Traditional Column Chromatography Research Articles

Examination and Chemical Analysis by GC-MS of Syzygium Cumini Extract(Bark)

The investigation focused on the analysis of the hexane extract obtained from the bark of Syzygium cumini originating from India. Through chromatographic techniques, both traditional column chromatography and gas chromatography mass spectrometry (GC-MS), the oily fraction of the bark was examined, leading to the identification of numerous ester and hydrocarbon compounds. While the initial hexane eluate yielded waxy substances, which were challenging to separate through column chromatography due to their limited quantity, GC-MS analysis facilitated the identification of 39 compounds. These compounds were matched with existing literature through comparisons of retention times, Kovats indexes, and interpretation of mass spectra. Many of these identified compounds find applications across industries such as perfumery, flavoring, deodorants, antiseptics, and pharmaceuticals. This study aimed to elucidate the chemical composition of the hexane extract from S. cumini bark, particularly focusing on the identification of hydrocarbons and esters. Key words: Syzygium cumini (bark), esters, hydrocarbons, signals, peak gas chromatography -mass spectrometry

A Simple, Low‐Blank Batch Purification Method for High‐Precision Boron Isotope Analysis

AbstractBoron (B) isotopes are widely used in the Earth sciences to trace processes ranging from slab recycling in the mantle to changes in ocean pH and atmospheric CO2. Boron isotope analysis is increasingly achieved by multi‐collector inductively coupled plasma mass spectrometry, which requires separation of B from the sample matrix. Traditional column chromatography methods for this separation have a well‐established track record but are time consuming and prone to contamination from airborne blank. Here, we present an extensive array of tests that establish a novel method for B purification using a batch method. We discuss the key controls and limitations on sample loading, matrix removal and B elution including sample volume, ionic strength, buffer to acid ratio and elution volume, all of which may also help optimize column‐based methods. We find consistent, low procedural blanks of 10 ± 16 pg and excellent reproducibility: 10 ng NIST RM 8301 foram [8301f] yields 14.58 ± 0.11‰ 2SD n = 15; 2.5 ng 8301f yields 14.60 ± 0.19‰ 2SD, n = 31; and overall long term 2SD on n = 218 samples pooling different sample sizes yields 14.62 ± 0.21‰ 2SD. This method also offers significant advantages in throughput, allowing the processing of 24 samples in ∼5 hr. This boron batch method thus provides a fast, reproducible, low‐blank method for purification of boron for high precision isotopic analyses.

Tunable reduced graphene oxide nanofiltration membrane for efficient retention and separation of dye/salt based on molecular interactions

Effective retention and separation of mixed dyes are critical to treating textile wastewater. Graphene oxide (GO) is an ideal material for treating polluted water attributed to its unique structure and abundant oxygen-containing groups. However, GO still has some limitations, such as unstable performance, poor dye retention and no selective separation performance. Here, we report a weakly reduced graphene oxide (rGO) membrane that can modulate its water permeability and dye retention by controlling the reduction temperature. The water flux (84.35 L m−2 h−1 bar−1) of rGO membranes decreased with increasing reduction temperature but the methylene blue (MB) dye rejection rate (99.09 %) increased with increasing reduction temperature. More interestingly, the rGO membrane has completely different dye rejection rates for MB and methyl orange (MO), allowing the separation of MB and MO mixtures, effectively replacing traditional column chromatography. In addition, we investigated the reasons for the different retention rates and selective separation of dyes by rGO membranes through reduction temperature, contact angle, interlayer distance, electrostatic interactions and molecular dynamics simulations. This work uses a non-expensive and low-energy method to prepare nanofiltration membranes that can be easily extended to construct other stable and efficient filtration membranes for the separation of different dyes and salts.

Synthesis of functional ionic liquid modified silica and its excellent performance in selective separation of artemisinin/artemisitene

To ensure the safety of drugs in clinical use and avoid side effects, the impurity content should be strictly controlled. Artemisitene (ARE) has quite similar structure to that of the antimalarial artemisinin, and thus is difficult to be removed from the target drug. The traditional column chromatography method to purify artemisinin has low separation efficiency and needs lots of organic solvents. In this work, functional ionic liquid (IL), 1-(trimethoxysilyl) benzene-3-vinylimidazolium chloride, modified silica materials were synthesized. Composition of the functional materials were characterized by energy dispersive spectroscopy, FT-IR, and X-ray photoelectron spectroscopy. It was indicated that the designed ionic liquid was successfully grafted onto SiO2. Adsorption capacity of the prepared ionic liquid-based material for artemisinin and artemisitene was evaluated, and it was demonstrated that adsorption of ARE by the functional material was a quick process, and the adsorption kinetics followed the Elovich Model. This kind of IL@SiO2 material exhibited excellent performance in selective separation of artemisitene from artemisinin. Mechanism exploration by spectroscopic analysis revealed that π-π conjugated interactions between the unsaturated bond (the C=C bond and aromatic ring) in the ionic liquid and artemisitene enhanced the molecular recognition capability of IL@SiO2 for ARE, resulting in selective separation of these two structurally analogues.

The applicability of high-speed counter-current chromatography for preparative separation of biosynthesis products: Glycosylation products as example.

Biosynthesis is a promising way to manufacture desired products, however, the purification of its final products is a tough work due to the huge amount of reaction matrix. Liquid stationary phase of high-speed counter-current chromatography could easily avoid the commonly disadvantages that occurred in traditional column chromatography in the field of biosynthesized products purification. This characteristic makes high-speed counter-current chromatography particularly applicable for final products separation in biosynthesis. In this study, the glycosylation products of Silybin B by one-pot glycosylation were successfully purified by high-speed counter-current chromatography to show the applicability of high-speed counter-current chromatography for preparative separation of biosynthesis products. An optimized n-hexane/ethyl acetate/methanol/water (2:5:2:3, v/v/v/v) system was applied in this study. As a result, four Silybin B glycosylation products, including 7mg of Silybin B-5-O-β-D-glucoside (SG-1), 12mg of Silybin B-3-O-β-D-glucoside (SG-2), 10mg of Silybin B-7-O-β-D-glucoside (SG-3), and 24mg of Silybin B-20-O-β-D-glucoside (SG-4), were simultaneously separated from 200mg of glycosylation crude products, with the purity of 89.3, 95.2, 96.4, and 97.5%, respectively. Their structures were identified by spectroscopic analysis.

The applicability of pH-zone-refining counter-current chromatography for preparative separation of biosynthesis products: Glycosylation products as example

Biosynthesis is a research hot-spot in recent years, however, the purification of its final products is a tough work. Liquid stationary phase and large-scale separation ability of PZRCCC could easily avoid the commonly disadvantages occurred in traditional column chromatography. These characteristics makes PZRCCC particularly applicable for final products separation in biosynthesis. In this study, the glycosylation products of ellagic acid by one-pot glycosylation were successfully purified by PZRCCC to show the applicability of PZRCCC for preparative separation of biosynthesis products. An optimized ethyl acetate/n-buthanol/water (3:3:5, v/v/v) system was applied in this study, where 5 mM trifluoroacetic acid (TFA) as the retainer and 30 mM triethylamine (TEA) as the eluter were added. As a result, four ellagic acid glycosylation products, including 51 mg of ellagic acid-4, 3’-O-β-D-diglucoside (EG-1), 24 mg of ellagic acid-4, 4’-O-β-D-diglucoside (EG-2), 11 mg of ellagic acid-4-O-β-D-glucosyl (1→2)-β-D-glucoside (EG-3) and 64 mg of ellagic acid-4-O-β-D-glucoside (EG-4) were simultaneously separated from 500 mg of glycosylation crude products, with the purity of 93.3%, 91.2%, 89.4% and 95.5%, respectively. Their structures were identified by spectroscopic analysis.

A triterpene glochidon from Phyllanthus debilis: Isolation, computational studies, and antidiabetic activity evaluation

Diabetes mellitus (DM) is a metabolic disease characterized by a dysfunction of pancreatic β -cells. It is well documented that oxidative stress and inflammation increase the severity of DM and its complications can be fatal. Research shows that certain triterpenoids can play a significant role in the inhibition of oxidative stress and inflammation. In this study, we isolated a novel triterpenoid glochidon, from the Phyllanthus debilis Klein ex Willd. (Family: Phyllanthaceae) using traditional column chromatography and characterized using spectroscopy. The compound was tested for antidiabetic activity through in vitro and in vivo experiments followed by computational studies. In vitro assays confirmed that glochidon has a dose-dependent moderate inhibitory activity against α -glucosidase, α -amylase, DPP-4, and PPAR- γ . Docking and MD results also show that glochidon has moderate efficacy to inhibit DPP-4 and PPAR- γ, when compare to standard agents and a strong tendency to interact with the GLUT1 protein. Computational ADME profiling determined that glochidon has excellent characteristics to act as a lead hypoglycemic compound. Results of the in vivo experiments show that at a dose of 20 mg/kg, glochidon significantly increased body weight, plasma insulin, high-density lipoprotein levels, and other biochemical markers. Additionally, it lowered the blood glucose, total cholesterol, triglycerides, low-density lipoprotein, and very low-density lipoprotein. • A novel triterpene, glochidon, is isolated from Phyllanthus debilis . • In vivo studies illustrated that glochidon can effectively reduce/plasma blood glucose, and effectively participate in pancreatic β cells repair. • Computational studies showed that glochidon has a modest to strong affinity to interact with DPP-4, PPAR-γ, and GLUT-1 proteins.

Determination of Phthalates in Marine Sediments Using Ultrasonic Extraction Followed by Dispersive Solid-Phase Extraction and Gas Chromatography-Mass Spectrometry.

A simple, rapid and novel method has been developed and validated for determination of 16 phthalates in marine sediment samples by gas chromatography coupled to mass spectrometry. Freeze dried samples were first ultrasonic extraction by n-hexane:methylene chloride (1:1, v/v) and n-hexane:ethyl acetate (1:1, v/v) and followed by dispersive solid-phase extraction cleanup. The linearity of this method ranged from 1 to 1,000μg/L, with regression coefficients ranging between 0.9993 and 0.9999. The limits of detection were in ng/g level, ranging between 0.1 and 0.25ng/g (dry weight). The concentration of the total phthalates in marine sediment samples from Waters of Dongji (Zhoushan, China), Yueqing Bay (Wenzhou, China) and Coastal Waters of Yuhuan (Taizhou, China) ranged from 235.4 to 608.7μg/kg with diisobutyl phthalate, dibutyl phthalate and di(2-ethylhexyl) phthalate being the major species, which constitutes of 94.6 and 98.1% of the total phthalates. The recoveries of spiked 16 phthalates at different concentration levels in sediment sample 3 of Waters of Dongji (Zhoushan, China) and sediment sample 3 of Yueqing bay (Wenzhou, China) were in the range of 78-117% and 83-114%, respectively, with relative standard deviations of 2.4-6.8% and 3.4-7.5% (n=5), respectively. The performance of the proposed method was also compared with traditional Soxhlet extraction and column chromatography cleanup on the same genuine sediment samples and comparable efficiencies were obtained. It is concluded that this method can be successfully applied for the determination of phthalates in different marine sediment samples.

Discovery and Targeted Isolation of Phenylpropanoid-Substituted Ester-Catechins Using UPLC-Q/TOF-HRMS/MS-Based Molecular Networks: Implication of the Reaction Mechanism among Polyphenols during Green Tea Processing

Tea is an important beverage source of dietary polyphenols and well known for containing phenolic structure diversity. A series of phenylpropanoid-substituted catechins, flavonols, flavan-3-hexoside, and proanthocyanidin are present in different herbs with various biological activities, inspiring our exploration of phenylpropanoid-substituted ester type of catechins (PSECs) due to the enrichment of galloylated catechins in tea. In this study, we used a guiding-screening-location-isolation integrated route including creating a hypothesized PSEC dataset, MS/MS data acquiring, construction of molecular networks, and traditional column chromatography and preliminarily identified 14 PSECs by MS/MS spectrum. Two of these PSECs were further purified and elucidated by NMR and CD spectra. Further MS detection in tea products and fresh leaves suggests that the production of the two new compounds was enhanced during tea processing. The synthesis mechanism was proposed to obtain these types of components for further investigation on their roles in human health protection. This study provides an example for the exploration of new functional ingredients from food sources guided by MS/MS data-based networking, and also new insights into the reaction mechanism to form new catechin conjugates among polyphenols in green tea.

Preparation of brazilein from Caesalpinia sappan by high performance countercurrent chromatography

Brazilein is among the main chemical constituents of Caesalpinia sappan. It has diverse pharmacological activities. Modern pharmacological studies have shown that the compound has antitumor, anti-inflammatory, antibacterial, antioxidant, immunomodulatory, and other pharmacological activities. Brazilein is often used as a stain in various industries. The separation of brazilein by traditional column chromatography will not only result in contamination of the chromatographic column materials, but also lead to loss of the active ingredient. Countercurrent chromatography is an advanced liquid-liquid chromatographic separation technique. It has been widely used for natural product separation and isolation as it offers several advantages, such as low solvent consumption, a highly selective solvent system, and high recoveries. Typical countercurrent chromatography techniques include centrifugal partition chromatography (CPC), high-speed countercurrent chromatography (HSCCC), and high performance countercurrent chromatography (HPCCC). It is well known that choosing a suitable solvent system is vital in countercurrent separation. Therefore, two methods were introduced for choosing a suitable solvent system. One is the generally useful estimation of solvent systems (GUESS) method, which employs thin-layer chromatography (TLC) to identify a suitable solvent system with minimal labor for the rapid purification of target compounds, and another is the Shake-Flash method. The solvent system could be determined by observing the distribution of the sample in the upper and lower phases. Two kinds of solvent systems were screened using the TLC-GUESS and Shake-Flash methods, and tested through the analysis mode of the HPCCC instrument. The results showed that chloroform-methanol-water (4:3:2, v/v/v) was the optimal solvent system for HPCCC separation. A total of 15.2 mg of brazilein and 5.7 mg of caesappanin C were obtained from an ethyl acetate extract with high purities (95.6% and 89.0%, analyzed by HPLC) in one step using the preparation mode of HPCCC, the reversed-phase liquid chromatography mode with the apparatus rotated at 1600 r/min, a flow rate of 10 mL/min, separation temperature of 25℃, and detection wavelength of 285 nm. Their structures were determined by spectroscopic and spectrometric analyses. Brazilein stained the solid packing material in the column and was difficult to elute. The results showed that the use of HPCCC for the separation of brazilein can not only prevent the loss of target active ingredients in Caesalpinia sappan, but also shorten the separation and purification times and improve the operating efficiency. Therefore, HPCCC can be used for the separation and preparation of other pigment compounds in Caesalpinia sappan and other dye plants.

HSCCC Separation of Three Main Compounds from the Crude Extract of Dracocephalum Tanguticum by Using Dimethyl Sulfoxide as Cosolvent

Separation of natural compounds directly from the crude extract is a challenging work for traditional column chromatography. In the present study, an efficient method for separation of three main compounds from the crude extract of Dracocephalum tanguticum has been successfully established by high-speed counter-current chromatography (HSCCC). The crude extract was directly introduced into HSCCC by using dimethyl sulfoxide as cosolvent. Ethyl acetate/n-butyl alcohol/0.3% glacial acetic acid (4: 1: 5, v/v) system was used and three target compounds with purity higher than 80% were obtained. Preparative HPLC was used for further purification and three target compounds with purity higher than 98% were obtained. The compounds were identified as chlorogenic acid, pedaliin and pedaliin-6″-acetate.

Evaluation of Antibacterial Activity of fractions from stem extract of Tinospora crispa (L.) Hook. f. & Thomson

The aim of this study is to evaluate the antibacterial activity of fractions from Tinospora crispa (L.) Hook. f. & Thomson stem extract. The extraction was fractionated by solvents with increasing polarity, then partioned with acidic water and base to concentrate alkaloids. There are totally 7 fractions named PD-hex, PD-K, PD-Cf2, PD-Cf1, PD-EtOAc, PD-BuOH and PD-N. With the help of disc diffusion method, 7 fractions were separately evaluated for their ability to inhibit the growth of some common bacterial species, including 3 Gram-positive and 3 Gram-negative bacteria. The result showed that Tinospora crispa was able to restrain the growth of the 3 Gram-positive species but not the 3 Gram-negative species. Antibacterial substances distributed in 6 over 7 fractions tested, excluding PD-K fraction. PD-K sample mainly contained strong basic alkaloid and soluble water. Especially, weak basic alkaloids in PD-Cf2 were able to restrict the bacterial growth stronger than stronger basic alkaloids in PD-K. On the other hand, ethyl acetate fraction (PD-EtOAc), which contained medium polar compounds, were able to restrict the growth of bacteria slightly better than the others. It was subjected to traditional column chromatography to isolate some components. The purified substance was structurally identified by thin-layer chromatography, high performance liquid chromatography and spectroscopic data analyses.

Isolation and gas chromatographic method for determination of osthole from Cnidii Fructus

The purpose of this research is to study the isolation and purification of osthole from Cnidii Fructus extract and to establish a gas chromatographic method for determining the osthole content from various Cnidii Fructus samples. Six solvents were used to extract Cnidii Fructus in order to evaluate their efficiency in extracting osthole. Vacuum fractional distillation and traditional column chromatography were compared to evaluate the efficiency in purifying osthole from Cnidii Fructus extract. Gas chromatographic method was used to determine osthole content in Cnidii Fructus extract. The analytical conditions are the following: nitrogen as the carrier gas, the flow rate of 40 mL/min; the split ratio of 120: 1. The column used was DB™-5 (30 m × 0.53 mm I.D., 1.5 μm) equipped with a flame ionization detector (FID). The initial oven temperature was programmed to be at 135°C for 12 minutes. The temperature was then raised to 215°C at a rate of 12°C /min for 20 minutes. The retention time of osthole was 24.1 min. Caffeine anhydrous was used as the internal standard with a retention time of 18.9 minutes. A comparative evaluation showed that aqueous alcoholic solvent was the most efficient solvent among six used in extraction of osthole from a Cnidii Fructus. Vacuum fractional distillation is useful for purifying osthole from Cnidii Fructus extract. It was found that the osthole content of commercial Cnidii Fructus samples varied from 0.05% to 2.14%. And the osthole content of Cnidii Fructus samples collected from Southern China was higher than those collected from Northern China.

A Revisited Purification of Li for ‘Na Breakthrough’ and its Isotopic Determination by MC‐ICP‐MS

The accurate and precise determination of Li isotopic composition by MC‐ICP‐MS suffers from the poor performance of traditional column chromatography. Previously established chromatographic processes cannot completely remove Na in complex geological samples, which is currently interpreted to be a result of Na breakthrough. In this study, Na breakthrough during single‐column purification was found to differ between simply artificial Na‐containing sample solutions, where a little Na residue was found, and silicate rocks, where a large amount of breakthrough occurred. A revised two‐step column purification for Li using 0.5 and 0.3 mol l−1 HCl as eluents was designed to remove the Na. This modified method achieves high‐efficiency Li purification from Na and consequently avoiding high Na/Li ratio interference for subsequent MC‐ICP‐MS analyses. The proposed method was validated by the analysis of a series of reference materials, including Li2CO3 (IRMM‐016, ‐0.10‰), basalt (BCR‐2: 2.68‰; BHVO‐2: 4.39‰), andesite (AGV‐2: 6.46‰; RGM‐2: 2.59‰), granodiorite (GSP‐2: −0.87‰) and seawater (CASS‐5, 30.88‰). This work reports early Na appearance prior to the elution curves in chromatography and emphasises its influence for subsequent Li isotope measurement. Based on the findings, the established two‐step method would be more secure than single‐column chemistry for Li purification.

Facile one-pot synthesis of novel highly functionalized dihydro-1H-pyrrole derivatives catalyzed by molecular iodine

An efficient, environmentally benign and molecular iodine promoted protocol was described for cascade synthesis of two kinds of novel dihydro-1H-pyrrole derivatives, 5 and 7. Compounds 5 were prepared via four-component reaction between diethyl acetylenedicarboxylate (DEAD), aromatic amines and phenylglyoxal monohydrate catalyzed by 10 mol% of iodine in ethanol at room temperature. In addition, using same reaction conditions, a three-component reaction between (E)-N-methyl-1-(methylthio)-2-nitroethenamine (NMSM), aromatic amines and arylglyoxal monohydrate was performed to access product 7. These transformations apparently proceed through an imine intermediate followed by iodine induced Mannich reaction and subsequent intra-molecular cyclization sequences. The protocol involves the formation of CN, CC and OH bonds leading to the preparation of a hexa substituted five membered ring with two stereo centres. The syntheses avoid the use of traditional column chromatography and recrystallization purification methods and, hence, follow the group-assisted purification (GAP) chemistry process.

On-line dynamic detection in the column chromatography separation based on an optical fiber surface plasmon resonance sensor.

In this design, we introduced a surface plasmon resonance (SPR) fiber-sensing probe into a column chromatography (CC) system to realize on-line dynamic detection in sample separation. The refractive index of the gel around the probe would be adjusted dynamically by the concentration change of the sample during CC separation. To demonstrate the separation and on-line detection process, bovine serum albumin (BSA) and riboflavin-5-phosphate sodium (FMN-Na) are chosen as the analytes in a Sephadex gel filtration chromatography system. The results show that the apparent reversible shift of the SPR spectrum can characterize the separation process. Specifically, the separated BSA with an outflow time of 8min can cause a resonance wavelength shift of 15.5nm, and the FMN-Na with an outflow time of 26min can cause a shift of 8.4nm. This on-line dynamic detection of SPR spectra has great potential to save time and simplify the analysis process compared to the complex thin layer chromatography detection steps in traditional manual CC.

Chemical Isolation, Quantification, and Separation of Skin Lipids from Reptiles.

Reptiles signal to conspecifics using lipids in their skin, primarily to enable mate tracking and assessment. The isolation of these lipids has utility in research focused on evolutionary patterns and mechanisms of chemical communication, in addition to understanding the waterproofing role of lipids in the evolution of terrestrial life. In an applied approach, such skin-based cues have potential use for wildlife managers dealing with invasive species. The main steps for quantifying reptile skin lipids in the protocol presented here include extraction, total lipid determination, and fractionation via column chromatography, the latter process resulting in purified eluates of compounds which can then either be analyzed to assign compound identifications (e.g., gas chromatography-mass spectrometry [GC-MS]) and/or used directly in more refined bioassays. Skin lipids can be extracted from living skin, shed skin, or dead whole animals, using nonpolar organic solvents (e.g., hexane, benzene, toluene). Extraction solubilizes the lipids and, then, the solvent can be evaporated to yield a measurable lipid-only extract. Fractionation involves the separation of the total lipid extract into specific eluates via traditional column chromatography. The total lipid extract is first bound to a substrate-based column (e.g., alumina) and, then, individual eluates ("fractions") of solvent at specific volumes are passed sequentially through the column to elute sets of compounds from the lipid mixture based on common polarity. The fractions progress in polarity at a standardized sequence by increasing the relative amount of polar solvent (e.g., diethyl ether) in nonpolar solvent. In this manuscript, we describe several methods for extracting skin lipids of reptiles and, then, provide a standard protocol for isolating different sets of compounds based on polarity, using traditional column chromatography. Whole lipid extracts or specific fractions can, then, be used in bioassays to determine any biological activity elicited by the compounds therein.

High efficiency and fast separation of active proteins by HIC chromatographic pie with sub-2 μm polymer packings

This paper reports the development of hydrophobic interaction chromatography (HIC) by synthesizing sub-2 μm polymer packings which was packed into a chromatographic pie for fast separation of native proteins at low pressures demonstrating high efficiency. Using styrene as monomer and ethylene dimethacrylate (EDMA)as swelling agent, the polystyrene seeds with an average particle size of 0.8 μm and monodisperse polymeric microspheres with a particle size of 1.5–5.0 μm were synthesized through dispersion polymerization and one-step swelling method, respectively. In order to separate active proteins, the microspheres were modified to hydrophobic chromatographic packings through covalent bonding with benzene methanol. Compared with the traditional column chromatography, the sub-2 μm polymer packings in chromatographic pie exhibited higher column efficiency for protein separation at lower column pressures, even at higher flow rates. The van Deemter curve showed that the flow rate had insignificant effect on column efficiency of chromatographic pie. Seven example proteins were clearly separated within 3 min at a flow rate of 10 mL/min. The applicability of this method was further demonstrated by the separation of human serum samples. The results indicated that this chromatographic mode can be potentially applied for the fast separation of complex active proteins, such as protein drugs from natural products.

Improved levulinic acid production from agri-residue biomass in biphasic solvent system through synergistic catalytic effect of acid and products

In this study, levulinic acid (LA) was produced from rice straw biomass in co-solvent biphasic reactor system consisting of hydrochloric acid and dichloromethane organic solvent. The modified protocol achieved a 15% wt LA yield through the synergistic effect of acid and acidic products (auto-catalysis) and the designed system allowed facile recovery of LA to the organic phase. Further purification of the resulting extractant was achieved through traditional column chromatography, which yielded a high purity LA product while recovering ∼85% wt. Upon charcoal treatment of the resultant fraction generated an industrial grade target molecule of ∼99% purity with ∼95% wt recovery. The system allows the solvent to be easily recovered, in excess of 90%, which was shown to be able to be recycled up to 5 runs without significant loss of final product concentrations. Overall, this system points to a method to significantly reduce manufacturing cost during large-scale LA preparation.

Quick Identification of Piperidine Alkaloid from Roots of Grewia nervosa and Their Glucosidase Inhibitory Activity.

Grewia nervosa is a herbal plant used in traditional medicine for different purposes. Bioassay-guided chemical fractionation of G. nervosa roots resulted in an identification of two known and one new compound, namely microgrewiapine A, homomicrogrewiapine, and N-methylmicrocosamine, respectively. Their structures were determined using combination of LC/HR-MS, 1 H-NMR, and IR spectral analyses and followed by comparison with those reported in the literature. The problematic separation of these alkaloids on traditional column chromatography (Silica gel, Octadecyl silane, Sephadex) was resolved by using HPLC. Structurally similar compounds from the piperidine family have been characterized by using HR-MS analysis in combination with NMR data of crude samples. The major constituent i.e. N-methylmicrocosamine isolated from the butanol fraction of methanol root extract (MRE) was found to possess the dose dependent α-glucosidase inhibition activity with an IC50 value of 53.40 μm. Furthermore, N-methylmicrocosamine showed maximum α-glucosidase inhibition of 97.48 ± 0.7% at 107.5 μm, which is approximately 1.3 × 103 fold higher than the activity shown by acarbose (97.72% inhibition at 61.95 mm), a standard anti-diabetic drug available commercially. This work also reports the in vitro α-glucosidase inhibitory activity of the major alkaloids isolated from G. nervosa for the first time.