Detection of pathological aortic tissues by infrared multispectral imaging and chemometrics

Processing of multispectral images is becoming an important issue, especially in terms of data mining for disease diagnosis. We report here an original image analysis procedure developed in order to compare 42 infrared multispectral images acquired on human ascending aortic healthy and pathological tissues. Each image contained about 2500 infrared absorption spectra, each composed of 1641 variables (wavenumbers). To process this large data set, we have restricted the spectral window used to the 1800-950 cm(-1) spectral range and selected 100 spectra from the aortic media, which is the most altered part of the aortic tissue in aneurysms. Prior to this selection, a spectral quality test was performed to eliminate 'bad' spectra. Our data set was first subjected to a discriminant analysis, which allowed separation of aortic tissues in two groups corresponding respectively to normal and aneurysmal states. Then a K-means analysis, based on 20 groups, allowed reconstruction of infrared images using false-colours and discriminated between pathological and healthy tissues. These results demonstrate the usefulness of such data processing methods for the analysis and comparison of a set of spectral images.     

Determination of water contents in leaves by a near-infrared multispectral imaging technique

The kinetics of water desorption from olive leaves was studied using a near-infrared (NIR) multispectral imaging spectrometer. This imaging spectrometer is capable of sensitively and rapidly recording NIR spectral images of leaves because it was constructed with an acousto-optic tunable filter and an InGaAs focal plane array NIR camera. The high sensitivity and fast scanning ability of the imaging spectrometer make it suitable for kinetic determination. The kinetics of water desorption from olive leaves, determined by this multispectral imaging instrument, show that rate of water desorption is strongly dependent on the environment in which the leaves were stored. Water desorbed from leaves faster when leaves were stored under dry conditions. The rate for leaves stored in 0% humidity environment is 1.5× faster than those stored in 50% humidity.     

Acanthus mollis L. leaves as source of anti-inflammatory and antioxidant phytoconstituents

This work expands the phytochemical composition knowledge of Acanthus mollis and evaluates antioxidant and anti-inflammatory activities which could be related with its traditional uses. Extracts from leaves, obtained by sequential extraction, were screened using TLC and HPLC-PDA. The ethanol extract was the most active on DPPH assay (IC₅₀ = 20.50 μg/mL) and inhibited nitric oxide (NO) production in RAW 264.7 macrophages (IC₅₀ = 48.31 μg/mL). Significant amounts of cyclic hydroxamic and phenolic acids derivatives were detected. A lower antioxidant effect was verified for a fraction enriched with DIBOA derivatives (IC₅₀ = 163.02 μg/mL), suggesting a higher contribution of phenolic compounds for this activity in ethanol extract. However, this fraction exhibited a higher inhibition of NO production (IC₅₀ = 32.32 μg/mL), with absence of cytotoxicity. These results support the ethnomedical uses of this plant for diseases based on inflammatory processes. To our knowledge, it is the first report to the anti-inflammatory activity for DIBOA derivatives.     

Laser picosecond microspectrofluorometry of haematoporphyrin in cells and liposomes.

The results of a laser picosecond microspectrofluorometric study of the spectral and kinetic characteristics of haematoporphyrin (Hp) fluorescence at various sites in cultured SPEV cells and phosphatidylcholine liposomes are presented. The computer-controlled detection system is based on the single-photon counting method with picosecond time resolution. In aqueous medium, the Hp fluorescence spectrum is characterized by two bands at 615 and 675 nm. In living cells and liposomes, Hp fluorescence is red shifted to 630 and 690 nm. In addition a new band at 665 nm is detected. The dependence of this band on the incubation time and Hp concentration was investigated. The fluorescence decay kinetics of Hp in a culture medium, liposome and a cell nuclear membrane were measured. Possible Hp aggregate formation in the lipid bilayer and its implications are discussed.     

Flavonoids in Leguminosae: analysis of extracts of T. pratense L., T. dubium L., T. repens L., and L. corniculatus L. leaves using liquid chromatography with UV, mass spectrometric and fluorescence detection

Reversed-phase LC on C-18 bonded silica with a methanol–ammonium formate gradient was used to determine the main flavonoids in leaves of four species of the Leguminosae family. The detection modes were diode-array UV absorbance, fluorescence, and (tandem) mass spectrometry. LC–UV was used for a general screening, sub-classification, and the calculation of total flavonoid contents. LC–FLU was included to identify isoflavones on the basis of their native fluorescence. Most structural information regarding aglycons, sugar moieties, and acidic groups was derived from LC–MS in both the full-scan and extracted-ion mode, using negative-ion atmospheric pressure chemical ionization. MS/MS did not provide much additional information, because the same fragments were observed as in full-scan MS.In T. pratense and T. repens, the main constituents were flavonoid glucoside–(di)malonates, while T. dubium and L. corniculatus mainly contained flavonoid (di)glycosides. Satellite sets comprising an aglycon, the glucoside and glucoside–malonates or –acetates, were abundantly present only in T. pratense. Generally speaking, the main aglycons and sugars in the four plant species are surprisingly different. In addition, while the results for T. pratense are similar to those reported in the literature, there is little agreement in the case of the other species. Finally, total flavonoid contents ranged from 50–65 mg/g for L. corniculatus and T. dubium, to 15 mg/g for T. pratense and only 1 mg/g for T. repens.     

GC-MS法在黔产宽叶缬草质控中的应用

宽叶缬草(ValerianaofficinalisL.var.latifoliaMiq.)系败酱科植物。主产贵州,我国从东北至华北也有分布。具有镇静、镇痛、降压、解痉等作用。目前,对其挥发油研究较多,但采用气相色谱-质谱对药材质量进行研究较少。本文利用GC-MS,以水杨酸甲酯为内标,对药材中乙酸龙脑酯进行含量测定,建立其质量控制的方法。     

Flavonoid Composition and Antibacterial Properties of Crocus sativus L. Petal Extracts

Saffron petals, which are the main by-products of Crocus sativus L. (Iridaceae family), are produced in large quantities and are known for their many beneficial properties. In this regard, this study aims to investigate the phenolic composition and antibacterial properties of hydroethanolic extracts from Crocus sativus L. petals collected from Serghina (province of Boulmane) in Morocco. The phenolic profiles were characterized using high-performance liquid chromatography coupled to a photodiode array and electrospray ionization mass spectrometry (HPLC-PDA-ESI/MS). The antibacterial potential was evaluated against four bacterial strains potentially causing food-borne disease (Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, and Listeria monocytogenes) using disc diffusion and broth micro-dilution assays. Results showed that a total of 27 phenolic compounds was detected in the Crocus sativus L. petal extracts, which were assigned to flavonoids (kaempferol, quercetin, isorhamnetin, and myricetin derivatives). The most abundant compound was represented by kaempferol-sophoroside isomer (20.82 mg/g ± 0.152), followed by kaempferol-sophoroside-hexoside (2.63 mg/g ± 0.001). The hydroethanolic extracts of Crocus sativus L. petals demonstrated bactericidal effects against Staphylococcus aureus and Listeria monocetogenes and bacteriostatic effects against Escherichia coli and Salmonella typhimurium. Therefore, the by-product Crocus sativus L. petal extracts might be considered as valuable sources of natural antibacterial agents with potential applications in the food and pharmaceutical industries.     

In-silico investigation of phenolic compounds from leaves of Phillyrea angustifolia L. as a potential inhibitor against the SARS-CoV-2 main protease (Mpro PDB ID:5R83) using a virtual screening method

There is currently a global COVID-19 pandemic caused by the severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) and its variants. This highly contagious viral disease continues to pose a major health threat global. The discovery of vaccinations is not enough to prevent their spread and dire consequences. To take advantage of the current drugs and isolated compounds, and immediately qualifying approach is required. The aim of our research is evaluation the potency for natural antiviral compounds against the SARS CoV-2 M^pro. Molecular docking of four phenolic compounds from Phillyrea angustifolia leaves with SARS-CoV-2 M^pro has been conducted. Similarly, the stability of selected ligand–protein interactions has been determined using MD simulations. Moreover, the quantitative structure–activity relationship (QSAR), MMGBSA binding energies, pharmacokinetics, and drug-likeness predictions for selected phenolic have been reported. The selected phenolic compounds (Luteolin-7-O-glucoside, Apigenin-7-O-glucoside, Demethyl-oleuropein, and Oleuropein aglycone) revealed strong binding contacts in the two active pockets of a target protein of SARS-CoV-2 M^pro with the docking scores and highest binding energies with a binding energy of ?8.2 kcal/mol; ?7.8 kcal/mol; ?7.2 kcal/mol and ?7.0 kcal/mol respectively. Both Demethyloleoeuropein and Oleuropein aglycone can interact with residues His41 and Cys145 (catalytic dyad) and other amino acids of the binding pocket of M^pro. According to QSAR, studies on pharmacokinetics and drug-like properties suggested that oleuropein aglycone could be the best inhibitor of SARS-CoV-2 for new drug design and development. Further in vivo, in vitro, and clinical studies are highly needed to examine the potential of these phenolic compounds in the fight against COVID-19.     

Identification and quantitation of polyphenols in leaves ofMyrtus communis L.

Summary A liquid-solid extraction and purification procedure (LSE) was developed to identify and quantify polyphenols in the leaf tissue ofMyrtus communis L. Identification and quantitation of individual compounds was performed using HPTLC, HPLC-DAD and HPLC-MS analysis. Leaves ofMyrtus communis L. contain small amounts of phenolic acids (caffeic, ellagic and gallic acids) and quercetin derivatives (quercetin 3-O-galactoside and quercetin 3-O-rhamnoside), whereas catechin derivatives (epigallocatechin, epigallocatechin 3-O-gallate, epicatechin 3-O-gallate) and myricetin derivatives (myricetin 3-O-galactoside, myricetin 3-O-rhamnoside) are present in large amounts. This is the first report on the occurrence of galloyl-derivatives of catechin and gallo-catechin inMyrtus communis L. leaves.     

Study of the distribution of actinides in human tissues using synchrotron radiation micro X-ray fluorescence spectrometry

This study aims at evaluating the capabilities of synchrotron radiation micro X-ray fluorescence spectrometry (SR micro-XRF) for qualitative and semi-quantitative elemental mapping of the distribution of actinides in human tissues originating from individuals with documented occupational exposure. The investigated lymph node tissues were provided by the United States Transuranium and Uranium Registries (USTUR) and were analyzed following appropriate sample pre-treatment. Semi-quantitative results were obtained via calibration by external standards and demonstrated that the uranium concentration level in the detected actinide hot spots reaches more than 100 μg/g. For the plutonium hot spots, concentration levels up to 31 μg/g were found. As illustrated by this case study on these unique samples, SR micro-XRF has a high potential for this type of elemental bio-imaging owing to its high sensitivity, high spatial resolution, and non-destructive character.

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Graphical Abstract SR micro-XRF study of the distribution of actinitides in human tissues. Left Location of the U-contaminated tissue sample in the human body. Middle U distribution derived from the high resolution SR micro-XRF scan on the tissue sample, indication of five U hot spots. Right Detail of the point measurement spectrum of U hot spot 3, intense U-L_α fluorescence peak located at 13.6 keV.

     

Analysis of flavonols ofSedum telephium L. leaves by capillary electrophoresis and HPLC-mass spectrometry

Summary Flavonol glycosides ofSedum telephium L. were analysed by MEKC. Baseline separation was achieved within 14 min using a fused silica capillary and a borate/phosphate buffer solution (35 mM, pH 5.8) containing 35 mM SDS and 4% MeOH. The applied voltage was 25 kV and the thermostating temperature was kept constant at 40°C. Injection was performed via the pressure mode for 3 s, the detection wavelength was 205 nm. The optimized MEKC method was used for the quantitative determination of flavonol glycosides in extracts ofS. telephium leaves. Analysis was also performed by HPLC-MS using an electrospray ionization (ESI) interface. The good agreement between the quantitative CE results and those obtained by LC clearly demonstrated the applicability of the methods presented.     

Analysis of the chemical elements in leaves infected by fumagina by X-ray fluorescence technique

Summary Energy dispersion X-ray fluorescence technique (EDXRF) was employed to study the effects of the fumagina disease through the elementary chemical composition of leaves. The experimental setup consisted of a Mo X-ray tube (K_μ=17.44 keV) with Zr filter and a Si(Li) detector. The measurements were performed with infected and healthy leaves of citric plants. The elements Ti, Mn, Fe, Cu and Zn were quantified. For all the elements of interest the measured detection limit was at the order of mg ^. g^-1.     

Latifolosides K and L, two new triterpenoid saponins from the bark of Llex latifolia.

Two new triterpenoid saponins, latifoloside K (1), 3-O-beta-D-glucopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl-(1-->2)-]-alpha-L-arabinopyranosyl 3beta-hydroxy-urs-12,18-dien-28-oic acid 28-O-beta-D-glucopyranosyl ester and latifoloside L (2), 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl-(1-->2)-]-alpha-L-arabinopyranosyl 3beta,19alpha-dihydroxyursolic acid, were isolated from the bark of Ilex latifolia Thunb. Also isolated were two known compounds, ilekudinoside A (3) and kudinoside G (4). Structural assignments were established on the basis of spectroscopic data and chemical evidence.     

Determination of isoliquiritigenin and its distribution in mice by synchronous fluorescence spectrometry

The aim of the present work was to develop a new method using synchronous fluorescence spectrometry (SFS) to determine the concentration of isoliquiritigenin (ISL) in mouse blood and tissues, and to investigate ISL's distribution among organs after an intraperitoneal (IP) dose of ISL. The synchronous fluorescence method was optimized with the sample pH, stability, metal ions, concentration of Al(3+), and surfactants. The proposed method was used to determine the ISL concentration in mouse blood, brain, heart, kidney, liver, spleen and lung after an IP injection of ISL. The optimal conditions for the determination of ISL using SFS were found to be: excitation and emission wavelengths of 469 and 557 nm, respectively; the use of 3% AlCl(3) as a fluorescence intensity enhancer; measuring samples within 1 h of collection, sample pH 7-8, isolation of samples from surfactants; and wavelength interval (Δλ) = 70 nm. After IP injection, the distribution of ISL in mouse organs was: liver > kidney > spleen > blood > lung > brain > heart. The blood concentration of ISL peaked at 60 min; concentrations of ISL in liver, kidney and spleen achieved maxima at 120 min. SFS provides a simple, but effective analytical method that will benefit the study of in vivo biological effects of ISL, including absorption, distribution, metabolism, and excretion.     

Coenzyme models. 32. Catalytic activity of polymer-bound thiazolium ions as estimated by flavin trapping technique

Three thiazolium-containing polymers, Th-7, Th-33, and Th-18-Py [where Th-x and Py mean x mol % thiazolium unit and pyridinium unit (54 mol %), respectively], were synthesized from partially p-chloromethylated polystyrene. The catalytic activities of these polymer catalysts in acyloin condensation of aldehydes and decarboxylation of α-keto acids were estimated kinetically by oxidative trapping of the key intermediate by flavin (flavin-trapping technique). In aqueous solution at 30°C, the catalytic activity of Th-18-Py and Th-33 in condensation of p-chlorobenzaldehyde was comparable with that of the cationic-micelle-bound thiazolium ion, whereas Th-7 and a monomeric thiazolium compound (N-benzylthiazolium bromide) scarcely exhibited any catalytic activity. The catalysis of the polymer-bound thiazolium ions was sensitively suppressed by increased ionic strength. These results suggest that the pendent thiazolium ion is activated by the relatively high charge density along the polymer chain: the cationic environment is able to facilitate dissociation of the thiazolium ion to the ylid form and deprotonation of the thiazolium-aldehyde adduct to the key intermediate.     

Chemical composition of Artemisia annua L. leaves and antioxidant potential of extracts as a function of extraction solvents

This study was conducted to investigate the chemical and nutritional composition of Artemisia annua leaves in addition to determination of antioxidant potential of their extracts prepared in different solvents. Chemical composition was determined by quantifying fat, protein, carbohydrate, fiber, tocopherol, phytate, and tannin contents. Extraction of A. annua leaves, for antioxidant potential evaluation, was carried out using five solvents of different polarities, i.e., hexane, chloroform, ethyl acetate, methanol and water. Antioxidant potential was evaluated by estimating total phenolic (TPC), flavonoid (TFC) contents, ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), DPPH radical scavenging activity and lipid peroxidation. Efficiency of different solvents was compared for the yield of antioxidant extracts from leaf samples and a clear variation was observed. The highest TPC, TFC, TEAC, DPPH radical scavenging and lowest lipid peroxidation were observed in MeOH extracts, whereas aqueous extract exhibited high ferric reducing antioxidant power; suggesting MeOH to be the most favorable extractant.     

Flavonoid separation by capillary electrophoresis. Effect of temperature and pH

Summary The use of capillary electrophoresis for the analysis of selected flavonols present in fruit juices and wines (kaempferol-3- rutinoside, rutin, avicularin, quercitrin, isoquercitrin, isorhamnetin, kaempferol and quercetin) was explored, and the effect of pH and temperature on the separation studied. The method had good reproducibility and analyses were carried out in less than 10 minutes.     

Analysis of salt stress induced changes in Photosystem II heterogeneity by prompt fluorescence and delayed fluorescence in wheat (Triticum aestivum) leaves

In order to investigate changes in the heterogeneity of PSII, prompt fluorescence induction curves (PFIC) and delayed fluorescence induction curves (DFIC) were measured in wheat leaves after salt treatment. From these data, antenna heterogeneity and reducing side heterogeneity were estimated. Results show that antenna size, which is further differentiated into α, β and γ PSII centers, is changed under salt stress conditions. At higher salt concentration, there is a decrease in the number of α PSII centers with simultaneous increase in the amount of β and γ PSII centers. Another aspect of antenna heterogeneity is explained in terms of connectivity (or grouping) between PSII centers which did not change significantly under salt stress. Reducing side heterogeneity was assessed by both DFIC and PFIC and results show that a significant increase in the conversion of Q(B)-reducing centers to Q(B)-non-reducing centers is observed under salt stress.