Gel Column Research Articles

Transient submillimeter-scale periodic banding of Ag2O precipitate through reaction–transport–reaction processes

We describe a new class of the periodic banding of Ag2O precipitates through reaction–transport–reaction processes in an agarose-hydrogel column; the gel contains NaNO3 as an additive and is inserted between Ag and Ti rods with an applied constant voltage of 4.0–7.0 V. Submillimeter-scale periodic dark-brown precipitation bands were transiently generated with high reproducibility in this system, in which (i) electrochemical reactions at the metal rods to generate Ag+ and OH−, (ii) transportation of the reactant ions by the electric field, and (iii) reactions to produce Ag2O are expected to couple. The bands successively emerged mainly toward the cathode, accompanied by substantial changes in the electric current through the gel. The periodic banding depended on the applied voltage, duration of application, and concentration of NaNO3 initially loaded in the gel. The banding was most clearly observed in a 2.0 mass% agarose gel column containing 0.005 M NaNO3 under a constant applied voltage of ∼5.5 V for ∼3 h. This optimal condition resulted in more than ten periodic bands, of which the bandwidth (w) and the distance between the adjacent bands (d) were randomly distributed around the average values: for the bands formed up to 2 h, w = 0.25 ± 0.04 mm and d = 0.42 ± 0.05 mm; for the bands formed after 2 h, w = 0.42 ± 0.11 mm and d = 0.68 ± 0.07 mm. The generated periodic bands were gradually painted out with time to form an almost continuous broad band, even after the applied voltage was discontinued, although immersion of the gel in deionized water for 3 h could suppress this uniformization. Observations using optical and scanning electron microscopes with an energy-dispersive X-ray detector suggested that the periodic bands were composed of gelatinous Ag2O and micrometer-scale (1–50 μm) clusters, which comprised Ag-abundant nanoparticles with considerable size dispersion (10–500 nm). The relationship between the periodic banding and inhomogeneous distribution of the reactant ions and potential applications of the observed banding phenomena are discussed.

Unique heterocyclic phenolic compounds from shrimp (Pandalus borealis) and beyond

Shrimps are the most consumed species among crustaceans and are well appreciated for their flavor and high nutritional value. This work investigated the antioxidative compounds of Northern shrimp (Pandalus borealis) and its processing discards (shells and heads) using various solvents and chromatographic techniques as well as mass spectrometry. Ethanol served as the best extraction medium, and the extracts obtained demonstrated strong antioxidant activity in a β-carotene-linoleate emulsion system. The antioxidative compounds of the extract were isolated using a silica gel column chromatography, followed by thin layer chromatography. This led to the identification of two highly polar and two low polarity compounds. These compounds, for the first time, were isolated and purified by using reversed-phase HPLC. Their structures were tentatively elucidated using electrospray mass spectrometry. These unique compounds were heterocyclic phenolic compounds and identified as 7-(3-butenyl)-2-hydroxy-6-(1,2,5,6-tetrahydropyridin-2-yl) quinoline and 7-(3-butenyl)-2-hydroxy-6-(1,2,5,6-tertahydropyridin-2-yl)-7,8-dihydroquinoline and their isomers. The proposed novel compounds in shrimp provide a reason for their oxidative stability and potential benefits, as well as possibly serving as substrates for the discoloration of shrimp.Graphical

Analytical Method for Melengestrol Acetate in Livestock Products Using LC-MS/MS

The present study verified that it is possible to analyze melengesterol acetate using the existing multi-residue method. Melengestrol acetate was extracted from livestock products using acidic acetonitrile acidified with acetic acid in the presence of n-hexane and anhydrous sodium sulfate. The crude extracts were cleaned up using an octadecylsilanized silica gel cartridge column. Separation by HPLC was performed using an octadecylsilanized silica gel column with linear gradient elution of 0.1 vol% formic acid and acetonitrile containing 0.1 vol% formic acid. For the determination of the analyte, tandem mass spectrometry with positive ion electrospray ionization was used. In recovery tests using four livestock products fortified with maximum residue limits levels of melengestrol acetate (0.001-0.02 mg/kg), the truenesses ranged from 82% to 100%, and the repeatabilities for the entire procedure ranged from 0.5 RSD% to 5.6 RSD%. In recovery tests using 11 livestock products fortified with 0.0005 mg/kg of melengestrol acetate, the truenesses ranged from 88% to 99%, and the repeatabilities ranged from 1.3 RSD% to 5.4 RSD%. The limit of quantification for melengestrol acetate in livestock products was 0.0005 mg/kg.

In vitro bioactivities and in silico enzyme interactions of abietatrien-3β-ol by bio-guided isolation from Nepeta italica subsp. italica

Abietatrien-3β-ol (ATO) was isolated from the aerial part of the Nepeta italica subsp. italica methanol-chloroform extract and studied antioxidant, enzyme inhibition, and DNA protection activities. The plant extract was fractionated by silica gel column chromatography using four different solvents. After the active chloroform fraction was divided into six subfractions under the guidance of bioactivity, ATO was isolated from the fourth active subfraction. The molecular structure of ATO was determined by the NMR techniques and confirmed with literature data. In the antioxidant test, ATO showed excellent DPPH˙ (IC50-1.18 ± 0.11 µg/mL), ABTS˙+ (IC50-1.82 ± 0.00 µg/mL), metal chelating (IC50-2.90 ± 0.05 µg/mL), superoxide anion scavenging (IC50-11.59 ± 0.27 µg/mL), reducing power (A0.5-21.09 ± 1.42 µg/mL), H2O2 (A0.5-57.81 ± 4.54 µg/mL), and phosphomolybdenum reducing (A0.5-124.23 ± 0.69 µg/mL) activities when compared to standards. The DNA protection potential was also found to be strong in Form I (47.89%) and Form II (4.56%) formations. ATO had high inhibitions in AChE (IC50-1.25 ± 0.04 µg/mL), BChE (IC50-1.26 ± 0.03 µg/mL), lipase (IC50-7.58 ± 0.27 µg/mL), and tyrosinase (IC50-9.60 ± 0.03 µg/mL). In molecular docking studies, ATO had a high binding affinity with α-amylase (−8.80 kcal/mol), tyrosinase (−8.10 kcal/mol), and urease (−8.10 kcal/mol) enzymes. In addition, by detailing the interaction of ATO with key enzymes that give the best interactions through molecular docking studies, with molecular dynamics studies, and by performing ADMET and DFT calculations, it was tried to explain that it could be a suitable drug candidate. In light of these studies, ATO is thought to be an effective enzyme inhibitor and a protective molecule against oxidation with its active antioxidant properties. Communicated by Ramaswamy H. Sarma

Structure elucidation and anticancer activity of a heteropolysaccharide from white tea

White tea, one of the six traditional teas in China, is made only through natural withering and low-temperature drying processes. It demonstrates diverse pharmacological and health-promoting effects, including antioxidant, antiviral, anticancer, and hypolipidemic activities. Despite the significance of polysaccharides in white tea leaves, their fine structure and physiological functions remain unexplored. In this study, the polysaccharide fragment WTP-80a with anticancer activity was isolated and purified from white tea through water extraction, alcohol precipitation, DEAE-52 ion exchange column chromatography, and sephacryl S-200 dextran gel column chromatography. WTP-80a exhibited a molecular weight of 1.14 × 105 Da and consisted of galactose (Gal), arabinose (Ara), rhamnose (Rha), and glucuronic acid (Glc-UA). The main chain skeleton of WTP-80a contained 3,6)-β-Galp-(1→, 3)-α-Galp-(1→, 5)-α-Araf-(1 → and 3)-α-Glcp-UA-(1→. Branch chains included α-Araf-(1 → and β-Rhap-(1 → connected to the C3 and C6 positions of →3,6)-β-Galp-(1→, respectively. In vitro anticancer experiments revealed that WTP-80a effectively hindered the proliferation, colony formation, migration, and invasion of B16F10 cells. Additionally, it induced apoptosis in B16F10 cells by blocking the G2/M phase, increasing active oxygen content, and reducing mitochondrial membrane potential. These findings provide a solid theoretical foundation for the application of white tea polysaccharides as anticancer products.

Isolation and Characterization of Antimicrobial Constituent(s) from the Stem of Cissus populnea Guill. & Perr.

Cissus populnea Guill. & Perr. (Vitaceae) is used in traditional medicine to treat microbial infections, venereal diseases and infertility, among others. The aim of this research is to isolate and characterize the antimicrobial constituent(s) from the stem of C. populnea. The n-butanol fraction of C. populnea, being most active, was subjected to silica gel column chromatography, which led to the isolation of white solid and white crystalline substances coded compounds C1 and C4C5, respectively. Spectral analysis (1D and 2D-NMR) of the isolated compounds and comparison with the literature data indicated C1 to be Bis-(2-ethyloctyl)-phthalate and C4C5 to be a mixture of stigmasterol and β-sitosterol; C4C5 exhibited a zone of inhibition ranging from 24 to 29 mm against the test organisms with Candida albicans being the most sensitive organism while Trichophyton rubrum was the least sensitive organism. Of the standard drugs, ciprofloxacin had 27–37 mm while fluconazole and fulcin exhibited zones of inhibition ranging from 34 mm to 29–32 mm, respectively. The MIC and MBC/MFC values for C4C5 ranges from 12.5 to 25.0 µg/cm3 and 25.0 to 50.0 µg/cm3 against methicillin-resistant Staphylococcus aureus, Staphylococcus. aureus, Escherichia coli, Candida albicans, Trichophyton rubrum and Trichophyton mentagrophyte, respectively. In conclusion, Bis-(-(2-ethyloctyl)-phthalate) and a mixture of stigmasterol and β-sitosterol were identified for the first time from the stem of C. populnea.

In silico and in vitro biopesticidal activity of Melia dubia (Cav.) plant leaves extract phytocompounds against selected enzymes, proteins, cell lines and Callosobruchus maculatus (Fab.)

Most synthetic pesticides have negative impacts on both human health and the environment, which has led to a global economic and ecological emergency for insect pest control. Crude extracts of phytocompounds from Melia dubia Cav. were tested for their pesticidal effects on a certain enzyme cell line. An in silico molecular docking analysis of phytocompounds showed that the enzymes Glutathione S-Transferase (7RKA), Mytocontrial (5H3F), Acetylcholinesterase (7QAK), GABA receptor (7WGT), and DNA nucleotidylexotransferase (6GO4) interacted strongly with the phytocompounds. Compared to Dichlorvos and Malathion, the substances Guanosine (1) and Medroxyprogesterone (2) showed higher in-silico biopesticidal efficacy against Callosobruchus maculatus (Fab.). A silica gel column chromatographic technique was used to isolate Compounds 1 and 2. In vitro studies revealed that, after 96 hours, Guanosine (90.4% and LC50 value 5.63 mg/ml) caused the maximum toxicity of C. maculatus compared to the reference pesticides Dichlorvos (84.6% and LC50 value 5.94 mg/ml) and Malathion (92% and LC50 value 5.62 mg/ml). Comparing the results to the reference drugs, guanosine (1) showed potential as a pesticidal agent. Therefore, these particular compounds may provide alternative treatments that enhance the plants under investigation's historical use.

Distribution, Associated Risks and Sources of Organochlorine Pesticides in Farmland Soils from Ethiope West Area of Delta State, Nigeria

rganochlorine pesticides (OCPs) usage provides many advantages for agriculture; however, there are also significant concerns to the environment and public health. Since there is little information available on OCPs' distribution, associated risks and sources in Nigerian farmland soils, this study was carried out. Soil samples were collected from farmlands in ten communities. Samples were extracted with hexane/dichloromethane and cleaned up in a column of silica gel and florisil. The OCPs were measured using a gas chromatograph-mass spectrometry (GC-MS). The ∑20 OCPs levels in the soils varied between 47.5 and 109 ng/g. The OCPs homologues distribution in the soils was in the order of ∑DDTs > ∑Drins > ∑Chlordane > ∑BHCs > ∑Endosulfan. The risks assessment result indicated that there was adverse ecological effect on organisms residing in the soils and there is the likelihood that this effect will be frequently observed. Moreover, there was potential non-carcinogenic and carcinogenic risks for persons exposed to OCPs in these farmland soils. The result of the source identification indicated that historical usage was the main source of OCPs in these farmland soils. Keywords: Soil, Farmland, OCPs, Non-carcinogenic, Carcinogenic, Ethiope West

New ring-A modified cycloartane triterpenoids from Dysoxylum malabaricum bark: Isolation, structure elucidation and their cytotoxicity

The Genus Dysoxylum (Meliaceae) consists of approximately 80 species that are abundant in structurally diverse triterpenoids. The present study focused on isolating new triterpenoids from the bark of Dysoxylum malabaricum, one of the predominant species of Dysoxylum present in India. The methanol-dichloromethane bark extract was subjected to LCMS profiling followed by silica gel column chromatography and HPLC analysis to target new compounds. Two new ring A-modified cycloartane-type triterpenoids (1 and 2) were isolated from the bark extract. Spectroscopic methods like NMR, HRESIMS data, and electronic circular dichroism calculations elucidated the structuresandabsolute configurations of the isolated compounds. These compounds were evaluated for their cytotoxic potential against breast cancer cells and displayed notable cytotoxicity. Compound 1 exhibited the highest cytotoxicity against the MDA-MB-231 cells and induced apoptotic cell death. Also, it was able to inhibit glucose uptake and increase nitric oxide production in breast cancer cells.

Antioxidant and Antibacterial Properties of 1,3-Dihydroxy-,2', 2'-Dimethylpyrano-(5,6)-Xanthone from Streptomyces sp. SU84.

<b>Background and Objective:</b> The SU84 was isolated from the rhizosphere of <i>Curcuma longa</i> and identified to be <i>Streptomyces</i> sp. via analysis of its 16S rDNA sequence, chemotaxonomy and morphology. This study aimed to isolate major compounds from the extract culture of strain SU84 and evaluate their antibacterial activity. <b>Materials and Methods:</b> The TLC and silica gel column chromatography were used to purify major compounds, elucidate 1,3-dihydroxy-,2',2'-dimethylpyrano-(5,6)-xanthone (compound <b>1</b>) and lupeol (compound <b>2</b>) using mass spectrometry and nuclear magnetic resonance. One new chemical, compound <b>1</b>, was first isolated from microbial sources. Antibacterial, antioxidant and cytotoxic properties of these compounds were carried out. <b>Results:</b> Various bioassays showed that compound <b>1</b> displayed antibacterial property against Gram-positive bacteria, with a minimum inhibitory concentration of 8-32 μg/mL and minimum bactericidal concentration of 32-128 μg/mL. In addition, the purified compounds were tested against normal cell lines using tetrazolium assay. The results did not show cytotoxic property against L929 and Vero cells, with IC<sub>50</sub> values of >512.00 μg/mL. Compounds <b>1</b> and <b>2</b> have also antioxidant properties, with IC<sub>50</sub> values of 16.67±7.48 and 38.86±8.45 μg/mL, respectively. <b>Conclusion:</b> The findings suggested that compounds of <i>Streptomyces</i> sp. SU84 displayed antibacterial and antioxidant properties without cytotoxic activity. Extensive studies of compound <b>1</b> may be useful for the advancement of improved methods for avoidance, control and management of bacterial infections and metabolic-related free radical contribution.

Development of superoxide dismutase based visual and spectrophotometric method for rapid differentiation of fresh and frozen-thawed buffalo meat

Study aimed to develop biomarker-based assay for rapid detection of fresh and frozen-thawed buffalo meat in the supply chain. The method is based on development of a solvent system and identification of suitable substrate and developer for screening of biomarkers. For the confirmation column chromatography, gel electrophoresis and Western Blotting were carried out. Validation was done by intra- and inter-day validation, storability study, and determination of thermal history. Best results were shown with pH 8.0 Tris-HCl; extraction buffer, 205 µM nicotinamide adenine dinucleotide hydrogen; substrate, 184 µM Nitroblue tetrazolium, and 1.9 µM phenazine methosulfate; developer. The thermal history ranged from 0.14 to 0.17 during storage at −20 °C. The intra- and inter-day assay precision (CV %) ranged from 5.3 to 6.5 %; in chilled and 14.1 – 9.2 % in frozen-thawed samples. The study confirmed SOD as a viable biomarker. Developed method using SOD has significant potential for rapidly differentiating chilled or frozen-thawed meat.

Study on chemical components of Hypericum himalaicum and mechanism of anti-inflammatory based on network pharmacology and molecular docking technology

The chemical constituents of ethyl acetate from Hypericum himalaicum were isolated by silica gel column chromatography, gel column chromatography, and high-performance liquid chromatography. The structure of the isolated compounds was identified by modern spectral techniques(NMR, MS, IR, and UV), and the potential anti-inflammatory targets and action pathways were analyzed and predicted by network pharmacology and molecular docking methods.Ten compounds were isolated from H. himalaicum and identified as 5,9,11-trihydroxy-3,3-dimethyl-3H,8H-benzo[6,7][1,4]dioxepino[2,3-f]chromen-8-one(1), betulinic acid(2), demethyltorosaflavone C(3), kaempferol(4), quercetin(5), hyperwightin B(6), toxyloxanthone B(7), 1,7-dihydroxy-xanthone(8), emodin(9), and 1,7-dihydroxy-4-methoxy-xanthone(10). Among them, compound 1 was a new compound, and compounds 2-10 were isolated from H. himalaicum for the first time. Network pharmacology screened 60 key anti-inflammatory targets. By acting on TNF, AKT1, CASP3, and other key targets, involving PI3K-AKT signaling pathway, IL-17 signaling pathway, VEGF signaling pathway, MAPK signaling pathway, and other signaling pathways, and phosphorylation, cell migration and movement, protein tyrosine kinase, and other biological processes were regulated to achieve anti-inflammatory effects. The results of molecular docking show that the above components have good binding properties with the core targets.

In vitro antimicrobial and antioxidant activities, essential oil composition, and in silico molecular modeling analysis of secondary metabolites from roots of Verbascum sinaiticum.

Verbascum sinaiticum is locally used to treat wound, stomachache, viral infection, cancer, sunstroke fever, abdominal colic, diarrhea, hemorrhage, anthrax, and hepatitis. The objective of this study was to identify the compounds and to evaluate the antimicrobial and antioxidant activity of the extracts and isolated compounds from V. sinaiticum. The 1H-NMR, 13C-NMR, and DEPT-135 were used to elucidate the structures of isolated compounds. Essential oils were extracted by hydrodistillation method and their chemical analyses were performed by GC-MS. The broth microdilution method was used to evaluate the antimicrobial activity. The radical scavenging activity of the extracts and isolated compounds were evaluated using DPPH method. Silica gel column chromatographic separation of root extracts afforded seven known compounds: 3'-(4''-methoxy phenyl)-3'-oxo-propionyl hexadecanoate (1), harpagoside (2), pulverulentoside I (3), scrophuloside B4 (4), scropolioside A (5), scropolioside-D2 (6), and harpagide 6-O-β-glucoside (7), which are all reported from this species for the first time. The EO extracts from leaves and roots were the most susceptible to Streptococcus agalactiae, with a 2 mg/mL MIC. The EO from roots was effective against Candida albicans and Trichophyton mentagrophytes, with a MIC of 8 mg/mL. The MeOH and CH2Cl2/CH3OH (1:1) root extracts showed the maximum activity against S. epidermidis with MIC values of 0.25 mg/mL. The strongest antibacterial effects were demonstrated against Staphylococcus epidermidis, which exhibited a 0.0625 mg/mL MIC for compound 1. The strongest radical scavenging activity was exhibited by the methanol extract (IC50 = 3.4 μg/mL), and compounds 4, 6, 5, 3, 7, and 2 with IC50 values of 3.2, 3.38, 3.6, 3.8, 4.2, and 4.7 μg/mL, respectively, in comparison with ascorbic acid (IC50 = 1.3 μg/mL). The results of the molecular docking analysis of compounds revealed minimal binding energies range from -38.5 to -43.1 kJ/mol, -33.1 to -42.7 kJ/mol, -34.7 to -39.3.7 kJ/mol, -25.5 to -37.6 kJ/mol against human myeloperoxidase (PDB ID: 1DNU), murA enzyme (PDB ID: 1UAE), human topoisomerase IIβ (PDB ID: 4fm9), S. epidermidis FtsZ (PDB number: 4M8I) proteins, respectively. The docking results and the in vitro antibacterial activity are in good agreement. These findings show that the isolated compounds 2-7 can act as potential antioxidants and strong antibacterials against Staphylococcus aureus and S. epidermidis. As a result, V. sinaiticum root extracts have the potential to be effective in treating diseases caused by bacteria and free radicals, as long as further investigation has been suggested for the ultimate decision of this plant's potential candidate.

Molecular docking, molecular dynamics, MM/PBSA approaches and bioactivity studies of nepetanudoside B isolated from endemic Nepeta aristata

Nepetanudoside B (NNB) was isolated from aerial parts of endemic Nepeta aristata crude extract (CH3OH-CHCl3) using silica gel (n-hexane, methanol, ethyl acetate, and dichlorometane, respectively) and sephadex LH-20 (65% Methanol-35% Chloroform) column chromatographies. Preparative-HPLC was used to purify NNB after activity-guided isolation of methanol sub-fractions with enzyme inhibitory and DNA protective properties. The NNB was determined using 1H,13C, COSY, HSQC, HMBC, and LC-MS/MS. The study compared the effects of NNB with conventional drugs in terms of its ability to inhibit enzymes such as urease, α-amylase, carbonic anhydrase (CA), lipase, α-glucosidase, and tyrosinase, as well as its ability to protect DNA. Enzyme kinetic and molecular docking were also used to evaluate this. NNB exhibited the best inhibitory activity on urease (1.28 ± 0.00 µg/mL), lipase (5.83 ± 0.10 µg/mL), BChE (3.73 ± 0.46 µg/mL), tyrosinase (7.39 ± 0.00 µg/mL), α-glucosidase (10.95 ± 0.00 µg/mL), α-amylase (22.11 ± 1.03 µg/mL) and AChE (25.68 ± 3.32 µg/mL), respectively. NNB has higher MolDock scores with binding energy in α-glucosidase (-233) and BChE (-8.90 kcal/mol). In enzyme kinetics studies, it was determined that urease, AChE, α-glucosidase, lipase, and CA were non-competitive , while BChE and tyrosinase were competitive inhibition mechanisms. Their Ki values were calculated as 0.09, 0.24, 0.09, 0.10, 0.08, 0.05, and 0.07 mM, respectively. Molecular dynamics simulation studies were performed for the interactions of NNB-BChE with MM/PBSA binding free energey RMSD, RMSF, Rg, SASA, and also the number of hydrogen bonds was calculated. The suitability and effectiveness of NNB have been proven in the food and pharmaceutical industries. The NNB molecule may lead to development studies as a BChE inhibitor. Communicated by Ramaswamy H. Sarma

A high-performance polymer composite column for coronavirus nucleic acid purification

Here, we report the development of a novel polymer composite (PC) purification column and kit. The performance of the PC columns was compared to conventional silica gel (SG) columns for the purification of nucleic acids from coronaviruses, including SARS-CoV-2, in 82 clinical samples. The results shows that PC-based purification outperforms silica gel (SG)-based purification by enabling a higher sensitivity (94%), accuracy (97%), and by eliminating false positives (100% specificity). The high specificity is critical for efficient patient triage and resource management during pandemics. Furthermore, PC-based purification exhibits three times higher analytical precision than a commonly used SG-based nucleic acid purification thereby enabling a more accurate quantification of viral loads and higher reproducibility.

Halogenated organic pollutants (HOPs) in marine fish collected from central-northern coastal waters in Vietnam

ABSTRACT In this work, three groups of halogenated organic pollutants (HOPs) including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine compounds (OCPs) were analysed simultaneously in twenty-six fish species from coastal waters along the North and Central of Vietnam. Samples were randomly collected, dry-free freeze for pre-treatment, extracted by accelerated solvent extraction combined with cleaning up on multi-layers silica gel column before analysing on the GC-MS/MS system. The concentration of analytes was quantified by internal standard method and controlled with corresponding label standards. The decreasing order of HOP concentrations was ∑20OCPs (mean/median: 158/139 ng/g-wet weight (ww), range: 31.1-406 ng/g-ww) > ∑28PCBs (mean/median: 46.6/36.5 ng/g-ww, range: 5.92-225 ng/g-ww) > ∑8PBDEs (mean/median: 28.7/4.76 ng/g-ww, range: 0.26-212 ng/g-ww). The mean concentration of BDE-209 was the highest distribution (76.5%) in PBDE group, followed by BDE-154 (6.6%), and BDE-153 (5.7%). For PCBs group, hexa-CBs were the most contribution among PCBs and up to 26.1%, followed by Penta-CBs (24.4%), and Tetra-CBs (18.2%) in concentration. The mean concentration of ∑DDTs, accounting to 61.6% of total OCPs, contributed the highest level in this OCP group. The ratio of (DDE+DDD)/DDT in all samples was higher than 1, showing that DDTs were mainly derived from historical. The equivalent toxicity (TEQ) values of 12 dl-PCBs in all samples ranged between 1.1-5.9 ng TEQ/g-ww. The estimated daily intake (EDI) is lower than the Acceptable Daily Intake (ADI) set by FAO/WHO, 1975 (20,000 ng/kg-bw/d for DDTs and 5,000 ng/kg-bw/d for γ-BHC). Intakes of HOPs through the consumption of the marine fish from the studied areas might not subject about health risks to residents living of the coastal areas. However, it is important to know current pollution status and further control marine food pollution in Vietnam as well as propose the appropriate solutions to improve this issue.

Red blood cell alloimmunization in blood transfusion-dependent β thalassemia major patients in Sana’a City-Yemen

The development of erythrocyte alloantibodies complicates transfusion therapy in β thalassemia major patients. These antibodies increase the need for blood and intensify transfusion complications. Data on erythrocyte alloimmunization is scarce in Yemeni thalassemia patients. We studied the frequency of alloimmunization in multitransfused β-thalassemia major patients and investigated risk factors that affect antibody formation. Blood samples were taken from 100 β thalassemia major patients who received multitransfused leukodepleted packed red-blood cells. Antibody screening and identification were performed by indirect antiglobulin test using the gel column technique. All patients were tested for autoantibodies using autocontrol and direct antiglobulin test. No adsorption test was done as no autoantibodies were detected in any patient. In our study of 100 β-thalassemia patients, 50 were male and 50 were female with ages ranging from 1 to 30 years. Alloantibodies were present in 6% of patients, while no autoantibodies were detected. Of the 17 alloantibodies identified, the majority were directed against Kell (41.2%) and Rh (29.4%) blood groups. Alloimmunization was significantly associated with age group and sex (p = 0.013, p = 0.030), respectively in β thalassemia major patients. The development of alloantibodies was not significantly associated with duration, total number of transfusions and splenectomy (P = 0.445, P = 0.125, P = 0.647). No autoantibodies found in patients with β thalassemia major. The study found low rates of erythrocyte alloimmunization in multitransfused β-thalassemia major patients, but significant alloantibodies were produced primarily from Kell and Rh blood groups, suggesting the need for providing phenotypically matched cells for selective antigens to improve transfusion efficiency.

Green extraction of puromycin-based antibiotics from Streptomyces albofaciens (MS38) for sustainable biopharmaceutical applications.

Background: Microbial secondary metabolites have shown promise as a source of novel antimicrobial agents. In this study, we aimed to isolate, characterize, and evaluate the antimicrobial activity of compound from a novel Streptomyces albofaciens strain MS38. The objective was to identify a potential bioactive compound with broad-spectrum antimicrobial properties. Methods: The isolated strain MS38 on starch casein agar was characterized using morphological, physiological, and molecular identification techniques. The compound was obtained from the fermented broth through extraction with n-butanol and further purification using silica gel column chromatography and high-performance liquid chromatography (HPLC). Structural elucidation was conducted using Ultraviolet (UV), Infrared (IR), nuclear magnetic resonance (NMR), and mass spectrometry (MS) techniques. The antimicrobial activity was evaluated using the agar well diffusion method and the microplate Alamar blue assay (MABA). Results: The isolated strain MS38 was identified as novel S. albofaciens based on morphological characteristics and confirmed by 16S sequences analysis and MALDI-TOF MS. The compound obtained from the fermented broth exhibited substantial antimicrobial activity against a variety of pathogenic bacteria and fungi. Structural analysis revealed a complex chemical structure with characteristic functional groups indicative of potential antimicrobial properties. The compound demonstrated strong activity against both Gram-positive (Staphylococcus Spp.) and Gram-negative (Klebsiella pneumoniae and Escherichia coli) bacteria, as well as fungi, including Candida albicans and Trichophyton rubrum. Conclusion: This study successfully isolated and characterized a bioactive compound from a novel S. albofaciens MS38. The compound exhibited significant antimicrobial activity against a range of pathogenic microorganisms. These findings underscore the importance of exploring microbial biodiversity for the discovery of novel antimicrobial agents. This study contributes to the growing knowledge of microbial secondary metabolites with potential therapeutic value.

Argininyl-Fructosyl-Galactose: A Novel Amino Acid Derivative improves Cisplatin-induced Intestinal Toxicity via Reactive Oxygen Species- mediated Apoptosis Pathway.

Based on the Maillard reaction principle of red ginseng, this study innovatively synthesized a new amino acid derivative by combining arginine with lactose through simulated synthesis and was separated and purified through repeated silica gel and polyacrylamide gel (Bio-gel P-II) column chromatography. The work was aimed at elucidating the synthesis of a novel amino acid derivative and investigating the intestinal protective activity of the novel amino acid derivative and possible molecular mechanism by establishing the intestinal injury model induced by cisplatin in mice. The purity and molecular weight of the amino acid derivatives were determined to be by electrospray ionization mass spectrometry (ESI-MS). Subsequently, by establishing cisplatin (20 mg/kg)-induced intestinal injury in vivo for 10 days and IEC-6 cell model. The biochemical indexes and histopathological analysis were used to evaluate the oxidative stress and inflammatory and pathological changes of intestinal tissue in mice. The protein expression levels of p-Nuclear transcription factor-κB (p-NF-κB), cleaved caspase 3/caspase 3, cleaved caspase 9/caspase-9, Bcl-2, Bax, cytochrome C, phosphatidylinositol 3-kinase (PI3K), Protein Kinase B (Akt), p-PI3K, p-Akt were quantified through immunofluorescence staining and western blot analysis. The new amino acid derivatives of chemical structure were identified to be 1- (arginine-Nαgroup)-1-deoxy-4-O-(β-D-galactopyranosyl)-D-fructose, named Argininylfructosyl- galactose (AFGA, C18H34N4O12). The results showed that pretreatment with a single AFGA dose remarkably alleviated cisplatin-evoked intestinal oxidative stress injury, and the levels of reactive oxygen species (ROS) were lessening in IEC-6 cells (p<0.05, p<0.01) and could effectively reduce the secretion of TNF-α and IL-1β in serum and the expression level of NF-κB protein in intestinal tissues (p<0.01). Meantime, AFGA also significantly suppressed the caspase 3, caspase 9, cytochrome C and Bax protein expression in intestinal tissue in mice (p<0.01), and regulated the PI3K/Akt pathway (p<0.05, p<0.01). Importantly, the molecular docking results of AFGA also suggested a better binding ability with the above-mentioned related target proteins. The results clearly revealed AFGA as a potential multifunctional therapeutic agent with a clear protective effect against cisplatin-induced intestinal injury may be related to the PI3K/Akt signaling pathway.

Medium Optimization and Fermentation Kinetics for Antifungal Compounds Production by an Endophytic Paenibacillus polymyxa DS-R5 Isolated from Salvia miltiorrhiza.

An endophytic bacterium Paenibacillus polymyxa DS-R5 which can effectively inhibit the growth of pathogenic fungi was isolated from Salvia miltiorrhiza in our previous study. By using hydrochloric acid precipitation, methanol extraction, silica gel column isolation, dextran gel chromatography column, and HPLC, 3 compounds with antifungal activity were isolated. To further improve the production of antifungal compounds produced by this strain, fermentation medium was optimized using one-factor-at-a-time, Plackett-Burman design, and Box-Behnken design experiments. Through statistical optimization, the optimal medium composition was determined to be as follows: 14.7g/l sucrose, 20.0g/l soluble starch, 7.0g/l corn steep liquor, 10.0g/l(NH4)2SO4, and 0.7g/lKH2PO4. In this optimized medium, the highest titer of antifungal compounds reached 3452 U/ml, which was 123% higher than that in the initial medium. In addition, in order to guide scale-up for production, logistic and Luedeking-Piret equations were proposed to predict the cell growth and antifungal compounds production. The fermentation kinetics and empirical equations of the coefficients (X0, Xm, μm, α, and β) for the two models were reported, which will aid the design and optimization of industrial processes. The degrees of fit between calculated values of the model and the experimental data were 0.989 and 0.973, respectively. The results show that the cell growth and product synthesis models established in this study may better reflect the dynamic process of antifungal compounds production and provide a theoretical basis for further optimization and on-line monitoring of the fermentation process.