromo acima da recomendação de consumo diário e, como resultado, a técnica de difração de raios-X em pó foi utilizada como ferramenta analítica para avaliar o estado de oxidação do cromo em tais amostras.

Characterization of self-assembled bone-like nano-hydroxyapatite/collagen composites / 中国组织工程研究

BACKGROUND: The materials that are similar to natural bone and can be used for repair of bone defects or as tissue engineering material have become the focus of research. OBJECTIVE: To investigate the feasibility of self-assembly of nano-hydroxyapatite collagen composite. METHODS: Collagen was immersed in 0.25% glutaraldehyde solution for 0.5 (group A), 24 (group B) and 72 hours (group C) for cross-linking reaction. In the group D, collagen was immersed in carbodiimide for 4 hours. After cross-linking reaction, collagen in each group was immersed in nano-hydroxyapatite solution for 7 days to prepare bone-like composite materials. The mineral phase analysis, composition, and microstructure of composite materials and natural bone were analyzed. RESULTS AND CONCLUSION: X-ray diffraction analysis: The amorphous diffraction peaks of the composites were slightly higher than those of the natural bone. The amorphous change of the composite was not obvious. With the prolongation of glutaraldehyde cross-linking time, the peak value of the crystal of the composite tended to increase. The amorphous diffraction peaks of the composites crosslinked with carbodiimide were slightly lower than those crosslinked with glutaraldehyde. Fourier transform infrared spectroscopy analysis: The chemical composition of the composites was similar to that of the natural bone, which was composed of collagen and hydroxyapatite, in which PO43-was partly replaced by CO32-ion in hydroxyapatite. Different cross-linking methods had no obvious effects on inorganic phase change of the materials. Scanning electron microscopy: The effects of different collagen cross-linking methods on the morphology of the formed crystals were not significantly different. Collagen fibers intertwined. A large number of fine needle-like crystals deposited on them, clustered, and were uniformly distributed. The crystal was nano-scaled in size. These results suggest that bone-like composite can be self-assessmbled with nano-hydroxyapatite precursor and collagen.

Micro-morphology and phase of zirconia-based nano-hydroxyapatite functional gradient biomaterials / 中国组织工程研究

BACKGROUND: The successfully prepared zirconia-based nano-hydroxyapatite functional gradient bioceramics has mechanical properties of strong interlayer bonding, high compressive and shear strength, but its biological properties are yet to be studied. OBJECTIVE: To detect the micro-morphology and phase of the zirconia-based nano-hydroxyapatite functional gradient bioceramics using scanning electron microscope and X-ray diffractometer. METHODS: Cylindrical zirconia-based nano-hydroxyapatite functional gradient bioceramics were longitudinally sectioned into thin-shaped specimens with turbine handpieces. The profile (intersections of layers) was polished with sandpaper. Its surface micro-morphology and layered structure were observed with a scanning electron microscope after spraying gold. The test piece was ground into a powder in an agate mortar and filtered with gauze. Ceramic powder was sieved with smaller particle size for phase analysis with X-ray diffractometer. RESULTS AND CONCLUSION: (1) Scanning electron microscopy showed that the gradient layers were tightly bound. The grain volume was basically uniform. There was a small amount of ZrO2 agglomeration. The closer to the surface layer, the higher the nHA content and the uniform small pores. (2) The X-ray diffractometer detected mainly the tetragonal phase ZrO2 and nHA diffraction peaks, and a small amount of β-TCP, α-TCP, CaZrO3 and a small amount of monoclinic phase ZrO2 crystal. (3) The research results indirectly indicate that the surface layer nHA is firmly bonded to the ZrO2 matrix layer under the transition of the gradient layer. ZrO2 based nHA functional gradient biomaterial is a ceramic material with excellent mechanical and biological properties.

Analysis of X-ray diffraction fingerprint of Calamina and its processed products / 中草药

Objective: To establish X-ray diffraction (XRD) fingerprint of Calamina and its processed products, compare the effects of different processing Methods on the main components of medicinal materials and determine the content of ZnO in the processed products. Methods: XRD was used to analyze 10 batches of Calamina and its processed products, and fingerprints of Calamina and its processed products were established respectively. Six different processing methods were compared, and the content of ZnO in all processed products was determined by K value method. Results: Fingerprints of Calamina and its processed products were preliminarily established. There were 23 common peaks in the fingerprints of Calamina, and there were 10 common peaks in the fingerprints of its processed products. After calcination, the ZnCO3 characteristic peak of the raw material was transformed into the characteristic peak of ZnO; The content of ZnO in the calcined product exceeded 56%. Conclusion: XRD fingerprints could be used for the identification and analysis of Calamina and its processed products. The new and reliable method was provided for quality evaluation of Calamina and its processed products.

Caracterización de materiales (pigmentos y cerámicas) para la conservación del patrimonio cultural y social en ciudad de La Habana / Characterization of materials (pigments and ceramics) for the conservation of cultural and social heritage in the city of Havana

RESUMEN Una de las direcciones de aplicación de la Ciencia de Materiales que realiza el Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear CEADEN es el apoyo mediante un grupo de técnicas físicas a la restauración y el mantenimiento de estructuras y objetos de la ciudad de La Habana, entre otras localidades de Cuba, que poseen interés artístico y social . En el presente trabajo se abordan varias aplicaciones en la caracterización de materiales para contribuir a las actividades de conservación del patrimonio cultural e histórico cubano que se encuentra en La Habana. Se presentan dos ejemplos de análisis por las técnicas de Fluorescencia de Rayos X y Difracción de rayos X de los pigmentos de obras en lienzos y de la paleta de una reconocida artista de la plástica cubana; así como el de tejas cerámicas que fueron utilizadas en la restauración de los techos de la residencia conocida como Casa Verde de 5ta Avenida en el Municipio Playa.

ABSTRACT One of the applications in Materials Science carried out at the Center for Technological Applications and Nuclear Development (CEADEN) is the technical support through several methods used, based on applied Physics for the restoration and maintenance of structures and objects holding artistic and social relevance in Havana city. The aim of this paper is to present two examples of X -ray Fluorescence and Diffraction materials characterization, intended to support conservation and restoration activities of the Cuban cultural and historic heritage: analyzed objects were pottery roof tiles for the restoration of the mansion known as The Green House at 5th Avenue, Miramar, as well as pigments from a Cuban fine artist's canvas and palette.

Biogenic Synthesis Of Silver Nanoparticles (AgNPs) Using Celosia Cristata L. Leaves Extract And Their Antimicrobial Activity Against Otorhinolaryngological Isolated Pathogen

This work focused on the biogenic synthesis of silver nanoparticles (AgNPs) by silver nitrate using Celosia cristata leaves extract in four different solvents namely petroleum ether, acetone, methanol, and water. Silver nitrate and leaves extract were used as a precursor and capping reducing agent respectively. Biogenic AgNPs were characterized and identified by UV-Vis spectrophotometer, X-ray diffraction (XRD), Field emission scanning electron microscope (FE-SEM), and energy dispersive spectroscopy (EDX). Disc diffusion method was used for antibacterial activity of AgNPs and effective antibacterial activity was shown against IS-3, IS-4, IS-6, and IS-7 as compared to a positive control (ciprofloxacin).

A new triterpenoid sapogenin from flowers of Bombax malabaricum / 中草药

Objective To study the chemical constituents from the flowers of Bombax malabaricum. Methods The compound was separated and purified by silica gel and gel column choromatography. The structure of the new compound was identified by NMR, HRMS (EIS), IR, UV, and single crystal X-ray diffraction. Results A new compound was isolated from the flowers of B. malabaricum and identified as 3β-acetoxy-22α,30-dihydroxyurs-20-ene. Conclusion Compound 1 was a ursane-type triterpenoid and named as mumian terpene A.

Preparation of silymarin-SBE-β-CD inclusion complex / 中草药

Objective: The inclusion compound of silymarin-SBE-β-CD was prepared. Methods: Phase solubility method was used to screen the inclusion materials of cyclodextrin and determine the type of inclusion. The technological conditions of silymarin inclusion complex were optimized by orthogonal design. The solubility of inclusion was determined and its structure was characterized by means of microscope, infrared spectrum analysis and X-ray diffraction analysis. Results: Due to its higher solubilization effect on silymarin, SBE-β-CD was determined as inclusion material. The ratio of drug to cyclodextrin was coated in the mode of 1:n. The process optimized by orthogonal design was as follow: molar ratio of silymarin to SBE-β-CD of 1:8, inclusion temperature of 60 ℃, and inclusion time of 3 h. Microscope, infrared spectrum analysis and X-ray diffraction analysis showed that the inclusion compound was formed and the drug existed in the inclusion compound as amorphous. Conclusion: The inclusion compound of silymarin-SBE-β-CD has been successfully prepared, which can significantly improve the solubility of the drug, and provide experimental basis for its clinical application.

SEM and XRD Identification of Mineral Chinese Medicine Alumen, Calcined Alumen, and Their Processed Products / 中国实验方剂学杂志

Objective: Ammonium alum is a common counterfeit of Alumen,and the processed product of ammonium alum is a common counterfeits of calcined Alumen. This paper aims to establish a method for identifying Alumen,calcined Alumen,ammonium alum and their processed products. Method: The samples were analyzed by scanning electron microscope (SEM) and X ray diffraction (XRD) in this paper. Result: Ammonium alum and Alumen showed obvious changes in morphology after processing. Both Alumen and ammonium alum showed obvious differences in morphology at×250 and×1 000 times microscope. Alumen presented irregular fragments,clear edge corners,smooth surface,scattered irregular small particles,occasional holes and longitudinal edges. Ammonium alum presented irregular clumps,blunt edges,not obvious edges and corners,uneven surface,scattered smaller and round-like particles. The difference in morphology was not obvious at×250 times microscope between Alumen and ammonium alum processed products. While at×1 000 times,the surface of calcined Alumen was uneven with coarse particles; the surface of counterfeit calcined Alumen was flat,and the coarse particle characteristics were not obvious. XRD can be used to rapidly and accurately identify the primary phase of Alumen,calcined Alumen,ammonium alum and ammonium alum processed products:KAl(SO4)2·12H2O,NH4Al(SO4)2·12H2O,KAl(SO4)2,and NH4Al(SO4)2 respectively, with 2θ angle characteristic value of 23,12,22 and 5 respectively for XRD peak. Conclusion: SEM and XRD techniques can be used for the identification of Alumen,calcined Alumen,ammonium alum and their counterfeit products.

Study on Ranunculaceae herbal decoction pieces using X-ray diffraction / 中国中药杂志

The powder X-ray diffraction(PXRD) technique was used to investigate fourteen kinds of Ranunculaceae herbal decoction pieces(RHDP) recorded in Chinese Pharmacopoeia and to explore a novel PXRD quality control method for RHDP. The results indicated that only three RHDP-Paeoniae Radix Alba, Paeoniae Radix Rubra, and Moutan Cortex, contained calcium oxalate monodydrate(COM), whereas no COM existed in other eleven kinds of RHDP. The difference in PXRD for Paeoniae Radix Alba and Paeoniae Radix Rubra from different growing areas were investigated. The quantitative analysis method for COM was discussed by considering the water-boiling manufacturing process of herbal decoction pieces. The water-boiling experiments revealed that the PXRD peaks from COM crystals in RHDP were enhanced significantly after boiling. Paeoniae Radix Alba, Paeoniae Radix Rubra, Moutan Cortex, Aconiti Lateralis Radix Praeparata, Aconiti Radix, Aconiti Kusnezoffii Radix, and Anemone Raddeanae Rhizoma exhibited a similar series of broader peaks in the 2θ region of 15° to 35°, whose origins were discussed on the basis of chemical constituents RHDP reported by other researchers. These diffraction broader peaks most likely originated from periodic orientation of benzene ring in organic molecular crystals of aconitine-and paeonolum-based alkaloids and glycosides chemical constituents, subsequently, possibly from some other organic constituents. The PXRD technique can be used to rapidly identify Cimicifuga heracleifolia with an amorphous dispersion peak and C. dahurica with a sharp-peak feature. Climatidis Radix et Rhizoma exhibited a series of sharp PXRD peaks. The PXRD method can provide a valuable quality control method for RHDP.

Quantitative Detection for Polymorph of Levonorgestrel by Powder X-ray Diffraction / 医药导报

Objective According to the clinical medicinal crystal form———form γ of levonorgestrel, to establish the quantitative analysis method for levonorgestrel form γ by powder X-ray diffraction (PXRD) . Methods Firstly, single crystal X-ray diffractometry and powder X-ray diffractometry were used to confirm that the prepared levonorgestrel form γ was 100％ polymorphic purity, which provided a standard sample for quantitative analysis by single peak method; then, the standard samples of different quality levonorgestrel form γ for powder X-ray diffraction were weighed, the peak intensity values of characteristic diffraction peaks d = 6.4 , d = 6. 1  and d = 5. 6  of form γ as quantitative parameters selected, a linear relationship between the peak intensity value and the quality of form γ was established; finally, the content of levonorgestrel form γ was quantitatively analyzed. Results The peak intensity values of characteristic diffraction peaks d = 6.4 , d = 6.1  and d = 5.6  of levonorgestrel form γ and the quality showed a good linear relationship.In the range of form γ masses of 5 mg to 50 mg, the regression linear equations wereY = 459.59X+5 536.5, R2 = 0.993 0, Y = 430.03X+6 867.6, R2 = 0.990 5,Y = 615.95X+ 6 209.5, R2 = 0.990 8,respectively. Conclusion The method is simple, rapid, accurate and reliable, it can be used as quality control method for levonorgestrel polymorphs.

Bioactive A-ring rearranged limonoids from the root barks of

Screening active natural products, rapid identification, and accurate isolation are of great important for modern natural lead compounds discovery. We hereby reported the isolation of seven new neotecleanin-type limonoids (-), seven new limonoids with 5-oxatricyclo[5.4.0.11., 4.]hendecane ring system (-), and two new precursors (-) together with four known limonoids (-) from the root barks of . Their structures, including their absolute configurations, were elucidated based on analyses of HR-ESI-MS, 1D/2D NMR, ECD spectrum calculations and single-crystal X-ray diffraction techniques. Compounds , , , , , , showed significant anti-inflammatory activities in LPS-induced RAW 264.7 cell line, BV2 microglial cells, and -stimulated THP-1 human monocytic cells. Walrobsin M () exhibited anti-inflammatory activity with IC value of 7.96±0.36 μmol/L, and down-regulated phosphorylation levels of ERK and p38 in a dose-dependent manner.

Conjugation of NMR and SAXS for multidomain protein structure determination: from sample preparation to model refinement / Conjugación de NMR y SAXS para la determinación estructural de proteínas multidominio: de la preparación de muestras al refinamiento de modelo

Abstract Experimental information from small angle X-ray scattering (SAXS) is conjugated with nuclear magnetic resonance (NMR) spectroscopy data for the improvement of protein structure determination, particularly for flexible, multidomain or intrinsically disordered proteins. Individually, each of these techniques presents capabilities and limitations: NMR excels in local information, providing atomic resolution, but is limited by protein size, whereas SAXS yields a global envelope of the protein with lower resolution, but revealing domain positions. Different conjugation methodologies use the complementarity of both technique´s independent constraints to accomplish a comprehensive protein structure determination and dynamics understanding at a moderate computational expense.

Resumen Se conjuga información experimental proveniente de dispersión de rayos X a ángulos pequeños (SAXS) con la espectroscopía de resonancia magnética nuclear (NMR) para perfeccionar la determinación de la estructura protéica, en particular de proteínas flexibles, de multidominio o intrínsecamente desordenadas. Individualmente, cada una de estas técnicas presenta capacidades y limitaciones: NMR se destaca en la información local, proporcionando resolución atómica, pero está limitada por el tamaño de la proteína, mientras que SAXS produce una envoltura global de la proteína con una resolución menor pero revelando las posiciones de los dominios. Las diferentes metodologías de conjugación utilizan la complementariedad de las restricciones independientes de ambas técnicas para seguir estrategias adecuadas de acuerdo con la proteína, logrando una determinación integral de la estructura y una comprensión de las dinámicas del sistema proteico a un costo computacional moderado.

Pedogenic iron oxides in soils of the Acre State, Brazil / Óxidos de ferro pedogênicos em solos do estado do Acre, Brasil

ABSTRACT: Iron oxides are environmental indicators and influence on physical and chemical behavior of soils. This research aimed to identify and characterize pedogenic iron oxides in soils of the Acre state, Brazil. The soils developed from sedimentary rocks of the Solimões Formation. Twenty one samples of subsurface horizons were collected from ten soil profiles. Soil samples were analyzed by x-ray diffractometry associated to selective chemical dissolutions. Fe contents in the clay minerals (Fes), in the pedogenic iron oxides (Fed) and in the poorly crystalline oxides (Feo) were determined. The Al3+-substitution and the mean crystal diameter of goethite and hematite were estimated. Soils presented low contents of Fes and Fed. The Fed/Fes ratio indicated soils in the intermediate stage of weathering, with dominance of goethite, hematite and maghemite. This condition of weathering was confirmed by the higher frequency of goethites and hematite with intermediate Al3+-substitution. Goethites have isodimensional forms and hematite have flat plaques forms.

RESUMO: Os óxidos de ferro são indicadores ambientais e influenciam o comportamento físico e químico dos solos. Este trabalho objetivou identificar e caracterizar os óxidos de ferro pedogênicos de solos do estado do Acre, desenvolvidos de rochas sedimentares da Formação Solimões. Vinte e uma amostras de horizontes subsuperficiais de dez perfis de solos foram analisadas por difratometria de raios x associada a dissoluções químicas seletivas. Os teores de Fe total (Fes), dos óxidos de Fe pedogênicos (Fed) e de baixa cristalinidade (Feo) foram determinados; e a Al3+-substituição e o diâmetro médio cristalino da goethita e da hematita foram estimados. Em geral, os solos apresentaram baixos teores de Fes e de Fed. A relação Fed/Fes indicou solos em estágio de intemperização intermediário, com dominância dos óxidos de Fe goethita, hematita e maghemita. Essa condição de intemperismo foi reforçada pela maior frequência de goethitas e hematitas com intermediária Al3+-substituição. As goethitas possuem formas isodimencionais e as hematitas ocorrem como placas achatadas.