2D Nuclear Magnetic Resonance Research Articles

Bioassay-guided isolation and in Silico characterization of cytotoxic compounds from Hemimycale sp. Sponge targeting A549 lung cancer cells

Bioassay-guided fractionation approach led to identification of two novel compounds; (4-(hydroxymethyl)-3-methoxy-1H-pyrazol (1) and mycalene (2), alongside with four known metabolites; octadecane (3), hexatriacontane (4), 1-heneicosanol (5) and heptatriacontanoic acid (6) from the Red Sea marine sponge Hemimycale sp. The ethyl acetate fraction showed a noticeable cytotoxic activity against the lung cancer cell line (A549) with IC50 value of 75.54 µg/ mL. Structural elucidation was achieved using a combination of 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS). To elucidate the potential mechanism of action behind the cytotoxic effects against lung cancer, a multi-faceted approach combining in silico network pharmacology, experimental validation, and molecular docking studies were employed. Both compounds, designated as 1 and 2, demonstrated significant binding affinities to predicted target proteins, with docking scores of -4.789 and − 4.421 kcal/mol, respectively. These results lay the groundwork for further investigation into the therapeutic potential of these novel compounds from Hemimycale sp. as promising candidates for lung cancer treatment.

NO inhibitory constituents from Glycosmis craibii var. glabra

Six novel compounds, comprising three quinolones (1a, 1b, and 2) and three flavanones (3–5), along with seven known analogs (6–13), were isolated from the 95% EtOH extract of the stems and leaves of Glycosmis craibii var. glabra. The structures of the new compounds were elucidated using HR-ESI-MS, UV, and 1D and 2D nuclear magnetic resonance (NMR) data analysis. The absolute configurations were determined through Mosher ester and electronic circular dichroism (ECD) spectral analysis. Compounds 2, 6, 9, and 10 demonstrated inhibition of nitric oxide (NO) production stimulated by lipopolysaccharide in BV-2 microglial cells, with IC50 values ranging from 13.5 to 20.1 μmol·L−1, comparable to the positive control, dexamethasone.

Synthesis, Characterization, Proteolytic Activity Inhibition, ADMET Prediction, and Molecular Docking Studies of Novel Indole Derivatives as Potential SARS-CoV-2 Protease Inhibitors

Both the main protease (Mpro) and papain protease (PLpro) are fundamental enzymes in SARS-CoV-2 life cycle. In this study, we have targeted these two enzymes using novel indole derivatives as antiviral agents. The synthesized compounds were thoroughly characterized by Fourier-transform infrared spectroscopy (FT-IR), UV-vis, 1H, 13C, and 2D nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HRMS), and melting point (m.p.). The optimized structure, reactivity, and stability of the synthesized compounds were calculated using Density Functional Theory (DFT) at the B3LYP/6-31G(d,p) level. Using in silico ADMET prediction along with molecular docking, we found that the synthesized compounds presented good docking scores and very low predicted inhibition constants (Pki) from low micromolar to nanomolar ranges. In particular, compounds 10 and 11 with respective Pki values of 1.68 μM and 387.71 nM for Mpro and 402.50 nM and 27.10 nM for PLpro. These two compounds are engaged in vast range of interactions with the active sites of both enzymes. Further in vitro investigations using fluorescence resonance energy transfer (FRET) assays demonstrated that compounds 10 and 11 inhibited Mpro proteolytic activity with approximate IC50 values of 20 µM and 10 µM, respectively. These findings suggest that these new indole derivatives could serve as promising candidates for the development of drugs against SARS-CoV-2 and potentially other future coronaviruses.

Bokeelamides: Lipopeptides from Bacteria Associated with Marine Egg Masses.

Moon snails (family: Naticidae) lay egg masses that are rich in bacterial species distinct from the surrounding environment. We hypothesized that this microbiome chemically defends the moon snail eggs from predation and pathogens. Herein, we report the discovery of bokeelamides, new lipopeptides from the egg mass-associated bacterium, Ectopseudomonas khazarica, which were discovered using mass spectrometry (MS)-based metabolomics. The structures of the bokeelamides were elucidated using two-dimensional (2D) nuclear magnetic resonance (NMR), tandem MS, Marfey's, and genomic analyses.

NMR coupled with multivariate data analysis for monitoring the degradation of a formulated therapeutic monoclonal antibody.

The function of a protein is directly coupled to its higher-order structure (HOS). Deviations in this critical quality attribute (CQA) may be linked to a decrease in the efficacy and/or safety of the final therapeutic product. High-resolution nuclear magnetic resonance (NMR) spectroscopy has been recently highlighted for protein HOS characterization, thanks to its ability to capture small changes at the molecular and structural levels (primary, secondary, tertiary and quaternary). The present study was carried out to demonstrate the ability of NMR (1D 1H and 2D 1H-13C experiments) coupled with multivariate data analysis (PCA and PLS regression) to monitor the degradation of a formulated mAb-like protein and for the simultaneous quantification of related CQAs, i.e., potency, purity and impurities (aggregates and fragments). The results indicate that this approach could be applied to mitigate product quality risks during development, manufacturing and stability studies of mAb therapeutics.

Chert outcrops differentiation by means of low-field NMR relaxometry

Siliceous rocks served as raw materials in the production of stone tools from the Middle Paleolithic onwards. Due to migration, the provenance of archaeological artefacts can differ from their natural outcrop location. The aim of this work was the application of 1D and 2D low-field nuclear magnetic resonance (LF-NMR) relaxometry to distinguish cherts by their original source. Herein, bedded cherts and accompanying nodular cherts coming from three different outcrops of Kraków-Częstochowa Upland were investigated. 1D and 2D (T1-T2) experiments of water-saturated and dry rock sample states delivered T1, T2 times and T1/T2 ratios of distinct hydrogen populations – parameters sensitive to pore size, surface properties, and hydrogen bonding length. In-depth analysis of NMR data showed substantial differences in the porosity, pore surface and pore structure properties of investigated chert samples tested in the three different saturation levels (100% water-saturated, dried and differential). Finally, principal component analysis (PCA) was performed to reduce the number of correlations obtained and highlight the most important NMR properties specific to the particular outcrop localization."Please check captured corresponding author email if correct.""The email is correct"

Mapping Natural Sugars Metabolism in Acute Myeloid Leukaemia Using 2D Nuclear Magnetic Resonance Spectroscopy.

Metabolism plays a central role in cancer progression. Rewiring glucose metabolism is essential for fulfilling the high energy and biosynthetic demands as well as for the development of drug resistance. Nevertheless, the role of other diet-abundant natural sugars is not fully understood. In this study, we performed a comprehensive 2D NMR spectroscopy tracer-based assay with a panel of 13C-labelled sugars (glucose, fructose, galactose, mannose and xylose). We assigned over 100 NMR signals from metabolites derived from each sugar and mapped them to metabolic pathways, uncovering two novel findings. First, we demonstrated that mannose has a semi-identical metabolic profile to that of glucose with similar label incorporation patterns. Second, next to the known role of fructose in driving one-carbon metabolism, we explained the equally important contribution of galactose to this pathway. Interestingly, we demonstrated that cells growing with either fructose or galactose became less sensitive to certain one-carbon metabolism inhibitors such as 5-Flurouracil and SHIN1. In summary, this study presents the differential metabolism of natural sugars, demonstrating that mannose has a comparable profile to that of glucose. Conversely, galactose and fructose contribute to a greater extent to one-carbon metabolism, which makes them important modulators for inhibitors targeting this pathway. To our knowledge, this is the first NMR study to comprehensively investigate the metabolism of key natural sugars in AML and cancer.

Isolation and Characterization of Stigmasterol from Psidium guajava Leaves: A Promising Bioactive Compound with Therapeutic Potential

This study aimed to isolate and characterize bioactive compounds from the leaves of Psidium guajava Linn. The hydroethanolic extract yielded 32% (80 g) from the crude material, which was subjected to column chromatography for fractionation. Structural elucidation of the isolated compound was performed using 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy, including COSY, HSQC, and HMBC experiments. The spectral data confirmed the presence of stigmasterol, characterized by its distinct chemical shifts and long-range correlations between carbon and proton atoms. Stigmasterol was isolated as a white, crystalline solid and identified by its unique physio-chemical properties, such as solubility in organic solvents, a melting point of 163-164°C, and molecular formula C29H48O. This compound is known for its significant biological activities, including antibacterial, antimalarial, anti-inflammatory, antioxidant, and anticancer effects. By employing advanced techniques like 1D and 2D NMR spectroscopy, the study provides precise structural elucidation of stigmasterol, contributing to natural product research and reinforcing the medicinal potential of guava leaves as a source of pharmacologically active compounds. This adds to the existing knowledge of the plant’s bioactive components and their applications in medicinal chemistry

Glucose hydrochar consists of linked phenol, furan, arene, alkyl, and ketone structures revealed by advanced solid-state nuclear magnetic resonance

The molecular structure of hydrochars produced from 13C-enriched glucose under various conditions has been elucidated based on advanced one- and two-dimensional (2D) 1H-13C and 13C–13C solid-state nuclear magnetic resonance (NMR) with spectral editing. Regardless of synthesis conditions, hydrochars consist mostly of oxygen-substituted arene rings (including diphenols) and furans connected by alkyl linkers rich in ketones. Cross-linking nonprotonated and methyne (C-H) alkyl carbons have been identified through spectrally edited 2D NMR. Alkenes and ‘quaternary’ C-O are observed only at low synthesis temperature, while some clusters of fused arene rings are generated at high temperature. Hydrochar composition is nearly independent of reaction time in the range from 1 to 5 h. Equilibration of 13C magnetization within 1 s shows that the materials are homogeneous on the 5-nm scale, refuting core–shell models of hydrochar microspheres. While furan C-O carbons bonded to alkyl groups or ketones show distinctive cross peaks in 2D NMR, phenolic C-OH is observed unambiguously by hydroxyl-proton selection. While methylene-linked furan rings are fairly common, the signal previously assigned to furan Cα-Cα linkages is shown to arise from abundant, stable catecholic ortho-diphenols, whose HO-C=C-OH structure is proved by 2D13C–13C NMR after hydroxyl-proton selection. Quantitative 13C NMR spectra of low- and high-temperature hydrochars have been matched by chemical-shift simulations for representative structural models. Mixed phenol and furan rings connected by ketones and alkyl linkers provide good fits of the experimental spectra, while literature models dominated by large clusters of fused rings and with few phenols or alkyl-linked ketones do not.

Experimental investigation on the oil occurrence and mobility of lacustrine shales in offshore area of China using 1D/2D nuclear magnetic resonance and centrifugal techniques

Shale oil occurrence mechanism and mobility have significant influences on hydrocarbons extraction from shale systems. However, the effects of petrophysical and petroleum geochemical properties on oil mobility are not understood. In this study, shales with different lithofacies were investigated using thin sections, scanning electron microscopy, nuclear magnetic resonance (NMR), and organic geochemical analysis. Shales at original, extracted, oil-saturated, and centrifugal states were systematically scanned using 1D and 2D NMR technologies. The multi-scaled pores were obtained by comparing the T2 spectra of samples at different states. The 2D NMR identification spectra for hydrocarbon-bearing components were established. The free oil, adsorbed oil, mobile oil contents were quantitatively evaluated and the geological controls on oil mobility were discussed.Results show that the siliceous shales have the highest total oil and movable oil contents, while the argillaceous shales have the lowest values due to the limited pore space and poor connectivity. Mobile oil mainly stores in interparticle pores, dissolution-related pores and bedding fractures. Its content increases with the increasing felsic minerals. Oil in siliceous shales are rich in low carbon-chain hydrocarbons and has high mobility. Based on oil distribution in multi-scaled pores, a strategy about the mobile oil distribution were proposed: Ultramicropores region is the immobile oil zone; Micropores region is the oil difficult-to-flow zone; Transition pores region is the oil easy-to-flow zone; Macropores region is the completely mobile oil zone. The mobile oil mainly accommodates in transition pores and macropores (pore size >20 nm and mobile oil saturation exceeds 60 %).

Cyclocarysaponins A–J, dammarane-type triterpenoid glycosides from the leaves of Cyclocarya paliurus

Ten previously undescribed dammarane-type triterpenoid glycosides, cyclocarysaponins A-J (1-10), were isolated from the leaves of Cyclocarya paliurus (Batal.) Iljinskaja. The structures of these compounds were characterized through detailed spectroscopic analysis, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). The cytotoxic activities of all isolates were assessed against five human cancer cell lines (Bel-7402, Caski, BGC-823, A2780, and HCT-116). Of the tested compounds, compounds 1, 7, and 9 exhibited selective cytotoxicity against one or more human cancer cell lines.

Oxidative stress-induced degradation of Brinzolamide: Isolation and in-depth characterization of unique hydroxylamine and oxime degradation products

Since the safety and efficacy of therapeutic products are strongly related to their stability and purity, impurities including the unavoidable degradation products may affect the pharmacological effect. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines Q3A requires the identification of process impurities and as well as degradation products in any drug substance to assess the inherent stability of the drug. The present work involves an ICH-guided degradation study for the Brinzolamide (BRZ), a topical ophthalmic drug which is generally used to lower the intraocular pressure (IOP) during glaucoma. Under oxidative stress at room temperature for 20 h, four degradation products (namely BRZ-Pk1, BRZ-PK2, BRZ-Pk3, and BRZ-Pk4) are isolated using advanced chromatographic techniques. Upon confirming the masses of the compounds using High-resolution mass spectrometry (HRMS), functional groups are identified with the help of Fourier-transform infrared spectroscopy (FT-IR). Extensive 1-dimensional (1D) and 2-dimensional (2D) Nuclear Magnetic Resonance spectroscopic (NMR) experiments especially 1D nOe, 1H-13C-HSQC and 1H-13C-HMBC unequivocally confirm the structures. Among the four compounds analyzed, three (BRZ-Pk1, BRZ-Pk2, and BRZ-Pk4) are novel, while BRZ-Pk3 was previously reported solely with mass spectrometric data. Nitrogen-based 2D NMR experiments are crucial for determining the oxidation state of hydroxylamine and oxime products within the molecules, and 1D nOe measurements help confirming E/Z isomerism (geometrical isomerism) for BRZ-Pk2 and BRZ-Pk4. All the proposed structures are justified with appropriate analytical data. The proposed mechanisms are expected to help in identifying the possible degradation pathways for similar pharmaceutical candidates.

Multi-site esterification: a tunable, reversible strategy to tailor therapeutic peptides for delivery.

Peptides are naturally potent and selective therapeutics with massive potential; however, low cell membrane permeability limits their clinical implementation, particularly for hydrophilic, anionic peptides with intracellular targets. To overcome this limitation, esterification of anionic carboxylic acids on therapeutic peptides can simultaneously increase hydrophobicity and net charge to facilitate cell internalization, whereafter installed esters can be cleaved hydrolytically to restore activity. To date, however, most esterified therapeutics contain either a single esterification site or multiple esters randomly incorporated on multiple sites. This investigation provides molecular engineering insight into how the number and position of esters installed onto the therapeutic peptide α carboxyl terminus 11 (αCT11, RPRPDDLEI) with 4 esterification sites affect hydrophobicity and the hydrolysis process that reverts the peptide to its original form. After installing methyl esters onto αCT11 using Fischer esterification, we isolated 5 distinct products and used 2D nuclear magnetic resonance spectroscopy, reverse-phase high performance liquid chromatography, and mass spectrometry to determine which residues were esterified in each and the resulting increase in hydrophobicity. We found esterifying the C-terminal isoleucine to impart the largest increase in hydrophobicity. Monitoring ester hydrolysis showed the C-terminal isoleucine ester to be the most hydrolytically stable, followed by the glutamic acid, whereas esters on aspartic acids hydrolyze rapidly. LC-MS revealed the formation of transient intramolecular aspartimides prior to hydrolysis to carboxylic acids. In vitro proof-of-concept experiments showed esterifying αCT11 to increase cell migration into a scratch, highlighting the potential of multi-site esterification as a tunable, reversible strategy to enable the delivery of therapeutic peptides.

In situ self-assembly of artesunate-β-cyclodextrin supramolecular nanomedicine as potential anti-cancer prodrug

Supramolecular nanomedicines have drawn great interest in cancer therapy, but their potential immunotoxicities restrict application in clinical translation. Herein, we constructed a supramolecular nanomedicine CD-Artesunate (CD-ATS) in situ by supramolecular polymerization and orthogonal self-assembly. The nanostructure was meticulously characterized using 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy, Mass spectrometry, Transmission Electron Microscopy (TEM), and particle size distribution analysis. β-cyclodextrin (β-CD) hosts are conjugated with artesunate (ATS) by click chemistry to improve the solubility and antitumor activity of ATS. Supramolecular nanomedicine was prepared through orthogonal self-assembly driven by host−guest complexation and hydrogen bonds. The results showed that the aqueous solubility of CD-ATS was 30 times better than that of free ATS. Furthermore, CD-ATS displayed a superior antitumor effect against HCT116 tumor cells compared to the first-line drug Taxol. This enhanced effect was attributed to the induction of excessive reactive oxygen species (ROS) generation, which subsequently triggered apoptosis.

Abietane diterpenoid salvipisone: Structure elucidation, conformational analysis, and antimicrobial activity

Salvipisone, an abietane diterpenoid, was isolated from the roots of Salvia aethiopis L. using a combination of chromatographic separation techniques. Its structure was elucidated employing a variety of spectroscopic methods, including ultraviolet (UV), infrared (IR), 1D and 2D nuclear magnetic resonance (NMR), and mass spectrometry. A comprehensive analysis of experimental 1D and 2D NMR data, incorporating 1H iterative full spin analysis and higher-order multiplet simulation, revealed discrepancies with previously reported NMR data for this compound. Detailed examination of the 1H NMR spectrum's spin-spin coupling structure provided insights into the relative populations of the three staggered conformers around the C12–C13 bond at room temperature. The conformer populations were determined using the relationship between the experimental values for vicinal coupling constants and the estimated ones for the preferred staggered conformers, yielding a ratio of approx. 80:4:16 for anti, gauche, and gauche′-conformers, respectively. Possible reasons for the observed unevenly populated staggered conformers were also discussed. The antimicrobial activity of salvipisone was evaluated using in vitro and in silico methods. In vitro antimicrobial assays demonstrated that salvipisone exhibited the highest inhibitory effect against Staphylococcus aureus ATCC and Enterococcus faecalis ATCC (MIC = 3.125 μg/mL), followed by Bacillus subtilis ATCC (MIC = 6.25 μg/mL). In contrast, concentrations above 100 μg/mL were necessary to inhibit Escherichia coli ATCC and Klebsiella pneumoniae ATCC. In silico studies suggested that salvipisone, particularly its keto form, has significant potential for inhibiting the enzyme gyrase, highlighting its mechanism of antimicrobial action. Our findings highlight the promising antimicrobial and inhibitory properties of salvipisone, particularly against Gram-positive bacteria such as S. aureus.

Intelligent Identification and Quantitative Evaluation Method of Fluid Components from T2-T1 2D NMR Logging

Summary T2-T1 2D nuclear magnetic resonance (NMR) logging plays an important role in fluid identification and reservoir evaluation. When the signal/noise ratio (SNR) is low, the response of the fluid component overlaps on the NMR 2D spectrum, and the fluid characteristic map obtained in the laboratory could not be directly applied to 2D NMR logging data. In this work, we proposed a T2-T1 2D NMR fluid identification and quantitative evaluation method based on blind source separation (BSS) and hierarchical clustering. This method fixes the number of fluid components of BSS as eight and utilizes a hierarchical clustering method to further process the 2D spectra obtained from BSS, so that each spectrum contains only one fluid component response. Subsequently, the fluid types are determined according to the response characteristics, and the fluid volumes are quantitatively calculated. Based on the synthetic data of T2-T1 2D NMR logging, this method was used to calculate the volumes of the fluid components, and the accuracy of the method was verified by comparing with the model and other four methods. This method was applied to 2D NMR logging data from Well Z and Well G and verified by oil test results. The results show that the relative error between the fluid volumes calculated by the proposed method and the model is smaller than other methods. The data processing results of Well Z and Well G are consistent with those of the oil test. Both synthetic data and actual logging data show that this method can provide the accurate fluid identification and quantitative evaluation results of T2-T1 2D NMR logging data.

An NMR study on the keto-enol tautomerism of 1,3-dicarbonyl drug precursors.

The effective implementation of drug precursor legislation has driven the innovation and design of new alternative substances. The application of 1,3-dicarbonyl precursors as alternative precursors for the synthesis of 1-phenyl-2-propanone (P2P) and 3,4-methylenedioxyphenyl-2-propanone (MDP2P) has created new challenges to legal control. Their 1,3-dicarbonyl structure allows the precursors to exist as an equilibrium mixture of the tautomeric diketo and keto-enolic forms during the nuclear magnetic resonance (NMR) analysis. In this study, the keto-enol tautomerism of four 1,3-dicarbonyl drug pre-precursors, α-phenylacetoacetamide (APAA), methyl α-phenylacetoacetate (MAPA), ethyl α-phenylacetoacetate (EAPA), and methyl 2-(benzo[d][1,3]dioxol-5-yl)-3-oxobutanoate (MAMDPA) were investigated through NMR. One-dimensional (1D) and 2D NMR were combined to assign signals for the diketo and keto-enolic tautomers. Results showed that the keto-enol tautomerism was solvent-dependent but was also influenced by the substituent present in the molecule. Further, the analysis results indicated that majority of substances existed mainly in the diketo form. The enol-keto equilibrium constant (Keq) was stable in dimethyl sulfoxide-d6 and chloroform-d, while unstable for some compounds in acetone-d6 and deuterated methanol. The presence of impurities in the seized sample may disrupt the equilibrium between keto-enol tautomers in 1,3-dicarbonyl precursors. After the optimization of several key quantitative parameters, a quantitative NMR method for the quantification of 1,3-dicarbonyl drug precursors were also developed to facilitate their quantitative analysis. This is the first study to investigate the keto-enol tautomerism and quantification of 1,3-dicarbonyl drug precursors by NMR, providing a new approach for structure analysis and quantification of new precursor analogues.

Arcopilins: A New Family of Staphylococcus aureus Biofilm Disruptors from the Soil Fungus Arcopilus navicularis.

Biofilms represent a key challenge in the treatment of microbial infections; for instance, Staphylococcus aureus causes chronic or fatal infections by forming biofilms on medical devices. Herein, the fungus Arcopilus navicularis was found to produce a novel family of PKS-NRPS metabolites that are able to disrupt preformed biofilms of S. aureus. Arcopilins A-F (1-6), tetramic acids, and arcopilin G (7), a 2-pyridone, were elucidated using HR-ESI-MS and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy. Their absolute configuration was established by the synthesis of MPTA-esters for 2, analysis of 1H-1H coupling constants, and ROESY correlations, along with comparison with the crystal structure of 7. Arcopilin A (1) not only effectively disrupts preformed biofilms of S. aureus but also potentiates the activity of gentamicin and vancomycin up to 115- and 31-fold times, respectively. Our findings demonstrate the potential application of arcopilins for the conjugated treatment of infections caused by S. aureus with antibiotics unable to disrupt preformed biofilms.

Complete 1H and 13C NMR assignment of cellulose oligomer in LiCl/DMSO

High-resolution solution-state 1H, 13C, and various 2D nuclear magnetic resonance (NMR) spectra of cellulose were obtained using cellulose oligomer dissolved in LiCl/dimethyl sulfoxide, which enabled the assignment of all 1H and 13C resonances. The observed resonances were classified into four groups of glucose rings, corresponding to internal residue, non-reducing end, and reducing ends with α- and β-anomeric configurations. This assignment included the OH protons, which are difficult to assign in cellulose using other solvent systems. NMR measurements and assignments were performed using different LiCl concentrations because information on the hydroxy protons is important for understanding the interaction between cellulose and the solvent. The resonances from the OH protons shifted downfield with increasing LiCl concentration, suggesting that LiCl was attracted to the hydroxy groups of cellulose in solution. Moreover, the magnitude of the shifts varied depending on the positions of the hydroxy groups, which indicated the regioselectivity of the interaction between LiCl and the cellulose hydroxy groups.Graphical abstract

Chemical Composition, Fatty Acids, Total Phenolics and Antioxidant Activity of the Desert Truffle Terfezia Boudieri Chatin in the Northern Region of Saudi Arabia

Terfezia boudieri Chatin (T. boudieri), which belongs to the Terfeziaceae family, is a desert truffle growing naturally from mycorrhizal relationships with plants that inhabit the slightly moist sandy soils of some desert or semi-desert regions. The chemical examination of the methanolic extract of T. boudieri led to the isolation of a new ketone and the known compound mannitol. The structures of the 2 isolated compounds were resolved using spectroscopic analysis including 1D and 2D Nuclear Magnetic Resonance (NMR), Infrared (IR) spectroscopy and were supported by literature data. The GC-MS analysis of the Fatty Acids (FAs) of T. boudieri oils showed high Unsaturated FA (UFA) profile (78.72%). The major FAs were linoleic acid (62.36%) and oleic acid (14.7%). Comparing the extracts obtained, the methanolic extract revealed the highest levels of Total Phenolic Content (TPC) of 185.56 mg GAE/100 g of truffle, thus the same extract showed the best results for antioxidant activity.