[Two new benzoyl-sesquiterpenes from Mesona chinensis].

Mesona chinensis is a common medicinal and edible plant in the Lingnan region of China, which has extensive pharmacological activity. However, the study of its chemical constituents is not sufficient. In this study, a variety of modern chromatographic separation techniques were used to isolate two compounds from 95% ethanol extract of the grass parts of M. chinensis. Their absolute configurations were determined by ultraviolet spectroscopy(UV), infrared spectroscopy(IR), high resolution mass spectrometry(HR-ESI-MS), 1D and 2D nuclear magnetic resonance(1D NMR and 2D NMR), and single-crystal X-ray diffraction(SC-XRD). Specifically, they were two new benzoyl-sesquiterpenes and named mesonanol A and mesonanol B, respectively. The results of the pharmacological activity evaluation showed that neither of the two new compounds showed obvious antiviral and anti-inflammatory activities.

Fabrication and characterization of curcumin-loaded composite nanoparticles based on high-hydrostatic-pressure-treated zein and pectin: Interaction mechanism, stability, and bioaccessibility.

We successfully designed curcumin (Cur)-loaded composite nanoparticles consisting of high-hydrostatic-pressure-treated (HHP-treated) zein and pectin with a pressure of 150 MPa (zein-150 MPa-P-Cur), showing nano-spherical structure with high zeta-potential (-36.72 ± 1.14 mV) and encapsulation efficiency (95.64 ± 1.23 %). We investigated the interaction mechanism of the components in zein-150 MPa-P-Cur using fluorescence spectroscopy, molecular dynamics simulation, Fourier-transform infrared spectrometry and scanning electron microscopy techniques. Compared with zein-P-Cur, the binding sites and binding energy (-53.68 kcal/mol vs. - 44.22 kcal/mol) of HHP-treated zein and Cur were increased. Meanwhile, the interaction force among HHP-treated zein, pectin, and Cur was significantly enhanced, which formed a tighter and more stable particle structure to further improve package performance. Additionally, Cur showed the best chemical stability in zein-150 MPa-P-Cur. And the bioavailability of Cur was increased to 65.53 ± 1.70 %. Collectively, composite nanoparticles based on HHP-treated zein and pectin could be used as a promising Cur delivery system.

Discrimination of opium from Afghanistan and Myanmar by infrared spectroscopy coupled with machine learning methods.

Afghanistan and Myanmar are two overwhelming opium production places. In this study, rapid and efficient methods for distinguishing opium from Afghanistan and Myanmar were developed using infrared spectroscopy (IR) coupled with multiple machine learning (ML) methods for the first time. A total of 146 authentic opium samples were analyzed by mid-IR (MIR) and near-IR (NIR), within them 116 were used for model training and 30 were used for model validation. Six ML methods, including partial least squares discriminant analysis (PLS-DA), orthogonal PLS-DA (OPLS-DA), k-nearest neighbour (KNN), support vector machine (SVM), random forest (RF), and artificial neural networks (ANNs) were constructed and compared to get the best classification effect. For MIR data, the average of precision, recall and f1-score for all classification models were 1.0. For NIR data, the average of precision, recall and f1-score for different classification models ranged from 0.90 to 0.94. The comparison results of six ML models for MIR and NIR data showed that MIR was more suitable for opium geography classification. Compared with traditional chromatography and mass spectrometry profiling methods, the advantages of MIR are simple, rapid, cost-effective, and environmentally friendly. The developed IR chemical profiling methodology may find wide application in classification of opium from Afghanistan and Myanmar, and also to differentiate them from opium originating from other opium producing countries. This study presented new insights into the application of IR and ML to rapid drug profiling analysis.

A Robust TabNet-Based Multi-Classification Algorithm for Infrared Spectral Data of Chinese Herbal Medicine with High-Dimensional Small Samples.

Robust classification algorithms for high-dimensional, small-sample datasets are valuable in practical applications. Faced with the infrared spectroscopic dataset with 568 samples and 3448 wavelengths (features) to identify the origins of Chinese medicinal materials, this paper proposed a novel embedded multiclassification algorithm, ITabNet, derived from the framework of TabNet. Firstly, a refined data pre-processing (DP) mechanism was designed to efficiently find the best adaptive one among 50 DP methods with the help of Support Vector Machine (SVM). Following this, an innovative focal loss function was designed and joined with a cross-validation experiment strategy to mitigate the impact of sample imbalance on algorithm. Detailed investigations on ITabNet were conducted, including comparisons of ITabNet with SVM for the conditions of DP and Non-DP, GPU and CPU computer settings, as well as ITabNet against XGBT (Extreme Gradient Boosting). The numerical results demonstrate that ITabNet can significantly improve the effectiveness of prediction. The best accuracy score is 1.0000, and the best Area Under the Curve (AUC) score is 1.0000. Suggestions on how to use models effectively were given. Furthermore, ITabNet shows the potential to apply the analysis of medicinal efficacy and chemical composition of medicinal materials. The paper also provides ideas for multi-classification modeling data with small sample size and high-dimensional feature.

Identification and determination of different processed products and their extracts of Crataegi Fructus by infrared spectroscopy combined with two-dimensional correlation analysis.

The fruit of Crataegus sp. is known as "Shanzha (SZ)" in China and is widely used in the food, beverage, and traditional Chinese medicine (TCM) industries. SZ usually requires thermal processing to reduce the irritation of its acidity to the gastric mucosa. Different processed products of SZ resulting from thermal processing have different or even opposite functions in clinical applications. In addition, 5-hydroxymethylfurfural (5-HMF) intermediates produced during thermal processing are carcinogenic to humans. Therefore, the aim of this study was to explore a rapid and accurate method by Fourier transform infrared spectroscopy (FT-IR) for the identification of different processed products and the determination of 5-HMF in extracts. In qualitative identification, a three-stage infrared spectroscopy identification method (raw spectra, the second derivative spectra, and two-dimensional correlation (2DCOS) spectra) was developed to distinguish different processed products of SZ step by step. In quantitative determination, partial least squares regression combined with different variable selection methods, especially the 2DCOS method, was applied to determine the 5-HMF content. The results show that temperature-induced 2DCOS synchronous spectra can effectively identify different processed products of SZ by shape, intensity, and position of auto-peaks or cross-peaks, and the variables selected by power spectra from concentration-induced 2DCOS synchronous spectra have better prediction ability for 5-HMF compared to full variables. The above results demonstrate that 2D-COS analysis is a potential tool in qualitative and quantitative analysis, which can improve sample identification accuracy and determination capabilities. This study not only establishes a rapid and accurate method for the identification of different processed products but also provides a practical reference for food safety and the efficient use of TCM.

Usefulness of mid-infrared spectroscopy as a tool to estimate body condition score change from milk samples in intensively fed dairy cows.

Directly measuring individual cow energy balance is not trivial. Other traits such as body condition score (BCS) and BCS change (ΔBCS) can, however, be used as an indicator of cow energy status. Body condition score is a metric used worldwide to estimate cow body reserves, but the estimation of ΔBCS was, until now, conditional on the availability of multiple BCS assessments. The aim of the present study was to estimate ΔBCS from milk mid-infrared (MIR) spectra and days in milk (DIM) in intensively fed dairy cows using statistical prediction methods. Daily BCS was interpolated from cubic splines fitted through the BCS records and daily ΔBCS was calculated from these splines. The ΔBCS records were merged with milk MIR spectra recorded on the same week. The dataset comprised 37,077 ΔBCS phenotypes across 9,403 lactations from 6,988 cows in 151 herds based in Quebec, Canada. Partial least squares regression (PLSR) and a neural network (NN) were then used to estimate ΔBCS from (1) MIR spectra only, (2) DIM only, or (3) MIR spectra and DIM together. The ΔBCS data in both the first 120 and 305 DIM of lactation were used to develop the estimates. Daily ΔBCS had a standard deviation of 4.40 × 10-3 BCS units in the 120-d dataset and of 3.63 × 10-3 BCS units in the 305-d dataset. A 4-fold cross-validation was used to calibrate and test the prediction equations. External validation was also conducted using more recent years of data. Irrespective of whether based on the first 120 or 305 DIM, or when MIR spectra only, DIM only or MIR spectra and DIM were jointly used as prediction variables, NN produced the lowest root mean square error (RMSE) of cross-validation (1.81 × 10-3 BCS units and 1.51 × 10-3 BCS units, respectively, using the 120-d and 305-d dataset). Relative to predictions for the entire 305 DIM, the RMSE of cross-validation was 15.4% and 1.5% lower in the first 120 DIM when using PLSR and NN, respectively. Predictions from DIM only were more accurate than those using just MIR spectra data but, irrespective of the dataset and of the prediction model used, combining DIM information with MIR spectral data as prediction variables reduced the RMSE compared with the inclusion of DIM alone, albeit the benefit was small (the RMSE from cross-validation reduced by up to 5.5% when DIM and spectral data were jointly used as model features instead of DIM only). However, when predicting extreme ΔBCS records, the MIR spectral data were more informative than DIM. Model performance when predicting ΔBCS records in future years was similar to that from cross-validation demonstrating the ability of MIR spectra of milk and DIM combined to estimate ΔBCS, particularly in early lactation. This can be used to routinely generate estimates of ΔBCS to aid in day-to-day individual cow management.

Mid-infrared spectroscopy for large-scale phenotyping of bovine colostrum gross composition and immunoglobulin concentration.

Immunoglobulin G is the fundamental antibody for acquisition of passive transfer of immunity in ruminant newborns. Colostrum, in fact, must be administered as soon as possible after birth to ensure a successful transfer of IgG from the dam to the calf. Assessment of colostrum Ig concentration and gross composition via gold standards is expensive, time consuming, and hardly implementable for large-scale investigations. Therefore, in the present study we evaluated the predictive ability of mid-infrared spectroscopy (MIRS) as an indirect determination method. A total of 714 colostrum samples collected within 6 h from parturition from Italian Holstein cows, 30% primiparous and 70% pluriparous, were scanned using a benchtop spectrometer after dilution in pure water. The prediction models were developed by correlating spectral information with the reference measurements: IgG concentration (93.54 ± 33.87 g/L), total Ig concentrations (102.82 ± 35.04 g/L), and content of protein (14.71 ± 3.51%), fat (4.61 ± 3.04%), and lactose (2.36 ± 0.51 mg/100 mg). We found a good to excellent performance in prediction of colostrum IgG concentration and traditional composition traits in cross-validation (R2CV ≥ 0.92) and a promising and good predictive ability in external validation with R2V equal to 0.84, 0.89, and 0.74 for IgG, protein, and fat, respectively. In the case of IgG and protein content, for example, the coefficient of determination in external validation was greater than 0.84. The other Ig fractions, A and M, presented insufficient prediction accuracy likely due to their extremely low concentration compared with IgG (4.56 and 5.06 g/L vs. 93.54 g/L). The discriminant ability of MIRS-predicted IgG and protein content was outstanding when trying to classify samples according to the quality level (i.e., low vs. high concentration of IgG). In particular, the cut-off that better discriminate low- from high-quality colostrum was 75.40 g/L in the case of the MIRS-predicted IgG and 13.32% for the MIRS-predicted protein content. Therefore, MIRS is proposed as a rapid and cheap tool for large-scale punctual IgG, protein, and lactose quantification and for the screening of low-quality samples. From a practical perspective, there is the possibility to install colostrum models in the MIRS benchtop machineries already present in laboratories in charge of official milk testing. Colostrum phenotypes collected on an individual basis will be useful to breeders for the definition of specific selection strategies and to farmers for management scopes. Finally, our findings may be relevant for other stakeholders, given the fact that colostrum is an emerging ingredient for the animal and human food and pharmaceutical industry.

Differential Analysis of Korean and Chinese Lingzhi or Reishi Medicinal Mushroom Ganoderma lucidum (Agaricomycetes) Spore Powder by Infrared Spectroscopy with Stoichiometry.

To investigate the differences between Korean Ganoderma lucidum spore powder (KP), broken-spo-roderm KP (BSKP), Chinese traditional G. lucidum spore powder (CP), and broken-sporoderm CP (BSCP), they were identified by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), second derivative infrared spectroscopy (SD-IR), dual-index sequence analysis (DISA) and X-ray diffraction (XRD). SEM showed that there were no significant differences in microstructure between the two kinds of spore powders. FT-IR spectra showed that the four spore powders appeared with characteristic peaks of 3400, 3006, 2925, 1745, 1535, 1454, 1249, 1074, 1049, and 896 cm-1, respectively, they were contained the characteristic peaks of total triterpenes, polysaccharides and fatty acids. DISA showed that the same species of spore powders, the overall similarity of before and broken the sporoderm was high with minor differences and there were no differences between the different kinds of spore powders. Similarity analysis showed that the four spore powders were in high agreement and were no differences. The polysaccharide, total triterpene, spore oil and protein content of the four spore powders were determined separately. The results showed that the active ingredients content of the batch of KP were lower than that of CP, that of BSKP were lower than that of BSCP, while the active ingredients content of both broken-sporoderm spore powders were higher than that of before broken-sporoderm. It is inferred that the structure of the main chemical and component of KP is the same as that of CP. This study provides a reference for the future development and application of G. lucidum.

Identification of Gentian-Related Species Based on Two-Dimensional Correlation Spectroscopy (2D-COS) Combined with Residual Neural Network (ResNet).

Gentian is a traditional Chinese herb with heat-clearing, damp-drying, inflammation-alleviating and digestion-promoting effects, which is widely used in clinical practice. However, there are many species of gentian. According to the pharmacopoeia, Gentiana manshurica Kitag, Gentiana scabra Bge, Gentiana triflora Pall and Gentianarigescens Franch are included. Therefore, accurately identifying the species of gentian is important in clinical use. In recent years, with the advantages of low cost, convenience, fast analysis and high sensitivity, infrared spectroscopy (IR) has been extensively used in herbal identification. Unlike one-dimensional spectroscopy, a two-dimensional correlation spectrum (2D-COS) can improve the resolution of the spectrum and better highlight the details that are difficult to detect. In addition, the residual neural network (ResNet) is an important breakthrough in convolutional neural networks (CNNs) for significant advantages related to image recognition. Herein, we propose a new method for identifying gentian-related species using 2D-COS combined with ResNet. A total of 173 gentian samples from seven different species are collected in this study. In order to eliminate a large amount of redundant information and improve the efficiency of machine learning, the extracted feature band method was used to optimize the model. Four feature bands were selected from the infrared spectrum, namely 3500-3000 cm-1, 3000-2750 cm-1, 1750-1100 cm-1 and 1100-400 cm-1, respectively. The one-dimensional spectral data were converted into synchronous 2D-COS images, asynchronous 2D-COS images, and integrative 2D-COS images using Matlab (R2022a). The identification strategy for these three 2D-COS images was based on ResNet, which analyzes 2D-COS images based on single feature bands and full bands as well as fused feature bands. According to the results, (1) compared with the other two 2D-COS images, synchronous 2D-COS images are more suitable for the ResNet model, and (2) after extracting a single feature band 1750-1100 cm-1 to optimize ResNet, the model has the best convergence performance, the accuracy of training, test and external validation is 1 and the loss value is only 0.155. In summary, 2D-COS combined with ResNet is an effective and accurate method to identify gentian-related species.

[Physicochemical properties and anti-inflammatory and immunomodulatory effects of Shengfupian polysaccharides].

In this study, the crude polysaccharides was extracted from Shengfupian and purified by Sevag deproteinization. Then, the purified neutral polysaccharide fragment was obtained by the DEAE-52 cellulose chromatography column and Sephadex G-100 co-lumn. The structure of polysaccharides was characterized by ultraviolet spectroscopy, infrared spectroscopy, ion chromatography, and gel permeation chromatography. To investigate the anti-inflammatory activity of Shengfupian polysaccharides, LPS was used to induce inflammation in RAW264.7 cells. The expression of the CD86 antibody on surface of M1 cells, the function of macrophages, and the content of NO and IL-6 in the supernatant were examined. An immunodepression model of H22 tumor-bearing mice was established, and the immunomodulatory activity of Shengfupian polysaccharides was evaluated based on the tumor inhibition rate, immune organ index and function, and serum cytokine levels. Research indicated that Shengfupian polysaccharides(80 251 Da) was composed of arabinose, galactose, glucose, and fructose with molar ratio of 0.004∶0.018∶0.913∶0.065. It was smooth and lumpy under the scanning electron microscope. In the concentration range of 25-200 µg·mL~(-1), Shengfupian polysaccharides exhibited little or no toxicity to RAW264.7 cells and could inhibit the polarization of cells to the M1 type and reduce the content of NO and IL-6 in the cell supernatant. It could suppress the phagocytosis of cells at the concentration of 25 µg·mL~(-1), while enhancing the phagocytosis of RAW264.7 cells within the concentration range of 100-200 µg·mL~(-1). The 200 mg·kg~(-1) Shengfupian polysaccharides could alleviate the spleen injury caused by cyclophosphamide, increase the levels of IL-1ß and IL-6, and decrease the level of TNF-α in the serum of mice. In conclusion, Shengfupian polysaccharides has anti-inflammatory effect and weak immunomodulatory effect, which may the material basis of Aconm Lateralis Radix Praeparaia for dispelling cold and relieving pain.

Determination on Tree Species Selection for Lingzhi or Reishi Medicinal Mushroom Ganoderma lucidum (Agaricomycetes) Cultivation by Fourier Transform Infrared and Two-Dimensional Infrared Correlation Spectroscopy.

As a wood-degrading Agaricomycetes mushroom, Ganoderma lucidum can be cultivated on broad-leaf hardwoods. Generally, producers care about the yield, but not the quality of G. lucidum cultivated by different tree species. In this study, five broad-leaf hardwood tree species-Quercus variabilis Bl. (Qv), Castanea mollissima Bl. (Cm), Liquidambar formosana Hance (Lf), Dalbergia hupeana Hance (Dh), and Platycarya strobilacea Sieb. et Zucc. (Ps)-were selected for cultivating of G. lucidum. The chemical compositions of G. lucidum fruiting bodies produced by these tree species were determined by Fourier transform infrared and two-dimensional infrared correlation spectroscopy in order to select the most suitable tree species for cultivation. The overall spectra showed less discrimination of each peak variation detected and properly kept most of the primary metabolites. The second derivative unfolded the stagnation of the first spectrum and more base peaks were detected especially in the range of the first two sections. The protein content contained in G. lucidum cultivated on Ps was 92%, like that on Dh. On the other hand, only 27% similarity was determined in G. lucidum cultivated on Ps and Qv. Therefore, the correlation of this range for the protein content can help in tree species selection. The active sequence of 2DIR spectral could be determined by the active bonding of the component reacted to the perturbation. The result could provide a scientific basis for the selection of tree species and the comprehensive utilization of broad-leaf tree resources on G. lucidum cultivation.

Liquid-Crystalline Order in the Phosphorus-Containing DenDrimers.

The structure of phosphorus-containing dendrimers has been studied by IR spectroscopy and optical polarization microscopy. The repeating units of dendrimer molecules are mesogens. This property arises from the conjugation of the aromatic ring and the hydrazone group. An analysis of the IR spectra showed that, with an increase in the generation number, the width of the stretching vibration bands ν(PN) and ν(PO) increases. Difficulties in packing molecules of higher generations cause conformational diversity. The shape of the dendrimer molecules was determined by analyzing the increments of dipole moments. Additionally, the modeling of the stacking of repeating links was performed. The spherical model of molecules does not satisfy the experimental dipole moments of the dendrimers. The flat disk model is more suitable for explaining step changes in dipole moments. The liquid-crystalline ordering of dendrimers under the action of applied pressure was found. With simultaneous heating and uniaxial compression, optical anisotropy appears in dendrimers. It is associated with the formation of liquid-crystalline order. However, a thermodynamically stable liquid-crystalline phase is not formed in this case. Dendrimers most likely have disk-shaped molecules.

[Rapid prediction of flavonoid content in Epimedium sagittatum by infrared spectroscopy].

Epimedii Folium is a well-known Chinese herbal medicine with the effect of nourishing kidney and strengthening Yang. Its main active ingredients are flavonoids. In this study, 60 samples of Epimedium sagittatum were collected for the determination of total flavonoids(TF) including the total amount of epimedin A, epimedin B, epimedin C, and icariin(abbreviated as ABCI) specified in the Chinese Pharmacopoeia as well as rhamnosylicariside Ⅱ and icariside Ⅱ. The calibration parameters of "first derivativemultiva-riate scattering correction in 1 900-650 cm~(-1) band(4-point smoothing)" and "first derivativestandard normal variable correction in 4 000-650 cm~(-1) full band(4-point smoothing)" were confirmed respectively. The quantitative model was established via Fourier infrared spectroscopy plus attenuated total reflection(FTIR-ATR) accessory combined with partial least squares(PLS) method and then used to predict the flavonoid content of 11 validation sets. The average prediction accuracy for ABCI in calibration set and validation set was 98.985% and 96.087%, respectively. The average prediction accuracy for TF in calibration set and validation set was 98.998% and 94.771%, respectively. These results indicated that FTIR-ATR combined with PLS model could be used for rapid prediction of flavonoid content in E. sagittatum, with the prediction accuracy above 94.7%. The establishment of this method provides a new solution for the detection of a large number of E. sagittatum samples.

Substitution of Copper by Magnesium in Malachite: Insights into the Synthesis and Structural Effects.

The phase width of the copper hydroxycarbonate malachite, Cu2CO3(OH)2, upon substitution with magnesium has been studied in detail. In extension of a previous study on amorphous precursors, the introduction of a hydrothermal aging step allowed the retrieval of crystalline hydroxycarbonate samples with up to 37 atom % Mg (metal content) that are suitable candidates as precursors to Cu/MgO catalysts for CO hydrogenation. Simultaneous refinements of X-ray powder diffraction and pair distribution function (PDF) data as well as complementary spectroscopic insight (X-ray absorption and infrared spectroscopy) revealed that samples with up to 18 atom % Mg are phase-pure magnesian malachites but the magnesium content can be increased beyond this threshold when mcguinnessite (CuMgCO3(OH)2) is accepted as a side phase. In a complementary study, a continuous increase of the magnesium fraction was found during aging and the corresponding structural evolution was studied by means of PDF. These findings add significant insight into the aging chemistry of crystalline Cu,Mg hydroxycarbonates. Furthermore, both phase-pure magnesian malachite and mcguinnessite-containing samples with up to 37 atom % Mg have been examined by thermogravimetry, X-ray powder diffraction, and N2 physisorption and were found to be promising candidates for use as precursors for the preparation of Cu/MgO catalysts.

Characterization and predictive modeling potential of aging time of roasted coffee using infrared spectroscopy.

Repackaging and tampering with labels of foods to extend their shelf life is an illegal practice, increasingly common in some Brazilian coffee retail markets. Fast, easy-to-use, and low-cost analytical techniques for the large-scale screening of aging time have been demanded lately to fight the growth of these frauds in retail coffee markets. In this work, Fourier transform infrared spectroscopy was evaluated as a provider of relevant regressors, chemically explainable, aiming for predictive models for estimating the aging of roasted and packaged coffees during their shelf life. Spectra of two Coffea arabica varieties (Bourbon and Obatã) were periodically acquired during eleven months of storage. The most relevant absorption bands were selected, which showed a moderate correlation with the storage time. They were identified as responses from lipids, phenolic compounds, and carbohydrates. From those responsive bands, logistic regression (sigmoid functions) models were fitted for each coffee variety, as well as for both together. Predictive models for Bourbon and Obatã showed high performances in validation data, with r (Pearson correlation) above 0.92 and root mean square error (RMSE) below 43 days. For both varieties, the logistic model showed r greater than 0.83 and RMSE equal to 56 days. Results corroborate the methodological approach efficacy towards agile technological innovations in the coffee value chain, as well as opening new application fronts for estimating the aging of other foods.

Elucidating the Infrared Spectral Properties of Succinic Molecular Acid Crystals: Illustration of the Structure and the Hydrogen Bond Energies of the Crystal and Its Deuterated Analogs.

Herein, the infrared spectroscopic properties of molecular succinic acid crystals (SA) and their four isotopic analogs [C2H4(COOH)2, h6-SA; C2H4(COOD)2, d2-SA; C2D4(COOH)2, d4-SA; C2D4(COOD)2, d6-SA] are reported. The correlation between the structure of succinic acid molecules and their corresponding hydrogen bond energies is elucidated. The effects related to the isotopic dilution as well as the changes in the spectrum recording temperature on the fine structures of the vO-H and vO-D bands are interpreted. The infrared spectral anomalies detected in the spectra of isotopically neat succinic nanocrystal acids are confirmed by theoretical calculations using density functional theory (DFT). According to previous spectroscopic studies of succinic acid and those carried out for α,ω-dicarboxylic acids, a decent agreement between the experimental results and the theoretical DFT simulations is obtained. Moreover, the spectra of single crystals of the h6 and d4 succinic acid variants prove that the vibrational coupling mechanism between the (COOH)2 cycles is rigorously convergent to that detected in the spectra of aromatic carboxylic acids, suggesting thereby that the promotion of symmetry-forbidden high stretching IR transitions plays a crucial role. Furthermore, the obtained experimental results reveal that the succinic acid shows a spectral behavior significantly different from that characteristic of hydrogen associations of other acids of homologous series, such as the glutaric, adipic, malonic, and pimelic acid crystals. The results obtained herein shed light on the way to explore the revealed structure of isotopic derivatives of succinic acid crystals and may prove to be useful results for understanding the nature of unconventional interactions as well as the macroscopic energy effects directing the development of hydrogen associations.

Mid-infrared spectroscopy for the rapid quantification of eucalyptus oil adulteration in Australian tea tree oil (Melaleuca alternifolia).

Essential oil distilled from Melaleuca alternifolialeaves, commonly known as tea tree oil, is well known for its biological activity, principally its antimicrobial properties. However, many samples are adulterated with other, cheaper essential oils such as eucalyptus oil. Current methods of detecting such adulteration are costly and time-consuming, making them unsuitable for rapid authentication screening. This study investigated the use of mid-infrared (MIR) spectroscopy for detecting and quantifying the level of eucalyptus oil adulteration in spiked samples of pure Australian tea tree oil. To confirm the authenticity of the tea tree oil samples, GC-MS analysis was used to profile 37 of the main volatile constituents present, demonstrating that the samples conformed to ISO specifications. Three chemometric regression techniques (PLSR, PCR and SVR) were trialled on the MIR spectra, along with a variety of pre-processing techniques. The best-performing full-wavelength PLSR model showed excellent prediction of eucalyptus oil content, with an R2CV of 0.999 and RMSECV of 1.08 % v/v. The RMSECV could be further improved to 0.82 % v/v through a moving window wavenumber optimisation process. The results suggest that MIR spectroscopy combined with PLSR can be used to predict eucalyptus oil adulteration in Australian tea tree oil samples with a high level of accuracy.

Biological activity of pectic polysaccharides investigated through biomembrane models formed at the air-water interface.

Pectin, a polysaccharide with potential bioactivity, was inserted in the aqueous subphase of monolayers of the selected lipids DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) and DPPE (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine), representing mammalian and bacterial membranes, respectively. Pectin condensed both monolayers but made the DPPC monolayer more fluid, while for DPPE, it made its monolayer more rigid, as detected with dynamic interfacial rheology. Complementary data using surface potential, infrared spectroscopy, and Brewster angle microscopy also showed distinctive effects of pectin on DPPE and DPPC. We believe these data can be correlated with the action of this polysaccharide with biological lipidic surfaces with different polar heads, which may be relevant, generally speaking, to understanding the molecular mechanism of this bioactive compound for pharmaceutical purposes.

Spectrophotometric determination of Zr(IV), Hg(II) and U(VI) in solution with their analytical applications: Structural characterization and molecular docking of the solid complexes.

Spectrophotometry was used to determine trace amounts of Zirconium(IV), Mercury(II) and Uranium(VI) in environmental, biological, pharmaceutical and industrial samples. The determination depend on the complexation reactions between albendazole reagent and metal ions [Zr(IV), Hg(II) and U(VI)] at 555 nm, 485 nm and 510 nm, respectively. The experimental conditions were explored to reach the optimum conditions for albendazole-metal ions interaction, including detection of a suitable wavelength, medium (pH), reagent concentration, surfactants effect, reaction time and temperature. Under optimum conditions, the complexes displayed apparent molar absorptivities of 0.8350 × 104, 0.6210 × 104 and 0.7012 × 104 L mol-1 cm-1; Sandell's sensitivity of 0.01092, 0.03230 and 0.03394 µg cm-2 and with linearity ranges of 1.0-120.0, 3.0-200.0 and 1.0-150.0 µg mL-1 for the developed methods, respectively. Furthermore, Elemental analysis, thermal analysis (TGA, DTG), IR, 1HNMR, spectroscopies, electrical molar conductivity and magnetic moment measurements were used to determine the structures and characteristics of the complexes. A careful examination of the IR spectra revealed that the ligand interacted with all of the metal ions described as a bidentate via the oxygen of the carbonyl of the ester moiety and the nitrogen atom of the heterocyclic CN group. An octahedral geometry for Zr(IV), Hg(II) and U(VI) complexes has been postulated based on magnetic and electronic spectrum data. The band gap values indicated that these complexes were semi-conductors and belong to the same class of extremely effective solar materials. The albendazole ligand and its complexes have been biologically tested against a variety of bacterial and fungal strains, and molecular docking studies have been conducted to evaluate the optimal binding site and its inhibitory action.

Efecto citotóxico de diterpenos derivados del ácido ent-kaureno aislados de Coespeletia moritziana (Sch. Bip. ex Wedd.) Cuatrec / Cytotoxic effect of ent-kaurene acid-derived diterpenes isolated from Coespeletia moritziana (Sch. Bip. Ex Wedd.) Cuatrec

The objective of the work was to study the cytotoxic effect of ent-kaurene acid derivatives obtained from Coespeletia moritziana (Sch. Bip. Ex Wedd.) Cuatrec., After analysis by GC/MS, IR and NMR. Isolating: kaurenic acid (I), grandifloric acid (II), 15-α-hydroxy kaurenic acid (III), 15 α-acetoxy-kaur 16-en-19-oic acid (IV), Kaurenol (V); and by hemisynthesis: 15,16-epoxy-17-acetoxy-kauran 19-oic acid (VI), 15-oxo-ent-kaur-16-en-19-oic acid (VIII), ester 2,3,4,6 -15-oxo-kaur-16-en-19-oic acid acetyl α-D-pyranosyl tetra-tetra (VII). Cytotoxicity was tested in human cancer cell lines: uterus (HeLa), lung (A-549), breast (MCF-7), African green monkey kidney non-tumor line (Vero) and human peripheral blood mononuclear cells (CMPS). Compound (I) was active against HeLa, A-549 and Vero. Compounds (II and VIII) showed moderate and good (IC50 ≤ 9 µM) cytotoxicity, respectively, against the five cell lines. Compound (V) showed moderate activity against A-549 and compound (VII), slight cytotoxicity against HeLa and A-549. Results that show the cytotoxic specificity of the isolated kaurenes and derivatives of Coespeletia moritzianaand their therapeutic potential.

El objetivo del trabajo fue estudiar el efecto citotóxico de derivados del ácido ent-kaureno obtenidos de Coespeletia moritziana (Sch. Bip. ex Wedd.) Cuatrec., previo análisis mediante GC/MS, IR y RMN. Aislandose: ácido kaurénico(I), ácido grandiflorénico (II), ácido 15-α-hidroxi kaurénico(III), ácido 15 α-acetoxi-kaur 16-en-19-oico (IV), Kaurenol (V); y por hemisíntesis: ácido 15,16-epoxi-17-acetoxi-kauran 19-oico (VI), ácido15-oxo-ent-kaur-16-en-19-oico (VIII), éster 2,3,4,6-tetra acetil α-D-piranosilo del ácido 15-oxo-kaur-16-en-19-oico (VII). La citotóxicidad fue ensayada en líneas celulares cancerosas humanas: útero (HeLa), pulmón(A-549), mama (MCF-7), línea no tumoral de riñón de mono verde africano (Vero) y células mononucleares humanas de sangre periférica (CMPS). El compuesto (I) resultó activo frente a HeLa, A-549 y Vero. Los compuestos (II y VIII), mostraron moderada y buena (IC50≤9µM) citotoxicidad respectivamente, frente a las cinco líneas celulares. El compuesto (V) presentó moderada actividad frente a A-549 y el (VII), leve citotoxicidad frente a HeLa y A-549. Resultados que evidencian la especificidad citotóxica de los kaurenos aislados y derivados de Coespeletia moritzianay su potencial terapéutico.