High Resolution NMR Spectroscopy as a Structural and Analytical Tool for Unsaturated Lipids in Solution

Comparative lipidomics profiles of planktonic and biofilms of methicillin-resistant and -susceptible Staphylococcus aureus

Staphylococcus aureus is a significant human pathogen causing acute life-threatening, and chronic infections often linked to biofilms. This study conducted a comparative lipidomic analysis of a methicillin-resistant (MRSA) and a methicillin-susceptible (MSSA) S. aureus strain in both planktonic and biofilm cultures using liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) spectroscopy. The developed protocol successfully differentiates between the strains in various living states (planktonic and biofilm) and growth media (Tryptic Soy Broth and Brain Heart Infusion) using S. aureus USA300 LAC (MRSA) and S. aureus Newman (MSSA). LC-MS and NMR lipidomics profiles revealed global differences and particular ones among the following classes of bacterial lipids: phosphatidylglycerols, diacylglycerols, monoglycosyldiacylglycerols, diglycosyldiacylglycerols, and cardiolipins. Lipid content was higher in the biofilm states for most of these classes. Growth media differences were significant, while differences between MRSA and MSSA were less pronounced but still detectable. Additionally, we provide data on hundreds of unknown compounds that differ based on living state, strain background, or growth media. This study offer insights into the dynamic nature of S. aureus lipid composition and the used methods are adaptable to other organisms.

Preventing mislabeling of organic white button mushrooms (Agaricus bisporus) combining NMR-based foodomics, statistical, and machine learning approach

Organic foods are among the most susceptible to fraud and mislabeling since the differentiation between organic and conventionally grown food relies on a paper-trail-based system. This study aimed to develop a differentiation model that combines nuclear magnetic resonance (NMR), statistical approach (principal component analysis - PCA and partial least square discriminant analysis - PLS-DA), and classification artificial neural network (cANN). The model was tested for hydrophilic and lipophilic extracts of Agaricus bisporus. As linear techniques, the PCA and PLS-DA analyses and cANN as a non-linear classification tool successfully discriminated organic from conventional samples regarding their NMR data. PLS-DA revealed higher similarity among the hydrophilic samples within the organic class and among the lipophilic samples within the conventional class. Both applied approaches demonstrated high statistical quality, but a higher level of classification confidence in the case of lipophilic extracts. The metabolites responsible for discrimination and observed (dis)similarities between classes were considered according to cultivation specificities.

Size matters: Biomolecular compositions of small and large extracellular vesicles in the urine of glioblastoma patients

The promise of urinary extracellular vesicles (uEVs) in biomarker discovery is emerging. However, the characteristics and compositions of different uEV subpopulations across normal physiological and pathological states require rigorous explication. We recently reported proteomic signatures of small (s)-uEVs (<200 nm membranous nanoparticles) and described putative biomarkers corresponding to the diagnosis, tumour burden and recurrence of the lethal adult primary brain tumour, glioblastoma. Here, we comprehensively characterise uEV populations with significantly different mean and mode particle sizes obtained by differential centrifugation at 100,000 × g (100K-uEVs; smaller) and 17,000 × g (17K-uEVs; larger) using Fourier-transform infrared spectroscopy and quantitative data-independent acquisition mass spectrometry. We show distinct differences in protein and lipid content, prominent protein secondary structures, and proteome distributions between uEV populations that can distinguish glioblastoma patients from healthy controls and correspond to clinically relevant tumour changes (i.e., recurrence and treatment resistance). Among the key findings is a putative seven-protein biomarker panel associated with 17K-uEVs that could distinguish all glioblastoma patients from healthy controls and accurately classify 98.2% of glioblastoma samples. These novel, significant findings demonstrate that both uEV populations offer individual and combined biomarker potential. Further research is warranted to elucidate the complete diagnostic, prognostic, and predictive capabilities of often-neglected 17K-uEV populations.

1H NMR profiling and chemometric analysis for ripening and production characterization of Grana Padano cheese

Grana Padano (GP) cheese is a renowned PDO Italian cheese whose nutritional characteristics and market price are influenced by the ripening stage. In this work, it was demonstrated that the combined use of untargeted 1H NMR profiling and chemometric analysis can be used as a powerful tool to quantitatively characterize GP ripening and production, focusing on both aqueous and lipid fractions. An initial exploratory analysis revealed substantial variations in the aqueous fraction attributable to aging time, year and season of production. Multivariate analysis was adopted to show these differences, mainly attributable to amino acids. In contrast, the lipid fraction analysis highlighted the impact of production season on fatty acid unsaturation, influenced by feed variations. As regards the production process, this study focuses on the variations induced by bactofugation. In this respect, the aqueous fraction was found to be extensively influenced by this centrifugation step, affecting compounds crucial to organoleptic characteristics.

Chitin Extracted from Black Soldier Fly Larvae at Different Growth Stages

The black soldier fly (BSF) Hermetia Illucens can grow rapidly and on a wide variety of organic materials, and it is extensively used as a means of disposing of household organic waste. Different phases of the life cycle of BSF larvae (BSFL) are used in this work to extract chitin after the removal of lipids, mineral salts, and proteins. Multiple techniques, such as X-ray diffractometry, infrared spectroscopy, solid-state Nuclear Magnetic Resonance (13C ss-NMR) and thermogravimetric analysis, are used to investigate the chemical and physical characteristics of the extracted samples of chitin, which shows a high degree of acetylation (from 78% to 94%). The extracted chitin shows an increase of the thermal stability of 20 °C in the initial stage of life and 35 °C at the end of the life cycle if compared with a commercial standard. Moreover, the extracted chitin shows an increase in the crystallinity degree during the BSFL growth time (from 72% to 78%).

Feasibility of omega-3 fatty acid fraction mapping using chemical shift encoding-based imaging at 3 T

PURPOSE

The aim of this work is to develop an ω-3 fatty acid fraction mapping method at 3 T based on a chemical shift encoding model, to assess its performance in a phantom and in vitro study, and to further demonstrate its feasibility in vivo.

METHODS

A signal model was heuristically derived based on spectral appearance and theoretical considerations of the corresponding molecular structures to differentiate between ω-3 and non-ω-3 fatty acid substituents in triacylglycerols in addition to the number of double bonds (ndb), the number of methylene-interrupted double bonds (nmidb), and the mean fatty acid chain length (CL). First, the signal model was validated using single-voxel spectroscopy and a time-interleaved multi-echo gradient-echo (TIMGRE) sequence in gas chromatography-mass spectrometry (GC-MS)-calibrated oil phantoms. Second, the TIMGRE-based method was validated in vitro in 21 adipose tissue samples with corresponding GC-MS measurements. Third, an in vivo feasibility study was performed for the TIMGRE-based method in the gluteal region of two healthy volunteers. Phantom and in vitro data was analyzed using a Bland-Altman analysis.

RESULTS

Compared with GC-MS, MRS showed in the phantom study significant correlations in estimating the ω-3 fraction (p < 0.001), ndb (p < 0.001), nmidb (p < 0.001), and CL (p = 0.001); MRI showed in the phantom study significant correlations (all p < 0.001) for the ω-3 fraction, ndb, and nmidb, but no correlation for CL. Also in the in vitro study, significant correlations (all p < 0.001) between MRI and GC-MS were observed for the ω-3 fraction, ndb, and nmidb, but not for CL. An exemplary ROI measurement in vivo in the gluteal subcutaneous adipose tissue yielded (mean ± standard deviation) 0.8% ± 1.9% ω-3 fraction.

CONCLUSION

The present study demonstrated strong correlations between gradient-echo imaging-based ω-3 fatty acid fraction mapping and GC-MS in the phantom and in vitro study. Furthermore, feasibility was demonstrated for characterizing adipose tissue in vivo.

Safety evaluation of Plukenetia volubilis seeds: a metabolomic profiling and network toxicology approach

Sacha Inchi (Plukenetia volubilis) seeds and oil have been integrated into daily diets. However, scientific reports have raised concerns regarding potential health risks associated with saponins and alkaloids in this seeds. This study employed a combination analysis using proton-NMR, GC-MS, LC-QTOF, and GNPS molecular networking to evaluate the chemical composition of these seeds. In silico toxicology analysis and in vitro cytotoxicity assays were conducted to investigate the potential toxicity effects of Sacha Inchi seeds and their contained metabolites. The results revealed that major components of these seeds are oils (linoleic, linolenic, and oleic acids) and sugars, with minor amounts of phytosterols and trigonelline, a pyridine alkaloid. GNPS analysis suggested the absence of saponins, instead, it identified trigonelline and a few other nitrogen-containing metabolites (amino acids and oligopeptides). In silico toxicology analysis indicated that this sample did not exhibit toxicity. Furthermore, in vitro cytotoxicity screening demonstrated no cytotoxic effects against NIH-3T3 cells, even at 400 μg mL-1. In general, these findings collectively indicated the absence of saponins, the presence of phytosterols and trigonellin (a pyridine alkaloid), and a low safety risk related to saponin and alkaloid content in the Sacha Inchi seeds.

A review of artificial sebum formulations, their compositions, uses and physicochemical characteristics

Sebum is a complex mixture of skin lipids responsible for lubrication, moisture retention and skin protection from external factors such as bacteria and fungi. The physicochemical properties of natural sebum are not well understood and are not easily accessible. Artificial sebum is widely used for sebum-related research such as dermal bioaccessibility, fingerprint production, dermatology, removal and sebum studies. It was found that the composition of artificial sebum affects the bioaccessibility of metals and drugs as well as the growth of some strains of bacteria. Squalene present in sebum was also found to be responsible for creating yellow stains on fabrics, whereas an increased concentration of fatty acids and triglycerides can lead to higher malodour of fabrics. Moreover, sebum and artificial sebum are poorly characterized with only 20 of 81 formulations characterized by certain techniques such as differential scanning calorimetry, nuclear magnetic resonance and thin-layer chromatography. This article reviews the artificial sebum formulations reported in the open literature between 1965 and 2023. We have discussed the compositions, uses and characterization techniques of artificial sebum used in the previous work and compared their properties to those of human sebum. A total of 81 artificial sebum formulations were found across the literature with 17 new formulations identified. The artificial sebum composition varies greatly between publications and there is no consistent formulation. There is a wide range of chemicals that are used as the main components of artificial sebum. We have highlighted the effect of chemical composition and individual compounds on the overall properties of the artificial sebum reported, and recommend that there is a great potential for creating personalized cosmetics and home care products once the characteristics of sebum are better understood.

A high-resolution 13C NMR approach for profiling fatty acid unsaturation in lipid extracts and in live Caenorhabditiselegans

Unsaturated fatty acids (UFA) play a crucial role in central cellular processes in animals, including membrane function, development, and disease. Disruptions in UFA homeostasis can contribute to the onset of metabolic, cardiovascular, and neurodegenerative disorders. Consequently, there is a high demand for analytical techniques to study lipid compositions in live cells and multicellular organisms. Conventional analysis of UFA compositions in cells, tissues, and organisms involves solvent extraction procedures coupled with analytical techniques such as gas chromatography, MS and/or NMR spectroscopy. As a nondestructive and nontargeted technique, NMR spectroscopy is uniquely capable of characterizing the chemical profiling of living cells and multicellular organisms. Here, we use NMR spectroscopy to analyze Caenorhabditis elegans, enabling the determination of their lipid compositions and fatty acid unsaturation levels both in cell-free lipid extracts and in vivo. The NMR spectra of lipid extracts from WT and fat-3 mutant C. elegans strains revealed notable differences due to the absence of Δ-6 fatty acid desaturase activity, including the lack of arachidonic and eicosapentaenoic acyl chains. Uniform 13C-isotope labeling and high-resolution 2D solution-state NMR of live worms confirmed these findings, indicating that the signals originated from fast-tumbling lipid molecules within lipid droplets. Overall, this strategy permits the analysis of lipid storage in intact worms and has enough resolution and sensitivity to identify differences between WT and mutant animals with impaired fatty acid desaturation. Our results establish methodological benchmarks for future investigations of fatty acid regulation in live C. elegans using NMR.

Enhancement of weak signals by applying a suppression method to high-intense methyl and methylene signals of lipids in NMR spectroscopy

Lipids play crucial roles in human biology, serving as energy stores, cell membranes, hormone production, and signaling molecules. Accordingly, their study under lipidomics has advanced the study of living organisms. 1-Dimensional (D) and 2D NMR methods, particularly 1D 1H and 2D 1H-1H Total Correlation Spectroscopy (TOCSY), are commonly used in lipidomics for quantification and structural identification. However, these NMR methods suffer from low sensitivity, especially in cases of low concentrated molecules such as protons attached to hydroxy, esters, aliphatic, or aromatic unsaturated carbons. Such molecules are common in complex mixtures such as dairy products and plant oils. On the other hand, lipids have highly populated fractions of methyl and methylene groups that result in intense peaks that overwhelm lower peaks and cause inhomogeneities in 2D TOCSY spectra. In this study, we applied a method of suppression to suppress these intense peaks of methyl and methylene groups to detect weaker peaks. The suppression method was investigated on samples of cheese, butter, a mixture of lipids, coconut oil, and olive oil. A significant improvement in peak sensitivity and visibility of cross-peaks was observed, leading to enhanced comparative quantification and structural identification of a greater number of lipids. Additionally, the enhanced sensitivity reduced the time required for the qualitative and comparative quantification of other lipid compounds and components. This, in turn, enables faster and more reliable structural identification and comparative quantification of a greater number of lipids. Additionally, it reduces the time required for the qualitative, and comparative quantification due to the enhancement of sensitivity.

A convenient method for the relative and absolute quantification of lipid components in liposomes by 1H- and 31P NMR-spectroscopy

OBJECTIVE

Liposomes are promising delivery systems for pharmaceutical applications and have been used in medicine in the recent past. Preparation of liposomes requires reliable characterization and quantification of the phospholipid components for which the traditional cumbersome molybdate method is used frequently. The objective was to improve relative and absolute quantification of lipid components from liposomes.

METHODS

A reliable method for quantification of lipid composition in liposome formulations in the 1-10 μmol range with 1H- and 31P NMR spectroscopy at 600 MHz has been developed. The method is based on three crystalline small-molecule standards (Ph3PO4, (Tol)3PO4, and Ph3PO) in CDCl3.

RESULTS

Excellent calibration linearity and chemical stability of the standards was observed. The method was tested in blind fashion on liposomes containing POPC, PEG-ceramide and a pH-sensitive trans-aminocyclohexanol-based amphiphile (TACH).1 Relative quantification (percentage of components) as well as determination of absolute lipid amount was possible with excellent reproducibility with an average error of 5%. Quantification (triplicate) was accomplished in 15 min based on 1H NMR and in 1 h based on 31P NMR. Very little change in mixture composition was observed over multiple preparative steps.

CONCLUSION

Liposome preparations containing POPC, POPE, DOPC, DPPC, TACH, and PEG-ceramide can be reliably characterized and quantified by 1H NMR and 31P NMR spectroscopy at 600 MHz in the μmol range.

PLGA-LEC/F127 hybrid nanoparticles loaded with curcumin and their modulatory effect on monocytes

Aim: To investigate the effect of surfactant type on curcumin-loaded (CUR) PLGA nanoparticles (NPs) to modulate monocyte functions. Materials & methods: The nanoprecipitation method was used, and PLGA NPs were designed using Pluronic F127 (F127) and/or lecithin (LEC) as surfactants. Results: The Z-average of the NPs was <200 nm, they had a spherical shape, Derjaguin-Muller-Toporov modulus >0.128 MPa, they were stable during storage at 4°C, ζ-potential ∼-40 mV, polydispersity index <0.26 and % EE of CUR >94%. PLGA-LEC/F127 NPs showed favorable physicochemical and nanomechanical properties. These NPs were bound and internalized mainly by monocytes, suppressed monocyte-induced reactive oxygen species production, and decreased the ability of monocytes to modulate T-cell proliferation. Conclusion: These results demonstrate the potential of these NPs for targeted therapy.

Oleogel classification, physicochemical characterization methods, and typical cases of application in food: a review

The harmful effects of trans and saturated fatty acids have attracted worldwide attention. Edible oleogels, which can structure liquid oils, are promising healthy alternatives to traditional fats. Active research on oleogels is focused on the interaction between unsaturated oils with different fatty acid compositions and low molecular weight or polymer oleogels. The unique network structure inside oleogels has facilitated their application in candies, spreads, meat, and other products. However, the micro- and macro-properties, as well as the functional properties of oleogels vary by preparation method and the system composition. This review discusses the characteristics of oleogels, serving as a reference for the application of oleogels in food products. Specifically, it (i) classifies oleogels and explains the influence of gelling factors on their gelation, (ii) describes the methods for measuring the physicochemical properties of oleogels, and (iii) discusses the current applications of oleogels in food products.

Depicting the Chemical Diversity of Bioactive Meroterpenoids Produced by the Largest Organism on Earth

In this investigation, we explored the diversity of melleolide-type meroterpenoids produced by Armillaria ostoyae, one of the largest and oldest organisms on Earth, using extracts from liquid and solid fermentation media. The study unveiled three unprecedented dimeric bismelleolides and three novel fatty-acid-substituted congeners, along with 11 new and 21 known derivatives. The structures were elucidated by 1D and 2D NMR spectroscopy and HRESI-MS, and ROESY spectral analysis for relative configurations. Absolute configurations were determined from crystal structures and through ECD spectra comparison. A compound library of melleolide-type meroterpenoids facilitated metabolomics-wide associations, revealing production patterns under different culture conditions. The library enabled assessments of antimicrobial and cytotoxic activities, revealing that the Δ2,4 double bond is not crucial for antifungal activity. Cytotoxicity was linked to the presence of an aldehyde at C1, but lost with hydroxylation at C13. Chemoinformatic analyses demonstrated the intricate interplay of chemical modifications on biological properties. This study marks the first systematic exploration of Armillaria spp. meroterpenoid diversity by MS-based untargeted metabolomics, offering insight into structure-activity relationships through innovative chemoinformatics.

Nuclear magnetic resonance analysis of extra virgin olive oil: classification through secoiridoids

BACKGROUND

Extra virgin olive oil (EVOO), a natural product with a multidisciplinary role, has been and is continuing to be studied from several points of view. Among them, its chemical analysis is of major importance and several methods have been used. Nuclear magnetic resonance (NMR) spectroscopy has inherent advantages, among them monitoring the chemical constituents without the need for a separation technique and without, for instance, possible carry-over effects. Additionally, several magnetic resonance spectroscopic techniques can provide a novel powered insight into the nature and properties of a sample under study. Moreover, -omics procedure can reveal new information and can lead to the classification of populations under study. The main objective of the present work was the possible classification of the EVOO samples based on their aldehyde content using a proposed unreferenced 1 H-NMR spectroscopic quantification method combined with a metabolomic approach. Moreover, the study of the impact of such elevated aldehyde content on several spectra regions of importance in the proton NMR spectra led to the proposal of a possible new isomer indicator.

RESULTS

Univariate analysis of 12 EVOO samples showed that oleacein, oleocanthal, elenolic acid, hydroxytyrosol/hydroxytyrosol derivatives and tyrosol/tyrosol derivatives strongly differentiated two classes of EVOO: OEH (for high aldehyde EVOO content) and OE (for non-high aldehyde content). Moreover, we pointed out the 'impact' of such elevated secoiridoid and derivatives content, through their moieties' units, on a range of several resonances of the 1 H-NMR spectrum. The metabolomic approach demonstrated the classification of EVOO samples based on their secoiridoid and derivatives content. Multivariate analysis showed a strong influence on the discrimination of the EVOO classes based on the protons resonating at the aldehyde region of the 1 H-NMR spectrum; the aldehyde protons corresponding to 5S,4R-ligstrodial and 5S,4R-oleuropeindial, oleacein, oleocanthal, elenolic acid, p-HPEA-EA, 3,4-DHPEA-EA, 5S,4R- and 5S,4S-ligstrodial and the proton corresponding to a new compound were reported for the first time. This isomer compound, reported for the first time, could serve as a possible indicator for EVOO classification.

CONCLUSIONS

An unreferenced quantification method was proposed and EVOO samples were classified into two classes: OEH and OE, according to their aldehyde content, gaining thus probably higher nutrient and possible pharmacological value. Moreover, we point out the 'impact' of such elevated aldehyde content on several spectral regions of the 1 H spectrum. Finally, a new compound was detected in the OEH samples and is reported for the first time. This compound could possibly be an indicator. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

1H-NMR Approach for the Discrimination of PDO Grana Padano Cheese from Non-PDO Cheeses

Protected Designation of Origin cheeses are products with high-quality standards that can claim higher prices on the market. For this reason, non-PDO cheeses with lower quality can be mislabeled as PDO or mixed with it for economic gain especially when the product is in a shredded form. Luckily, the production of PDO cheese is subjected to strict procedural specification rules that result in a product with a defined profile of its metabolites, which can be used for authentication purposes. In this study, an NMR metabolomic approach combined with multivariate analysis was implemented to build a classification model able to discriminate PDO Grana Padano cheese from a large dataset of competitors. The great advantage of the proposed approach is a simple sample preparation, obtaining a holistic overview of the analyzed samples. The untargeted approach highlighted a "typical profile" of Grana Padano samples, which could be used for protection purposes. In parallel, the targeted results allowed us to identify potential chemicals, such as lactate, some amino acids and lipids. These initial results could open the road to a potential new additional tool to check the authenticity of PDO cheeses in the future.

1H NMR-based metabolomics study of the lipid profile of omega-3 fatty acid supplements and some vegetable oils

Omega-3 fatty acids, which consist of alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), are a type of polyunsaturated fatty acids that are crucial for enhancing human health. These three omega-3s are regarded as vital dietary nutrients because it cannot synthesize them on its own. Therefore, they must be obtained through dietary sources. On the other hands, there are concerns regarding the quality and quantity of omega-3 in dietary sources and supplements. In this study, 1H NMR spectroscopy and multivariate analysis were harnessed for non-destructive profiling of fatty acids in commercially available omega-3 supplements and plant-based oils. Results disclosed substantial disparities in omega-3 content from 8 to over 50 %, with some revealing unexpected adulteration. Notably, in one fish oil sample DHA could not be detected indicating the possibility of adulteration. Additionally, the research delineated the fatty acid composition of plant-based oils, emphasizing variations in alpha-linolenic acid (ALA) and linoleic acid (LA) content among flaxseed, chia seed, and walnut oils. Chia seeds emerged as a rich source of ALA (57-65 %mol), while walnuts contained considerable LA (44-53 % mol). The findings emphasize the power of metabolomics as a rapid and affordable tool for finding omega-3 fatty acids content and adulteration in commercial dietary products.

Ganoderma adspersum (Ganodermataceae): Investigation of Its Secondary Metabolites and the Antioxidant, Antimicrobial, and Cytotoxic Potential of Its Extracts

Ganoderma is a genus of wood-degrading mushrooms with medicinal importance. Most Ganoderma species have been studied extensively for their secondary metabolites, biological activities, and ecological value. In this study, the biological activities of the extracts of G. adspersum growing wild on Morus alba trees in the region of Western Thrace (Greece) were evaluated, and the petroleum ether, dichloromethanolic, and methanolic extracts were studied further for their secondary metabolites. Six substances were isolated by chromatographic (Clumn Chromatography (C.C.), High Performance Liquid Chromatography (HPLC)) and spectroscopic methods (Nuclear Magnetic Resonance (NMR)), which were classified in the following categories: (a) unsaturated fatty acids: cis-oleic acid (1); (b) sterols: ergosta-7,22-dien-3-one (2), ergosta-7,22-dien-3-ol (3), and ergosta-5,7,22-trien-3-ol (4); and (c) lanostane-type triterpenoids: applanoxidic acid G (5) and applanoxidic acid A (6). Finally, the biological activities of the extracts were estimated for their antioxidant, antimicrobial, and cytotoxic potential. The methanolic extract of G. adspersum showed the highest total antioxidant activity. The results of the antimicrobial activities indicated that all of the extracts had a minimum inhibitory concentration (MIC) ranging between 39.1 and 312.5 μg/mL. The evaluation of the cytotoxic activity of the samples showed once again that the methanolic extract was the most potent among the examined extracts, with half-maximal inhibitory concentration (IC50) values of 19.22 μg/mL (Hep2c cells), 32.9 μg/mL (RD cells), and 8.94 μg/mL (L2OB cells). Moreover, the bioactivity scores of the isolated secondary metabolites were calculated using the online computer software program Molinspiration. The compounds showed promising bioactivity scores for drug targets.

Impact of Conventional and Potential New Metal-Based Drugs on Lipid Metabolism in Osteosarcoma MG-63 Cells

This work investigated the mechanisms of action of conventional drugs, cisplatin and oxaliplatin, and the potentially less deleterious drug Pd2Spermine (Spm) and its Pt(II) analog, against osteosarcoma MG-63 cells, using nuclear-magnetic-resonance metabolomics of the cellular lipidome. The Pt(II) chelates induced different responses, namely regarding polyunsaturated-fatty-acids (increased upon cisplatin), suggesting that cisplatin-treated cells have higher membrane fluidity/permeability, thus facilitating cell entry and justifying higher cytotoxicity. Both conventional drugs significantly increased triglyceride levels, while Pt2Spm maintained control levels; this may reflect enhanced apoptotic behavior for conventional drugs, but not for Pt2Spm. Compared to Pt2Spm, the more cytotoxic Pd2Spm (IC50 comparable to cisplatin) induced a distinct phospholipids profile, possibly reflecting enhanced de novo biosynthesis to modulate membrane fluidity and drug-accessibility to cells, similarly to cisplatin. However, Pd2Spm differed from cisplatin in that cells had equivalent (low) levels of triglycerides as Pt2Spm, suggesting the absence/low extent of apoptosis. Our results suggest that Pd2Spm acts on MG-63 cells mainly through adaptation of cell membrane fluidity, whereas cisplatin seems to couple a similar effect with typical signs of apoptosis. These results were discussed in articulation with reported polar metabolome adaptations, building on the insight of these drugs' mechanisms, and particularly of Pd2Spm as a possible cisplatin substitute.

Drug-excipient compatibility studies in formulation development: A case study with benznidazole and monoglycerides

Monoglycerides (MGs) such as glycerol monolaurate (GML) and glycerol monostearate (GMS) have been used as excipients in oral formulations because of their emulsifying effect as well as their ability to inhibit the precipitation and intestinal efflux of drugs. Excipient-drug compatibility studies, however, have been underexplored. In this study, benznidazole (BNZ) was selected as a drug model due to the difficulty in improving its solubility and because of the potential impact on public health (it is the only drug currently used to treat Chagas disease). The effect of different processing conditions (maceration, ball milling, and melting) on the physical-chemistry properties of BNZ/MGs mixtures was investigated to guide the rational development of new solid formulations. GML was more effective in improving the solubility of BNZ, which could be due to its more malleable structure, less hydrophobic nature, and greater interaction with BNZ. The formation of hydrogen bonds between the imidazole group of BNZ and the polar region of GML was confirmed by spectroscopy analyses (IR, 1H NMR). The higher the monoglyceride content in the mixture, the higher the BNZ solubility. Regardless of the method of processing the mixture, the drug was found to be crystalline. Polarized light microscopy analysis showed the presence of spherulites. Overall, these findings suggest that preparation methods of BNZ:MGs formulations that involve thermal or/and mechanical treatment have a low impact on the solid properties of the material, and this allows for the production of formulations with reproducible performance.

Chemometric analysis applied to 1 H NMR and FTIR data for a quality parameter distinction of red fruit (Pandanus conoideus, lam.) oil products

INTRODUCTION

Red fruit oil (RFO) is a natural product extracted from Pandanus conoideus Lam. fruit, a native plant from Papua, Indonesia. Recent studies indicate that RFO is popularly consumed as herbal medicine. Therefore, the quality of RFO must be assured.

OBJECTIVES

This study aimed to develop a chemometric analysis applied to 1 H nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) data for important quality parameter distinction of red fruit oil (RFO), especially regarding the degree of unsaturation and the amount of free fatty acids (FFA).

MATERIALS AND METHODS

Forty samples consisting of one crude RFO, thirty-three commercial RFOs, and three oils as blends, including olive oil, virgin coconut oil, and black seed oil, were analysed by 1 H NMR and FTIR spectroscopy. After appropriate preprocessing of the spectra, principal component analysis (PCA) and partial least squares regression (PLSR) were used for model development.

RESULTS

The essential signals for modelling the degree of unsaturation are the signal at δ = 5.37-5.27 ppm (1 H NMR) and the band at 3000-3020 cm-1 (FTIR). The FFA profile represents the signal at δ = 2.37-2.20 ppm (1 H NMR) and the band at 1680-1780 cm-1 (FTIR). PCA allows the visualisation grouping on both methods with > 98% total principal component (PC) for the degree of unsaturation and > 88% total PC for FFA values. In addition, the PLSR model provides an acceptable coefficient of determination (R2 ) and errors in calibration, prediction, and cross-validation.

CONCLUSION

Chemometric analysis applied to 1 H NMR and FTIR spectra of RFO successfully grouped and predicted product quality based on the degree of unsaturation and FFA value categories.

A new flavonoid glycoside from the aerial parts of Diplotaxis erucoides (L.) DC. growing in Algeria

The phytochemical study of the 70% ethanol extract of the aerial parts of Diplotaxis erucoides afforded one new flavonoid glycoside, namely kaempferol-3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside]-7-O-α-L-rhamnopyranoside (1), named diploerucoside A and seven known compounds including one flavonoid (2), one phenolic glycoside (3), one monoterpene (4), one triterpene (5), one sitosterol (6) and two monoglycerolipids (7, 8). Their structures were established by extensive spectroscopic analysis including 1 D- and 2 D-NMR (1H, 13C, 1H-1H COSY, HSQC and HMBC), mass spectrometry (HR-ESI-MS) and by comparison with the data reported in the literature.

Development and Pharmacokinetic Evaluation of Novasomes for the Trans-nasal Delivery of Fluvoxamine Using Arachidonic Acid-Carboxymethyl Chitosan Conjugate

Depression is the major mental illness which causes along with loss of interest in daily life, a feeling of hopelessness, appetite or weight changes, anger and irritability. Due to the hepatic first-pass metabolism, the absolute bioavailability of fluvoxamine (FVM) after oral administration is about 50%. By avoiding the pre-systemic metabolism, nasal delivery would boost bioavailability of FVM. Additionally, the absorption is anticipated to occur more quickly than it would via the oral route because of the existence of microvilli and high vasculature. A nonionic surfactant, cholesterol and an arachidonic acid-carboxymethyl chitosan (AA-CMCS) conjugate were used to develop FVM-loaded novasomes. To investigate the effects of surfactant concentration, AA-CMCS conjugate concentration and stirring speed on the novasomes' characteristics, a Box-Behnken design was used. The dependent variables chosen were zeta potential, polydispersity index and particle size. The AA-CMCS conjugate was confirmed by 1H-NMR and FTIR. Using Design Expert software (version 7; Stat-Ease Inc., Minneapolis, MN, USA), novasomes were further optimized. The chosen optimal formulation (NAC8) was made up of AA-CMCS conjugate, Span 60 and cholesterol. Particle size, zeta potential and PDI values for NAC8 formulation were 101 nm, -35 mV and 0.263, respectively. The NAC8 formulation's DSC and TGA analysis demonstrated that the medication had been uniformly and amorphously distributed throughout the novasomes. The NAC8 formulation showed 99% and 90% FVM release and permeation, respectively, and the novasome adherence time was 24 h. An improved antidepressant effect along with five-fold increase in bioavailability of FVM was observed after trans-nasal administration of NAC8 formulation compared to the reference commercially available Flumin® tablets. FVM-loaded novasomes administered via the nasal route may therefore constitute an advancement in the management of depression.

Structural Studies of Monounsaturated and ω-3 Polyunsaturated Free Fatty Acids in Solution with the Combined Use οf NMR and DFT Calculations-Comparison with the Liquid State

Molecular structures, in chloroform and DMSO solution, of the free fatty acids (FFAs) caproleic acid, oleic acid, α-linolenic acid, eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA) are reported with the combined use of NMR and DFT calculations. Variable temperature and concentration chemical shifts of the COOH protons, transient 1D NOE experiments and DFT calculations demonstrate the major contribution of low molecular weight aggregates of dimerized fatty acids through intermolecular hydrogen bond interactions of the carboxylic groups, with parallel and antiparallel interdigitated structures even at the low concentration of 20 mM in CDCl3. For the dimeric DHA, a structural model of an intermolecular hydrogen bond through carboxylic groups and an intermolecular hydrogen bond between the carboxylic group of one molecule and the ω-3 double bond of a second molecule is shown to play a role. In DMSO-d6 solution, NMR and DFT studies show that the carboxylic groups form strong intermolecular hydrogen bond interactions with a single discrete solvation molecule of DMSO. These solvation species form parallel and antiparallel interdigitated structures of low molecular weight, as in chloroform solution. This structural motif, therefore, is an intrinsic property of the FFAs, which is not strongly affected by the length and degree of unsaturation of the chain and the hydrogen bond ability of the solvent.

Design and characterization of Lactotransferrin peptide-loaded dextran-docosahexaenoic acid nanoparticles: an immune modulator for hepatic damage

The primary objective of this research was to create injectable delivery formulations using Lactotransferrin (LTF) peptide-loaded dextran nanoparticles coated with docosahexaenoic acid. These nanoparticles, designated as LLDDNP, underwent a lyophilization process. The study encompassed a comprehensive investigation, including physicochemical characterization, in vivo assessment of biomarkers, and an examination of immune response through cytokine modulation. The zeta potential of LLDDNP was - 24.5 ± 12 mV, while their average particle size was 334.9 z.d.nm. The particles exhibited a conductivity of 2.10 mS/cm, while their mobility in the injectable dosage form was measured at - 3.65 µm cm/Vs. The scanning electron microscopy investigation, the lyophilization processes resulted in discrete particles forming particle aggregations. However, transmission electron microscopy analysis revealed that LLDDNP is spherical and smooth. The thermogram showed that about 95% of LLDDNP's weight was lost at 270 °C, indicating that the particles are extremely thermal stable. The XRD analysis of LLDDNP exhibited clear and distinctive peaks at 2θ angles, specifically at 9.6°, 20.3°, 21.1°, 22°, 24.6°, 25.2°, 36°, and 44.08°, providing compelling evidence of the crystalline nature of the particles. According to proton NMR studies, the proton dimension fingerprint region of LLDDNP ranges from 1.00 to 1.03 ppm. The in vitro release of LTF from LLDDNP was found to follow zero-order kinetics, with a commendable R2 value of 0.942, indicating a consistent and predictable release pattern over time. The in vivo investigation revealed a significant impact of hepatotoxicity on the elevation of various cytokines, including IL-1β, IL-6, IL-8R, TNF-α, IL-2, IL-4, IL-10, and IFN-γ. Additionally, the presence of hepatotoxicity led to an increase in apoptosis markers, namely caspase 3 and caspase 9, as well as elevated levels of liver biomarkers such as CRP, ALP, ALT, and AST. In contrast, the treatment with LLDDNP modulated the levels of all biomarkers, including cytokines level in the treatment group extremely high significant at p < 0.001.

Accumulation of Linoleic Acid by Altered Peroxisome Proliferator-Activated Receptor-α Signaling Is Associated with Age-Dependent Hepatocarcinogenesis in Ppara Transgenic Mice

Long-term ligand activation of PPARα in mice causes hepatocarcinogenesis through a mechanism that requires functional PPARα. However, hepatocarcinogenesis is diminished in both Ppara-null and PPARA-humanized mice, yet both lines develop age-related liver cancer independently of treatment with a PPARα agonist. Since PPARα is a master regulator of liver lipid metabolism in the liver, lipidomic analyses were carried out in wild-type, Ppara-null, and PPARA-humanized mice treated with and without the potent agonist GW7647. The levels of hepatic linoleic acid in Ppara-null and PPARA-humanized mice were markedly higher compared to wild-type controls, along with overall fatty liver. The number of liver CD4+ T cells was also lower in Ppara-null and PPARA-humanized mice and was negatively correlated with the elevated linoleic acid. Moreover, more senescent hepatocytes and lower serum TNFα and IFNγ levels were observed in Ppara-null and PPARA-humanized mice with age. These studies suggest a new role for PPARα in age-associated hepatocarcinogenesis due to altered lipid metabolism in Ppara-null and PPARA-humanized mice and the accumulation of linoleic acid as part of an overall fatty liver that is associated with loss of CD4+ T cells in the liver in both transgenic models. Since fatty liver is a known causal risk factor for liver cancer, Ppara-null and PPARA-humanized mice are valuable models for examining the mechanisms of PPARα and age-dependent hepatocarcinogenesis.

Seedpod extracts of Wrightia tinctoria shows significant anti-inflammatory effects in HepG2 and RAW-264.7cell lines

W. tinctoria, an Indian herb Indrajao, has significant therapeutic potential. While studies have highlighted the anti-inflammatory potential of the leaves and bark of this plant, similar efficacy of the seed-pods remains unexplored. We demonstrate significant anti-inflammatory effects of the hexane fraction (Fr-B) of ethyl acetate extract of the seedpods in reducing lipopolysaccharide and palmitate mediated inflammation in RAW264.7 macrophages and HepG2 cells. GC-MS and NMR profiling of Fr-B revealed the existence of hexadecanoic acid, ethyl hexadecanoate, 9,12-octadecanoic acid, 9,12,15-octadecatrienoic acid, 9,12,15-octadecatrienoic acid ethyl ester, ethyl linoleate and octadecanoic acid ethyl esters.

Characterization of trehalolipid biosurfactant produced by the novel marine strain Rhodococcus sp. SP1d and its potential for environmental applications

BACKGROUND

Biosurfactants are surface-active compounds with environmental and industrial applications. These molecules show higher biocompatibility, stability and efficiency compared to synthetic surfactants. On the other hand, biosurfactants are not cost-competitive to their chemical counterparts. Cost effective technology such as the use of low-cost substrates is a promising approach aimed at reducing the production cost. This study aimed to evaluate the biosurfactant production and activity by the novel strain Rhodococcus sp. SP1d by using different growth substrates. Therefore, to exploit the biosurfactant synthesized by SP1d for environmental applications, the effect of this compound on the bacteria biofilm formation was evaluated. Eventually, for a possible bioremediation application, the biosurfactant properties and its chemical characteristics were investigated using diesel as source of carbon.

RESULTS

Rhodococcus sp. SP1d evidence the highest similarity to Rhodococcus globerulus DSM 43954^T and the ability to biosynthesize surfactants using a wide range of substrates such as exhausted vegetable oil, mineral oil, butter, n-hexadecane, and diesel. The maximum production of crude biosurfactant after 10 days of incubation was reached on n-hexadecane and diesel with a final yield of 2.38 ± 0.51 and 1.86 ± 0.31 g L^- 1 respectively. Biosurfactants produced by SP1d enhanced the biofilm production of P. protegens MP12. Moreover, the results showed the ability of SP1d to produce biosurfactants on diesel even when grown at 10 and 18 °C. The biosurfactant activity was maintained over a wide range of NaCl concentration, pH, and temperature. A concentration of 1000 mg L^- 1 of the crude biosurfactant showed an emulsification activity of 55% towards both xylene and olive oil and a reduction of 25.0 mN m^- 1 of surface tension of water. Eventually, nuclear magnetic resonance spectroscopy indicated that the biosurfactant is formed by trehalolipids.

CONCLUSIONS

The use of low-cost substrates such as exhausted oils and waste butter reduce both the costs of biosurfactant synthesis and the environmental pollution due to the inappropriate disposal of these residues. High production yields, stability and emulsification properties using diesel and n-hexadecane as substrates, make the biosurfactant produced by SP1d a sustainable biocompound for bioremediation purpose. Eventually, the purified biosurfactant improved the biofilm formation of the fungal antagonistic strain P. protegens MP12, and thus seem to be exploitable to increase the adherence and colonization of plant surfaces by this antagonistic strain and possibly enhance antifungal activity.

Cuticular profiling of insecticide resistant Aedes aegypti

Insecticides have made great strides in reducing the global burden of vector-borne disease. Nonetheless, serious public health concerns remain because insecticide-resistant vector populations continue to spread globally. To circumvent insecticide resistance, it is essential to understand all contributing mechanisms. Contact-based insecticides are absorbed through the insect cuticle, which is comprised mainly of chitin polysaccharides, cuticular proteins, hydrocarbons, and phenolic biopolymers sclerotin and melanin. Cuticle interface alterations can slow or prevent insecticide penetration in a phenomenon referred to as cuticular resistance. Cuticular resistance characterization of the yellow fever mosquito, Aedes aegypti, is lacking. In the current study, we utilized solid-state nuclear magnetic resonance spectroscopy, gas chromatography/mass spectrometry, and transmission electron microscopy to gain insights into the cuticle composition of congenic cytochrome P450 monooxygenase insecticide resistant and susceptible Ae. aegypti. No differences in cuticular hydrocarbon content or phenolic biopolymer deposition were found. In contrast, we observed cuticle thickness of insecticide resistant Ae. aegypti increased over time and exhibited higher polysaccharide abundance. Moreover, we found these local cuticular changes correlated with global metabolic differences in the whole mosquito, suggesting the existence of novel cuticular resistance mechanisms in this major disease vector.

Silage for upcycling oil from saithe (Pollachius virens) viscera - Effect of raw material freshness on the oil quality

The main objective of this study was to investigate how the freshness of saithe (Pollachius virens) viscera affected the quality, composition and yield of oil obtained by silaging. Minced viscera with and without liver were stored separately for up to 3 days at 4 °C before silaging at pH 3.8 for 6 days at 10 °C. An antioxidant mixture was added to evaluate the effect on the lipid oxidation. Oil was extracted thermally from untreated raw material during storage (day 0-3) and after silaging. For oil obtained after silaging of viscera with liver, the oil yields increased significantly when the raw material was stored for more than one day prior to the treatment. Use of fresh raw material (collected at day 0) led to significantly lower oxidation compared to longer raw material storage. After one day of storage, the oxidation was less dependent on the freshness. Silaging with antioxidants resulted in significantly lower formation of oxidation products compared to acid without antioxidants and the most significant differences were observed after one day of storage. Contents of docosahexaenoic acid (DHA) and total omega-3 fatty acids decreased significantly when the raw material was stored for 1-3 days prior to silaging compared to fresh raw material. Results obtained by high resolution nuclear magnetic resonance (NMR) spectroscopy indicated that oxidation of esterified DHA might explain the DHA decrease. The free fatty acid content was highest when fresh raw material was used and was most likely affected by the formation of cholesteryl esters observed in NMR spectra after longer storage. The study shows that although the oil quality is reduced during silaging, processing shortly after catch and use of antioxidants can optimize the quality resulting in less oxidized oil richer in omega-3 fatty acids.

Design, physicochemical characterisation, and in vitro cytotoxicity of cisplatin-loaded PEGylated chitosan injectable nano / sub-micron crystals

The study aimed to develop cisplatin-loaded PEGylated chitosan nanoparticles. The optimal batch of cisplatin-loaded PEGylated chitosan nanoparticles had a + 49.9 mV zeta potential, PDI of 0.347, and % PDI of 58.9. Nanoparticle zeta size was 741.4 z. d.nm, the size in diameter was 866.7 ± 470.5 nm, and nanoparticle conductivity in colloidal solution was 0.739 mS/cm. Differential scanning calorimetry (DSC) revealed that cisplatin-loaded PEGylated chitosan nanoparticles had sharp endothermic peaks at temperatures at 168.6 °C. The thermogravimetric analysis (TGA) showed the weight loss of cisplatin-loaded PEGylated chitosan nanoparticles, which was observed as 95% at 262.76 °C. XRD investigation on cisplatin-loaded PEGylated chitosan nanoparticles exhibited distinct peaks at 2θ as 9.7°, 20.4°, 22.1°, 25.3°, 36.1°, 38.1°, 39.5°, 44.3°, and 64.5°, confirming crystalline structure. The ¹H NMR analysis showed the fingerprint region of cisplatin-loaded PEGylated chitosan nanoparticles as 0.85, 1.73, and 1.00 ppm in the proton dimension and de-shielded proton peaks appeared at 3.57, 3.58, 3.58, 3.59, 3.65, 3.67, 3,67, 3,67, 3.70, 3.71, 3.77, 3.78 and 4.71 ppm. The ¹³C NMR spectrum showed specified peaks at 63.18, 69.20, and 70.77 ppm. The FT-IR spectra of cisplatin loaded PEGylated nanoparticles show the existence of many fingerprint regions at 3186.52, 2931.68, 1453.19, 1333.98, 1253.71, 1085.19, 1019.60, 969.98, 929.53, 888.80, 706.13, and 623.67 cm^-1. The drug release kinetics of cisplatin loaded PEGylated chitosan nanoparticles showed zero order kinetics with 48% of drug release linearity fashion which has R² value of 0.9778. Studies on the MCF-7 ATCC human breast cancer cell line in vitro revealed that the IC50 value 82.08 µg /mL. Injectable nanoparticles had good physicochemical and cytotoxic properties. This method is novel since the application of the PEGylation processes leads to an increased solubility of chitosan nanoparticles at near neutral pH.

On the Use of Deuterated Organic Solvents without TMS to Report 1H/13C NMR Spectral Data of Organic Compounds: Current State of the Method, Its Pitfalls and Benefits, and Related Issues

The quite popular, simple but imperfect method of referencing NMR spectra to residual 1H and 13C signals of TMS-free deuterated organic solvents (referred to as Method A) is critically discussed for six commonly used NMR solvents with respect to their δH and δC values that exist in the literature. Taking into account the most reliable data, it was possible to recommend 'best' δX values for such secondary internal standards. The position of these reference points on the δ scale strongly depends on the concentration and type of analyte under study and the solvent medium used. For some solvents, chemically induced shifts (CISs) of residual 1H lines were considered, also taking into account the formation of 1:1 molecular complexes (for CDCl3). Typical potential errors that can occur as a result of improper application of Method A are considered in detail. An overview of all found δX values adopted by users of this method revealed a discrepancy of up to 1.9 ppm in δC reported for CDCl3, most likely caused by the CIS mentioned above. The drawbacks of Method A are discussed in relation to the classical use of an internal standard (Method B), two 'instrumental' schemes in which Method A is often implicitly applied, that is, the default Method C using 2H lock frequencies and Method D based on Ξ values, recommended by the IUPAC but only occasionally used for 1H/13C spectra, and external referencing (Method E). Analysis of current needs and opportunities for NMR spectrometers led to the conclusion that, for the most accurate application of Method A, it is necessary to (a) use dilute solutions in a single NMR solvent and (b) to report δX data applied for the reference 1H/13C signals to the nearest 0.001/0.01 ppm to ensure the precise characterization of new synthesized or isolated organic systems, especially those with complex or unexpected structures. However, the use of TMS in Method B is strongly recommended in all such cases.

Evaluation of NMR predictors for accuracy and ability to reveal trends in 1 H NMR spectra of fatty acids

Four different nuclear magnetic resonance (NMR) predictors have been evaluated for their ability to predict 600-MHz ¹ H spectra of free fatty acids and fatty acid methyl esters of 20 common fatty acids. The predictors were evaluated on two main criteria: (1) their accuracy in direct prediction of the spectra (absolute accuracy) and (2) the ability to reveal trends or predict the change that occurs in the spectra as a result of a change in the fatty acid carbon chain, or by esterification of the free fatty acids to methyl esters (relative accuracy). The absolute accuracy in chemical shift prediction for fatty acids was good, compared with previous reports on a broader range of compounds. All four predictors had median prediction errors for chemical shifts of the signals in fatty acid methyl esters well below 0.1 ppm and as low as 0.015 ppm for one of the predictors. However, all predictors also had outliers with errors far above the upper interquartile range. In general, they also fail to reproduce trends of diagnostic value that were observed in the experimental data or properly predict the result of a minor change in molecular structure. All four predictors depend on experimental data from different origins. This may be a limiting factor for the relative accuracy of the predictors.

Molecular Basis for the Selectivity of DHA and EPA in Sudlow's Drug Binding Sites in Human Serum Albumin with the Combined Use of NMR and Docking Calculations

Medium- and long-chain saturated and unsaturated free fatty acids (FFAs) are known to bind to human serum albumin (HSA), the main plasma carrier protein. Atomic-level structural data regarding the binding mode in Sudlow's sites I (FA7) and II (FA4, FA3) of the polyunsaturated ω-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), however, are largely unknown. Herein, we report the combined use of saturation transfer difference (STD) and Interligand NOEs for Pharmacophore Mapping (INPHARMA) NMR techniques and molecular docking calculations to investigate the binding mode of DHA and EPA in Sudlow's sites Ι and ΙΙ of HSA. The docking calculations and the significant number of interligand NOEs between DHA and EPA and the drugs warfarin and ibuprofen, which are stereotypical ligands for Sudlow's sites I and II, respectively, were interpreted in terms of competitive binding modes and the presence of two orientations of DHA and EPA at the binding sites FA7 and FA4. The exceptional flexibility of the long-chain DHA and EPA and the formation of strongly folded structural motives are the key properties of HSA-PUFA complexes.

Upgrading Marine Oils from Cod (Gadus morhua) On-Board the Deep-Sea Vessels-From Waste to Value

Significant amounts of marine raw material are lost on-board the deep-sea vessels due to fast quality degradation. Optimal on-board handling and processing strategies can upgrade these resources from waste to food ingredients rich in nutrients such as omega-3 fatty acids. The objective of this study was to investigate the effect of raw material freshness and sorting on the quality, composition and yield of oil produced thermally from cod (Gadus morhua) residuals on-board a commercial trawler. Oil was produced from whole viscera fractions with liver or out-sorted livers right after a catch and after chilled storage for up to 6 days. The results showed that significantly higher oil yields could be obtained if the raw materials were stored for 1 day or longer. However, an undesired emulsion was formed when viscera were stored for 4 days. All oils were rich in health beneficial omega-3 fatty acids, but viscera oils had generally lower quality with higher levels of free fatty acids and oxidation products. However, out-sorting of the liver was not necessary to meet guidelines for high-quality fish oil. Both viscera and liver could be stored for up to 2 days at 4 °C prior to oil production and still meet quality criteria for food applications. These results demonstrate a large potential in upgrading currently wasted marine raw materials into high-quality food ingredients.

Biomarker Quantification, Spectroscopic, and Molecular Docking Studies of the Active Compounds Isolated from the Edible Plant Sisymbrium irio L

Phytochemical investigation of the ethanolic extract of the aerial parts of Sisymbrium irio L. led to the isolation of four unsaturated fatty acids (1–4), including a new one (4), and four indole alkaloids (5–8). The structures of the isolated compounds were characterized with the help of spectroscopic techniques such as 1D, 2D NMR, and mass spectroscopy, and by correlation with the known compounds. In terms of their notable structural diversity, a molecular docking approach with the AutoDock 4.2 program was used to analyze the interactions of the identified fatty acids with PPAR-γ and the indole alkaloids with 5-HT1A and 5-HT2A, subtypes of serotonin receptors, respectively. Compared to the antidiabetic drug rivoglitazone, compound 3 acted as a potential PPAR-γ agonist with a binding energy of −7.4 kcal mol−1. Moreover, compound 8 displayed the strongest affinity, with binding energies of −6.9 kcal/mol to 5HT1A and −8.1 kcal/mol to 5HT2A, using serotonin and the antipsychotic drug risperidone as positive controls, respectively. The results of docked conformations represent an interesting target for developing novel antidiabetic and antipsychotic drugs and warrant further evaluation of these ligands in vitro and in vivo. On the other hand, an HPTLC method was developed to quantify α-linolenic acid in the hexane fraction of the ethanol extract of S. irio. The regression equation/correlation coefficient (r2) for linolenic acid was Y = 6.49X + 2310.8/0.9971 in the linearity range of 100–1200 ng/band. The content of α-linolenic acid in S. irio aerial parts was found to be 28.67 μg/mg of dried extract.

NMR-Based Metabolite Profiling and the Application of STOCSY toward the Quality and Authentication Assessment of European EVOOs

Extra virgin olive oil (EVOO) possesses a high-value rank in the food industry, thus making it a common target for adulteration. Hence, several methods have been essentially made available over the years. However, the issue of authentication remains unresolved with national and food safety organizations globally struggling to regulate and control its market. Over the course of this study, the aim was to determine the origin of EVOOs suggesting a high-throughput, state-of-the-art method that could be easily adopted. A rapid, NMR-based untargeted metabolite profiling method was applied and complemented by multivariate analysis (MVA) and statistical total correlation spectroscopy (STOCSY). STOCSY is a valuable statistical tool contributing to the biomarker identification process and was employed for the first time in EVOO analysis. Market samples from three Mediterranean countries of Spain, Italy, and Greece, blended samples from these countries, as well as monocultivar samples from Greece were analyzed. The NMR spectra were collected, with the help of chemometrics acting as "fingerprints" leading to the discovery of certain chemical classes and single biomarkers that were related to the classification of the samples into groups based on their origin.

Metabolite Profiling of Premium Civet Luwak Bio-Transformed Coffee Compared with Conventional Coffee Types, as Analyzed Using Chemometric Tools

Luwak (civet) coffee is one of the most precious and exotic coffee commodities in the world. It has garnered an increasing reputation as the rarest and most expensive coffee, with an annual production. Many targeted analytical techniques have been reported for the discrimination of specialty coffee commodities, such as Luwak coffee, from other ordinary coffee. This study presents the first comparative metabolomics approach for Luwak coffee analysis compared to other coffee products, targeting secondary and aroma metabolites using nuclear magnetic resonance (NMR), gas chromatography (GC), or liquid chromatography (LC) coupled with mass spectrometry (MS). Chemometric modeling of these datasets showed significant classification among all samples and aided in identifying potential novel markers for Luwak coffee from other coffee samples. Markers have indicated that C. arabica was the source of Luwak coffee, with several new markers being identified, including kahweol, chlorogenic acid lactones, and elaidic acid. Aroma profiling using solid-phase micro-extraction (SPME) coupled with GC/MS revealed higher levels of guaiacol derivatives, pyrazines, and furans in roasted Luwak coffee compared with roasted C. arabica. Quantification of the major metabolites was attempted using NMR for Luwak coffee to enable future standardization. Lower levels of alkaloids (caffeine 2.85 µg/mg, trigonelline 0.14 µg/mg, and xanthine 0.03 µg/mg) were detected, compared with C. arabica. Other metabolites that were quantified in civet coffee included kahweol and difurfuryl ether at 1.37 and 0.15 µg/mg, respectively.

Triacylglycerol Composition and Chemical-Physical Properties of Cocoa Butter and Its Derivatives: NMR, DSC, X-ray, Rheological Investigation

In recent years, the food industry has become increasingly involved in researching vegetable fats and oils with appropriate mechanical properties (ease of transport, processing, and storage) and a specific lipidic composition to ensure healthy products for consumers. The chemical-physical behavior of these matrices depends on their composition in terms of single fatty acids (FA). However, as we demonstrate in this work, these properties, as well as the absorption, digestion and uptake in humans of specific FAs, are also largely determined by their regiosomerism within the TriAcylGlycerols (TAG) moieties (sn-1,2,3 positions). The goal of this work is to study for the first time vegetable fats obtained directly from a sample of natural cocoa butter (CB) through a process that manipulates the distribution of FAs but not their nature. Even if the initial percentage of each FA in the mixture remains the same, CB derivatives seem to show improved chemical-physical features. In order to understand which factors account for their physical and chemical characteristics, and to check whether or not the obtained new matrices could be considered as valid alternatives to other vegetable fats (e.g., palm oil (PO)), we carried out an experimental investigation at both the macroscopic and molecular level including: (i) Differential Scanning Calorimetry (DSC) analyses to examine thermal features; (ii) rheological testing to explore mechanical properties; (iii) powder X-ray diffraction (PXRD) to evaluate the solid-state phases of the obtained fats; and (iv) ¹H and ¹³C Nuclear Magnetic Resonance (NMR, 1D and 2D) spectroscopy to rapidly analyze fatty acid composition including regioisomeric distribution on the glycerol backbone. These last results open up the possibility of using NMR spectroscopy as an alternative to the chromatographic techniques routinely employed for the investigation of similar matrices.

Cuticular profiling of insecticide resistant Aedes aegypti

Insecticides have made great strides in reducing the global burden of vector-borne disease. Nonetheless, serious public health concerns remain because insecticide-resistant vector populations continue to spread globally. To circumvent insecticide resistance, it is essential to understand all contributing mechanisms. Contact-based insecticides are absorbed through the insect cuticle, which is comprised mainly of chitin polysaccharides, cuticular proteins, hydrocarbons, and phenolic biopolymers sclerotin and melanin. Cuticle interface alterations can slow or prevent insecticide penetration in a phenomenon referred to as cuticular resistance. Cuticular resistance characterization of the yellow fever mosquito, Aedes aegypti , is lacking. In the current study, we utilized solid-state Nuclear Magnetic Resonance (ssNMR) spectroscopy, gas chromatography/mass spectrometry (GC-MS), and transmission electron microscopy (TEM) to gain insights into the cuticle composition of congenic cytochrome P450 monooxygenase insecticide resistant and susceptible Ae. aegypti . No differences in cuticular hydrocarbon content or phenolic biopolymer deposition were found. In contrast, we observed cuticle thickness of insecticide resistant Ae. aegypti increased over time and exhibited higher polysaccharide abundance. Moreover, we found these local cuticular changes correlated with global metabolic differences in the whole mosquito, suggesting the existence of novel cuticular resistance mechanisms in this major disease vector.

Segmented Flow Strategies for Integrating Liquid Chromatography-Mass Spectrometry with Nuclear Magnetic Resonance for Lipidomics

Building an accurate lipid inventory relies on coordinated information from orthogonal analytical capabilities. Integrating the familiar workflow of liquid chromatography (LC), high-resolution mass spectrometry (HRMS), and tandem mass spectrometry (MS/MS) with proton nuclear magnetic resonance spectroscopy (1H NMR) would be ideal for building that inventory. For absolute lipid structural elucidation, LC-HRMS/MS can provide lower-level structural information with superior sensitivity, while 1H NMR can provide invaluable higher-order structural information for the disambiguation of isomers with absolute chemical specificity. Digitization of the LC eluent followed by splitting the microfractions into two flow paths in a defined ratio for HRMS/MS and NMR would be the ideal strategy to permit correlation of the MS and NMR data as a function of chromatographic retention time. Here, we report an active segmentation platform to transform analytical flow rate LC eluent into parallel microliter segmented flow queues for high confidence correlation of the MS, MS/MS, and NMR data. The practical details in implementing this strategy to achieve an integrated LC-MS-NMR platform are presented, including the development of an active segmentation technology using a four-port two-way valve to transform the LC eluent into parallel segmented flows for online MS analysis followed by offline segment-specific 1H NMR and optimization of the detector response toward segmented flow. To demonstrate the practicality of this novel platform, it was tested using lipid mixture samples.

Positional Distribution of Fatty Acids in Processed Chinook Salmon Roe Lipids Determined by 13C Magnetic Resonance Spectroscopy (NMR)

Recently, there has been great interest in the lipidomic of marine lipids and their potential health benefits. Processing of seafood products can potentially modify the characteristics and composition of lipids. The present study investigated the effect of processing methods (salting and fermentation) on the positional distribution of fatty acids of Chinook salmon roe using ¹³C nuclear magnetic resonance spectroscopy (NMR). The NMR analysis provided information on the carbonyl atom, double bond/olefinic, glycerol backbone, aliphatic group, and chain ending methyl group regions. The obtained data showed that docosahexaenoic acid (DHA) is the main fatty acid esterified at the sn-2 position of the triacylglycerides (TAGs), while other fatty acids, such as eicosapentaenoic acid (EPA) and stearidonic acid (SDA), were randomly distributed or preferentially esterified at the sn-1 and sn-3 positions. Fermentation of salmon roe was found to enrich the level of DHA at the sn-2 position of the TAG. The processing of roe by both salt drying and fermentation did not appear to affect the proportion of EPA at the sn-2 position. This present study demonstrated that fish roe processing can enhance the proportion of DHA at the sn-2 position and potentially improve its bioavailability.

NMR-Based Characterization of Citrus Tacle Juice and Low-Level NMR and UV-Vis Data Fusion for Monitoring Its Fractions from Membrane-Based Operations

Tacle is a citrus variety which recently gained further interest due to its antioxidant and biological properties. This study suggests using Nuclear Magnetic Resonance (NMR) imaging to characterize Tacle juice's metabolic composition as it is intimately linked to its quality. First, polar and apolar solvent systems were used to identify a significant fraction of the Tacle metabolome. Furthermore, the antioxidant capacity and the total content of flavonoids, polyphenols and β-carotene in the juice were investigated with UV-Visible spectroscopy. Tacle juice was clarified and fractionated by ultrafiltration (UF) and nanofiltration (NF) membranes in order to recover and purify its bioactive principles. Finally, the second part of this work sheds light on the spectrophotometric assays and 1H-NMR spectra of fractions coming from membrane operations coupled with a multivariate data analysis technique, PCA, to explore the impact of UF and NF processes on the metabolic profile of the juice.

Characterization and Optimization of Culture Conditions for Aurantiochytrium sp. SC145 Isolated from Sand Cay (Son Ca) Island, Vietnam, and Antioxidative and Neuroprotective Activities of Its Polyunsaturated Fatty Acid Mixture

Aurantiochytrium is a heterotrophic marine microalga that has potential industrial applications. The main objectives of this study were to isolate an Aurantiochytrium strain from Sand Cay (Son Ca) Island, Vietnam, optimize its culture conditions, determine its nutritional composition, extract polyunsaturated fatty acids (PUFAs) in the free (FFA) and the alkyl ester (FAAE) forms, and evaluate the antioxidation and neuroprotection properties of the PUFAs. Aurantiochytrium sp. SC145 can be grown stably under laboratory conditions. Its culture conditions were optimized for a dry cell weight (DCW) of 31.18 g/L, with total lipids comprising 25.29%, proteins 7.93%, carbohydrates 15.21%, and carotenoid at 143.67 µg/L of DCW. The FAAEs and FFAs extracted from Aurantiochytrium sp. SC145 were rich in omega 3-6-9 fatty acids (40.73% and 44.00% of total fatty acids, respectively). No acute or subchronic oral toxicity was determined in mice fed with the PUFAs in FFA or FAAE forms at different doses over 90 days. Furthermore, the PUFAs in the FFA or FAAE forms and their main constituents of EPA, DHA, and ALA showed antioxidant and AChE inhibitory properties and neuroprotective activities against damage caused by H₂O₂- and amyloid-ß protein fragment 25-35 (Aβ_25-35)-induced C6 cells. These data suggest that PUFAs extracted from Aurantiochytrium sp. SC145 may be a potential therapeutic target for the treatment of neurodegenerative disorders.

Phytochemical Analysis and Biological Activity of Salvia compressa Vent

Background

Salvia extracts have various biological activities and are rich sources of bioactive metabolites.

Objectives

We identified five phytochemicals from S. compressa extract and assessed its biological properties.

Methods

The plant's shoots were extracted using dichloromethane, and the constituents were isolated using column chromatography. High-resolution NMR spectroscopy characterized the chemical structures of the compounds (1 - 5). The cytotoxic effect of the extract was examined against MCF-7 cells by MTT reduction assay, while cisplatin was tested as a reference cytotoxic compound. The antibacterial activity was assessed using nutrient broth micro-dilution (NBMD), and chloramphenicol was used as the positive control.

Results

Citrostadienol (1), β-sitosterol (2), two glyceride esters of linolenic, linoleic, and palmitic acids (3, 4), and geraniol (5) were isolated from S. compressa for the first time. The extract showed activity against MCF-7 breast cancer cells and reduced cell viability to 68.2 ± 13.1% compared to the control drug at the concentration of 50 µg/mL, while it was not active against seven test bacteria.

Conclusions

The anti-complementary activity of the isolated steroids suggests S. compressa for future anti-inflammatory research.

Isolation and In Silico Prediction of Potential Drug-like Compounds with a New Dimeric Prenylated Quinolone Alkaloid from Zanthoxylum rhetsa (Roxb.) Root Extracts Targeted against SARS-CoV-2 (Mpro)

A new dimeric prenylated quinolone alkaloid, named 2,11-didemethoxy-vepridimerine A, was isolated from the root bark of Zanthoxylum rhetsa, together with twelve known compounds. The structure of the new compound was elucidated on the basis of spectroscopic investigations (NMR and Mass). The interaction of the isolated compounds with the main protease of SARS-CoV-2 (Mpro) was evaluated using molecular docking followed by MD simulations. The result suggests that 2,11-didemethoxy-vepridimerine A, the new compound, has the highest negative binding affinity against the Mpro with a free energy of binding of -8.5 Kcal/mol, indicating interaction with the Mpro. This interaction was further validated by 100 ns MD simulation. This implies that the isolated new compound, which can be employed as a lead compound for an Mpro-targeting drug discovery program, may be able to block the action of Mpro.

Asymmetric Synthesis of Methoxylated Ether Lipids: Total Synthesis of n-3 Polyunsaturated Docosahexaenoic Acid-Like Methoxylated Ether Lipid

The first total synthesis of a docosahexaenoic acid (DHA)-like methoxylated ether lipid (MEL) is reported. This compound constitutes an all-cis methylene skipped hexaene framework identical to that present in DHA, the well-known omega-3 polyunsaturated fatty acid. The polyene C22 hydrocarbon chain, bearing a methoxyl group in the 2-position and R-configuration at the resulting chiral center, is attached by an ether linkage to the pro-S hydroxymethyl group (sn-1 position) of a glycerol backbone. The asymmetric synthesis is highly convergent and based on the polyacetylene approach involving iterative copper-promoted coupling reactions of propargyl bromides with terminal alkynes and semihydrogenation of the resulting hexayne. Starting from enantiopure R-solketal and racemic epichlorohydrin, the targeted MEL was accomplished in an 8.2% yield over eight steps (longest linear sequence) involving an enantio- and diastereopure glyceryl glycidyl ether key C6-building blocks from which the polyynes were constructed.