Conventional Column Chromatography Research Articles

Synthesis of 1,2,3-Triazole Functionalized Derivatives of Metronidazole as Potent Inhibitors of Urease: Synthesis via Click Chemistry, In Vitro Urease Inhibition, Kinetics and Molecular Docking Studies

Current study is based on multistep synthesis of sixteen new 1,2,3-triazole functionalized derivatives of metronidazole drug 3-18 by using a Cu(I)-catalyzed 1,3-dipolar azide-alkyne cycloaddition (CuAAC) reaction via a click chemistry approach. All the compounds were purified by using conventional silica gel column chromatography with isocratic eluent. Their structures were confirmed by using various spectroscopic techniques including UV, IR, LR and HR MS, 1H-, 13C-NMR, and 2D-NMR spectroscopy. The library of 1,2,3-triazole derivatives of metronidazole 3-18 was evaluated for urease inhibitory activity, and cytotoxicity against normal cells. Compound 8 (IC50= 6.8 ± 0.8 µM) was found to be the most potent urease inhibitor, while acetohydroxamic acid (IC50 = 20.3 ± 0.4 µM) was used as experimental standard. Compounds 5 (IC50 = 7.9 ± 0.9 µM), 6 (IC50 = 9.5 ± 0.2 µM), 7 (IC50 = 8.5 ± 1.0 µM), 10 (IC50 = 9.3 ± 1.1 µM), and 18 (IC50 = 7.2 ± 0.6 µM) were also found to be potent inhibitors of urease. Parent drug metronidazole also showed a potent urease enzyme inhibitory activity with IC50= 10.54 ± 0.8 µM. All compounds were found to be non-cytotoxic against the human fibroblast (B.J.) cell line. Molecular docking and kinetic studies were performed for compounds 5-8, 10, and 18 which showed that these compounds are competitive inhibitors of urease enzyme inhibition. Urease inhibition is a therapeutic approach to help in the treatment of peptic ulcers, caused by ureolytic bacteria. The initial findings presented herein therefore, deserve further studies.

Chromatographic separation of saponin glycosides from roots of Asparagus racemosus (Wild.) using a modified approach

AbstractAsparagus racemosus (Wild.) (Family: Liliaceae) is extensively used as lactogenic, and the presence of saponin glycosides was found to be responsible for the biological activity. The studies were performed to isolate saponin glycosides from bioactive n‐butanol fraction of methanolic extract prepared from Asparagus racemosus; through a combined application of alumina‐based vacuum column chromatography and silica gel‐based open column chromatography. The process yielded two steroidal saponins, and the comparative spectral studies of the purified saponins revealed them to be shatavarin‐IV and asparanin‐A. This modified and comparatively simple approach for the separation of shatavarin‐IV and asparanin‐A from the roots of Asparagus racemosus is the first report on the isolation of asparanin‐A from Asparagus racemosus using the conventional column chromatography method. The isolated compounds may serve as standards for ensuring the quality of raw materials.

Unprecedented formation of azulicorroles from the scrambling of azulitripyrrane

In this study, we have prepared new tripyrranes embedded with azulene bearing two meso-pentafluorophenyl substituents. They were obtained as diastereomers in high yield which were separated using conventional column chromatography. Their distinct solution structures were unambiguously confirmed by NMR and mass analysis. Our synthetic strategy is simple and straightforward due to the reactivity of 1,3-positions of azulene, which underwent Lewis acid-catalyzed condensation with pyrrole-2-carbinol. These diastereomers were further subjected to acid-catalyzed (CF3COOH) condensation with pyrrole dicarbinol to afford the target N-confused azuliporphyrin (reduced form) in trace amount. However, we obtained the tris-meso-pentafluorophenyl substituted azulicorrole (AzCorA) as major product due to an unprecedented scrambling of the azulitripyrranes. The structural characterization of newly synthesized key precursors and macrocycles was done with the aid of high-resolution mass analyses, and 1H and 2D NMR analyses. The single crystal X-ray structure obtained for AzCorArevealed that the azulene subunit is tilted by 34.03[Formula: see text] due to the steric congestion of inner-NHs.

Isolation, In Vitro and In Silico Anti-Alzheimer and Anti-Inflammatory Studies on Phytosteroids from Aerial Parts of Fragaria × ananassa Duch.

Based on the pharmacological importance of different species of fragaria, this research was carried out for the isolation of bioactive compounds from Fragaria × ananassa. Using the conventional gravity column chromatography followed by small analytical column purification, two major components were isolated from the plant materials. The structures of both compounds (1 and 2) were accurately confirmed with GC-MS analysis by comparison of the fragmentation pattern within the library of the instrument. Further, the NMR analysis was also used to supplement the structural evidence. Compound 1 was observed to be 4,22-cholestadien-3-one, while compound 2 was identified as stigmast-4-en-3-one. Both compounds were evaluated for anticholinesterase, COX/LOX inhibitions and antioxidant assays. Compound 1 exhibited the IC50 values of 20.29, 27.35, 10.70, 80.10 and 7.40 μg/mL against acetylcholinesterase, butyrylcholinesterase, COX-2, COX-1 and 5-LOX, respectively. Similarly, the IC50 values of compound 2 against the same targets were 14.51, 10.65, 8.45, 109.40 and 8.71 μg/mL. Similarly, both compounds were less potent in ABTS and DPPH targets with IC50 values in the range of 185.83–369.86 μg/mL. Despite the low potencies of these compounds in antioxidant targets, they can be considered as supplementary targets in Alzheimer and inflammation. The molecular docking studies for the in vitro anti-Alzheimer and anti-inflammatory targets were also performed, which showed excellent binding interactions with the respective target proteins. In conclusion, the isolated phytosteroids from Fragaria × ananassa were evaluated scientifically for anti-Alzheimer and anti-inflammatory activities using in vitro and molecular docking approaches.

Highly Efficient Separation of Ultratrace Radioactive Copper Using a Flow Electrolysis Cell.

Preparing compounds containing the radioisotope 64Cu for use in positron emission tomography cancer diagnostics is an ongoing area of research. In this study, a highly efficient separation method to recover 64Cu generated by irradiating the target 64Ni with a proton beam was developed by employing a flow electrolysis cell (FE). This system consists of (1) applying a reduction potential for the selective adsorption of 64Cu from the target solution when dissolved in HCl and (2) recovering the 64Cu deposited onto the carbon working electrode by desorbing it from the FE during elution with 10 mmol/L HNO3, which applies an oxidation potential. The 64Cu was selectively eluted at approximately 30 min under a flow rate of 0.5 mL/min from the injection to recovery. The newly developed flow electrolysis system can separate the femtomolar level of ultratrace radioisotopes from the larger amount of target metals as an alternative to conventional column chromatography.

Recovery and Seasonal Variation of Cinnamtannin B-1 from Laurel (Laurus nobilis L.) Pruning Wood Wastes.

Cinnamtannin B-1 (C-B1) is a commercially-available trimeric A-type procyanidin with remarkable cellular actions mainly derived from its high radical scavenging activity. C-B1 is the main phenolic compound of laurel wood, which has previously been isolated by a combination of conventional chromatographic techniques. The first aim of this work was to find laurel trees containing as much C-B1 as possible, and learn about the influence of variables, such as gender and harvest time, on the production of C-B1 by the tree. It was found that all studied trees tend to give higher C-B1 percentages in the May-July period, from 6 % to 18 %, and lower ones around March (spring) and November (fall), from 1 % to 8 %. In a general way, it also seems that the female trees tend to produce a bit more C-B1 (from 2.8 % to 17.3 %) than male ones (from 1.7 % to 13.4 %). In addition, eight minor phenolic compounds [(-)-ent-catechin (1), (-)-ent-epicatechin-(4α→8)-ent-epicatechin (2), (epi)catechin-(4→8)-(epi)afzelechin-(4→8)-(epi)catechin (3), (+)-epiafzelechin-(4β→8)-epicatechin (4), (-)-epicatechin (5), (-)-afzelechin-(4α→8)-epicatechin (6), (epi)afzelechin-(4→8)-(epi)afzelechin-(4→8)-(epi)catechin (7) and (+)-epicatechin-(4β→8,2β→O-7)-epicatechin-(4β→8)-catechin (C-D1)] were found and quantified in the ethyl acetate extract of the wood samples. The second aim of this work was to improve the recovery of C-B1 from laurel wood. The use of the fast centrifugal partition chromatography (FCPC) technique has allowed for a recovery of 96 % of a technical-grade C-B1 (64 % in a previous protocol using conventional column chromatography on silica gel and size-exclusion chromatography).

Chemical constituents of Scrophulariae Radix and their antitumor activities in vitro

The present study investigated the chemical constituents of Scrophulariae Radix and their antitumor activities in vitro. The compounds in the ethyl acetate extract were separated and purified by conventional column chromatographies(such as silica gel, Sephadex LH-20, and ODS column) and semi-preparative high-performance liquid chromatography(HPLC), and their structures were identified by various spectral techniques such as nuclear magnetic resonance(NMR) and mass spectrometry(MS). Twenty-three compounds were isolated and identified as benzyl-β-D-(3',6'-di-O-acetyl) glucoside(1), 5-O-p-methoxybenzoyl kojic acid(2), 5-O-methoxybenzoyl kojic acid(3), 7-O-methylbenzoyl kojic acid(4), 5-O-benzoyl kojic acid(5), methyl ferulate ethyl ether(6), trans-ferulic acid(7), trans-isoferulic acid(8), trans-caffeic acid(9), trans-caffeic acid methyl ester(10), caffeic acid ethyl ester(11), trans-cinnamic acid(12), trans-p-methoxycinnamic acid(13), trans-p-hydroxycinnamic acid(14), trans-p-hydroxycinnamic acid methyl ester(15), 2-(3,4-dihydroxyphenethyl) alcohol(16),(p-hydroxyphenyl) propanoic acid(17), coniferaldehyde(18), sinapaldehyde(19), benzyl β-primeveroside(20), 5-(hydroxymethyl) furfural(21), furan-2-carboxylic acid(22), and decanedioic acid(23). Among them, compound 1 is a new benzyl glucoside, compounds 2-4 are new pyranone compounds, compound 5 is a new natural product of pyranone. The NMR data of compounds 5 and 6 are reported for the first time. Compounds 6 and 20 were isolated from the Scrophularia plant for the first time. Compounds 8, 11, 14, 16, 18, 19, 22, and 23 were isolated from this plant for the first time. The in vitro cytotoxic activities of these compounds against three tumor cell lines(HepG2, A549, and 4 T1) were evaluated. The results showed that compounds 10 and 15 showed cytotoxic activities against HepG2 cells with IC_(50) values of(19.46±0.48) μmol·L~(-1) and(46.10±1.21) μmol·L~(-1).

Seleno-Functionalization of BODIPY Fluorophores Assisted by Oxidative Nucleophilic Hydrogen Substitution

Background: The most current reported methods of chalcogen insertion into BODIPY’s nuclei are based on nucleophilic substitution reactions of halogenated derivatives, metal-catalyzed cross-coupling reactions, or assistance by radical mechanisms. Recent reports describe Oxidative Nucleophilic Hydrogen Substitution (ONHS) reactions involving the functionalization of BODIPY nuclei by thiols, but the generalities of the strategy for other chalcogens was not yet demonstrated. Herein we report our contribution on the selenium-functionalization of BODIPY by ONHS in high yield. Objective: Aryl-Se-functionalization of 2,6-brominated BODIPY’s nuclei by ONHS reaction. Method: The procedure consists of a direct reaction of 2,6-brominated BODIPYs with in situ generated PhSeH in THF, at room temperature, under a nitrogen atmosphere. The corresponding products were isolated and purified by conventional flash column chromatography. Full structure characterization was performed by 1H, 13C, 19F, and 77Se NMR and DFT calculation. Results: Densely functionalized 2,6-dibrominated/3,5-diseleno-BODIPYs were obtained as corresponding products, leading to versatile molecular scaffolds. Their structural features were contrary to those initially expected by the original experimental applied conditions. A mechanistic investigation was performed to conclude that ONHS reaction is governing the transformation, thereby damaging the nucleophilic substitution of the halogen atoms. Conclusion: To sum up, new densely functionalized BODIPY derivatives were synthesized by a highly selective, simple, fast, metal-free, and efficient insertion of PhSe- residues into the 3,5-positions, governed by an Oxidative Nucleophilic Hydrogen Substitution (ONHS) reaction in high yields. It was observed that the presence of halogen (Br) into the 2,6-positions of the BODIPY core is mandatory for the ONHS reaction, which is completely inert when the 2,6-hydrogenated analogues are used in the same experimental conditions.

Studies on phenylpropanoids from Eleocharis dulcis and their hepatoprotective activities

To study phenylpropanoids from Eleocharis dulcis and their hepatoprotective activities. The compounds were separated and purified from ethyl acetate part by conventional column chromatography and preparative liquid chromatography, and their structures were identified by various spectral techniques. The HL-7702 cells damage model of hepatocytes induced by APAP was used to screen and evaluate the hepatoprotective activities of these compounds. Sixteen compounds were isolated from ethyl acetate part of E. dulcis, and their structures were identified as 6'-(4″-hydroxy-3″-methoxy-phenylpropenyl)-1-(10-methoxy-phenylacetone)-1'-O-β-D-glucopy-ranoside(1), susaroyside A(2), clausenaglycoside B(3), clausenaglycoside C(4), clausenaglycoside D(5), emarginone A(6), emarginone B(7), thoreliin B(8), 4-O-(1',3'-dihydroxypropan-2'-yl)-dihydroconiferyl alcohol 9-O-β-D-glucopyranoside(9), 2-[4-(3-methoxy-1-propenyl)-2-methoxy-phenoxy]-propane-1,3-diol(10), 6'-O-(E-cinnamoyl)-coniferin(11), methyl 3-(2-O-β-D-glucopyranosyl-3,4,5,6-tetramethoxyphenyl) propanoate(12), clausenaglycoside A(13), 9-O-(E-cinnamoyl)-coniferin(14), 6'-O-(E-cinnamoyl)-syringin(15), 2'-O-(E-cinnamoyl)-syringin(16). Among them, compound 1 was a new compound. Compounds 2-16 were isolated from this plant for the first time. Among them, compounds 2 and 8 showed certain hepatoprotective activities.

Synthesis of Embelin-Fe complex from Embelia ribes fruits and characterization

• Embelin was isolated from the fruits of the traditionally used medicinal plant Embelia ribes. . • An Embelin-Fe complex was prepared at room temperature following a simple scheme. • The compound was isolated using conventional column chromatography. • Its purity was confirmed using NMR, IR and Mass spectroscopy. Herbal medicine has been used for the prevention and treatment of various health ailments from time immemorial. Embelia Ribes fruits contain several chemical constituents like Embelin, volatile oil, fixed oil, resin, tannin, Christem Bine (Alkaloid) and phenolic acids like Caffeic acid etc. In the present work, Embelin (2, 5-dihydroxy-3- undecyl-p-benzoquinone), is one of the active chemical constituents which is present in the Embelia ribes fruits with known activities was extracted using chloroform solvents and isolated through column chromatography techniques. An Embelin-Fe complex was generated using the isolated Embelin. The synthetic method employed for generating the Embelin-Fe complex was simple and room temperature based. The generated complex is expected to have applications including increased bio activity, as well as possible catalytic potential.

Antioxidant properties, phenolic and mineral profiling, assessment of angiotensin I converting enzyme (ACE) inhibitory potential of Elsholtzia communis (Collett & Hemsl.) Diels from North East India

IntroductionElsholtzia communis (Collett & Hemsl.) Diels, (family: Lamiaceae) is a wild edible plant consumed as a vegetable by many tribes of the North-Eastern states of India. The objective of our study was to explore the antioxidant capacity, phenolic and mineral composition and angiotensin-I converting enzyme (ACE) inhibitory properties of E. communis. MethodsThe leaf, stem, and root extract of E. communis were screened for their antioxidant and ACE inhibitory properties. Quantification of ten phenolics was conducted using reverse phase HPLC-DAD analysis and the five phenolics were isolated using conventional column chromatography and correlated with antioxidant activities using Pearson's coefficient. An assessment of dietary minerals present in the leaf, stem, and root of this herb was carried out using ion chromatography. ResultsThe leaf exhibited the most potent DPPH scavenging and ACE inhibitory activity with IC50 value of 20.38± 0.061 µg/mL and 20.34± 0.025 µg/mL respectively. Leaf was recognized as the most prominent source of TPC, TFC, K+, Na+, Ca2+ and Mg2+. The HPLC analysis had established the stem as a rich source of gallic acid (1.08±0.002 mg/g DW), quercetin (0.26±0.001 mg/g DW) and p-coumaric acid (0.17± 0.001 mg/g DW), while catechol (0.19±0.005 mg/g DW) and vanillic acid (0.07±0.005 mg/g DW) contents were found to be highest in the leaf. NMR and HRMS data confirmed the structures of the isolated phenolics. ConclusionThus, diverse pharmacological behavior and distinctive presence of nutraceuticals and important dietary minerals suggest that this herb may be useful in the future development of herbal formulations.

High-Throughput Process Development: II-Membrane Chromatography.

Membrane chromatography is gradually emerging as an alternative to conventional column chromatography. It alleviates some of the major disadvantages associated with the latter, including high-pressure drop across the column bed and dependence on intraparticle diffusion for the transport of solute molecules to their binding sites within the pores of separation media. In the last decade, it has emerged as a method of choice for final polishing of biopharmaceuticals, in particular, monoclonal antibody products. The relevance of such a platform is high in view of the constraints with respect to time and resources that the biopharma industry faces today.This protocol describes the steps involved in performing HTPD of a membrane chromatography step. It describes the operation of a commercially available device (AcroPrep™ Advance filter plate with Mustang S membrane from Pall Corporation). This device is available in 96-well format with a 7μL membrane in each well. We will discuss the challenges that one faces when performing such experiments as well as possible solutions to alleviate them. Besides describing the operation of the device, the protocol also presents an approach for statistical analysis of the data that are gathered from such a platform. A case study involving the use of the protocol for examining ion-exchange chromatography of the Granulocyte Colony Stimulating Factor (GCSF), a therapeutic product, is briefly discussed. This is intended to demonstrate the usefulness of this protocol in generating data that are representative of the data obtained at the traditional lab scale. The agreement in the data is indeed very significant (regression coefficient 0.9866). We think that this protocol will be of significant value to those involved in performing high-throughput process development of membrane chromatography.

Application of choline chloride deep eutectic solvents and high-speed counter-current chromatography to the extraction and purification of flavonoids from the thorns of Gleditsia sinensis Lam.

Flavonoids are the most important and effective constituents in the thorns of Gleditsia sinensis Lam., which have been known to show antimicrobial, antiviral, anticancer, and anticoagulant activities. However, efficient extraction and separation methods for these flavonoids are not currently established. To develop an efficient method for efficient extraction and rapid separation of flavonoids from the thorns of G. sinensis using choline chloride deep eutectic solvents (DESs) and high-speed counter-current chromatography (HSCCC). As for extraction, DES composed of choline chloride and 1,4-butanediol at 1:4 mole ratio, at an extraction temperature of 55°C, 20% of water content, 1:30 mg/mL for solid-liquid ratio, and 45 min for extraction time were selected as the optimised extraction method for flavonoids from the thorns of G. sinensis. As for separation, dichloromethane-methanol-n-butanol-water (4:3:0.5:2, v/v) was applied to develop a successful strategy for purification of the flavonoids by HSCCC. Totally, five flavonoids, including padmatin (1, 3.7 mg), isovitexin (2, 2.5 mg), 3',5,5',7-tetrahydroxyflavanonol (3, 11.2 mg), 7,4'-dihydroxy-5,3'-dimethoxyflavanonol (4, 4.1 mg), and quercetin (5, 3.8 mg), were successfully obtained from 250 mg of the extracted flavonoids by HSCCC. Results demonstrated that the combination of DES and HSCCC is a powerful technique for the extraction, and isolation of flavonoids from the thorns of G. sinensis compared with conventional organic solvent extraction and column chromatography, which have been proven to provide higher extraction efficiency for flavonoids and rapidly obtain the quality control markers of flavonoids from the investigated plant.

Isolasi Dan Karakterisasi Senyawa Steroid Dari Ekstrak Biji Mahoni (Swietenia mahagoni Jacq.)

Mahogany seeds (Swietenia mahagoni Jacq.) Have many benefits as drugs such as febrifuge, diabetes (Diabetes Mellitus), high blood pressure, fat decay, colds, colitis, diarrhea, wounds, and ulcers. Swietenia mahagoni Jacq Contain steroid compounds. This study aims to determine the characterization of steroid compounds isolated from mahogany seed extract (Swietenia mahagoni Jacq.). Extracts were obtained from maceration processes using n-hexane, ethyl acetate, and ethanol 70% solvents with percent of rendament of 6.34%, 7.34%, and 8% respectively. The test results for the chemical content of ethyl acetate extract positively contained steroids. 5 grams of extract was carried out using conventional column chromatography to produce 6 fractions. Fraction 6 were selected and continued with preparative thin layer chromotography and produced 2 isolates. Isolates P2b which showed one tonggal stain on the TLC profile with a value of Rf 0.50 were continued to be analyzed by UV-Vis and FT-IR spectrophotometry.The results of UV-Vis spectrophotometric isolates P2b had maximal absorption at a wavelength of 253.50 nm. FT-IR data shows the presence of functional groups C-H, C-O, C = O, C = C, and O-H whichare thought to be steroid compounds.

Isolation, identification, biological estimation, and profiling of glucosinolates in Isatis indigotica roots

Four main glucosinolates (progoitrin, epiprogoitrin, gluconapin, and neoglucobrassicin) were isolated and identified from Isatis indigotica roots (Isatidis Radix). Among these, neoglucobrassicin was the first indole glucosinolate isolated from this herb, and its structure was elucidated by NMR, MS, and X-ray diffraction analysis. The glucosinolate components of Isatidis Radix have been profiled by combined use of a conventional preparative column chromatography method and a new UHPLC-QTOF-MS/MS method, and validated by simultaneous analysis of intact and desulfurized GLS. A total of 16 glucosinolates (GLS) including 12 aliphatic GLS, two aromatic GLS, and two indole GLS were identified on the basis of their UV profiles, MS/MS data, and/or by comparison with reference substances. Among these nine GLS were reported from I. indigotica for the first time. The total GLS, four isolated GLS, and (R,S)-goitrin (a degraded product of progoitrin and epiprogoitrin) have been estimated in vitro for anti-influenza viral, anti-bacterial, and anti-inflammatory activities. All the glucosinolate samples were inactive against H3N2 virus and four pathogenic bacteria, and two previously unnoticed GLS (gluconapin and neoglucobrassicin) showed significantly anti-inflammatory activity against the respiratory burst of mouse macrophages.

Isolation of stigmasterol from hexane extract of leaves of Pisonia grandis R.Br, in vitro anti-diabetic and its molecular docking studies

Pisonia grandis R.Br belonging to the family Nyctaginaceae is a widely distributed evergreen tree in India known for its medicinal uses. The study was aimed to investigate the anti-diabetic property in the leaves of Pisonia grandis R.Br. The isolation and purification were performed by the conventional column chromatography and the resultant yield was found to be a white crystalline powder, which was further subjected for characterization through IR, 1H NMR, 13C NMR and Mass spectroscopy. From the characterization data, the isolated compound was identified as stigmasterol, it was first time isolated from the hexane extract of the leaves. The α-amylase inhibitory activity of stigmasterol from the hexane extract of the leaves of Pisonia grandis R.Br showed high potent activity with an IC50 value of 46μg/ml. The anti-diabetic activity of the compound against α-amylase and four other diabetic enzymes- α-glucosidase acid phosphatase, endo-β-N acetaglucosaminidase and β-glucuronidase were further investigated by molecular docking studies and proved that stigmasterol can be a potential anti-diabetic agent.

A new strategy based on acid-alkali complexation for rapidly and accurately fishing phytochemicals in Sennae Folium

ObjectiveThere are some anthraquinones, anthraquinones and flavonones in Sennae Folium which exhibited significant acidity, such as sennoside A/B and sennoside C/D. The current strategies used in separating these components are mainly based on conventional column chromatography which is time consuming, laborious and costly. This study is aimed at exploring a method of precipitation extraction of acid components in Sennae Folium. Using alkaloid as a “hook”, it is reasonable to use the principle of “acid-alkali complexation” to "fish" the acidic components in Sennae Folium. MethodsIsothermal titration calorimeter (ITC) was used to measure the extraction efficiency of different alkaloids. Then, alkaloid determined by ITC was mixed with extracting solution of Sennae Folium to form complex. High performance liquid chromatography coupled with mass spectrometry (HPLC-MS2) was used to investigate the ingredients “fished” by berberine (Ber). The mechanism of “fishing” process was explained by ITC, optical activity, fluorescence spectrometry and scanning electron microscope. ResultsThe ITC results proved that the choice of “hook” was particularly important in the process of “fishing”. Among the hooks, the fishing efficiency of the isoquinoline alkaloids (Ber) was the highest, reaching 10.3%. Nine ingredients were detected and determined by HPLC-MS2, and the main components were sennoside A/B and sennoside C/D. Based on ITC test of Ber and sennoside A, the combination mechanism of the two ingredients was a chemical reaction with a nearly binding ratio (2:1). Fluorescence and optical properties of the active ingredients were changed after complexation. By scanning electron microscope, we found that two types of components had obviously self-assembled behavior during the formation process. ConclusionBer successfully “fished” the main acidic components, sennoside A/B and sennoside C/D, from Sennae Folium. Combined with different characterizations, the “fishing” process was determined as a chemical association reaction induced by electrostatic interaction or π-π stacking. Therefore, with special identification ability, the “fishing” process had the potential of practical application.

Unusual Racemization of Tertiary P-Chiral Ferrocenyl Phosphines.

Tertiary phosphines are generally known to withstand inversion under moderate conditions. In this work, a remarkable racemization process of three P‐chiral ferrocenyl phosphines is reported. Subjected to conventional column chromatography as highly enantioenriched compounds, they greatly experienced racemization when collected at the column outlet within minutes. Initially, attention was drawn to this unusual inversion behavior after observing that the superb enantiomeric excess of these ligands (>95 % ee in all cases) was almost lost in their corresponding ruthenium(II) complexes. Successively excluding possible racemization causes, these P‐chiral ferrocenyl phosphines were found to undergo a significant, acid‐catalyzed racemization process at room temperature within a few minutes. This process is mainly observed during standard column chromatography by using conventional silica or alumina, but can also be triggered deliberately by addition of certain acids. Therefore, the stereochemical preservation of P‐chiral phosphines during their purification may per se not always be guaranteed, since column chromatography is the most frequently used technique for purifying such types of compounds.

Radical scavenging and antiproliferative effect of novel phenolic derivatives isolated from Nerium indicum against human breast cancer cell line (MCF-7)—an in silico and in vitro approach

Multiple drug resistance and increased side effects due to allopathic drugs has warned scientific community with a global alarm to identify molecules from natural sources to combat diseases with minimum or no side effects. The present investigation was aimed to identify and isolate secondary metabolites from traditionally used Nerium indicum using conventional column chromatography which led to the isolation of two compounds, C-I (fractions NB4f1) and C-II (fractions NC13b1). Further characterized, it is elucidated using spectral data and identified as N-(4-hydroxy-phenyl)-2-methoxy-2-phenyl-acetamide, molecular formula C15H15NO3, and molecular weight 257.3 (C-I) and N-(4-hydroxy-phenyl)-2-phenyl-N-phenylacetyl-acetamide, molecular formula C22H19NO3, and molecular weight 345.4 (C-II). Further, the isolated compounds were investigated using in silico approach by Autodock tool with four different proteins specific for cancer and in vitro assessed cell proliferation, and apoptosis against human breast cancer MCF 7 cell line. The results of the in silico model demonstrated potent binding affinity of both compounds with the proteins representing that the isolated molecules could be a drug of choice for cancer. Further, the isolated compounds revealed significant inhibition of cell proliferation (IC50 values 21μg/mL for C-I, 19μg/mL for C-II) with induced apoptosis with nuclear condensation effect on the MCF 7 cells in in vitro condition even at very low concentration. Compound treatment to MCF-7 cell line represented bright fetches indicating condensed chromatins and higher level of nuclear fragmentation with DAPI staining, indicating higher cell death due to induced apoptosis and confirmed using flow cytometry analysis representing inhibition of cell proliferation at S phase. Graphical abstract.

Improved protein A resin for antibody capture in a continuous countercurrent tangential chromatography system.

Continuous countercurrent tangential chromatography (CCTC) enables steady-state continuous bioprocessing with low-pressure operation and high productivity. CCTC has been applied to initial capture of monoclonal antibodies (mAb) from clarified cell culture harvest and postcapture polishing of mAb; however, these studies were performed with commercial chromatography resins designed for conventional column chromatography. In this study, a small particle size prototype agarose resin (20-25 µm) with lower cross-linking was co-developed with industrial partner Purolite and tested with CCTC. Due to increased binding capacity and faster kinetics, the resulting CCTC process showed more than a 2X increase in productivity, and a 2X reduction in buffer consumption over commercial protein A resins used in previous CCTC studies, as well as more than a 10X productivity increase versus conventional column operation. Single-pass tangential flow filtration was integrated with the CCTC system, enabling simple control of eluate concentration. A scale-up exercise was conducted to provide a quantitative comparison of CCTC and batch column chromatography. These results clearly demonstrate opportunities for using otherwise unpackable soft small particle size resins with CCTC as the core of a continuous bioprocessing platform.