Column Chromatographic Separation Research Articles

Preparation of Quaternary Ammonium Separation Material based on Coupling Agent Chloromethyl Trimethoxysilane (KH-150) and Its Adsorption and Separation Properties in Studies of Th(IV).

In this research, the authors studied the synthesis of a silicon-based quaternary ammonium material based on the coupling agent chloromethyl trimethoxysilane (KH-150) as well as its adsorption and separation properties for Th(IV). Using FTIR and NMR methods, the silicon-based materials before and after grafting were characterized to determine the spatial structure of functional groups in the silicon-based quaternary ammonium material SG-CTSQ. Based on this, the functional group grafting amount (0.537 mmol·g-1) and quaternization rate (83.6%) of the material were accurately calculated using TGA weight loss and XPS. In the adsorption experiment, the four materials with different grafting amounts showed different degrees of variation in their adsorption of Th(IV) with changes in HNO3 concentration and NO3- concentration but all exhibited a tendency toward anion exchange. The thermodynamic and kinetic experimental results demonstrated that materials with low grafting amounts (SG-CTSQ1 and SG-CTSQ2) tended to physical adsorption of Th(IV), while the other two tended toward chemical adsorption. The adsorption mechanism experiment further proved that the functional groups achieve the adsorption of Th(IV) through an anion-exchange reaction. Chromatographic column separation experiments showed that SG-CTSQ has a good performance in U-Th separation, with a decontamination factor for uranium in Th(IV) of up to 385.1, and a uranium removal rate that can reach 99.75%.

Isolation, Characterization and Antibacterial Activity Study of Bioactive Compounds from Leaves of Cyphostemma cyphopetalum

Background:: Cyphostemma cyphopetalum is a herbaceous climber species within the Vitaceae family, found in various tropical and subtropical regions of Africa. It has a history of traditional use in Ethiopia for treating various health issues in humans and livestock, includ-ing snake bites, rabies, and eczema. Despite its reported ethnomedicinal uses, there is a lack of sufficient scientific literature regarding the isolation and characterization of its bioactive chem-ical compounds. Objective:: The objective of this work was to isolate bioactive compounds from the leaves of Cyphostemma cyphopetalum, characterize their chemical structures using FTIR and NMR spec-troscopy, and evaluate their antimicrobial activities. Methods:: Isolation was done using column chromatographic separation techniques. Spectro-scopic techniques, including Fourier transform infrared and nuclear magnetic resonance, were used for functional group identification and structural elucidation. Moreover, the paper disc dif-fusion bioassay method was used to evaluate the antibacterial activity of the isolated bioactive compounds. Results:: Three fractions were successfully isolated using chloroform with dichloromethane and chloroform with ethyl acetate as eluting solvents and silica gel as a stationary phase. After care-ful interpretation of the experimental results and comparison with the literature, the isolated fractions were constituted mainly by stigmasterol (fraction 1), β-sitosterol (fraction 2), and trans-resveratrol (fraction 3). The antibacterial activities of each isolated fraction were tested against Ralstonia solanacearum, a gram-negative bacterium, and Staphylococcus aureus, a gram-positive bacterial pathogen.Comparatively, the highest mean inhibitory value of 10.03 ± 0.13 mm was exhibited by fraction 2, which was followed by 6.25±0.05 mm inhibition activity recorded for fraction 1 against R. solanacearum, while fraction 3 did not exhibit any bacterial activity against both the strains. Conclusion:: We have successfully isolated and characterized three compounds (1-3) from leaves of C. cyphopetalum and evaluated their antibacterial activity. A maximum mean inhibi-tory value of 10.03 ± 0.13 mm was exhibited by compound 2 against R. solanacearum.

Camphorsulfonic Acid-Catalyzed Synthesis of a Series of 2-Aryl/heteroaryl/alkyl-1H-anthra[ 1,2-d]imidazole-6,11-dione Derivatives

Abstract: Anthraquinone moiety is very common among naturally occurring bioactive compounds. Many commercially available drug molecules also possess anthraquinone moiety. In recent times, among many other anthraquinone derivatives, specifically, 2- substituted-1H-anthra[1,2-d]imidazole-6,11-diones are gaining extra attention due to their significant anti-cancer, anti-HIV, anti-inflammatory activities, etc. This study aimed to report a simple, straightforward, organocatalyzed method for the efficient synthesis of a series of 2-aryl/heteroaryl/alkyl-1H-anthra[1,2-d]imidazole-6,11-diones from the reactions of 1,2-diaminoanthraquinone and various aldehydes using a catalytic amount of camphorsulfonic acid as an efficient organocatalyst in aqueous ethanol under refluxed conditions. Under the same optimized reaction conditions, along with aryl or heteroaryl aldehydes, aliphatic aldehydes also underwent a smooth reaction and afforded the desired products in excellent yields. All the synthesized compounds were obtained pure in excellent yields by simple filtration and washing subsequently with ethanol. The use of less toxic solvent, low-cost, commercially available metal-free organocatalyst, no column chromatographic separation, good yields, and easy isolation procedure are some of the major advantages of this newly developed protocol.

Interference with VIP to distinguish between real and false VIPoma:national study from the French Endocrine Tumors Group

Abstract Background Vasoactive Intestinal Peptide-secreting tumors (VIPomas) are digestive neuroendocrine tumors in which the hormonal secretion is life threatening. Biological confirmation is obtained by demonstrating an elevation in plasma VIP, usually using radioimmunoassay (RIA) method. In some cases, an analytical interference is suspected. We developed three different techniques to detect the interference in VIP RIA. Methods Three techniques were used: RIA after Sephadex column chromatography separation, RIA after Polyethylene Glycol (PEG) precipitation and125I-labelled VIP binding test. We included patients with suspicion of false positive VIP (FPV) elevation. We then compared results with those of a group of ‘real’, proven VIPoma (RV). Results A total of 15 patients with FPV elevation and 9 RV patients were included. Interference was detected in all FPV patients versus none in RV. Clinical and biochemical parameters did not differ between FPV and RV patients, but VIP concentration in RIA was significantly higher in FVP patients than in RV patients (228pmol/l vs 66 pmol/l, p=0.038). Using 125I-labelled VIP binding test, median proportion of radioactivity in the pellet was significantly higher in FVP than in RV patients (53% vs 13%, p < 0.0001). A 20.5% threshold presented excellent performances (Sensitivity 100% [79.6-100], specificity 100% [70.1-100]). Conclusions We developed three different laboratory techniques to reveal interference in RIA VIP assays. The diagnostic performance of all three was excellent. These techniques must be employed in cases of discordance between VIP elevation and clinical presentation.

Cationic Europium-Organic Framework for Chromatographic Column Separation of Ionic Dyes and Stimuli-Responsive Chromic Properties.

A novel 3D europium-based cationic framework (Eu-CMOF) has been constructed solvothermally by employing a viologen derivative as an organic functional building unit. Notably, Eu-CMOF demonstrates its capability as a proficient aqueous-phase ion-exchange host, facilitating the remarkable rapid chromatographic column separation of new coccine and malachite green (NC3-/MG+), as well as new coccine and methylene blue (NC3-/MLB+), in mere 2 to 4 min. Adsorption thermodynamics and kinetics of anionic dyes demonstrate that Eu-CMOF exhibits a higher adsorption capacity for NC3-, as evaluated by the Langmuir model, reaching a value of 173 mg·g-1. The pseudo-second-order rate constant is determined to be 3.84 × 10-3 mg-1·g·min-1. Additionally, Eu-CMOF displays reversible photochromic and amine- and ammonia-induced vapochromic behaviors. Further mechanistic studies reveal that these chromic behaviors are primarily attributed to the generation of free viologen radical stimulated by Xe-light or electron-rich amine/ammonia. This research contributes to the development of advanced materials with applications in rapid chromatographic separation and stimuli-responsive chromic properties, showcasing the potential of Eu-CMOF as a versatile platform for practical applications.

The isolation, structure characterizations and anti-photoaging activities of sulfated polysaccharides isolated from Sargassum fusiforme

BackgroundOur previous study found that crude polysaccharide extracted from Sargassum fusiforme (PSF) exhibited excellent anti-photoaging activity, but the composition responsible for this activity remained unknown.ResultsIn this study, three fractions (P1, P2 and P3) obtained by hot water extraction and column chromatographic separation from PSF were structurally characterized. The anti-photoaging activities of these isolated polysaccharides were evaluated using HaCaT cells. The results showed that P1, P2 and P3 were acidic polysaccharides with 42.94%, 40.75% and 2.21% uronic acid. In addition, the contents of sulfate groups were 3.01%, 10.05% and 7.44%, respectively. Moreover, their content of reducing sugar was low, and none of the fractions had a triple-stranded helical structure. P1 had the largest average molecular weight of 208.89 kDa, while P2 and P3 had a relatively lower molecular weight of 154.09 and 151.71 kDa, respectively. Treatment with P2 effectively safeguarded the viability of HaCaT cells exposed to UVB irradiation. Additionally, it inhibited the secretion of MMP-1 and MMP-3 while elevating the content of hydroxyproline (HYP) in the cell supernatant. Methylation and NMR analysis suggested the main structure of P2 might be → [4)-β-ManA-(1]23 → 4)-β-ManA-(1 → 3)-β-d-Glcp-(1 → 4)-β-d-Glcp-(1 → 4)-β-d-Glcp-(1 → . The two terminal groups of β-ManA-(1 → and β-d-Glcp-(1 → were connected via the glycosidic bonds of → 3, 4)-O-3 in β-ManA-(1 → and O-6 in → 4, 6)-β-d-Glcp-(1 → , respectively.ConclusionsThese findings will open new avenues for exploring the potential use of Sargassum fusiforme polysaccharide, particularly P2, as a functional ingredient with anti-photoaging activity.Graphical

Rapid Separation and API Grades Identification of Base Oil in Low Viscosity Gasoline Engine Oil SN 0W-16.

Using low viscosity engine oil is one of the most economical and easily achievable ways to improve fuel economy. Base oil is a main component in low viscosity engine oils, and therefore, the separation and identification of its are of great significance for oil product developers to prepare high-performance lubricants. However, the extraction methods reported for base oils mainly adopt membrane dialysis, which not only fails to completely separate the base oil but also wastes a large amount of solvent. The reason for this result is that the concentration of substances inside and outside the membrane cannot always be in an imbalanced state of permeation resulting from manual operation. Additionally, most studies primarily focus on the characterization of base oil components, while there are few reports on grade identification. For the above reasons, an economically effective separation technique of base oil from low viscosity gasoline engine oil SN 0W-16 is successfully established by combining improved Soxhlet extraction and a column chromatography separation method. By applying this method, the yield of extracting base oil generally exceeds 96%, and the solvent can also save more than 3 times. Besides, an exclusion method is built through several simple characterization steps including viscosity index (VI), FT-IR, size-exclusion chromatography (SEC), and hydrocarbon composition, which can quickly identify the American Petroleum Institute (API) grade and brand of the base oils.

A comparative study on the synergistic activities of fractions and crude essential oil of Syzygium aromaticum

BackgroundSyzygium aromaticum has been used for over a century because it has biological qualities for several health-related problems, and the crude essential oils are known to contain several components that could be responsible for synergistic or antagonistic potentials in relation to their biological uses. The study was designed to compare the biological activities of the crude essential oil from the bud of Syzygium aromaticum and fractions obtained from column chromatography.Materials and methodsThe essential oil was extracted by hydrodistillation, and two prominent fractions, C1 and C2, were obtained from the column chromatography separation of the crude essential oil. The quantitative phytochemical analysis was done by standard methods, the antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging assays. The antifungal activities were assessed by the agar diffusion method, while the anti-inflammatory activity was done using a lipoxygenase inhibitory assay. The major component observed in the crude and fractions was determined by gas chromatography–mass spectrometry (GC–MS) analysis.ResultsThe phytochemical analysis showed that phenolic acid, tannin, saponin, flavonoids, alkaloids, cardiac glycosides, and terpenoids were present in variable quantities in all of the fractions and crude essential oil. The half-maximal inhibitory concentration (IC50) value for DPPH scavenging activity ranged from 226.1 to 301.2 µg/mL while that of ABTS scavenging activity ranged from 211.0 to 316.0 µg/mL. The lowest value of IC50 for both DPPH and ABTS was observed in fraction C1. The crude essential oil with a minimum inhibitory concentrations (MIC) value of 8.00 mg/mL was the most efficient against Candida albicans, Aspergillus penicillum, and Aspergillus niger. The anti-inflammatory assay showed C1 to have the lowest value of IC50 for the lipoxygenase assay. The major component observed in the crude essential oil as well as fraction C1 was eugenol, while fraction C2 had β-caryophyllene as the major component.ConclusionsThe result showed that all fractions as well as the crude essential oil exhibited antioxidant, antifungal, and anti-inflammatory activities, and the crude essential oil was synergic only with respect to its antifungal activity, while fraction C1 was more efficient as an anti-inflammatory and antioxidant agent.

Characterization and Identification of Novel Steroids from Nauclea pobeguinii Leaves

Nauclea pobeguinii is a plant in the Rubiaceae family endemic to the swamp forest region of the world. Its extract is widely used in traditional medicine for the treatment of a wide variety of ailments such as malarial, Jaundice, gonorrhea, fever, and stomach discomfort. While other parts of the plant have been examined for the bioactive principles responsible for the medicinal properties, limited information is available in the literature as regards the leaves, hence this study. N. pobeguinii leaves were collected, air-dried, and pulverized. The pulverized sample was extracted with solvents (n-hexane, ethyl acetate, and ethanol) of varying polarity to obtain the crude extracts. Repeated column and thin layer chromatographic separation of the crude extracts afforded three compounds, which were characterized by their IR, 1H, 13C-NMR, and 2D-NMR spectral data. A comparison of the data with literature confirmed the compounds to be 2-hydroxylstigmastane acetate (1), Ergosta-5,6-epoxy-22-en-3-yl-acetate (2), and β-sitosterol (3). Compounds 1 and 2 are novel to N. pobeguinii.

Asymmetric synthesis, characterization of chiral trans and cis-3-chloro/oxo/thio-4-styryl-β-lactams using (R)-(+)-1-phenylethylamine and their efficient column chromatographic separation

Diverse chiral trans and cis-3-chloro/oxo/thio-4-styryl-β-lactams were efficiently synthesized using chiral 3′-phenylallylidene-[(R)-1′-phenylethyl] amine and substituted ethanoic acids. Moore ketenes derived from chloro/phenythio/benzylthio ethanoic acids (Cl/PhS/BzS) affords both chiral trans- and cis β-lactams, with a preference for trans-stereochemistry. However, Bose-Evans ketenes obtained from 2-methoxy/phenoxyethanoic acids (MeO/PhO), led to the exclusive formation of cis-diastereomers only. Further, individual diastereomers of trans- and cis-β-lactams were separated via efficient column chromatography. The relative cis and trans configuration of the C-3 and C-4 protons in chiral β-lactams was established using coupling constant value ranging from J = 1.4 to 2.1 Hz (in case of trans) and J = 4.3 to 5.2 Hz (in case of cis) respectively. Structural confirmation of β-lactams was done using FT-IR, NMR (1H,13C,1H-1H COSY and 1H-13C HSQC), elemental analysis, ESI-MS and X-ray crystallography.

Five previously undescribed citrinin derivatives from the endophytic fungus Penicillium citrinum GZWMJZ-836

Penicillium citrinum GZWMJZ-836 is an endophytic fungus from Drynaria roosii Nakaike. Five previously undescribed citrinin derivatives (1–5) and six intermediates related to their biosynthesis (6–11) were obtained from the extract of this strain's solid fermentation using multiple column chromatography separations, including high-performance liquid chromatography. The structures of these compounds were determined through comprehensive spectroscopic analyses, primarily using NMR and HRESIMS data. The stereochemistry was mainly confirmed by ECD calculations, and the configurations of C-7′ in compounds 4 and 5 were determined using 13C NMR calculations. Compounds 4–5 and 8 showed antibacterial activity against five strains, with minimum inhibitory concentration values ranging from 7.8 to 125 μM. Compounds 4 and 7 exhibited inhibitions against three plant pathogenic fungi, with IC50 values ranging from 66.6 to 152.1 μM. Additionally, a putative biosynthetic pathway for compounds 1–5 derived from citrinin was proposed.

Alpha-hydroxyisobutyric acid-assisted solid-liquid chromatography for the separation of lutetium-177 from neutron-irradiated natural ytterbium

Abstract The production method of no-carrier added Lutetium-177 (177Lu) was developed from a neutron-activated natural ytterbium (Yb) using column chromatography separation method. Dowex W50 X8 resin and a combination of alpha-hydroxyisobutyric acid (α-HIBA) and hydrochloric acid (HCl) were used as column filler and eluent, respectively. HCl increased the desorption and separation between 177Lu and Yb at a concentration of 0.25 M, while the optimal α-HIBA concentration was 0.15 M, resulting in 177Lu yield of 81.19 % and low impurities (175Yb: 9.28 %, and 169Yb: 2.09 %). Nevertheless, further study using an enriched 176Yb target is essential to significantly increase the specific activity of 177Lu.

Solvent- and Catalyst-Free Synthesis of gem-Difluorinated and Polyfluoroarylated Compounds with Nucleophilic or Electrophilic Fluorine-Containing Reaction Partners, Respectively

A novel, efficient and environmentally friendly solvent-free and catalyst-free approach for the synthesis of structurally diverse gem-difluorinated and polyfluoroarylated derivatives with readily available nucleophilic and electrophilic fluorine-containing reaction partners, difluoroenoxysilane and pentafluorobenzaldehyde, is described. This neat protocol is induced by the direct hydrogen-bond interactions between fluorinated and non-fluorinated reactants without the use of heavy metal catalysts or volatile organic solvents and with no need for column chromatographic separation for most cases.

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

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

Purification, characterization, and antioxidant ability of polysaccharides from Phascolosoma esculentas.

The polysaccharide was extracted from Phascolosoma esculenta (PEP). Two purified polysaccharides (PEP-1 and PEP-2) were obtained by the column chromatography separation method. The molecular weights of PEP-1 and PEP-2 were 33.6 and 5.7 × 103 kDa, respectively. PEP-1 and PEP-2 had the same monosaccharides composition, but their molar ratios varied. The invitro antioxidant activity of the PEP, PEP-1, and PEP-2 were investigated by scavenging free radicals like 3-ethylbenzoth-iazoline-6-sulfonic acid (ABTS), •OH, and 2,2-diphenyl-1-picrylhydrazyl (DPPH). Additionally, the invivo antioxidant activity of PEP-1 was examined using the Caenorhabditis elegans (C. elegans) organism. Results showed that PEP-1 was much more effective than PEP and PEP-2 at scavenging DPPH, •OH, and ABTS radicals. Additionally, PEP-1 strengthened C. elegans' ability to endure oxidative stress. PEP-1 possessed the invivo antioxidant capacity, including the reactive oxygen species (ROS) content reducing, and protective effect on antioxidant enzyme activities in C. elegans. In summary, PEP, PEP-1, and PEP-2 might have the potential to develop as functional foods and clinical medications.

Conjugation through Si-O-Si bonds, silsesquioxane (SQ) half cage copolymers, extended examples via SiO0.5/SiO1.5 units: multiple emissive states in violation of Kasha's rule.

We previously reported that phenyl- and vinyl-silsesquioxanes (SQs), [RSiO1.5]8,10,12 (R = Ph or vinyl) functionalized with three or more conjugated moieties show red-shifted absorption- and emission features suggesting 3-D conjugation via a cage centered LUMOs. Corner missing [PhSiO1.5]7(OSiMe3)3 and edge opened, end capped [PhSiO1.5]8(OSiMe2)2 (double decker, DD) analogs also offer red shifted spectra again indicating 3-D conjugation and a cage centered LUMO. Copolymerization of DD [PhSiO1.5]8(OSiMevinyl)2 with multiple R-Ar-Br gives copolymers with emission red-shifts that change with degree of polymerization (DP), exhibit charge transfer to F4TNCQ and terpolymer averaged red-shifts suggesting through chain conjugation even with two (O-Si-O) end caps possibly via a cage centered LUMO. Surprisingly, ladder (LL) SQ, (vinylMeSiO2)[PhSiO1.5]4(O2SiMevinyl) copolymers offer emission red-shifts even greater for analogous copolymers requiring a different explanation. Here we assess the photophysical behavior of copolymers of a more extreme SQ form: the half cage [PhSiO1.5]4(OSiMe2Vinyl)4, Vy4HC SQs. We again see small red-shifted absorptions coupled with significant red-shifted emissions, even with just a half cage, thus further supporting the existence of pπ-dπ and/or σ*-π* conjugation through Si-O-Si bonds and contrary to most traditional views of Si-O-Si linked polymers. These same copolymers donate an electron to F4TCNQ generating the radical anion, F4TCNQ-. as further proof of conjugation. Column chromatographic separation of short from longer chain oligomers reveals a direct correlation between DP and emission λmax red-shifts as another indication of conjugation. Further, one- and two-photon absorption and emission spectroscopy reveals multiple excited fluorescence-emitting states in a violation of Kasha's rule wherein emission occurs only from the lowest excited state. Traditional modeling studies again find HOMO LUMO energy levels residing only on the aromatic co-monomers rather than through Si-O-Si bonds as recently found in related polymers.

Study on the inhibitory effect of fermentation extract of Microporus vernicipes on Candida albicans.

Candida albicans is one of the most common species of Candida, which cause various mucosal and systemic infectious diseases. However, the resistance rate to existing clinical antifungal drugs gradually increases in C. albicans. Therefore, new antifungal drugs must be developed to solve the current problem. This study discovered that the solid fermented ethyl acetate crude extract of Microporus vernicipes had inhibitory activity on C. albicans. This study determined that the Mv5 components had significantly inhibited the activity of C. albicansusing column chromatography separation component screening. The components included 23 compounds of fatty acids and their derivatives, alkaloids, phenols, and other classes using ultra-high performance liquid chromatography tandem high-resolution mass spectrometry (UHPLC-HR-MS) analysis, with fatty acids constituting the primary components. The mechanism of action showed that the minimum inhibitory concentration (MIC) of Mv5 components against C. albicans was 15.63μg/mL, while minimum fungicidal concentration (MFC) was 31.25μg/mL. Mv5 components can inhibit the early biofilm formation and destroy the mature biofilm structure. It can inhibit the germ tube growth of C. albicans, thereby inhibiting the transformation of yeast morphology to hyphae. We detected 193 differentially expressed genes, including 156 upregulated and 37 downregulated genes in the Mv5 components of the MIC concentration group. We detected 391 differentially expressed genes, including 334 upregulated and 57 downregulated expression genes in the MFC concentration group. Among these differentially expressed genes, the genes related to mycelium and biofilm formation were significantly downregulated. GO enrichment analysis presented that single-organism process metabolic process, and cellular processes were the biological processes with the most gene enrichment. Kyoto Encyclopedia of Genes and Genomes (KEGG)of Mv5 components were mainly enriched in metabolic pathways, such as meiosis yeast and amino acid metabolism. Therefore, it is believed that the fermentation extract of M. vernicipes inhibits C. albicans, which can provide clues for developing effective antifungal drugs.

Structural and functional characterization of cold-active sialidase isolated from Antarctic fungus Penicillium griseofulvum P29

The fungal strain, Penicillium griseofulvum P29, isolated from a soil sample taken from Terra Nova Bay, Antarctica, was found to be a good producer of sialidase (P29). The present study was focused on the purification and structural characterization of the enzyme. P29 enzyme was purified using a Q-Sepharose column and fast performance liquid chromatography separation on a Mono Q column. The determined molecular mass of the purified enzyme of 40 kDa by SDS-PAGE and 39924.40 Da by matrix desorption/ionization mass spectrometry (MALDI-TOF/MS) analysis correlated well with the calculated mass (39903.75 kDa) from the amino acid sequence of the enzyme. P29 sialidase shows a temperature optimum of 37 °C and low-temperature stability, confirming its cold-active nature. The enzyme is more active towards α(2 → 3) sialyl linkages than those containing α(2 → 6) linkages.Based on the determined amino acid sequence and 3D structural modeling, a 3D model of P29 sialidase was presented, and the properties of the enzyme were explained. The conformational stability of the enzyme was followed by fluorescence spectroscopy, and the new enzyme was found to be conformationally stable in the neutral pH range of pH 6 to pH 9. In addition, the enzyme was more stable in an alkaline environment than in an acidic environment. The purified cold-active enzyme is the only sialidase produced and characterized from Antarctic fungi to date.

Antioxidant and sun screening activity of <em>Mangifera zeylanica </em>bark extracts

Mangifera zeylanica is an indigenous plant in Sri Lanka with a rich history in traditional medicine. The bark of this plant, collected from two distinct regions of the country, has been explored in this study for its potential as a source of antioxidants and sun protection agents. Methanolic and aqueous extracts, and their separated fractions obtained from column chromatographic separation, were investigated. Phytochemical analysis of the extracts revealed the presence of flavonoids and polyphenols. Methanolic inner bark extracts collected from two regions and aqueous extract of inner bark collected from Rambukkana exhibited lower IC50 values of 7.378, 17.56 and 16.82 μg/mL while the separated fraction 01 of methanolic inner bark extracts of Galle and Rambukkana have also shown lower IC50 values of 11.71 and 13.00 μg/mL showing their potent antioxidant activity. Moreover, the methanolic inner bark extracts of Galle and Rambukkana exhibited a Sun Protection Factor (SPF) of 30.97 ± 0.11 and 29.88 ± 0.02 at the concentration of 1024 μg/mL. Among the separated fractions, fraction 01 of these extracts possessed the highest Sun Protection Factors of 30.19 ± 1.35 and 30.63 ± 0.19. The findings suggest that chemical compounds separated into fraction 01 are responsible for their sun protection activity and antioxidant activity. These findings underline the potential of fraction 01 methanolic extracts of M. zeylanica bark extracts as valuable sources of antioxidants and sun protection agents.

Column chromatography separation of lanthanide(III) bisphthalocyaninate and phthalocyanine ligand

During the synthesis of double-decker f-metal phthalocyanine complexes Ln(Pc)2 free phthalocyanine ligands can be also formed, however, routine column chromatography is not effective for their separation. The preliminary reduction of the complexes with hydrazine hydrate affords the low mobile forms, which can be re-oxidized in the chromatography columns after the free ligand is eluted.