Column Chromatography Research Articles

A headspace injection double-column dual-detector gas chromatography system for the analysis of 12 volatile compounds such as ethanol in human blood

Based on the technical methods of GB/T 42430-2023 and GA/T 204-2019, this study established an analytical method for headspace injection double-column dual-detector (hydrogen flame ion detector) gas chromatography for the simultaneous analysis of at least 12 volatile compounds, including ethanol, in human blood using two different equipment platforms and chromatographic columns. A 100 μL blood or urine sample and a 0.04 g/L tert-butanol working solution prepared as an internal standard are introduced into the headspace sample bottle and then sealed, mixed, and placed on the headspace sampler rack. Using different equipment platforms and columns, methodological parameters such as the limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy of the method were systematically evaluated. The chromatographic separation of acetone, alcohols and benzenes using the established method was satisfactory. The linear ranges, linear correlation coefficients (r), and LODs of acetone and six alcohols, including ethanol, were 0.10-3.00 g/L, >0.997, and 0.05 g/L, respectively. The LOQs were 0.10 g/L for all other compounds, excluding n-propanol (0.005 g/L). Additionally, the linear ranges, r values, LODs, and LOQs of benzene and four benzene derivatives were 0.05-50 mg/L, >0.995, 0.02 mg/L, and 0.05 mg/L, respectively (Column J&W DB-BAC1 UI and Column Rtx-BAC-PLUS 2). The average recoveries of compounds on J&W DB-BAC1 UI and Rtx-BAC-PLUS 2 columns ranged from 92.2% to 111.6%, and the relative standard deviations (RSDs, n=6) ranged from 0.4% to 7.4%. The LOD, LOQ, precision, accuracy, and linearity of the established method met the requirements of relevant standards, and no significant differences arose between the methodological parameters of the two platforms. CNAS-GL006 (2019) and JJF 1059.1-2012 were used as guides to evaluate the uncertainty of ethanol on two different sets of equipment platforms and chromatographic columns. The ethanol uncertainty was mainly derived from the calibration curve; however, the confidence probability was 95% (k=2). According to the analysis of the verification samples and real samples, the established method is suitable for the high-precision quantitative analysis of acetone and six alcohols and five benzene derivatives in human blood and other body fluids. It can be used in practical scenarios such as judicial identification and the detection of poisons.

Antidyslipidaemic evaluation of coagulin C and withacoagulin isolated from Withania coagulans (Stocks) dunal berries in hypertension induced secondary dyslipidemia in albino mice

Vascular diseases like hypertension has often been associated with dyslipidemia. Sustained elevated blood pressure for not less than four weeks develops gross irregularities inside arteriolar lumen. The pathological changes might be due to intimal arteriosclerotic thickening causing tapering of the structural narrowing along the arterioles. It might also be due to occurrence of irregular damage in the vascular structure from focal arteriolar constriction and lead to secondary dyslipidemia. The pharmacological intervention may lead to rectification and therapeutic benefit against dyslipidemia.The withanolides coagulin C and withacoagulin were isolated by flash chromatography from the extracts of Withania coagulans (Stocks) Dunal berries. The withanolides were characterized using 1H NMR and 13C NMR, UV and mass spectrometry and confirmed as coagulin C and withacoagulin. The oral toxicity of coagulin C and withacoagulin were investigated in albino mice followed by their antidyslipidemic activity with two dose levels i.e. 25 mg/kg and 50 mg/Kg p.o. This dyslipidemia was secondary to hypertension which was developed by DOCA salt model (25 mg/kg; s.c.+ 2% NaCl). Mice were administered dose of 10, 50 and 500 mg/kg coagulin C and withacoagulin orally for 28 days daily for sub-acute toxicity effect.Coagulin C and withacoagulin were found to be tolerated upto 2000 mg/kg p.o. during acute toxicity study in mice. Coagulin C and withacoagulin were claimed to possess No-Observed Adverse Effect Level (NOEL) at the dose of 500 mg/kg orally. The high dose (50 mg/Kg) withacoagulin has highly significant difference in total cholesterol, triglyceride, HDL, LDL and VLDL levels in comparison to disease control group along with highly significant difference in triglyceride and VLDL level compared to animals of vehicle control group. Coagulin C at both the low (25 mg/Kg) and high dose (50 mg/Kg) have highly significant difference in comparison to vehicle control, disease control and positive control in controlling total cholesterol, triglyceride, LDL and VLDL levels in the experimental animals indicating that coagulin C is not much as effective as withacoagulin in the normalization of altered lipid profile of the experimental animals.On the basis of spectroscopic analysis the isolated compounds from Withania coagulans (Stocks) Dunal berries were confirmed to be coagulin C and withacoagulin. Acute oral toxicity test in mice was found to have safe profile even at high dose for both the compounds. On development of secondary dyslipidemia due to DOCA salt induced hypertension in albino mice, both the isolated compounds showed different degree of correction in the altered lipid profile of the animals. Whereas withacoagulin has been found to have more significant and successful in controlling the altered lipid profile, coagulin C has only marginal effect. The docking studies also confirm the result and hence it can be suggested that withacoagulin is better than coagulin C in managing the alteration of lipid profile of the experimental mice.

Eco-friendly Synthesis of Indole Conjugated Chromeno[d]Pyrimidines as Anti-cancer Agents and their Molecular Modelling Studies

Introduction: Many medicinally active new chemical entities depend on indole conjugated chromeno[d]pyrimidine derivatives as a building block. The synthesis of 4-(1H-indol-3-yl)-3,4- dihydro-1H-chromeno[4,3-d]pyrimidine-2,5-dione 4 were achieved in the current study by treating 4- hydroxy-2H-chromen-2-one 1, indole aldehydes 2, and urea/thiourea 3 in the presence of L-proline. Methods: By adopting the above protocol, we were able to synthesize eight compounds, i.e. 4-(1Hindol- 3-yl)-3,4-dihydro-1H-chromeno[4,3-d]pyrimidine-2,5-diones (4a-4h), in the presence of Lproline as a catalyst in ethanol as solvent for 2-3 hours at 70-75°C with decent yields of 80-85%, and their structures were ascertained by various spectral techniques. They were further screened for their potentiality to inhibit cancer growth in HepG2 and MDA-MD-231 cells. Results: The scope of the synthesis of biological relevant Indole conjugated Chromeno[ d]Pyrimidines by three-component reaction (MCRs) process was investigated. The most optimised conditions obtained were 0.3 eq of L-proline for 2 hours at 70-75°C which gave the best yield (85%). The few advantages of this newly developed method are excellent yields, no metal catalyst, less toxic solvents, simple workup no chromatographic column purifications. On further screening for their anticancer activities, out of all, the compound 4b displayed noteworthy cytotoxicity with IC50 values of 8.1 and 9.2 μM against HepG2 and MDA-MD-231, respectively. Additionally, in silico studies also supported that compound 4b had favourable binding energy (-7.8 kcal/mol) when compared to the co-crystal ligand (LS5) in inhibiting the human cyclin-dependent kinase 2 (CDK2) protein. Conclusion: In conclusion, we have developed a simple, convenient, and efficient method for the synthesis of structurally diverse indole conjugated chromeno[d]pyrimidine analogues in the presence of L-proline as catalyst in ethanol as solvent with good yields. Further, the in vitro cytotoxic studies against HepG2 and MDA-MD-231 cells demonstrated that the synthesized compounds had good to reasonable activity, except for compound 4d.

Utilization of Silica Gel for the Synthesis of Geranyl Laurate and Citronellyl Laurate

Geraniol and citronellol are monoterpenoid alcohols with diverse pharmacological activities. This research focuses on synthesized of geranyl laurate and citronellyl laurate using silica gel as an esterification catalyst. The FTIR peak spectra of silica gel showed that Si-OH, Si-O-Si group were observed. XRD showed that the silica gel is an amorphous phase. The reaction was conducted under reflux using a Dean–Stark trap. The reaction was monitored by TLC and then the product was purified using column chromatography. This work reported that silica gel can be utilized as a catalyst for preparing geranyl laurate and citronellyl laurate which proven by the spectra of FTIR, 1H-NMR, and 13C-NMR of the geranyl laurate and citronellyl laurate formed. The IR spectra of geranyl laurate and citronellyl laurate showed the presence of a carbonyl group (C=O) at 1744-1745 cm-1 and C-O from ester at 1170-1176 cm-1. The peak number and its chemical shift on 1H-NMR and 13C-NMR spectra further verified the structure of geranyl laurate and citronelyl laurate. In conclusion, silica gel can be utilized as a catalyst for preparing geranyl laurat and citronellyl laurate. Therefore a silica gel-based catalyst is promising to be developed for esterification applications.

Ascorbic Acid and α-Tocopherol in the Inactivated SARS-CoV-2 Vaccine Formulation: Induction of the Th1 Pattern in Aged Mice.

Aging is physiologically associated with a decline in the function of the immune system and subsequent susceptibility to infections. Interferon-gamma (IFN-γ), a key element in the activation of cellular immunity, plays an important role in defense against virus infections. Decreased levels of IFN-γ in the elderly may explain their increased risk for viral infectious diseases such as COVID-19. There is accumulating evidence that ascorbic acid (vitamin C [VitC]) and α-tocopherol together help improve the function of the immune system in the elderly, control infections, and decrease the treatment duration. A SARS-CoV-2 strain was isolated from a patient and then cultured in the Vero cell line. The isolated and propagated virus was then inactivated using formalin and purified by the column chromatography. The inactivated SARS-CoV-2 was formulated in the Alum adjuvant combined with VitC or α-tocopherol and/or both of them. The vaccines were injected twice to young and aged C57BL/6 mice. Two weeks later, IFN-γ, IL-4, and IL-2 cytokines were assessed using ELISA Kits. Specific IgG and IgG1/IgG2a were assessed by an in-house ELISA. In addition, the expression of PD1 and TERT genes in the spleen tissue of the mice was measured using real-time PCR. IL-4 and IFN-γ cytokines showed a significant increase in both aged and young mice compared with the Alum-based vaccine. In addition, our results exhibited a significant decrease and increase in specific total IgG and the IgG2a/IgG1 ratio, respectively. Furthermore, the vaccine formulated in α-tocopherol + VitC led to decreased PD1 and increased TERT gene expression levels. In conclusion, our results demonstrated that α-tocopherol + VitC formulated in the inactivated SARS-CoV-2 vaccine led to a shift toward Th1, which may be due to their effect on the physiology of cells, especially aged ones and changing their phenotype toward young cells.

Untargeted metabolic analysis of Epaltes mexicana by LC-QTOF-MS: Terpenes with activity against human cancer cell lines.

Epaltes mexicana is a plant widely used in traditional medicine and as a food in Mexico; however, its phytochemical and pharmacological studies are limited. This study aimed to identify the active secondary metabolites of Epaltes mexicana and determine its cytotoxic activity on cancer cell lines. Three organic extracts were obtained by maceration using n-hexane, dichloromethane, and methanol. The n-hexane extract was fractioned by simple column chromatography. Eight terpenes were annotated in collection 6 (C6) by LC-QTOF-MS using a gradient elution and Electrospray Ionization (ESI) in positive ion mode: 1) Gibberellin A15, 2) farfugin A, 3) dehydromyodesmone, 4) eremopetasitenin A1, 5) hydroxyisonobilin, 6) anhydrocinnzeylanine, 7) nigakilactone H and 8) taxodione. On the other hand, C6 showed a concentration-dependent cytotoxic effect on cancer cell lines MCF-7 (Emax = 74.69 ± 6.19 % and IC50 = 6.31 μg/mL), MDA-MB-231 (Emax = 79.28 ± 12.12 % and IC50 = 124.21 μg/mL), and SiHa (Emax = 82.96 ± 6.02 % and IC50 = 124.31 μg/mL). The C6 did not show a cytotoxic effect against DU-145 and non-cancerous cells from the mammary glands MCF-10 A. These results indicate cytotoxic specificity on cancer cell lines and support the hypothesis that terpenes identified in E. mexicana must be investigated and developed for non-clinical and clinical trials as potential anti-cancer drugs.

Isolation and Partial Characterization of 11-Octadecenoic Acid Methyl Ester and Bis (2-ethylhexyl) Phthalate from Celtis integrifolia Lam

Introduction: Celtis integrifolia Lam is a traditional medicinal plant used as a remedy for the cure of diarrhea, measles, bleeding, ecbolic, sore throat and as an antinociceptive agent. Aim: The study was aimed at the isolation and partial characterization of phytocompounds from Celtis integrifolia crude extract. Methodology: The stembark sample was powdered and extracted using maceration technique with methanol. The extract was filtered using cotton wool and clarified using Whatmann No.1 filter paper. The filtrate was concentrated on a rotavapor at 45oC. The crude extract was then reconstituted in water and partitioned successively with n-hexane, ethyl acetate, and n-butanol. The ethyl acetate and the n-hexane fractions were concentrated and subjected to purification on column chromatography. Results: Gradient elution of extract fractions on open-column chromatography yielded two compounds coded CiL1 and CiL2 from the n-hexane and ethyl acetate fractions respectively. The isolated compounds were characterized using spectroscopic data from Fourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, gas chromatography-mass spectrometry (GC-MS) and literature database. Compound CiL1 with Rf = 0.43 in hexane: Ethyl acetate (9:1) was identified as 11-Octadecenoic acid methyl ester while Compound CiL2 isolated from ethyl acetate fraction as a yellow substance with Rf = 0.38 in hexane: ethyl acetate (8:2) was identified as bis (2-ethylhexyl) phthalate. Conclusion: The study showed the presence of 11-octadecenoic acid methyl ester and bis (2-ethylhexyl) phthalate in the stembark extract of Celtis integrifolia Lam. These two phytocompounds are reported for the first time from Celtis integrifolia Lam based on available literature. Since the presence of phytochemical substances is believed to be the basis of any observed pharmacological activity, the study therefore lends credence to the traditional medicinal uses of Celtis integrifolia Lam.

Identification of novel anti-obesity saponins from the ovary of sea cucumber (Stichopus japonicus)

The potential anti-obesity effects of sea cucumber extract have been reported. However, the individual saponins responsible for these effects are yet to be isolated and characterized. This study aimed to identify the most effective sea cucumber body part for inhibiting lipid accumulation in adipocytes and to elucidate the compounds responsible for this effect using nuclear magnetic resonance (NMR) techniques. Sea cucumber ovary 80 % ethanol extract (SCOE) demonstrated remarkable efficacy in inhibiting adipocyte differentiation compared to other sea cucumber body parts with 50 % or 80 % ethanol extracts. SCOE anti-obesity effect was evaluated in C57BL/6 mice fed a high-fat diet, which revealed significant reductions in body weight, serum lipids, adipose tissue, and liver weight. Using column chromatography, eight saponins were isolated from the SCOE, four of which exhibited potent inhibitory effects on adipocyte differentiation. Of these, three active saponins, holotoxins A, B, and D1, were newly identified. These findings highlight the potential of SCOE and its saponins as effective anti-obesity agents.

Simultaneous quantification of 2-pyrrolidone-5-carboxylic acid (PCA), urocanic acid (UCA), and histidine (His) in the stratum corneum by HPLC-PDA

Located in the epidermis, the stratum corneum is the most superficial layer of the skin, acting as a barrier against aggression from the external environment, preventing dehydration, and maintaining the water balance of the skin. The stratum corneum contains the Natural Hydration Factor (NMF), a mixture of hygroscopic molecules derived from filaggrin. The NMF includes 2-pyrrolidone-5-carboxylic acid (PCA), urocanic acid (UCA), and histidine (His), target biomarkers that were extracted by tape-stripping from the stratum corneum of participants for quantification in HPLC-PDA. By extracting the stratum corneum, we developed a protocol to optimize, through audience definition, the quantification of NMF biomarkers. Chromatographic analysis was performed using a YMC-Triart C18 chromatographic column, with a gradient elution of mobile phase composed of triethylammonium phosphate and acetonitrile mixture, and a photodiode array detector. HPLC-PDA procedure was selective, linear (in the range from 0.2 to 5.0 µg/mL), accurate (recovery from 92.7 to 115.1 %), precise (RSD from 0.3 to 12.1 %), and with proper detection and quantification limits. The measurement uncertainty was evaluated from validation data, with combined standard uncertainty values of 0.025–0.12 µg/mL (2.1–5.6 %), 0.004–0.28 µg/mL (2.4–12.6 %), and 0.016–0.16 µg/mL (3.2–7.9 %) for His, PCA, and UCA, respectively. Statistical analyses were performed using Monte Carlo simulation and the Mann-Whitney test, as our results were not homoscedastic and deviated from normality. The results indicate that the best audience for quantifying biomarkers were participants up to 35 years old, with all phototypes, and, preferably, female.

Selective Oxidation of Benzo[d]isothiazol-3(2H)-Ones Enabled by Selectfluor.

A metal-free and Selectfluor-mediated selective oxidation reaction of benzo[d]isothiazol-3(2H)-ones in aqueous media is presented. This novel strategy provides a facile, green, and efficient approach to access important benzo[d]isothiazol-3(2H)-one-1-oxides with excellent yields and high tolerance to various functional groups. Furthermore, the purification of benzoisothiazol-3-one-1-oxides does not rely on column chromatography. Moreover, the preparation of saccharine derivatives has been achieved through sequential, double oxidation reactions in a one-pot aqueous media.

Organic suspension droplet solid-phase dispersive liquid–liquid microextraction ultra-high performance liquid chromatography tandem mass spectrometry determination of antibiotic residues in water samples

A method was developed for the simultaneous detection of 38 antibiotic residues, which included 8 sulfonamides, 14 fluoroquinolones, 9 macrolides, and 7 anthelminthics, in drinking water, tap water, and environmental water. The method involved organic suspension droplet solid-phase dispersive liquid–liquid microextraction, followed by ultra-high performance liquid chromatography tandem mass spectrometry for the analysis of the water samples. Hypersil GOLD C18 chromatography column (100 × 2.1 mm, 1.9 μm) be used for separation of target analytes that were eluted by a gradient mobile phase composition of 0.2 % formic acid–water as mobile phase A and acetonitrile as mobile phase B at a flow rate of 0.2 mL min−1. Using 0.2 mL of octanoic acid as the extractant and 0.3 mL of acetonitrile as the dispersant. Under optimal conditions, the standard curve exhibits a good linear relationship within the range of 1–50 μg L−1. The spiked recovery rate of the method ranges from 63 % to 96 %, with a relative standard deviation of 0.6 % to 7.3 % (n = 6). The detection limit of the method is between 0.1 and 0.2 μg L−1. This method is characterized by its simplicity, speed, and high sensitivity, which sets the groundwork for investigating the exposure levels and environmental behavior of antibiotics.

Model-based investigation of the pH-dependent chromatographic separation of itaconic acid from aqueous solution using strongly hydrophobic adsorbents

In this study, we propose a model for the simulation of the pH-dependent separation of dicarboxylic acids from aqueous solutions using strongly hydrophobic adsorbents. Building upon results of our previous study, where we experimentally investigated the pH-dependent adsorption behavior of the individual acid species of itaconic acid (IA) on a strongly hydrophobic adsorbent using in-line Raman spectroscopy, we utilize a transport-dispersive model as the basis for our simulation model. Instead of considering IA as a single component in our model, we simulated each acid species of IA individually. For this purpose, we expanded the transport-dispersive model with reaction terms in all aqueous phases. The reaction terms include all dissociation reactions of all involved components for each time step and spatial discretization. This model enables the time and spatial dependent simulation of the pH value in the chromatographic column and thus the time and spatial dependent knowledge of each acid species concentration. The consideration of activity coefficients due to high local ionic strength is achieved using the Truesdell–Jones (TdJ) model. The simulation model is successfully validated using experimental data from our previous study and used in a simulation study that demonstrates the potential of the model approach for analyzing associated separation tasks.

Regioselective Ligand Substitution of Thiolate-Protected Gold Nanoclusters with Porphyrins

Hybridization of photofunctional organic molecules like porphyrins with inorganic nanomaterials provides interesting photophysical properties like photo-induced electron transfer, energy transfer, or photoemission from charge transfer states. For fine tuning of these photo-functionalities, precise control over organic-inorganic interfaces, including spatial distances and orientations of organic molecules against inorganic nanomaterial, should be crucial. However, control and evaluation of the interfaces are quite difficult, mainly due to heterogeneous and unclear environments on the surface of inorganic nanomaterials like metal nanoparticles and metal nanosheet, which basically have size and/or composition distributions.Among the inorganic nanomaterials, atomically-precise metal nanoclusters (MNCs) are one of the homogeneous materials with uniform composition and distinct surface structure at an atomic level. Thus, MNCs can be an appropriate model to evaluate the effects of organic-inorganic interfaces on photophysical properties of the hybridized materials. Nevertheless, even in one of the most common and simplest MNCs like thiolate-protected Au25 cluster ([Au25(SR)18]–, SR = thiolate), two kinds of inequivalent ligands (S1, S2 in Figure 1) are present on surface. Thus, control over the regioselectivity should be required to archive precise substitution of photo-functional molecules, which has yet to be reported. In this work, we have controlled regioselectivity in the modification of [Au25(SC2Ph)18]– (SC2Ph = phenylethanethiolate) with porphyrinthiol ligands (Por) through ligand-exchange reactions. An advantage of Por as a photofunctional ligand for Au25 cluster is more bulkiness than that of original ligands (SC2Ph), which aids the isolation of mono-porphyrin-coordinated Au25 cluster ([Au25(SC2Ph)17(Por)1]–, Au25-Por1 ). Moreover, synthetic flexibility of porphyrins enabled us to control the regioselectivity in Au25-Por1 systematically.We sythesized a series of Por with a thiol moiety at different positions to evaluate the steric effect on the regioselectivity in ligand-exchange reactions (Figure 1). Porphyrin thiol with different substituents at meso-phenyl groups were also synthesized to evaluate the electronic effect. Substitution of porphyrins onto Au25 clusters was conducted by ligand-exchange reactions of [Au25(SC2Ph)18]– with 1 equivalent of Por in tetrahydrofuran. After the careful purification of the reaction mixture through size-exclusion column chromatography, we have successfully isolated Au25-Por1 in ca. 20% yield. The characterizations of Au25-Por1 were performed by MALDI-TOF-MS and 1H NMR spectroscopy, which confirmed the high purities of a series of Au25-Por1 .The regioselectivity in Au25-Por1 was evaluated through 1H NMR measurements. When using para-substituted porphyrin (PorSH) as an incoming ligand, 1H NMR spectrum of Au25-SPor1 in acetone-d 6 indicated the presence two kinds of regioisomers with the ratio of 2.5:1. Interestingly, the regioselectivity increased up to 80% (4:1) in Au25 cluster with more steric meta-substituted porphyrin (Au25-S m Por1 ), whereas the ratio reached to almost 1:1 in the case of Au25 cluster with less steric phenyl-spacer introduced porphyrin (Au25-SPhPor1 ). Because S2 position in the Au25 clusters was less steric than S1 position, we concluded that more steric ligands like m PorSH tend to be introduced at S2 position favorably. On the other hand, we hardly observed the electronic effect of Por on the regioselectivity in Au25-Por1 , indicating the importance of steric factor of an incoming ligand for precise control over the exchanged position (Figure 1). This is the first report to control over ligand-exchange position of MNCs, which could be achieved through ligand design.Finally, we briefly evaluated the photophysical properties of Au25-Por1 in toluene solution. When the Soret band of coordinated-porphyrins was photoexcited, the fluorescence quenching was clearly observed in each Au25-Por1 . Judging from the energy diagram of Au25-Por1 , electron transfer from Au25 to singlet excited state of porphyrin ligand would occur to form charge separated state. It should be noted that the quenching efficiency depended on not only the distance between electron donor and acceptor, but also the position of the coordinated chromophore. These results suggest the importance of precise modification of organic-inorganic interfaces to tune photodynamics of chromophore-nanocluster systems.In conclusion, we have successfully controlled the regioselectivity in the ligand-exchange reactions of thiolate-protected gold nanoclusters with porphyrinthiol derivatives through the steric effect. The essential roles of the ligand-introduced position on altering photodynamics of porphyrin-coordinated MNCs were also clarified, which provides an interesting insight into fine-tuning of photofunctional materials.Figure 1.Reaction scheme of ligand-exchange reaction of [Au25(SC2Ph)18]– with Por. The R groups of SR ligands were omitted for clarity. Figure 1

Phytochemical Profiling and Antioxidant Evaluation of Rhododendron arboreum Sm leaf and flower: Integrative Analysis using Advanced Analytical Techniques

ABSTRACT Objective This study investigates the biological activities of Rhododendron arboreum Sm from the eastern Himalayas, addressing a literature gap on its properties. It explores the plant's phytochemical, antioxidant, and medicinal characteristics. Significance: Evaluating methanolic extracts of R. arboreum offers valuable insights into its bioactive potential. Comprehensive GC-MS analysis identified a diverse array of compounds, highlighting the plant's chemical composition. Methods: Methanolic leaf and flower extracts underwent sequential extraction and phytochemical profiling using column chromatography, TLC, and GC-MS analysis. Spectral studies aided compound identification, and antioxidant activity was assessed via spectrophotometric assays. Results: Column chromatography separated methanol leaf and flower extracts into 17 and 24 distinct fractions, respectively. TLC analysis showed specific Rf values for leaf (0.58, 0.65, 0.75, 0.8, 0.86, 0.9) and flower samples (0.91, 0.38, 0.48, 0.51, 0.56, 0.6, 0.65, 0.75, 0.85, 0.96). GC-MS analysis revealed a variety of organic functional groups, including aliphatic hydrocarbons, aromatic compounds, heterocyclic molecules, phenolic compounds, steroids, terpenoids, alcohols, esters, and other bioactive compounds. FTIR spectra identified functional groups such as hydroxyls, primary amines, alkanes, and alkynes. NMR data indicated a complex molecular composition with diverse proton environments. Leaf extracts demonstrated superior antioxidant activity compared to flower extracts in DPPH, ABTS, hydrogen peroxide scavenging, lipid peroxidation inhibition, and FRAP assays. Conclusion: The study identifies diverse phytochemicals in R.arboreum extracts and highlights their potential applications in pharmaceuticals, nutraceuticals, and functional foods, owing to the superior antioxidant activity of leaf extracts compared to flowers.

Anthocyanin-Rich Fraction of Black Rice Bran Extract Protects against Amyloid β-Induced Oxidative Stress, Endoplasmic Reticulum Stress, and Neuronal Apoptosis in SK-N-SH Cells.

Alzheimer's disease (AD) is the most common neurodegenerative disorder in the aging population. An accumulation of amyloid plaques and neurofibrillary tangles causes degeneration of neurons, leading to neuronal cell death. The anthocyanin-rich fraction of black rice (Oryza sativa L. variety "Luem Pua") bran (AFBRB), extracted using a solution of ethanol and water and fractionated using Amberlite XAD7HP column chromatography, contains a high anthocyanin content (585 mg of cyanidin-3-O-glucoside and 24 mg of peonidin-3-O-glucoside per gram of the rich extract), which has been found to reduce neurodegeneration. This study focused on the neuroprotective effects of AFBRB in Aβ25-35-induced toxicity in the human neuroblastoma cell line (SK-N-SH). SK-N-SH was exposed to Aβ25-35 (10 µM) to induce an AD cell model in vitro. Pretreatment with AFBRB (0.1, 1, or 10 µg/mL) or C3G (20 µM) was conducted for 2 h prior to the treatment with Aβ25-35 (10 µM) for an additional 24 h. The results indicate that AFBRB can protect against the cytotoxic effect of Aβ25-35 through attenuation of intracellular ROS production, downregulation of the expression of the proteins Bax, cytochrome c, cleaved caspase-9, and cleaved caspase-3, upregulation of the expression of Bcl-2 in the mitochondrial death pathway, and reduction in the expression of the three major markers of ER stress pathways in similar ways. Interestingly, we found that pretreatment with AFBRB significantly alleviated Aβ-induced oxidative stress, ER stress, and apoptosis in SK-N-SH cells. This suggests that AFBRB might be a potential therapeutic agent in preventing neurodegenerative diseases.

Systematic Preparation of a 66-IgG Library with Symmetric and Asymmetric Homogeneous Glycans and Their Functional Evaluation.

Immunoglobulin G (IgG) antibodies possess a conserved N-glycosylation site in the Fc domain. In FcγRIIIa affinity column chromatography, unglycosylated, hemiglycosylated, and fully glycosylated IgG retention times differ considerably. Using retention-time differences, 66 different trastuzumab antibodies with symmetric and asymmetric homogeneous glycans were prepared systematically, substantially expanding the scope of IgGs with homogeneous glycans. Using the prepared trastuzumab with homogeneous glycans, thermal stability and antibody-dependent cellular cytotoxicity were investigated. In some glycan series, a directly proportional relationship was observed between the thermal unfolding temperature (Tm) and the calorimetric unfolding heat (ΔHcal). Antibody function could be deduced from the combination of a pair of glycans in an intact form. Controlling glycan structure through the combination of a pair of glycans permits the precise tuning of stability and effector functions of IgG. Overall, our technology can be used to investigate the effects of glycans on antibody functions.

Characterization of the Phytotoxic Potential of Seven Copaifera spp. Essential Oils: Analyzing Active Compounds through Gas Chromatography-Mass Spectrometry Molecular Networking.

In recent years, there has been a need for environmentally friendly compounds for weed management in agriculture. This study is aimed to assess the phytotoxic constituents of oils obtained from oleoresins of seven Copaifera species (known as copaiba oils). Copaiba oils were separated from the resins by hydro-distillation, and the distillates were analyzed using gas chromatography-mass spectrometry (GC-MS) to characterize their chemical compositions. Multivariate analyses and molecular networking of GC-MS data were conducted to discern patterns in the chemical composition and phytotoxic activity of the oils, with the aim of identifying key compounds associated with phytotoxic activity. Seed germination bioassay revealed strong or complete germination inhibition against the monocot, Agrostis stolonifera but not the dicot Lactuca sativa. GC-MS analysis showed variations in composition among Copaifera species with some common compounds identified across multiple species. Caryophyllene oxide and junenol were associated with the observed phytotoxic effects. Automated flash chromatography was used to isolate the major compounds of the oils. Isolated compounds exhibited differing levels of phytotoxicity compared to the oils, suggesting the importance of interactions or synergism among oil components. These findings highlight the potential of copaiba oils as natural herbicidal agents and underscore the importance of considering species-specific responses in weed management strategies.

Separation and purification of bovine nasal cartilage-derived chondroitin sulfate and evaluation of its binding to bovine serum albumin

This study employs an optimized and environmentally friendly method to extract and purify chondroitin sulfate (CS) from bovine nasal cartilage using enzymatic hydrolysis, ethanol precipitation, and DEAE Sepharose Fast Flow column chromatography. The extracted CS, representing 44.67 % ± 0.0016 of the cartilage, has a molecular weight of 7.62 kDa. Characterization through UV, FT-IR, NMR spectroscopy, and 2-aminoacridone derivatization HPLC revealed a high content of sulfated disaccharides, particularly ΔDi4S (73.59 %) and ΔDi6S (20.61 %). Interaction studies with bovine serum albumin (BSA) using fluorescence spectroscopy and molecular docking confirmed a high-affinity, static quenching interaction with a single binding site, primarily mediated by van der Waals forces and hydrogen bonding. The interaction did not significantly alter the polarity or hydrophobicity of BSA aromatic amino acids. These findings provide a strong foundation for exploring the application of CS in tissue engineering and drug delivery systems, leveraging its unique interaction with BSA for targeted delivery and enhanced efficacy.

Bioactivity-driven fungal metabologenomics identifies antiproliferative stemphone analogs and their biosynthetic gene cluster

IntroductionFungi biosynthesize chemically diverse secondary metabolites with a wide range of biological activities. Natural product scientists have increasingly turned towards bioinformatics approaches, combining metabolomics and genomics to target secondary metabolites and their biosynthetic machinery. We recently applied an integrated metabologenomics workflow to 110 fungi and identified more than 230 high-confidence linkages between metabolites and their biosynthetic pathways.ObjectivesTo prioritize the discovery of bioactive natural products and their biosynthetic pathways from these hundreds of high-confidence linkages, we developed a bioactivity-driven metabologenomics workflow combining quantitative chemical information, antiproliferative bioactivity data, and genome sequences.MethodsThe 110 fungi from our metabologenomics study were tested against multiple cancer cell lines to identify which strains produced antiproliferative natural products. Three strains were selected for further study, fractionated using flash chromatography, and subjected to an additional round of bioactivity testing and mass spectral analysis. Data were overlaid using biochemometrics analysis to predict active constituents early in the fractionation process following which their biosynthetic pathways were identified using metabologenomics.ResultsWe isolated three new-to-nature stemphone analogs, 19-acetylstemphones G (1), B (2) and E (3), that demonstrated antiproliferative activity ranging from 3 to 5 µM against human melanoma (MDA-MB-435) and ovarian cancer (OVACR3) cells. We proposed a rational biosynthetic pathway for these compounds, highlighting the potential of using bioactivity as a filter for the analysis of integrated—Omics datasets.ConclusionsThis work demonstrates how the incorporation of biochemometrics as a third dimension into the metabologenomics workflow can identify bioactive metabolites and link them to their biosynthetic machinery.

Phytochemical and biological investigation of Astragalus Caprinus L

Backgroundcultivated and wild plants are used to treat different ailments. The Astragalus genus is found in temperate and dry climates; thus, it is found in Egypt and the arab world. Astragalus caprinus has a good amount of bioactive chemicals, which may help explain its therapeutic effects in reducing the risk of consequences from disease.MethodThe phytochemical investigation of the herb and roots of Astragalus caprinus L. included the analytical characterization for the petroleum ether components by GC/MS, unsaponifiable matter (unsap. fraction), and fatty acids (FAME) investigation by GLC analysis. Main flavonoids were chromatographically isolated from ethyl acetate and n-butanol extracts. In vitro antimicrobial activity has been tested against the Gram-positive bacteria Staphylococcus aureus and Streptococcus mutans for different plant extracts, the Gram-negative bacteria Pseudomonas aeruginosa and Klebsiella pneumonia, the fungus Candida albicans and Aspergillus niger, and the Escherichia coli bacterium. Metabolite cytotoxicity was examined using the MTT assay against HepG-2 (human liver carcinoma) and MCF-7 (breast carcinoma).ResultsIdentifying the important components of the herb and root petroleum ether extracts was achieved. Using column chromatography, luteolin, cosmosiin (apigenin-7-O-glucoside), and cynaroside (luteolin-7-O-glucoside) were separated and identified using UV, NMR, and Mass Spectroscopy. Root extracts displayed potential antimicrobial activity against most of the tested pathogens. Both extracts (herb and roots) were active against the MCF-7 cell line and HepG-2 cell line with IC50 62.5 ± 0.64 and 72.4 ± 2.3 µg/ml, and 75.9 ± 2.5 and 96.8 ± 4.2 µg/ml, respectively.ConclusionAstragalus caprinus seems to be a promising source of bioactive compounds that could potentially aid in preventing disease complications and address common health issues in developing countries. Moreover, the various parts of this plant could be utilized as natural raw materials for producing health-boosting products that could address common health issues in developing countries.