2D Nuclear Magnetic Resonance Research Articles

Chemical Constituents of the Deep-sea Gammarid Shrimp-Derived Fungus Penicillium citrinum XIA-16.

One new alkaloid, (S)-2-acetamido-4-(2-(methylamino)phenyl)-4-oxobutanoic acid (1), was isolated from the deep-sea-derived Penicillium citrinum XIA-16, together with 25 known compounds including ten polyketones (2-11), eight alkaloids (12-19), six steroids (20-25), and a fatty acid (26). Their planar and relative structures were determined by an analysis of 1D and 2D nuclear magnetic resonance (NMR) as well as high resolution electrospray ionization mass spectroscopy (HR-ESI-MS) data. The absolute configuration of 1 was determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Penicitrinol B (6) significantly inhibited RSL3-induced ferroptosis (EC50 =2.0 μM) by reducing lipid peroxidation and heme oxygenase 1 (HMOX1) expression. Under the concentration of 10 μM, penicitrinol A (7) was able to inhibit cuproptosis with the cell viabilities of 68.2 % compared to the negative control (copper and elesclomol) with the cell viabilities of 14.8 %.

Butyl succinate-mediated control of Bacillus velezensis ce 100 for apple anthracnose caused by Colletotrichum gloeosporioides.

Microbial biocontrol agents have become an effective option to mitigate the harmfulness of chemical pesticides in recent years. This study demonstrates the control efficacy of Bacillus velezensis CE 100 on the anthracnose causal agent, Colletotrichum gloeosporioides. In vitro antifungal assays revealed that the culture filtrate and volatile organic compounds of B. velezensis CE 100 strongly restricted the mycelial development of C. gloeosporioides. Moreover, a bioactive compound, butyl succinate, was isolated from the n-butanol crude extract of B. velezensis CE 100 (bce), and identified by liquid chromatography-electrospray ionization hybrid ion-trap and time-of-flight mass spectrometry (LC-ESI-QTOF-MS) and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR). Treatment with purified butyl succinate at a concentration of 300μg mL-1 strongly controlled conidial germination of C. gloeosporioides with an inhibition rate of 98.66%, whereas butyl succinate at a concentration of 400μg mL-1 showed weak antifungal action on the mycelial growth of C. gloeosporioides with an inhibition rate of 31.25%. Scanning electron microscopy revealed that the morphologies of butyl succinate-treated hyphae and conidia of C. gloeosporioides were severely deformed with shriveled and wrinkled surfaces. Furthermore, butyl succinate was able to control carbendazim-resistant C. gloeosporioides, demonstrating that it could be a promising agent for the suppression of other carbendazim-resistant fungal pathogens. An in vivo biocontrol assay demonstrated that the strain ce 100 broth culture and butyl succinate showed higher control efficacy on apple anthracnose than bce. Our findings provide insight into the antifungal potential of B. velezensis ce 100 and its butyl succinate for efficient control of phytopathogenic fungi, such as C. gloeosporiodes, in plant disease protection. This is the first study to demonstrate the antifungal potential of bacteria-derived butyl succinate for control of C. gloeosporioides.

Anti-Wrinkling Effect of 3,4,5-tri-O-caffeoylquinic Acid from the Roots of Nymphoides peltata through MAPK/AP-1, NF-κB, and Nrf2 Signaling in UVB-Irradiated HaCaT Cells.

Nymphoides peltata has been widely used pharmacologically in traditional Chinese medicine to treat heat strangury and polyuria. The aim of this study was to isolate the bioactive components from N. peltata and evaluate their potential use as antioxidant and anti-wrinkle agents. Phytochemical investigation of the methanolic extract of N. peltata roots led to the isolation of 15 compounds (1-15), which were structurally determined as α-spinasterol (1), 3-O-β-D-glucopyranosyl-oleanolic acid 28-O-β-D-glucuronopyranoside (2), 4-hydroxybenzoic acid (3), protocatechuic acid (4), vanillic acid (5), p-coumaric acid (6), caffeic acid (7), ferulic acid (8), neochlorogenic acid (neo-CQA) (9), chlorogenic acid (CQA) (10), cryptochlorogenic acid (crypto-CQA) (11), isochlorogenic acid B (3,4-DCQA) (12), isochlorogenic acid A (3,5-DCQA) (13), isochlorogenic acid C (4,5-DCQA) (14), and 3,4,5-tri-O-caffeoylquinic acid (TCQA) (15). Of these 15 compounds, compound 2 was a new oleanane saponin, the chemical structure of which was characterized by 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data and high-resolution electrospray ionization mass spectrometry (HRESIMS), as well as chemical reaction. Biological evaluation of the isolated compounds revealed that 3,4,5-tri-O-caffeoylquinic acid (TCQA) significantly improved Nrf2 levels in an Nrf2-ARE reporter HaCaT cell screening assay. TCQA was found to potently inhibit the Nrf2/HO-1 pathway and to possess strong anti-wrinkle activity by modulating the MAPK/NF-κB/AP-1 signaling pathway and thus inhibiting MMP-1 synthesis in HaCaT cells exposed to UVB. Our results suggest that TCQA isolated from N. peltata might be useful for developing effective antioxidant and anti-wrinkle agents.

New Cytotoxic Monoalkyl Glycerol Ether from the Red Sea Soft Coral Nephthea mollis.

A new monoalkyl glycerol ether, 3-(n-henicosyloxy)propane-1,2-diol (1), was isolated from the CH2 Cl2 /MeOH crude extract of the Red Sea soft coral Nephthea mollis. Additionally, three known related analogs were identified: chimyl alcohol (2), batyl alcohol (3), and 3-(icosyloxy)propane-1,2-diol (4). The chemical structure of 3-(n-henicosyloxy)propane-1,2-diol was determined using advanced spectroscopic analyses, including 1D, 2D Nuclear Magnetic Resonance (NMR), Electron Ionization mass spectra (EI-MS), and High-Resolution Electron Spray Ionization mass spectra (HR-ESI-MS) analyses. Furthermore, the identification of chimyl alcohol, batyl alcohol and 3-(icosyloxy)propane-1,2-diol was achieved by studying their EI mass fragmentation analyses and comparing their mass data with those previously reported in the literature. The cytotoxic activity of the Nephthea mollis crude extract and 3-(n-henicosyloxy)propane-1,2-diol was evaluated against five human cancer cell lines: HepG2 (hepatocellular carcinoma), MCF-7 (breast carcinoma), NCI-1299 (lung carcinoma), HeLa (cervical cancer cell), and HT-29 (colon adenocarcinoma). Moreover, 3-(n-henicosyloxy)propane-1,2-diol revealed moderate cytotoxicity against the HeLa cell lines with an IC50 value of 24.1 μM, while showing inactivity against the remaining cell lines (IC50 >100 μM).

Impact of Extraction Method on the Structure of Lignin from Ball-Milled Hardwood.

Understanding the structure of hardwoods can permit better valorization of lignin by enabling the optimization of green, high-yield extraction protocols that preserve the structure of wood biopolymers. To that end, a mild protocol was applied for the extraction of lignin from ball-milled birch. This made it possible to understand the differences in the extractability of lignin in each extraction step. The fractions were extensively characterized using 1D and 2D nuclear magnetic resonance spectroscopy, size exclusion chromatography, and pyrolysis-gas chromatography-mass spectrometry. This comprehensive characterization highlighted that lignin populations extracted by warm water, alkali, and ionic liquid/ethanol diverged in structural features including subunit composition, interunit linkage content, and the abundance of oxidized moieties. Moreover, ether- and ester-type lignin-carbohydrate complexes were identified in the different extracts. Irrespective of whether natively present in the wood or artificially formed during extraction, these complexes play an important role in the extractability of lignin from ball-milled hardwood. Our results contribute to the further improvement of lignin extraction strategies, for both understanding lignin as present in the lignocellulosic matrix and for dedicated lignin valorization efforts.

Structure elucidation and gene cluster of the O-antigen of Shewanella xiamenensis strain DCB-2-1 containing an amide of d-glucuronic acid with d-alanine and its bonding with U, Cr and V

The aim of this work was to examine the structure and gene cluster of O-OPS of S. xiamenensis strain DCB-2-1 and survey its conceivability for chelating uranyl, chromate and vanadate ions from solution. O-polysaccharide (OPS, O-antigen) was isolated from the lipopolysaccharide of Shewanella xiamenensis DCB-2-1 and studied by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and sugar analysis. The following structure of the brunched pentasaccharide was established: [Display omitted] where d-β-GlcpA(d-Ala) is d-glucuronic acid acylated with NH group of d-Ala. The OPS structure established is unique among known bacterial polysaccharide structures. Interestingly, that dN-(d-glucuronoyl)-d-alanine derivative is not found in bacterial polysaccharides early.The O-antigen gene cluster of Shewanella xiamenensis strain DCB-2-1 has been sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the OPS structure. Based on the analysis of the IR spectra of the isolated polysaccharide DCB-2-1 and the products of its interaction with UO2(NO3)2 ∗ 6H2O, NH4VO3 and K2Cr2O7, a method of binding them can be proposed. Laboratory experiments show that the use of polysaccharide can be effective in removing uranyl, chromate and vanadate from solution.

Type I Lipoteichoic Acid (LTA) Purification by Hydrophobic Interaction Chromatography and Structural Analysis by 2D Nuclear Magnetic Resonance (NMR) Spectroscopy.

Type I lipoteichoic acid (LTA) is a glycerolphosphate polymer found in the cell envelope of diverse Gram-positive bacteria. The glycerolphosphate backbone is often further decorated with D-alanine and/or sugar residues. Here, we provide details of a 1-butanol extraction and purification method of type I LTA by hydrophobic interaction chromatography. The protocol has been adapted from methods originally described by Fischer et al. (Eur J Biochem 133:523-530, 1983) and further optimized by Morath et al. (J Exp Med 193:393-397, 2001). We also present information on a 2D nuclear magnetic resonance (NMR) analysis method to gain chemical and structural information of the purified LTA material.

Anti-quorum Sensing and Anti-biofilm Effect of Nocardiopsis synnemataformans RMN 4 (MN061002) Compound 2,6-Di-tert-butyl, 1,4-Benzoquinone Against Biofilm-Producing Bacteria.

In this study, the anti-biofilm compound of 2,6-Di-tert-butyl, 1,4-benzoquinone was purified from Nocardiopsis synnemataformans (N. synnemataformans) RMN 4 (MN061002). To confirm the compound, various spectroscopy analyses were done including ultraviolet (UV) spectrometer, Fourier transform infrared spectroscopy (FTIR), analytical high-performance liquid chromatography (HPLC), preparative HPLC, gas chromatography-mass spectroscopy (GC-MS), liquid chromatography-mass spectroscopy (LC-MS), and 2D nuclear magnetic resonance (NMR). Furthermore, the purified compound was shown 94% inhibition against biofilm-producing Proteus mirabilis (P. mirabilis) (MN396686) at 70µg/mL concentrations. Furthermore, the metabolic activity, exopolysaccharide damage, and hydrophobicity degradation results of identified compound exhibited excellent inhibition at 100µg/mL concentration. Furthermore, the confocal laser scanning electron microscope (CLSM) and scanning electron microscope (SEM) results were shown with intracellular damages and architectural changes in bacteria. Consecutively, the in vivo toxicity effect of the compound against Artemia franciscana (A. franciscana) was shown to have a low mortality rate at 100µg/mL. Finally, the molecular docking interaction between the quorum sensing (QS) genes and identified compound clearly suggested that the identified compound 2,6-Di-tert-butyl, 1,4-benzoquinone has anti-quorum sensing and anti-biofilm activities against P. mirabilis (MN396686).

Isolation and Structural Characterization of a major degradation product of Ambrisentan using Q-TOF-MS, NMR and FTIR

Ambrisentan, an endothelin receptor antagonist, is subjected to forced degradation under neutral hydrolytic conditions, leading to a potential unknown impurity. This neutral degradation product (DP) has been detected using reverse-phase ultra-performance liquid chromatography (UPLC), where it has eluted at 1.24 relative retention time to the Ambrisentan peak. DP was isolated using semi-preparative HPLC from the degradation mixture. Later, the structure of DP was elucidated using high-resolution mass spectrometry, 2D Nuclear magnetic resonance spectroscopy (NMR), and Fourier transformed infrared spectroscopy (FTIR) spectroscopic techniques and characterized as 2-(2,2- diphenylvinyloxy)-4,6-dimethylpyrimidine.

Chemical Analysis of an Isotopically Labeled Molecule Using Two-Dimensional NMR Spectroscopy at 34 μT.

Low-field nuclear magnetic resonance (NMR) spectroscopy, conducted at or below a few millitesla, provides only limited spectral information due to its inability to resolve chemical shifts. Thus, chemical analysis based on this technique remains challenging. One potential solution to overcome this limitation is the use of isotopically labeled molecules. However, such compounds, particularly their use in two-dimensional (2D) NMR techniques, have rarely been studied. This study presents the results of both experimental and simulated correlation spectroscopy (COSY) on 1-13C-ethanol at 34.38 μT. The strong heteronuclear coupling in this molecule breaks the magnetic equivalence, causing all J-couplings, including homonuclear coupling, to split the 1H spectrum. The obtained COSY spectrum clearly shows the spectral details. Furthermore, we observed that homonuclear coupling between 1H spins generated cross-peaks only when the associated 1H spins were coupled to identical 13C spin states. Our findings demonstrate that a low-field 2D spectrum, even with a moderate spectral line width, can reveal the J-coupling networks of isotopically labeled molecules.

Anti-inflammatory activity via NO production inhibition of compounds from Vietnamese Lycopodium casuarinoides Spring

In our investigation of the methanol extract derived from the aerial parts of Vietnamese Lycopodium casuarinoides Spring, we successfully isolated two novel secondary metabolites: 3β,21α,24-trihydroxyserrat-14-en-29-yl-E-4′-hydroxy-3′-methoxycinnamate (1) and lycocasuarinol A (2), and eight known compounds, namely α-onocerin (3), salcolin A (4), salcolin B (5), (2 R,3 R)-dihydrokaempferol (6), apigenin (7), huperzinine (8), 4-methoxycinnamic acid (9), and (E)-p-coumaric acid (10). The structural elucidation of these compounds was accomplished through high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy techniques. All isolates were tested for their potential to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 cells. Notably, the flavonoids (2 R,3 R)-dihydrokaempferol (6) and apigenin (7) exhibited significant inhibitory activity against NO production, with IC50 values of 3.4 µM and 3.0 µM, respectively. These values surpassed the inhibition observed with the positive control, celastrol. Furthermore, a comparison of the guaiacyl glyceryls salcolin A (4) and salcolin B (5), differing in their threo-β- and erythro-guaiacyl glyceryl moieties, revealed potential structure-activity relationships. These findings suggest that the extract from Lycopodium casuarinoides and its phytochemical constituents hold promise as potential anti-inflammatory agents

Bidesmosidic and monodesmosidic triterpenoid saponins from the grain of Amaranthus hypochondriacus

Five known bidesmosidic triterpenoid saponins (1–5) and their hydrolysates, namely two new monodesmosidic triterpenoid saponins (1′ and 2′) and three known saponins (3′–5′), were isolated from Amaranthus hypochondriacus seeds. The structures of the new compounds were determined using interpreting 1D and 2D nuclear magnetic resonance (NMR) data and high-resolution electrospray ionisation mass spectrometry (HRESI-MS) analyses as 3-O-β-D-glucuronopyranosyl-30-normedicagenic acid (1′) and 3-O-[α-L-rhamnopyranosyl (1 → 3)-β-D-glucuronopyranosyl] bayogenin (2′). For the first time, 5 and 5′ were isolated from Medicago plants as the first examples of glycosides in medicagenic acid from Amaranthus plants. While bidesmosidic saponins showed no cytotoxicity, monodesmosidic saponins, except for 1′, showed moderate cytotoxicity against human cervix adenocarcinoma (HeLa) cells. In addition, monodesmosidic saponins showed anti-fungal activity against the rice blast fungus (Pyricularia oryzae).

Labile Metabolite Profiling in Human Blood Using Phosphorus NMR Spectroscopy.

Phosphorus metabolites occupy a unique place in cellular function as critical intermediates and products of cellular metabolism. Human blood is the most widely used biospecimen in the clinic and in the metabolomics field, and hence an ability to profile phosphorus metabolites in blood, quantitatively, would benefit a wide variety of investigations of cellular functions in health and diseases. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy are the two premier analytical platforms used in the metabolomics field. However, detection and quantitation of phosphorus metabolites by MS can be challenging due to their lability, high polarity, structural isomerism, and interaction with chromatographic columns. The conventionally used 1H NMR, on the other hand, suffers from poor resolution of these compounds. As a remedy, 31P NMR promises an important alternative to both MS and 1H NMR. However, numerous challenges including the instability of phosphorus metabolites, their chemical shift sensitivity to solvent composition, pH, salt, and temperature, and the lack of identified metabolites have so far restricted the scope of 31P NMR. In the current study, we describe a method to analyze nearly 25 phosphorus metabolites in blood using a simple one-dimensional (1D) NMR spectrum. Establishment of the identity of unknown metabolites involved a combination of (a) comprehensively analyzing an array of 1D and two-dimensional (2D) 1H/31P homonuclear and heteronuclear NMR spectra of blood; (b) mapping the central carbon metabolic pathway; (c) developing and using 1H and 31P spectral and chemical shift databases; and finally (d) confirming the putative metabolite peaks with spiking using authentic compounds. The resulting simple 1D 31P NMR-based method offers an ability to visualize and quantify the levels of intermediates and products of multiple metabolic pathways, including central carbon metabolism, in one step. Overall, the findings represent a new dimension for blood metabolite analysis and are anticipated to greatly impact the blood metabolomics field.

Polyporenic Acids from the Mushroom Buglossoporus quercinus Possess Chemosensitizing and Efflux Pump Inhibitory Activities on Colo 320 Adenocarcinoma Cells.

Polyporenic acids N-R (1-5), five novel 24-methylene lanostane triterpenes along with seven known polyporenic acids (6-12), were identified from the fruiting bodies of Buglossoporus quercinus. The isolation of compounds 1-12 was performed by a combination of multistep flash chromatography and reversed-phase high-performance liquid chromatography (HPLC). The structure determination was carried out by extensive spectroscopic analysis, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) experiments. The isolated fungal metabolites were investigated for their antiproliferative activity in vitro by 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on the resistant Colo 320 human colon adenocarcinoma cell line expressing P-glycoprotein (ABCB1). The lanostane triterpenes exerted moderate antiproliferative activity with IC50 values in the range of 20.7-106.2 μM. A P-glycoprotein efflux pump modulatory test on resistant Colo 320 cells highlighted that fungal metabolites 3, 5, 8, and 10-12 have the ability to inhibit the efflux pump activity of cancer cells. Moreover, the drug interactions of triterpenes with doxorubicin were studied by the checkerboard method. Compounds 3-4, and 7-12 interacted in a synergistic manner, while an outstanding potency was detected for compound 9, which was defined as strong synergism (CI = 0.276). The current study reveals that B. quercinus is a remarkable source of fungal steroids with considerable chemosensitizing activity on cancer cells.

Experimental Study on Spontaneous Imbibition of Coal Samples of Different Ranks Based on the NMR Relaxation Spectrum.

The comprehension of the mechanisms governing spontaneous water imbibition in gas-water systems plays a significant role in the operation of hydraulic fracturing and the development of coalbed methane (CBM). In this study, nuclear magnetic resonance (NMR) techniques were used to investigate the pore structure and fluid behavior of different rank coal samples during spontaneous imbibition. Analyses were conducted on the 1D NMR T2 spectrum, 2D NMR T1-T2 spectrum, and layer division T2 spectra to achieve accurate and detailed information about the internal pore structure of coal and the characteristics of fluid transport during spontaneous imbibition. Low-rank coal exhibits good pore connectivity and favorable pore sorting characteristics, indicating favorable reservoir conditions. High-rank coal has larger pore spaces and highly developed micropores, which are highly beneficial for gas adsorption. However, its poor pore sorting characteristics and connectivity limit the migration and diffusion of fluids within the reservoir. The imbibition capacity follows a specific order of contribution, with small pores (10-50 nm) having the most significant role, followed by micropores (2-10 nm), ultramicropores (r < 2 nm), mesopores (50-1000 nm), macropores (1000-10,000 nm), and microfractures (r ≥ 10,000 nm). Low-rank coal stands out due to the restricted development of ultramicropores and small pores, leading to a different contribution of imbibition capacity compared to other samples, where macropores and microfractures dominate over all pore types. The coal reservoirs with favorable pore sorting characteristics and pore connectivity tend to exhibit a tendency toward rapid saturation and attainment of a prompt stable state during the hydraulic fracturing process. Finally, the mechanism of the late retreat effect of imbibition and the laws governing different coal ranks, pore structures, and fluid transport were discussed. This study offers comprehensive analyses of the mechanism of coal spontaneous imbibition and the characteristic laws of fluid seepage, providing insights into the optimization of CBM recovery and reservoir management.

Unusual formation of Ir(III) complexes with non‐symmetrical NacNac ligands: Synthesis, characterization, and evaluation of catalytic activity in transfer hydrogenation reduction reactions

A new type of trans‐dichloro‐Ir(III) complexes derived from non‐symmetrical NacNac‐type ligands was unexpectedly obtained as the main reaction product from the former ligands and the dimeric species [Ir(COD)Cl2]. One equivalent of LH was reacted with an excess of [Ir(COD)Cl]2 in dichloromethane or toluene as solvent and at room temperature. The general formula of the product is [IrCl2(COD)L] and was isolated as a sole product instead of the expected Ir(I) compound [Ir(COD)L]; all the new Ir(III) were prepared in high yields as microcrystalline solids. They were all stable under laboratory atmosphere, lasting for weeks in solution and for months in solid state. The structure of each compound was examined by 1D and 2D nuclear magnetic resonance (NMR) and high‐resolution mass spectrometry (HRMS). Complex 1k was selected for an X‐ray diffraction study. Finally, an evaluation was made of the catalytic activity of all complexes in the transfer hydrogenation reaction of ketones and imines.

Conundrum of dehydroascorbic acid and homocysteine thiolactone reaction products: Structural characterization and effect on peptide and protein N-homocysteinylation.

An excessive blood level of homocysteine (HcySH) is associated with numerous cardiovascular and neurodegenerative disease conditions. It has been suggested that direct S-homocysteinylation, of proteins by HcySH, or N-homosteinylation by homocysteine thiolactone (HTL) could play a causative role in these maladies. In contrast, ascorbic acid (AA) plays a significant role in oxidative stress prevention. AA is oxidized to dehydroascorbic acid (DHA) and if not rapidly reduced back to AA may degrade to reactive carbonyl products. In the present work, DHA is shown to react with HTL to produce a spiro bicyclic ring containing a six-membered thiazinane-carboxylic acid moiety. This reaction product is likely formed by initial imine condensation and subsequent hemiaminal product followed by HTL ring opening and intramolecular nucleophilic attack of the resulting thiol anion to form the spiro product. The reaction product was determined to have an accurate mass of 291.0414 and a molecular composition C10H13NO7S containing five double bond equivalents. We structurally characterized the reaction product using a combination of accurate mass tandem mass spectrometry, 1D and 2D-nuclear magnetic resonance. We also demonstrated that formation of the reaction product prevented peptide and protein N-homocysteinylation by HTL using a model peptide and α-lactalbumin. Furthermore, the reaction product is formed in Jurkat cells when exposed to HTL and DHA.

Sarcodonol A–D from fruiting bodies of Sarcodon imbricatus inhibits HCoV-OC43 induced apoptosis in MRC-5 cells

Four new 26-carboxylated ergostane-type sterols (Sarcodonol A–D) were isolated from 70% ethanol extracts of dried fruiting bodies of Sarcodon imbricatus. Their chemical structures were elucidated using 1D- and 2D-nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry, and confirmed by comparison with previously reported data. As far as we know, this is the first instance of isolating a 26-carboxylated ergostane-type sterol from nature. The determined antiviral efficacy of sarcodonol A–D (1–4) against HCoV-OC43 in MRC-5 cells confirmed that sarcodonol D (4) had significant antiviral activity. Notably, sarcodonol D (4) potently blocked virus infection at low-micromolar concentration and showed high SI (IC50 = 2.26 μM; CC50 > 100 μM; SI > 44.2). In addition, this research shows that the antiviral effect of sarcodonol D (4) via reduced apoptosis increased by viral infection is through mitochondrial stress regulation. This suggests that sarcodonol D (4) is a potential candidate for use as an antiviral treatment.

Chemical Constituents of Macaranga grandifolia

The chemical analysis of dichloromethane (DCM) extract of Macaranga grandifolia (Blanco) Merr. resulted in the isolation and identification of several compounds. From the leaves, vedelianin (1), squalene (2), β-carotene (3) and polyprenol (4) were isolated. The barks contained a mixture of stigmasterol (5a) and β-sitosterol (5b). Additionally, the fruits yielded saturated fatty acid (6). The elucidation of structure 1 was accomplished through the utilization of comprehensive 1D and 2D NMR spectroscopic techniques. The identification of the structures of compounds 2-6 was achieved through a comparative analysis of their nuclear magnetic resonance (NMR) data with the literature data.

DIBENZOCYCLOOCTADIENE LIGNANS ISOLATED FROM THE ROOTS OF SCHISANDRA CAULIFLORA AND THEIR NITRIC OXIDE INHIBITION ACTIVITY ON LPS STIMULATED RAW 264.7 CELLS

Objectives: To isolate and determine the chemical structure of some compounds from the roots of Schisandra Cauliflora and their inhibitory activity on nitric oxide production. Methods: The roots of Schisandra cauliflora, which were collected in Vinh Phuc in April 2022, were processed before being extracted and isolated to obtain compounds. Compounds structures were elucidated based on extensive spectroscopic analyses, including 1D- and 2D-nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (HR-ESI-MS), and CD spectra. The obtained compounds were evaluated for inhibitory activity on nitric oxide production on LPS stimulated RAW 264.7 cells. Results and conclusion: From the methanol extract of the roots of Schisandra cauliflora, three dibenzocyclooctadiene lignans were isolated, including ananonin J, ananolignan F, and ananolignan C. Their structures were elucidated. All the compounds inhibited nitric oxide productions on LPS stimulated RAW 264.7 cells with IC50 values of 45.24 ± 1.46, 41.32 ± 1.45, and 48.71 ± 1.34µM, respectively, compared to that of the positive control of dexamethasone (IC50 14.20 ± 0.54µM). This is the first time these lignan compounds have been isolated from the roots of Schisandra cauliflora.