NMR Analysis Research Articles

Structural characterization, antioxidant and immunomodulatory activities of a polysaccharide from a traditional Chinese rice wine, Guangdong Hakka Huangjiu

Hakka Huangjiu, a traditional Chinese rice wine, boasts a rich history and is known for its immunomodulatory, antibacterial, anti-aging and anti-fatigue effects. However, there is limited research on the primary active components and molecular mechanism of the bioactivity of Hakka Huangjiu. To address this gap, this study assessed the structural characteristics, antioxidant, and immunomodulatory activities of the polysaccharide-1 of Guangdong Hakka Huangjiu (HP1). Structural analysis revealed that HP1 had a low molecular weight polysaccharide of 5550 Da, primarily consisting of glucose (93.2 %), with smaller amounts of xylose, mannuronic acid and galactose. Methylation and NMR analysis suggested that the main glycosidic linkages present in HP1 are α-D-Glcp-(1→, →4)-α-D-Glcp-(1 → and →6) -α-D-Glcp-(1→. Furthermore, HP1 exhibited dose-dependent DPPH·, ABTS+ and OH· scavenging activity. HP1 exhibited significant protection of HepG2 cells from H2O2 damage. Additionally, HP1 induced the release of NO, TNF-α, IL-6 and iNOS in RAW264.7 cells. HP1 treatment significantly increased mRNA expression of TNF-α, IL-6, iNOS, COX-2, IL-1β and TGF-β1. These results suggested that polysaccharides HP1 may have potential as a novel natural antioxidant and immunomodulatory product for use in nutraceuticals and functional foods.

New naphtho[2,1-b]furan-2,5-dione and isocoumarin derivatives from bambusicolous fungus Gelatinomyces siamensis

Two new compounds, 6-hydroxy-1-(4-hydroxyphenyl)naphtho[2,1-b]furan-2,5-dion (1) and 3-methyl-6-α-L-rhamnopyranosyl-2H-chromen-2-one (2), along with three known compounds (3-5) were isolated from the rare bambusicolous fungus Gelatinomyces siamensis. The structures were elucidated through the analysis of IR, NMR and HRESIMS spectrographic data. Compound 1 exhibited cytotoxicity against HeLa, HT29, MCF-7 and PC-3 cells, but was not toxic against normal Vero cells. The most abundant metabolite, oosporein (5), exhibited significant cytotoxic effects against all tested cancer cells.

Design, synthesis, and mechanism study of novel tetrahydroisoquinoline derivatives as antifungal agents.

In screening for natural-derived fungicides, a series of 32 novel tetrahydroisoquinoline derivatives were designed and synthesized based on tetrahydroisoquinoline alkaloids. Their structures were verified by 1H NMR, 13C NMR, HRMS, and single X-ray crystal diffraction analysis. Most of the target products exhibited medium to excellent antifungal activity against 6 phytopathogenic fungi in vitro at a concentration of 50mg/L. Interestingly, compounds A13 and A25 with EC50 values of 2.375 and 2.251mg/L against A. alternate were similar to boscalid (EC50 = 1.195mg/L). The in vivo experiments revealed that A13 presented 51.61 and 70.97% protection activities against A. alternate at the dosage of 50 and 100mg/L, respectively, which were equal to that of boscalid (64.52 and 77.42%). SDH enzyme assays and molecular docking studies indicated that compound A13 may act on SDH. In addition, the SEM analysis showed that compound A13 could strongly damage the mycelium morphology. These results revealed that A13 may be a promising lead compound for the development of natural-derived fungicides.

Lignans and phenols with potential anti-inflammatory effect from the stems of Mallotus paxii Pamp

Phytochemical investigation of the stems of Mallotus paxii Pamp. led to the isolation and identification of four new compounds, including three neolignans (1–3) and one phenol (13), along with eight known neolignans (4–12) and one known phenol (14). Their structures were determined by spectroscopic methods, including NMR, MS and ECD analyses. Bioassay demonstrated that malloapelin A (4) exhibited a most potent anti-inflammatory activity to NO release with IC50 value of 21.32 μM. Furthermore, malloapelin A (4) markedly decreased the secretion of TNF-α, iNOS, and NF-κB and inhibited the expression of COX-2 and NF-κB/p65 in LPS-induced RAW264.7 cells in a dose-dependent manner.

Assembling phthalaldehyde and o-aminochalcones by Pd(II) catalyzed tandem reaction for synthesizing isoindoloindonole fluorophores

One-pot synthesis of isoindoloindonoles having various auxochrome, from easily available starting materials phthalaldehyde and o-aminochalcone, involving palladium(II) acetate catalysis in acetic acid is reported. A mechanism based on the formation of 2-aryl-2H-isoindol-1-ol (22) intermediate is proposed for the formation of the tetracyclic core of isoindoloindonoles. The possible intramolecular cyclization via the direct participation of the carbonyl vs the adjacent αβ-conjugated double bond was evaluated. Thus, a detailed study on how the presence of electronically different groups at the β position of chalcones affects the outcome of the cyclization reaction and the photophysical properties of the resulting isoindoloindolones is presented here. Furthermore, the core structure was determined using NMR, mass and single-crystal X-ray diffraction analysis.

Water-in-oil emulsions as micro-reactors for achieving extremely rapid and high hydrogen uptakes into clathrate hydrates

As humanity transitions to a low-carbon future, hydrogen, with its high energy density and zero carbon emissions, is gaining prominence, and efficient hydrogen storage is thus a critical area of research. Storing hydrogen in a solid form by forming hydrates, ensuring straightforward formation and dissociation, environmental friendliness, and stability, is emerging as a new technology. In particular, the use of thermodynamic promoters such as tetrahydrofuran (THF) to form binary hydrogen hydrates enables hydrogen storage under much milder conditions compared to traditional compression and liquefaction processes. However, slow hydrate formation kinetics currently hinder commercialization, necessitating breakthroughs in this area. This study reports extremely rapid and high hydrogen uptake in binary hydrogen + THF hydrates by utilizing a water-in-oil emulsion. A hydrogen storage capacity of approximately 51.23 mmol H2/mol H2O and the hydrogen uptake rate of 91.71 mol min−1 m−3 water were achieved, significantly outperforming existing studies conducted at pressures below 15 MPa. This remarkable kinetics was achieved by controlling the distribution of THF within a ternary emulsion system composed of water, isooctane, and THF. Phase equilibrium measurements and a series of kinetic tests validated that using an excess of THF over stoichiometric amounts can lead to such high and rapid hydrogen uptake. Consequently, a hydrate formation mechanism in the emulsified system was suggested based on the results of a Raman analysis, water droplet size measurements, and 1H NMR analysis. These results will pave the way for further advances in practical hydrate-based hydrogen storage technology.

Fabrication of Uniform Melatonin Microparticles Potentially for Nasal Delivery: A Comparison of Spray Drying and Spray Freeze Drying.

Insomnia is a major health concern, and melatonin (MLT) is key for initiating sleep. Delivering MLT nasally can enhance brain bioavailability by targeting the olfactory region. This study aimed to fabricate MLT embedded microparticles for nasal delivery. MLT-cyclodextrin (CD) derivatives complex microparticles (MCCMPs) were fabricated by spray drying and spray freeze drying MLT and CD derivative solutions. Phase solubility and 1H-1H ROSEY NMR analysis assessed MLT-CD assembly. The effects of formulation compositions and process parameters on microparticle structural attributes were investigated. The in vitro nasal release and deposition performances were evaluated by a modified paddle-over-disk apparatus and 3D-printed nasal cavity cast, respectively. Sodium sulphobutylether-β-cyclodextrin (SBE-β-CD) exhibited the best complexation ability with MLT, with the indole structure of MLT included in its cavity. Spray dried MCCMPs showed dense structure with high density, while the spray freeze dried counterpart showed the brittle and porous structure with low density. Despite the porous structure may promote the release rate of spray freeze dried samples, the high hydrophilicity of the CD derivative overshadows this advantage. Samples prepared by spray drying not only exhibited rapid release rates but also could deposit more effectively in the olfactory region, as they avoid breakage due to their higher mechanical strength. The optimal sample showed ~ 86.70% of the MLT released at 20min and ~ 10.57% of the deposition fraction in the olfactory region. This work compares MCCMPs fabricated by spray drying and spray freeze drying, providing the optimal formulation and process combinations.

Chemical Profiling, Enzyme Inhibitory Activity and Antioxidant Capacity of South African Herbal Teas: Buddleja saligna, Lippia javanica, L. scaberrima and Phyla dulcis.

Herbal teas are used in South Africa as digestives to lower glycaemia and for other indications. However, the chemical composition of the infusions and their effect on enzymes related to metabolic syndrome is poorly known. The composition of infusions and methanol extracts of B. saligna (Scrophulariaceae), Lippia javanica, L. scaberrima, and Phyla dulcis (Verbenaceae) was assessed and the effect of the infusions and extract was determined towards α-glucosidase, α-amylase, and pancreatic lipase. The commercial herbal products were extracted separately with MeOH or hot water to obtain the extract/infusion for comparative studies. Total phenolic, total flavonoid and antioxidant capacity were assessed. The fingerprints of the MeOH extracts and infusions were compared by HPLD-DAD. The extract constituents were tentatively identified by HPLC-MS/MS and NMR analyses. From the extracts/infusions, 57 compounds were identified, including iridoids, phenylpropanoid glycosides, flavonoids, and caffeic acid derivatives, among others. The MeOH extracts and infusions showed strong inhibition towards α-glucosidase with IC50 in the range of 0.13-0.84 µg/mL for the phenolic-enriched infusion extract (PEI) and 0.47-0.50 µg/mL for the MeOH extracts, respectively. The P. dulcis PEI showed higher inhibition towards α-glucosidase, and the MeOH extract of L. scaberrima was better than the PEI. At 100 µg/mL, the PEI from the four herbal teas reduces the activity of α-amylase by 23.03-28.61%, with L. javanica as the most active tea. Three of the species are high in phenylpropanoid glycosides, while P. dulcis contains rosmarinic acid. Some 26 compounds were identified in the infusion from B. saligna, 28 from L. scaberrima, and 21 from P. dulcis. Four of them are common in all the teas, namely decaffeoylverbascoside, verbascoside, isoverbascoside, and tuberonic acid hexoside. Ten compounds occur in two of the teas and seventeen, fifteen, and eleven compounds were detected only in B. saligna, L. scaberrima, and P. dulcis, respectively. Most of the compounds are reported for the first time from the crude drug infusions. The results give some support for the traditional use of herbal teas as digestives and/or indications for diabetes. The chemical fingerprints set the basis for quality control of the crude drugs, based on the main constituents and differential compounds occurring in the samples.

Experimental Spectroscopic and Computational Studies on A New Synthesized Sulfisoxazole Derivative; Molecular Docking, Drug-likeness, ADME, Toxicity Predictions and Carbonic Anhydrase II Activity Investigations

In this paper, 5-Dimethylamino-2-hydroxy-3-methoxy benzaldehyde sulfisoxazole (5DHMS) and Cu(5DHMS)2 compounds have been synthesized. The molecular structure characterizations were performed using experimental and computational methods. In the experimental part of the study, CHNS, FT-IR, NMR, TGA, and LC-MS analysis techniques were used. In the theoretical part, Density Functional Theory (DFT) was selected for the calculation level. Firstly, optimized structures were obtained from the predicted 3D structures. Vibrational modes were calculated using the optimized structures of the compounds. The vibrational modes of each compound were analyzed in detail using potential energy distribution (PED). Molecular electrostatic potential and HOMO-LUMO maps were drawn. Global chemical reactivity descriptors of compounds were determined. Moreover, the solvent media effects on chemical reactivity descriptors were revealed in detail. Protein-ligand interactions with the target receptor carbonic anhydrase II enzyme were performed. In addition, some important biological activity parameters such as drug-likeness, toxicity, and ADME predictions were examined in silico.

Valorizing Biopolyester Suberin: Modification of Cellulose Nanocrystals and Performance Assessment in 3D-Printed Biobased Acrylates.

Suberin, a common biomass processing waste, is a complex biopolymer and a promising source for the biorefinery of chemicals. Six different approaches for the extraction of birch outer bark suberin fatty acids (SFAs) were explored, and their application in grafting the surface of cellulose nanocrystals (CNCs) was investigated. Successful CNC functionalization was controlled with FTIR and NMR analyses. In-depth research allowed us to evaluate the interface of the nanocellulose and polymer matrix. Three structurally distinct SFA-grafted CNCs were integrated into a vegetable oil-based acrylate resin in an ultralow concentration of 0.1 wt %. Five biobased acrylic resin formulations were prepared: without reinforcement, with CNC, and with three distinct SFA-grafted CNCs. Vat photopolymerization (VP) 3D printing was utilized for sample preparation. The effects of grafted CNC components on 3D-printed samples' thermal stability, thermomechanical properties, and wettability were evaluated in detail. CNC functionalization enhanced the interface with the polymer matrix, yielding up to a 2-fold increase in elongation and up to a 2.5-fold increase in strength in tensile and flexural tests compared to the polymeric matrix. The CNC-SFA-modified filler demonstrated performance comparable to, or even better than, petroleum-based chemical modification routes found in the existing literature. This study highlights a promising approach for green functionalization of CNCs and verifies its use in interface enhancement using a biobased acrylate matrix.

Targeted isolation of barrigenol-like triterpenoids from the husks of Xanthoceras sorbifolia Bunge based on feature-based molecular networking and their antitumor activities

The husks of Xanthoceras sorbifolia Bunge have gradually attracted widespread attention in recent years due to the abundant resources and ideal pharmacological activities, with barrigenol-like triterpenoid saponins being its biological constituents. In this study, a feature-based molecular networking (FBMN) was utilized to perform the targeted isolation of triterpenoids. As a result, six undescribed barrigenol-type saponins (1–6) along with fourteen known analogues (7–22) were isolated from the extract of X. sorbifolia husk. Their structures were determined through a comprehensive analysis of NMR and HRMS spectroscopic data. Among them, compounds 1–3 are a specific type of saponin featuring a fucose moiety attached at C-21. The antitumor activities of isolated compounds were evaluated and compounds 7, 9 and 10 showed significant inhibitory activities against A549 and HepG2 cell lines in a dose-dependent manner.

Purification, structural characterization and immunomodulatory activity of a polysaccharide isolated from Scutellaria baicalensis stem-leaf

In our research, a novel polysaccharide (named SSP-3a) with uniform molecular weight was extracted from Scutellaria baicalensis stem-leaf. The structural analysis revealed that SSP-3a was an acidic polysaccharide with a heavy average molecular weight of 1.83 × 105 Da. By HPLC, the primary constituents of SSP-3a were mannose (11.60 %), glucuronic acid (42.99 %), glucose (23.43 %), and xylose (22.04 %). According to FT-IR and 1H NMR analysis, it was confirmed to be a β-configuration pyranose with a CO stretching vibrational peak. The immunomodulation results also showed that SSP-3a not only significantly promoted RAW264.7 cell proliferation and phagocytosis, but also stimulated the release of NO and cytokines. Furthermore, mechanistic studies suggested that SSP-3a had the ability to trigger MAPKs and NF-κB immunological signaling pathways via TLR4 receptors. The findings suggested that SSP-3a might be a beneficial active component for the food and pharmaceutical industries.

DTX3L ubiquitin ligase ubiquitinates single-stranded nucleic acids.

Ubiquitination typically involves covalent linking of ubiquitin (Ub) to a lysine residue on a protein substrate. Recently, new facets of this process have emerged, including Ub modification of non-proteinaceous substrates like ADP-ribose by the DELTEX E3 ligase family. Here, we show that the DELTEX family member DTX3L expands this non-proteinaceous substrate repertoire to include single-stranded DNA and RNA. Although the N-terminal region of DTX3L contains single-stranded nucleic acid binding domains and motifs, the minimal catalytically competent fragment comprises the C-terminal RING and DTC domains (RD). DTX3L-RD catalyses ubiquitination of the 3'-end of single-stranded DNA and RNA, as well as double-stranded DNA with a 3' overhang of two or more nucleotides. This modification is reversibly cleaved by deubiquitinases. NMR and biochemical analyses reveal that the DTC domain binds single-stranded DNA and facilitates the catalysis of Ub transfer from RING-bound E2-conjugated Ub. Our study unveils the direct ubiquitination of nucleic acids by DTX3L, laying the groundwork for understanding its functional implications.

DTX3L ubiquitin ligase ubiquitinates single-stranded nucleic acids

Ubiquitination typically involves covalent linking of ubiquitin (Ub) to a lysine residue on a protein substrate. Recently, new facets of this process have emerged, including Ub modification of non-proteinaceous substrates like ADP-ribose by the DELTEX E3 ligase family. Here, we show that the DELTEX family member DTX3L expands this non-proteinaceous substrate repertoire to include single-stranded DNA and RNA. Although the N-terminal region of DTX3L contains single-stranded nucleic acid binding domains and motifs, the minimal catalytically competent fragment comprises the C-terminal RING and DTC domains (RD). DTX3L-RD catalyses ubiquitination of the 3’-end of single-stranded DNA and RNA, as well as double-stranded DNA with a 3’ overhang of two or more nucleotides. This modification is reversibly cleaved by deubiquitinases. NMR and biochemical analyses reveal that the DTC domain binds single-stranded DNA and facilitates the catalysis of Ub transfer from RING-bound E2-conjugated Ub. Our study unveils the direct ubiquitination of nucleic acids by DTX3L, laying the groundwork for understanding its functional implications.

Ergot alkaloid control in biotechnological processes and pharmaceuticals (a mini review).

The control of ergot alkaloids in biotechnological processes is important in the context of obtaining new strain producers and studying the mechanisms of the biosynthesis, accumulation and secretion of alkaloids and the manufacturing of alkaloids. In pharmaceuticals, it is important to analyze the purity of raw materials, especially those capable of racemization, quality control of dosage forms and bulk drugs, stability during storage, etc. This review describes the methods used for qualitative and quantitative chemical analysis of ergot alkaloids in tablets and pharmaceutic forms, liquid cultural media and mycelia from submerged cultures of ergot and other organisms producing ergoalkaloid, sclerotias of industrial Claviceps spp. parasitic strains. We reviewed analytical approaches for the determination of ergopeptines (including their dihydro- and bromine derivatives) and semisynthetic ergot-derived medicines such as cabergoline, necergoline and pergolide, including precursors for their synthesis. Over the last few decades, strategies and approaches for the analysis of ergoalkaloids for medical use have changed, but the general principles and objectives have remained the same as before. These changes are related to the development of new genetically improved strains producing ergoalkaloids and the development of technologies for the online control of biotechnological processes and pharmaceutical manufacturing ("process analytical technologies," PAT). Overall, the industry is moving toward "smart manufacturing." The development of approaches to production cost estimation and product quality management, manufacturing management, increasing profitability and reducing the negative impact on personnel and the environment are integral components of sustainable development. Analytical approaches for the analysis of ergot alkaloids in pharmaceutical raw materials should have high enough specificity for the separation of dihydro derivatives, enantiomers and R-S epimers of alkaloids, but low values of the quantitative detection limit are less frequently needed. In terms of methodology, detection methods based on mass spectrometry have become more developed and widespread, but NMR analysis remains in demand because of its high accuracy and specificity. Both rapid methods and liquid chromatography remain in demand in routine practice, with rapid analysis evolving toward higher accuracy owing to improved analytical performance and new equipment. New composite electrochemical sensors (including disposable sensors) have demonstrated potential for real-time process control.

Synthesis of para‐Carboxamidostilbene Derivatives as Antihyperglycemia Agents and Their In Silico ADMET and Molecular Docking Studies

AbstractIn this project, para‐carboxamidostilbene derivatives were synthesized using the Heck coupling reaction, confirmed through various analytical techniques such as FT‐IR, HRMS, and NMR analyses, and tested in vitro to evaluate their α‐amylase inhibitory activity. In silico molecular docking was employed to model the binding interactions of compounds with α‐amylase. Pharmacokinetic properties (ADME) and drug‐likeness were also examined. Structure activity relationship (SAR) analysis was conducted to establish the relationship between the chemical structure and α‐amylase inhibitory activity. The synthesized compounds exhibited significant α‐amylase inhibitory activity with IC50 values ranging from 15.0 to 37.5 µM in comparison with acarbose (IC50 = 30.2 ± 1.9 µM). Among them, compounds 6d–6f and 7c–7f demonstrated promising inhibitory activity. Furthermore, molecular docking studies revealed strong interactions between the studied molecules and the α‐amylase binding pocket. The drug‐likeness prediction results indicated that all synthesized compounds adhered to Lipinski's rule of five, suggesting their suitability as drug‐like molecules. Additionally, the assessment of ADMET properties indicated favorable absorption profiles, particularly in terms of human intestinal absorption (HIA). Overall, this study successfully identified several para‐carboxamidostilbene derivatives as potential α‐amylase inhibitors for the treatment of T2DM.

Trialkoxysilane Grafting in Alcohols: A Simple Approach towards Modified Silica-Based Materials.

The grafting of trialkoxysilanes is the most common method for the surface functionalization of silica gel, and it is usually carried out in the presence of toluene or other solvents such as acetonitrile or acetone. Here, we replaced these solvents with alcohols to afford silica materials containing alkoxy groups linked to the silicon atom. The grafting of N,N-dimethyl-3-amino- or 3-amino-propyltrimethoxysilane was carried out in the presence of several alcohols containing an unsubstituted alkyl chain (C7 and C14), a PEG functionalized chain, or an amino-substituted chain (N,N-dimethylamino, pyridyl). Materials were characterized via solid-state 13C- and 29Si CPMAS NMR and thermogravimetric analysis to prove that alcohols are not "innocent" solvents but take part in the reaction and lead to [RSi(OR1)-(OSi)2] systems where the OR1 group proceeds from the alcohol used in the synthesis. As a proof of concept, we briefly studied the catalytic activity of some of these materials with the aim of showing how different modifications can influence the course of a selected reaction. Finally, a quaternary ammonium salt (QAS)-based silica was prepared containing both an alkyl-QAS and an alkoxy-QAS linked to silicon atoms. This could represent an interesting approach for the development of new antifouling-based materials and, overall, the described strategy could be useful for the preparation of new organosilica materials.

Spectrochemical Insights into Aromatic Hydrocarbons in 1,2-Disubstituted Naphthalenes: Investigations Using 1D and 2D NMR Spectroscopy and X-Ray Crystallography Analysis

Naphthalene and its derivatives are often determined as markers of environmental pollution, although they are also recognized as crucial building blocks in many beneficial compounds. In the course of this study, a range of 1,2-disubstituted naphthalenes bearing nitro, amine, sulfonate, chlorine, and hydroxyl substituents were synthesized and characterized using several spectroscopic techniques, including FT-IR,1H NMR,13C NMR, DEPT-90, DEPT-135, DEPTq, elemental analysis, and high-resolution mass (HRMs). The NMR analysis of the aromatic hydrocarbon moiety in these compounds emphasized the impact of substituent variations on the appearance of 1H and 13C NMR signals. To resolve the issue of overlapping one-dimensional (1D) 1H NMR signals and determine the connectivity of hydrogen and carbon atoms from the aromatic naphtayl ring, we employed a “two-dimensional” experiment, using homonuclear correlation spectroscopy (2D 1H-1H COSY) and heteronuclear single quantum correlation (2D 1H - 13C HSQC) and heteronuclear multiple‐bond correlation spectroscopy (2D 1H - 13C HMBC). This work also investigated the correlation between 1H NMR signals and thin-layer chromatography (TLC) data. X-ray crystallography data validates that the presence of a specific group, not aligned coplanarly with the naphthyl ring, exerts a spatial influence on the manifestation of 1H NMR signals, alongside other electronic effects. This study will offer NMR data, providing insights into the potential applications and analyses of naphthalene derivatives across various theoretical and practical domains.

Investigating the efficacy of naphthalene-thiazole hybrid hydrazones as α-glucosidase inhibitors

In this study, a series of hydrazone derivatives containing naphthalene and thiazole hybrids were synthesized through the condensation of (E)-4-methyl-2-(2-(naphthalen-1-ylmethylene)hydrazineyl) thiazole-5-carbohydrazide with various carbonyl compounds, including aldehydes and ketones, whether carbocyclic aromatic or heterocyclic, using a grinding method with drops of acetic acid. The elucidation of the structures of the synthesized hydrazone derivatives was achieved through the analysis of NMR, IR, and mass spectrometry data. All the newly prepared compounds were assessed for their in vitro α-glucosidase inhibition profiles and the results revealed a diverse range of inhibitory potentials, ranging from 9.3 ± 1.0 to 70.5 ± 1.8 μM, in contrast to the reference acarbose (with an IC50 value of 45.2 ± 1.3 μM). In an attempt to explain the observed inhibitions of synthesized naphthalene containing thiazole compounds, molecular docking was performed to determine the binding modes between the synthesized compounds from one side and the active residues of α-glucosidase from the other side. Compounds 4d, 4e, 4c, and 8 demonstrated the strongest binding affinities, with binding energies of -10.5, -9.8, -9.6, and -9.5 kcal/mol, respectively.

Antibacterial and antioxidant activities of a new phenolic coumpound from the roots barks of Cassia arereh Delile (Fabaceae)

Phytochemical study of the root barks of Cassia arereh resulted in the isolation of a new phenolic ester, 3′-hydroxy-4′-methoxystyrenyl-(E)-p-coumarate (1) isolated for the first time from natural source, alongside eight known compounds (2–9). Compounds 1, 7 and 8 are depicted for the first time from Cassia genus. The structures of all compounds were established through NMR analysis (1D and 2D), High Resolution Mass Spectrometry (HRMS) and comparison with previously reported data in literature. Antioxidant activity was investigated through DPPH method while the antibacterial activity was done by the disc diffusion method on Escherichia coli and Salmonella typhimurium strains. Results showed that the methanol extract and compound 7 displayed significant (p < 0.01) DPPH radical scavenging activity which is comparable to BHT used as standard with IC50 values of 118.04 and 122.24 µg/mL respectively. Otherwise, the same extract and compound 7 also showed significant antibacterial activity against S. typhi and E. coli with MIC values of 30 and 40 µg/mL, respectively.This research confirm the traditional use of Cassia arereh to treat ailments and provide supplementary data on its chemical profile and pharmacological potential.