Thin Layer Chromatography Analysis Research Articles

Qualitative Detection of Triterpenes and Quantification of Betulinic Acid from Hexane Extract of Simarouba glauca Leaves by Gas Chromatography-Mass Spectrometry and High-Performance Thin Layer Chromatography

The present study focuses on the efficiency of high-performance thin layer chromatography and gas chromatography-mass spectrometry analysis in qualitative and quantitative analysis of triterpenoid from the terpene fraction of hexane extract of Simarouba glauca leaves. The total terpenoid content of the hexane extract was assessed which shows that 73.69 % of the extract content is terpenoid. The terpene fraction extracted in petroleum ether from the hexane extract of Simarouba glauca leaves was subjected to gas chromatography-mass spectrometry and high-performance thin layer chromatography analysis. Gas chromatography-mass spectrometry analysis results indicated seventeen compounds out of which only one was triterpene (Squalene an important bioactive triterpenoid). In high-performance thin layer chromatography the separation was achieved by using hexane:ethyl acetate in a 5:5 proportion as mobile phase and anisaldehyde sulphuric acid reagent was used for derivatization which imparted violet color to the triterpenoid containing bands. Detection and quantification of betulinic acid and other triterpenes was done by densitometric scanning at 525 nm. Betulinic acid produced compact spots at Rf 0.66. Linear range of betulinic acid was prepared using concentrations 1-7 μg/spot with a correlation coefficient R2 and standard deviation of 0.96004 %±19.68 % respectively. The results indicated the presence of 10 triterpenoids showing different Rf values including betulinic acid. This study confirmed the presence of betulinic acid in the terpene fraction of the hexane extract of Simarouba glauca leaves.

Potency of hyaluronic acid from eggshell–membrane for open gingival embrasure reconstruction following orthodontic tooth movement (a histomorphological study)

The aim of this research was to assess the effectiveness of eggshell-membrane (ESM)-containing hyaluronic acid (HA) in the treatment of open gingival embrasure (OGE) following orthodontic tooth movement (OTM).This study is an in vivo quasi experimental research. A total of 24 Cavia cobaya were equally divided into two groups, treatment (10% HA injection) and control (phosphate-buffered saline [PBS]). A separator was inserted between mandibular incisors to induce an OGE. A volume of 20 μl of either PBS (n = 12) or ESM extract (n = 12) was locally injected within the interdental papilla. Decapitation of animals was made on day 1, 4, and 7 postinjection. The staining was done using hemotoxylin and eosin to observe angiogenesis and Mallory to observe the collagen density. Fourier-transform infrared spectroscopy (FTIR) and thin-layer chromatography (TLC) analysis were performed to detect the amount of HA available in ESM. The results were then compared with independent t-tests and the Mann-Whitney test. The level of statistical significance was set at 0.05.The FTIR and TLC analysis showed that HA was successfully identified in the ESM samples. Local injection of 10% HA induced an increase of angiogenesis compared to the control group on day 1 and 4 postinjection (P < 0.05). Significant differences (P < 0.05) were also noted in the collagen density and the growth of interdental papilla on day 4 and 7 postinjection.ESM has the potential effect of regenerating the interdental papilla construction after OTM by increasing the collagen fiber density and inducing angiogenesis.

Comparative Phytochemical and HPTLC Analysis of Nisha (Curcuma Longa Linn.) Chunra (powder), Amalaki (Phyllanthus emblica Linn.) Churna (Powder), and Nisha Amalaki Churna (Powder)

Aim: The aim of this study was to evaluate phytochemical constituent and high-performance thin-layer chromatography (HPTLC) analysis of Nisha churna, Amalaki churna, and Nishamalaki churna. Introduction: Nisha churna, Amalaki churna, and Nishamalaki churna are important formulations, which are used in many disorders and a constituent of numerous Ayurvedic formulations. Materials and Methods: This study was conducted on Nisha churna, Amalaki churna, and Nishamalaki churna (authenticated), as per standard method. Results: Identification of steroid, alkaloids, and amino acids were confirmed by authenticated phytochemical standard parameter. Conclusion: Physiochemical analysis including HPTLC of Nisha churna, Amalaki churna, and Nishamalaki churna will help in further standardization.

In Vitro Anti-Inflammatory Potential of Anaphyllum wightii Schott: An Endemic Plant of Southern Western Ghats

Inflammation is a protective mechanism offered by the body’s immune system after an injury, microbial infection, or any other physical or chemical damage. The role of cyclooxygenase and lipoxygenase enzymes in the inflammation process has been well established, and research works are focused on developing plant-based cyclooxygenase and lipoxygenase inhibitors that can provide potential anti-inflammatory drugs with no side effects. Even though there are previous reports suggesting the anti-inflammatory potential of the rhizome of the plant, no reports are available regarding the anti-inflammatory property of the leaves of Anaphyllum wightii. Hence the present study was intended to assess the anti-inflammatory activity of the leaves of Anaphyllum wightii and also to confirm the activity of rhizome in vitro. The anti-inflammatory action of the rhizome and the two morphological variants of leaves (broad and narrow leaves) of Anaphyllum wightii were determined by their inhibitory effects on cyclooxygenase and lipoxygenase enzymes. In the case of the cyclooxygenase inhibition assay, the narrow leaf extract showed the least IC50 value (43.182 µg/ml), whereas the broad leaf extract showed the least IC50 (38.174 µg/ml) for the lipoxygenase enzyme. Thus the present study revealed that the leaf extracts of Anaphyllum wightii exhibit significant anti-inflammatory potential compared to that of the rhizome extract. Hence the leaves may contain promising anti-inflammatory agents that may provide potential drugs for treating chronic inflammatory diseases. Also, this study could detect the presence of Ursolic acid, a potential anti-inflammatory agent, in Anaphyllum wightii through high resolution liquid chromatograph mass spectrometeric and high performance thin layer chromatographic analyses.

Phytochemical and Comparative Assessment of Bark and Root Extracts of Ixora barbata Roxb. ex. Sm. and Ixora coccinea L. Using High-Performance Thin Layer Chromatography Assay

The present study deals with the extraction and quantification of phytochemicals, which play a key role in the pharmaceutical world. In this article, we focused on the study of plant secondary metabolites and analyzed ethanolic and methanolic extracts of bark and roots of two species of Ixora using the highperformance thin layer chromatography technique. Alcoholic extracts of bark and root of both the plants revealed the presence of alkaloids, terpenoids, glycosides, phenols, saponins, sterols, tannins, etc., but both extracts were devoid of flavonoids and coumarins. Analysis of alkaloid content revealed the highest amount of total alkaloid content in the methanolic extract of roots of Ixora coccinea (146 mg/ gm) followed by the methanolic extract of bark of Ixora coccinea (138 mg/g). The lowest total alkaloid content was observed in the methanolic extract of bark of Ixora barbata (64 mg/g). Both ethanolic, as well as methanolic extracts of Ixora coccinea, showed higher amounts of alkaloid content when compared to Ixora barbata in similar solvents. As per high-performance thin layer chromatography analysis, the highest amount of camptothecin was recorded in ethanolic extract of root of Ixora coccinea (117 μg/ml) followed by ethanolic extract of bark of Ixora barbata (64.43 μg/ml). The lowest amount of camptothecin was observed in methanolic extract of bark of Ixora coccinea (12.64 μg/ml). The results obtained from the present high-performance thin layer chromatography analysis also revealed that the above-mentioned selected plants are a source of a number of other phytoconstituents. This is the first reported study on the high-performance thin layer chromatography analysis of Ixora barbata. The study includes quantification of camptothecin compound in both methanolic and ethanolic extracts of Ixora barbata for which there are no previously published reports.

Liquisolid Compact Technique for the Enhancement of Solubility and Dissolution Rate of Ambrisentan: Quality by Design Approach

Soluble epoxide hydrolase inhibitors have been reported as antihypertensive, anti-inflammatory, antiulcer and anticancer actions and protect the brain, heart and kidney from damage. Exploring soluble epoxide hydrolase inhibition activity of traditional medicinal plants helps to uncover the new target to treat various complications associated with inflammatory mediators. The present study was planned to explore soluble epoxide hydrolase inhibition activity of fifty medicinal plants commonly used in the traditional medicinal system. The dried plant material of each species was grounded into a coarse powder and separately macerated with absolute methanol and ethyl acetate for 7 d. Then the solvents were evaporated and obtained extracts were solubilized in dimethyl sulfoxide (10 mg/ml) and soluble epoxide hydrolase enzyme inhibitory potencies were evaluated using a fluorescent reporting system. Moreover, preliminary phytochemical screening and high-performance thin layer chromatography analysis were carried out for two extracts that showed potent soluble epoxide hydrolase inhibition activities. The results revealed that 10 methanolic extracts and 20 ethyl acetate extracts were potentially effective in suppressing soluble epoxide hydrolase activity with inhibitory concentration value of less than 10 μg/ml. Among the 30 potentially effective plants, four seed extracts (Celastrus paniculatus, Nigella sativa, Wrightia tinctorial, Vernonia anthhelmintica and Embelia ribes), one leaves extracts (Bergera koengii), one rhizome extracts (Curcuma longa) and one root extracts (Vetiveria zizanioides) were common in both methanolic and ethyl acetate extract. In conclusion, the study report suggests that various natural products used in the traditional medicinal system have many promising soluble epoxide hydrolase inhibitors. Methanolic extracts of seeds of Celastrus paniculatus and Nigella sativa have potent soluble epoxide hydrolase inhibition activities. Further research is warranted to identify a greater number of medicinal plants and active principles responsible for soluble epoxide hydrolase inhibition activities

Evaluation of Soluble Epoxide Hydrolase Inhibition Activity of 50 Traditional Medicinal Plants: Exploring Old Drugs for the New Pharmacological Target

Soluble epoxide hydrolase inhibitors have been reported as antihypertensive, anti-inflammatory, antiulcer and anticancer actions and protect the brain, heart and kidney from damage. Exploring soluble epoxide hydrolase inhibition activity of traditional medicinal plants helps to uncover the new target to treat various complications associated with inflammatory mediators. The present study was planned to explore soluble epoxide hydrolase inhibition activity of fifty medicinal plants commonly used in the traditional medicinal system. The dried plant material of each species was grounded into a coarse powder and separately macerated with absolute methanol and ethyl acetate for 7 d. Then the solvents were evaporated and obtained extracts were solubilized in dimethyl sulfoxide (10 mg/ml) and soluble epoxide hydrolase enzyme inhibitory potencies were evaluated using a fluorescent reporting system. Moreover, preliminary phytochemical screening and high-performance thin layer chromatography analysis were carried out for two extracts that showed potent soluble epoxide hydrolase inhibition activities. The results revealed that 10 methanolic extracts and 20 ethyl acetate extracts were potentially effective in suppressing soluble epoxide hydrolase activity with inhibitory concentration value of less than 10 μg/ml. Among the 30 potentially effective plants, four seed extracts (Celastrus paniculatus, Nigella sativa, Wrightia tinctorial, Vernonia anthhelmintica and Embelia ribes), one leaves extracts (Bergera koengii), one rhizome extracts (Curcuma longa) and one root extracts (Vetiveria zizanioides) were common in both methanolic and ethyl acetate extract. In conclusion, the study report suggests that various natural products used in the traditional medicinal system have many promising soluble epoxide hydrolase inhibitors. Methanolic extracts of seeds of Celastrus paniculatus and Nigella sativa have potent soluble epoxide hydrolase inhibition activities. Further research is warranted to identify a greater number of medicinal plants and active principles responsible for soluble epoxide hydrolase inhibition activities

Active Fractions of Dichloromethane Extract of Artemisia turanica Inhibit Proliferation of HeLa and KB Cell Lines Via Apoptosis Induction

Purpose: Artemisia is an important genus of Iranian flora. The current study on the aerial parts of A. turanica was conducted to determine the most potent extract and its fractions in the cytotoxic assays. Materials and Methods: The cytotoxic effects of 13 fractions (1–13) from dichloromethane extract on three cancer cell lines (KB, HeLa, and U87MG) were assessed. Preliminary phytochemical analysis of more potent cytotoxic fractions was carried out using thin-layer chromatography (TLC) and different spray reagents. Results: Dichloromethane extract showed the best bioactivity against cancerous cell lines. Fractions 4, 6, 7, and 9 of this extract had potential effective components in the inhibition of the proliferation of KB cancer cells. In addition, fractions 4 and 6 were able to inhibit the growth of HeLa cell line. The active fractions decreased the mitochondrial membrane potential level, and played a critical role in caspase-3 and 9 activation and generation of reactive oxygen species. The cytotoxic activity of these fractions was found to be not significant toward U87MG cells. TLC analysis suggested the probable presence of terpenoids as the main component of most of the selected fractions. Conclusion: The species is suggested as the potential source of cytotoxic phytochemicals.

TLC-Based Metabolite Profiling and Bioactivity-Based Scientific Validation for Use of Water Extracts in AYUSH Formulations.

We aimed to develop a chromatographic method for scientific validation of water extract of some important Indian traditional plants used in AYUSH-based formulation as immunomodulator and to evaluate their bioactive potential. Fruits of Phyllanthus emblica L. and Piper nigrum L., stem of Tinospora cordifolia (Willd.) Miers, rhizome of Curcuma longa L., leaves of Ocimum sanctum L. and Achillea millefolium L., roots of Withania somnifera L., and stem bark of Azadirachta indica A. Juss. were coarsely powdered and extracted in three different solvents (water, ethanol, and hydroethanol). The antioxidant potential was determined through 1, 1-diphenyl-2-picrylhydrazyl and ferric reducing capacity methods. Thin-layer chromatography (TLC) was carried out for the comparative metabolite profiling of the extracts using toluene, ethyl acetate, and formic acid (5 : 4 : 1, v/v/v) as a solvent system. In vitro immunomodulatory activity of the extracts has been tested on splenocyte proliferation and pinocytic assay. Hydroethanolic extract (HEE) of most of the plant materials has the highest phenolic and flavonoid contents, followed by water extract (WE) and ethanolic extract (EE), whereas the water extracts of most of the plant material showed better antioxidant activity. Almost all extract exhibited splenocyte proliferation and pinocytic activity in a dose-dependent manner. But water extract showed significantly higher splenocyte proliferation and pinocytic activity as compared to the other two extracts. TLC analysis resulted in detection of totally 63 and 56 metabolites at 254 nm and 366 nm, respectively. Through principal component analysis (PCA), it was observed that metabolite pattern of different extracts from same plant materials may be different or similar. This preliminary result can be used for quality evaluation and to develop a synergy-based polyherbal combination of water extracts of selected plant materials.

A Novel Agarase, Gaa16B, Isolated from the Marine Bacterium Gilvimarinus agarilyticus JEA5, and the Moisturizing Effect of Its Partial Hydrolysis Products.

We recently identified a β-agarase, Gaa16B, in the marine bacterium Gilvimarinus agarilyticus JEA5. Gaa16B, belonging to the glycoside hydrolase 16 family of β-agarases, shows less than 70.9% amino acid similarity with previously characterized agarases. Recombinant Gaa16B lacking the carbohydrate-binding region (rGaa16Bc) was overexpressed in Escherichia coli and purified. Activity assays revealed the optimal temperature and pH of rGaa16Bc to be 55 °C and pH 6–7, respectively, and the protein was highly stable at 55 °C for 90 min. Additionally, rGaa16Bc activity was strongly enhanced (2.3-fold) in the presence of 2.5 mM MnCl2. The Km and Vmax of rGaa16Bc for agarose were 6.4 mg/mL and 953 U/mg, respectively. Thin-layer chromatography analysis revealed that rGaa16Bc can hydrolyze agarose into neoagarotetraose and neoagarobiose. Partial hydrolysis products (PHPs) of rGaa16Bc had an average molecular weight of 88–102 kDa and exhibited > 60% hyaluronidase inhibition activity at a concentration of 1 mg/mL, whereas the completely hydrolyzed product (CHP) showed no hyaluronidase at the same concentration. The biochemical properties of Gaa16B suggest that it could be useful for producing functional neoagaro-oligosaccharides. Additionally, the PHP of rGaa16Bc may be useful in promoting its utilization, which is limited due to the gel strength of agar.

Extraction and Purification of Secondary Metabolites of Paris polyphylla (Smith) Using Column Chromatography.

Paris polyphylla Smith is an erect and herbaceous plant. It has rich chemical constituents such steroidal saponins, phytosterols, flavonoids, and alkaloids that possess antimicrobial and anticancer activities. In the current investigation, we examined the effect of different solvents in the extraction yield and further purification via column chromatography. The ground powdered rhizomes of P. polyphylla was extracted with 100% hexane, 100% ethyl acetate, 70% ethanol, and 70% methanol. The extracts were filtered, evaporated using a rotary evaporator, concentrated, and measured. Subsequently, the solvent with high extraction yield was further purified using column chromatography. Ethanol produced the highest extraction yield as compared to the other solvents. About 30 fractions were eluted which was pooled into four fractions based on the Rf values and bands observed through thin layer chromatography (TLC) analysis.

Isolation and identification of flavonoids from avocado leaves (Persea americana Mill)

Leaves of avocado (Persea americana Mill) contains bioactive compounds that can act as natural antioxidants. This study was conducted to isolate and identify the flavonoid compounds of avocado leaves. Research stages includes maceration, fractionation, thin-layer chromatography analysis, isolation and purification of compounds also identification of isolates in two-dimensional thin-layer chromatography and by using three different types of solvents. Isolates were identified using ultraviolet-visible spectrophotometry and infrared spectrophotometry. From the results obtained one isolate FA6 showed a single compound. Based on the results by testing the purity of isolates using two-dimensional thin-layer chromatography and by using three different types of solvents, isolates FA6 is a pure compound. Identification by using ray-visible spectrophotometry FA6 isolates showed maximum wavelength at 280.6 nm and 342.0 nm on bands II and on band I. Infrared spectrum ofisolate FA6 showed aromatic OH groups, aliphatic CH, C = O stretching, C = C aromatic, and C-O-C stretch. From the results obtained isolates FA6 is a class of flavonoids group flavones or flavonol (3-OH substitional).&#x0D;

A New Saddle-Shaped Aza Analog of Tetraphenylene: Atroposelective Synthesis and Application as a Chiral Acylating Reagent

A New Saddle-Shaped Aza Analog of Tetraphenylene: Atroposelective Synthesis and Application as a Chiral Acylating Reagent

Development and comprehensive greenness assessment for MEKC and HPTLC methods for simultaneous estimation of sertaconazole with two co-formulated preservatives in pharmaceutical dosage forms

Four greenness assessment tools: National Environmental Methods Index (NEMI), Ecoscale Assessment (ESA), Green Analytical Procedure Index (GAPI) and the most recent Analytical GREEness metric (AGREE) were tested to evaluate two proposed MEKC and HPTLC methods for the simultaneous determination of the antifungal drug sertaconazole (SER) and two co-formulated preservatives methyl paraben (MEP) and sorbic acid (SOR). Method I was micellar electrokinetic capillary chromatography (MEKC). Electrophoretic conditions were optimized to improve separation, sensitivity, and rapidity. The proposed method used a fused silica capillary (50 cm × 50 μm id), and the background electrolyte was 50 mM acetate buffer pH 4.6 containing 15 mM SDS with 17 s injection time. The applied voltage was 30 kV. The diode array detector (DAD) was set at 210 nm for measurement of SER and 254 nm for both MEP and SOR. The Three compounds were resolved in less than 6 min with migration times 3.07, 4.29, and 5.97 min for SER, MEP, and SOR respectively. The described method was linear over the range of 5–100 μg/mL for SER, MEP and SOR with correlation coefficients >0.9995. For method II: high-performance thin-layer chromatography (HPTLC) analysis was carried out on aluminum-backed sheet of silica gel using chloroform-ethyl acetate (3:7) as mobile phase. Retardation factors were 0.20, 0.71, and 0.88 for SER, MEP, and SOR respectively. Quantification was achieved with UV densitometry at 210 nm for SER and 254 nm for MEP and SOR. The linearity ranges were 0.1–1 μg/spot for the three drugs with correlation coefficients >0.9998. The analytical performance of both methods was thoroughly validated according to International Conference on Harmonization (ICH) guidelines with respect to system suitability, linearity, ranges, precision, accuracy, specificity, robustness, detection and quantification limits. The proposed MEKC and HPTLC methods were successfully applied for estimation of the studied drugs in laboratory prepared mixtures and in the cream and spray dosage forms.

Production and characterization of biosurfactant produced by Lactobacillus lactis grown in media containing Crude Palm Oil (CPO)

Biosurfactants are surface-active compounds produced by a wide variety of diverse microorganisms. The structural diversity of biosurfactants depends on microorganisms and growth conditions (such as substrate and pH). The unique structure of biosurfactants provides unique properties for specific applications. Biosurfactant production still needs to be explored using a variety of microorganisms and growth conditions for producing the diversity of biosurfactant structures. Production and characterization of biosurfactant by Lactobacillus lactis using Crude Palm Oil (CPO) as an additional carbon source has been conducted. The optimization condition of biosurfactant production by L. lactis using media containing various concentrations of CPO was evaluated. Optical density, surface tension, and emulsification index were observed daily for 12 days. Optimal biosurfactant production condition was achieved when L. lactis was grown on media Nutrient Broth containing 10% (v/v) of CPO and incubated for 8 days. Biosurfactants were obtained for 80 mg/L media. Based on Thin Layer Chromatography (TLC) analysis and Fourier Transform Infra-Red (FT-IR) Spectroscopy, produced biosurfactant was identified as a glycolipid biosurfactant containing functional groups of hydroxyl, ester, carboxylic, methyl, and methylene. Produced biosurfactants exhibited the Critical Micelle Concentration (CMC) value of 1 g/L with a surface tension value of 49.46 mN/m. The emulsion system of produced biosurfactant was water in oil (w/o). The produced biosurfactant showed an emulsification index of 41-71% with soybean oil, palm oil, sunflower oil, olive oil, and lubricant oil. The stable emulsion was reached up to 30 days when soybean oil, olive oil, and lubricant oil were used as the water-immiscible compound.

Global genome and comparative transcriptomic analysis reveal the inulin consumption strategy of Lactiplantibacillus plantarum QS7T

Sichuan pickle is a natural combination of probiotics and dietary fibers, in which a strain Lactiplantibacillus plantarum QS7T was found to be capable of efficiently metabolizing inulin. However, the underlying molecular mechanism of inulin consumption by the strain QS7T is unclear. Therefore, this study firstly investigated the metabolic characteristics of inulin in the strain QS7T, and the results showed it could grow very well on the medium containing inulin as a carbon source (maximum OD600 nm, 1.891 ± 0.028) and degrade both short-chain oligofructose and long-chain fructan components through thin layer chromatography analysis. Genomic sequencing and analysis revealed a high percentage of functional genes associated with carbohydrate transport and metabolism, particularly glycoside hydrolase (GH) genes responsible for hydrolysing carbohydrates, within the genome of the strain QS7T. Furthermore, comparative transcriptomic analysis of L. plantarum QS7T in response to inulin or glucose indicated that functional genes associated with inulin consumption including several genes encoding PTS sugar transporters and two predicted GH32 family genes encoding beta-fructofuranosidase and beta-fructosidase were significantly up-regulated by inulin compared to the gene expression on glucose. In conclusion, we obtained a mechanistic understanding of interplay between probiotic L. plantarum QS7T derived from Sichuan pickle and natural dietary fiber, inulin; totally two operons including a sacPTS1 operon responsible for metabolizing short-chain oligofructose primarily in the cytoplasm and a fos operon responsible for extracellularly degrading all moderate and long-chain fructan components linked to inulin consumption by L. plantarum QS7T.

Investigating Antiarthritic Potential of Nanostructured Clove Oil (Syzygium aromaticum) in FCA-Induced Arthritic Rats: Pharmaceutical Action and Delivery Strategies.

The combined application of clove oil in a lipid nanocarrier opens a promising avenue for bone and joints therapy. In this study, we successfully developed a tunable controlled-release lipid platform for the efficient delivery of clove oil (CO) for the treatment of rheumatoid arthritis (RA). The ultra-small nanostructured lipid carriers co-loaded with CO (CONCs) were developed through an aqueous titration method followed by microfluidization. The CONCs appeared to be spherical (particle size of 120 nm), stable (zeta potential of −27 mV), and entrapped efficiently (84.5%). In toluene:acetone:glacial acetic acid (90:9:1 percent v/v/v) solvent systems, high-performance thin layer chromatography (HPTLC) analysis revealed the primary components in CO as eugenol (RF = 0.58). The CONCs greatly increased the therapeutic impact of CO in both in vitro and in vivo biological tests, which was further supported by excellent antiarthritic action. The CONC had an antiarthritic activity that was slightly higher than neat CO and slightly lower than standard, according to our data. The improved formulation inhibited serum lysosomal enzymes and proinflammatory cytokines while also improving hind leg function. This study provides a proof of concept to treat RA with a new strategy utilizing essential oils via nanodelivery.

Characterizing of a new α-agarase AgaE from Thalassomonas sp. LD5 and probing its catalytically essential residues

A new α-agarase AgaE belonging to glycoside hydrolase (GH) family 96 was identified and cloned from marine bacterium Thalassomonas sp. LD5. AgaE consists of 926 amino acids with a theoretical molecular mass of 97 kDa. The optimum temperature and pH for recombinant AgaE were 35 °C and 7.0, respectively. In contrast to known α-agarases, the activity of AgaE does not depend on Ca2+, but on Na+. Thin-layer chromatography and 13C NMR analysis revealed that AgaE endohydrolytic of agarose to produce agarotetraose and agarohexaose as the final main products. Extensive site-directed mutagenesis studies on the conserved carboxylic amino acids of GH96 revealed two essential amino acids for AgaE, D779 and D781. Replacing D779 with G779 leads to complete inactivation of the enzyme, while D781G results in 70% loss of activity. Later studies showed that site D781 involved in the binding of Na+, and its mutation raised the optimal concentration of Na+ 4 times higher than that of the wild type. However, attempts to rescue the mutant's activities with sodium azide were failed. Kinetic parameters comparison of AgaE, AgaD, another α-agarase from LD5, and their mutants revealed that the former aspartic acid plays critical role in the catalysis.

High-performance thin-layer chromatographic analysis of three components in Arnebia guttata Bunge

High-performance thin-layer chromatographic analysis of three components in Arnebia guttata Bunge

Synthesis and properties of vinyl benzyl alcohol copolymers with styrene

Objectives. Synthesis and study of the properties of copolymers of vinyl benzyl alcohol (VBA) with styrene with antimicrobial properties.Methods. The study employed infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy, thin-layer chromatography, viscometry, and elemental analysis. The sessile drop method and the pencil method were respectively utilized to determine the contact angles and hardness of the films. The process of testing the film coatings’ resistance to the effects of molds consisted of contaminating the film coatings applied to the glass with mold spores of the All-Russian Collection of Microorganisms in a solution of mineral salts without sugar (Czapek–Dox medium).Results. Homopolymers of vinyl benzyl acetate and its copolymers with styrene were synthesized in this study. Homo- and copolymers of VBA were obtained by saponification. IR and proton NMR (1H NMR) spectroscopy determined the composition of the copolymers. Employing IR spectroscopy, the degree of saponification was monitored by the appearance of the hydroxyl group absorption band and the disappearance of the ester group absorption band. According to the IR spectroscopy data, only an insignificant (~3%) amount of ester groups remains in the saponified copolymers. The influence of the copolymers’ composition on their solubility in various solvents is demonstrated. IR spectroscopy of the copolymers revealed hydrogen-bond formation between the unreacted ester groups and hydroxyl groups formed due to the saponification. The viscometry of the solutions of mixtures of saponified and unsaponified copolymers, solutions of mixtures of saponified copolymer with polyvinyl acetate, and viscometry of saponified copolymers in various solvents all support this conclusion. These bonds’ concentration depends on the copolymer’s composition and can be controlled by the nature of the solvent from which these copolymers’ films are formed. Saponified copolymer solutions form smooth, transparent film coatings with excellent adhesion to metals and silicate glass surfaces. The contact angle of these films, like the hardness, decreases as the VBA units’ concentration in the copolymers increases and depends on the solvent polarity used to form the films. It has been demonstrated that increasing the VBA units concentration suppresses the microorganisms’ growth.Conclusions. Film coatings made of copolymers of styrene with VBA have been shown to have high biocidal activity against molds; can be used to protect structural materials and products from the effects of microorganisms.