DMSO Solution Research Articles

Comparative Transcriptome Analysis of the Pest Galeruca daurica (Coleoptera: Chrysomelidae) Larvae in Response to Six Main Metabolites from Allium mongolicum (Liliaceae)

Plants are important ecological factors and food resources, which can significantly affect the occurrence and distribution of insects. The metabolites in host plants can affect the feeding, spawning, and avoidance behaviors of herbivorous insects. Galeruca daurica (Joannis) is a phytophagous pest that has seriously occurred in the desert steppe of Inner Mongolia in recent years, only infesting the leaves of Allium plants. In order to clarify the effects of plant metabolites on the gene expression in G. daurica larvae at the transcriptome level, we fed the larvae of G. daurica with Allium tuberosum leaves soaked in 10% DMSO solutions containing d-galactose, β-d-glucopyranose, l-rhamnose, isoquercitrin, isoflavone, and rutin, respectively, used the larvae fed on A. tuberosum leaves soaked in a 10% DMSO solution as the control, and screened out the differentially expressed genes (DEGs) by performing high-throughput transcriptome sequencing. The results showed that a total of 291 DEGs were identified compared to the solvent control (DMSO), including 130, 34, 29, 21, 72, and 97 in the isoquercitrin, isoflavone, rutin, d-galactose, β-d-glucopyranose, and l-rhamnose treatment groups, respectively. GO and KEGG enrichment analysis showed that most DEGs were enriched in various metabolic pathways, implying that these six main primary and secondary metabolites in Allium plants may affect various metabolic processes in the larvae of G. daurica.

Synthesis and structural studies on zinc(II) macrocyclic and hetrocyclic complexes derived from schiff base and mixed ligands of 1,4-dihydroquinoxaline-2,3-dione, orthophenylene diamine and hydroquinone

In this study two new zinc(II) complexes involving oxygen and nitrogen donor sequences derived from 1,4-dihydroquinoxaline-2,3-dione (QXD), o-phenylenediamine (OPD) and hydroquinone (HQ) were synthesized through a template procedure. The structural elucidation of these complexes was carried out using measurement of molar conductance in 1x10-3 M solution of DMSO and various spectral techniques; 1H and 13C NMR, FT-IR, UV-VIS and AAS. The results showed that the zinc(II) ion coordinates with the Schiff base ligands in octahedral geometry, leading to the formation of stable macrocyclic and heterocyclic structures. The cyclic ligand (L) was found to coordinate as NNNN donor, through four imine nitrogen atoms which were formed up on condensation of the –NH2 groups on o-phenylenediamine with C=O group on quinoxaline dione in a 2:2 mole ratio, in the presence of one mole equivalent of ZnCl2 in ethanol medium. It also indicates the formation of a new mixed ligand zinc(II) complex with an OO OO O O coordination around zinc(II). The study contributes to the understanding of the coordination chemistry of zinc(II) with Schiff bases and provides insights into the development of novel zinc-based complex compounds. KEY WORDS: Macrocyclic and mixed ligand, 1,4-Dihydroquinoxaline-2,3-dione, o-Phenylenediamine, Hydroquinone Bull. Chem. Soc. Ethiop. 2025, 39(1), 49-64. DOI: https://dx.doi.org/10.4314/bcse.v39i1.4

Synthesis and characterization of 3,5-bis((2-hydroxybenzylidene)amino)-N-(2-hydroxyphenyl)benzamide and Zn(II) complex: Investigation of chromic, fluorescence and DPPH radical scavenging behaviours

Novel amido-Schiff base 3,5-bis((2-hydroxybenzylidene)amino)-N-(2-hydroxyphenyl)benzamide (2a) has been obtained by the reaction of Schiff base 1a with 2-hydroxyaniline in the presence of coupling agent N,N′-dicyclohexylcarbodiimide. Schiff base (1a) which serves as the starting compound in amide synthesis was produced from the condensation of 3,5-diaminobenzoic acid with salicylaldehyde in a 1:2 mol ratio. Tetrahedral geometry with 1:1 [M:L] stoichiometry Zn(II) complex (3a) was newly synthesized by the complexation reaction of ligand 2a with zinc(II) nitrate. 1a and 2a displayed a broad emission band at λem = 456 and 472 nm with a blue fluorescent in pure DMSO, while 3a emitted a strong greenish-blue fluorescent with the λem = 485 nm (λexc = 365 nm). The fluorescence efficiency of 1a was poor compared to the others. The λem in aqueous DMSO solution (v/v, 1:1) had ∼8–33 nm red-shift with respect to that of pure solution. The λem gave ∼1–15 nm red-shift with very low emission efficiency in acidic DMSO media. The results suggested that the aggregation caused quenching properties of 1a–3a in pure, aqueous, and acidic DMSO system with a 50 % water fraction. The fluorescence of the compounds appeared to be visibly very bright in basic DMSO media. All the compounds were also screened for antioxidant activity using UV–Vis spectroscopy. They were found to be not effective DPPH radical scavengers in DMSO.

Recognition of carboxylic acids and phosphonic acids using a 1,8-diphenylanthracene-based diguanidine in solution and solid states

A 1,8-diphenylanthracene-based diguanidine 1 has been designed and synthesized for the recognition of carboxylic acids and phosphonic acid derivatives. The diguanidine 1a forms 1:1 complexes with the dicarboxylic acids and the diphosphonic acid derivatives in a DMSO solution, and the formation of these complexes was confirmed by a DOSY NMR analysis. The binding mode towards the guanidyl group (Type I, Type II, two existing types of binding modes toward three nitrogen atoms) with a diphosphonic acid derivative was successfully demonstrated by the 2D NOESY analysis. The diguanidine 1a does not show any fluorescence in a DMSO solution, but after the addition of carboxylic acids, the formation of a stable complex or the formation of the protonated guanidinium (1a+2H+) were distinguishable by the observation of a light-blue fluorescence around 430 nm. These fluorescence observations can be determined the stability of the complexes of the diguanidine 1a with carboxylic acids. On the other hand, the DMSO solution of diguanidine 1a showed a light-blue fluorescence after the addition of phosphonic acids. Interestingly, diguanidine 1a recognized methylphosphonic acid 9a in the solid state by grinding and showed a green fluorescence, while the other phosphonic acids 9 and dicarboxylic acids (4d: pimelic acid, 4f: azelaic acid) showed a light-blue fluorescence in the solid state, and a selectivity was observed. These fluorescence characteristics of the diguanidine 1 are applicable for the detection of carboxylic acids and phosphonic acids, especially for methylphosphonic acid 9a in the solid state.

Synthesis, Characterization and Analytical Study of New Azo Compounds for using as acid-base indictors

A diazotization method was used to synthesize new azo compounds, to which phenol was subsequently added to diazonium salt solution in basic medium at temperatures ranging from 0 to 5 °C and compounds were characterized by FT-IR, 1H-NMR, and 13C-NMR spectroscopy. The potential of the compounds as acid-base indicators was tested by determining their ionization and protonation constants at different pH levels (1 to 14) using a DMSO solution of the synthesized compounds. UV-Vis spectra shown as maximum wavelength (380-390 nm) observed at pH 1-7 occurs, indicating the cationic formula (protonated form of compound H2 and H4), another peak (470-530 nm) appears at pH 8-13, indicating the ionic formula (deprotonated form of compound H2 and H4), where for compound H5 observed at 560 nm at pH 1-7. Another peak appears 505 nm at pH 8-13 attributable to absorption the ionic formula (deprotonated form of compounds H5). Molecules H2, H4, and H5 showed distinct color changes when shifted to acidic and basic conditions. Furthermore, these compounds showed exceptional accuracy in drawing conclusions about the phenomenon.

Synthesis, Structural Determination, DFT Calculation and Biological Evaluation Supported by Molecular Docking Approach of Some New Complexes Incorporating (E)‐N'‐(3,5‐di‐Tert‐Butyl‐2‐Hydroxybenzylidene) Isonicotino Hydrazide Ligand

ABSTRACTThe synthesis and structural analysis of complexes derived from (E)‐N′‐(3,5‐di‐tert‐butyl‐2‐hydroxybenzylidene) isonicotino hydrazide (ITB ligand) were examined using multiple analytical techniques. These techniques included TGA, decomposition point determination, elemental analysis (CHN), spectroscopic (IR, NMR, mass spectrometry) analysis, magnetic susceptibility, conductivity, as well UV–Vis spectrum analysis, along with theoretical studies. Molar conductance values indicated that the Cd (II), Co (II), Cu (II), Ni (II), and Zn (II) complexes are non‐electrolytes in fresh DMSO solutions, with conductance values ranging from 8.5 to 14.35 Ω−1 cm2 mol−1. IR spectra suggested which the ligand coordinates through the metal ions in a tridentate fashion, utilizing the (N & O) donor sites from the (CN & CO & CO) groups in the hydroxybenzylidene moiety. Analytical data from solution complexation, job's method suggested a 1:1 (metal:ligand) molar ratio. The stability order of the complexes was determined as ITBCo > ITBCu > ITBNi > ITBZn > ITBCd, consistent with the stability constant (Kf) values. The pH profile indicated that the studied complexes exhibit stability upon a wide pH scale, typically between (pH = 4:10). Magnetic and electronic spectral analyses helped deduce the ligand coordination abilities and the geometric structures of the complexes. In vitro (antimicrobial & anticancer) performances of the studied complexes were tested versus various (microbial strains & cancer cell lines), revealing higher activity in the chelates assessed to the free (ITB) ligand. The antioxidant potential was also assessed using the DPPH assay. Finally, molecular docking was performed toward estimate the binding efficiency between various protein receptors and the compounds, with results aligning with the biological investigations.

NIR-Sensitive Squaraine Dye-Peptide Conjugate for Trypsin Fluorogenic Detection.

Trypsin enzyme has gained recognition as a potential biomarker in several tumors, such as colorectal, gastric, and pancreatic cancer, highlighting its importance in disease diagnosis. In response to the demand for rapid, cost-effective, and real-time detection methods, we present an innovative strategy utilizing the design and synthesis of NIR-sensitive dye-peptide conjugate (SQ-3 PC) for the sensitive and selective monitoring of trypsin activity by fluorescence ON/OFF sensing. The current research deals with the design and synthesis of three unsymmetrical squaraine dyes SQ-1, SQ-2, and SQ-3 along with a dye-peptide conjugate SQ-3-PC as a trypsin-specific probe followed by their photophysical characterizations. The absorption spectral investigation conducted on both the dye alone and its corresponding dye-peptide conjugates in water, utilizing SQ-3 and SQ-3 PC respectively, reveals enhanced dye aggregation and pronounced fluorescence quenching compared to observations in DMSO solution. The absorption spectral investigation conducted on dye only and corresponding dye-peptide conjugates in water utilizing SQ-3 and SQ-3 PC, respectively, reveals not only the enhanced dye aggregation but also pronounced fluorescence quenching compared to that observed in the DMSO solution. The trypsin-specific probe SQ-3 PC demonstrated a fluorescence quenching efficiency of 61.8% in water attributed to the combined effect of aggregation-induced quenching (AIQ) and fluorescence resonance energy transfer (FRET). FRET was found to be dominant over AIQ. The trypsin-mediated hydrolysis of SQ-3 PC led to a rapid and efficient recovery of quenched fluorescence (5-fold increase in 30 min). Concentration-dependent changes in the fluorescence at the emission maximum of the dyes reveal that SQ-3 PC works as a trypsin enzyme-specific fluorescence biosensor with linearity up to 30 nM along with the limit of detection and limit of quantification of 1.07 nM and 3.25 nM, respectively.

Effect of Leaving Centrosymmetric Character on Spectral Properties in Mono-, Bi-, and Triphotonic Absorption Spectroscopies.

Numerical simulations of the absorption bands of photoswitch E-o-tetrafluoroazobenzene in DMSO solution under one-, two-, and three-photon absorption conditions combined with the analysis of the behavior of transition probability under distortion of planarity reveal many similarities between the mono- and triphoton spectroscopic behaviors with a two-photon spectrum being set apart. The position of the absorption peak for the studied nπ* and ππ* transitions appears shifted to lower energies (longer wavelengths) than the conventional estimate based on vertical excitation from the ground-state potential energy minimum.

Spectral-luminescence properties of PV corrolazines with axial alkoxide ligands

New phosphorus(V) complexes of octaphenyl substituted tetrapyrazinocorrolazines (TPyzCA) containing in the axial positions alkoxide ligands [TPyzCAP(OC2H4X)2] (X = Pr, NMe2, OH) were synthesized using the one-pot procedure and effect of acid on their spectral luminescence and photochemical properties was studied. The presence of fused pyrazine rings increases the ability to bind axial ligands compared to benzo-fused corrolazine (TBzCA). Excited state properties are strongly dependent on the solvation effects. The effect of excited state quenching by photoinduced electron transfer is observed only for the dimethylaminoethoxide complex of TPyzCA in polar solvents, like THF or DMSO. Still, it is absent in dichloromethane, toluene, and for TBzCA derivatives. The hydroxyethoxide complex of TPyzCA and dimethylaminoethoxide complex of TBzCA exhibit efficient fluorescence and high singlet oxygen generation ability in DMSO solution.

Synthesis, antimicrobial activity, molecular docking and MD simulation studies, in silico ADME investigations and thermo-acoustic studies of heterocyclic dihydropyrimidine substituted 1,3,4-thiadiazole scaffolds

The connections between the chemical structures and antibacterial properties of different functional groups including organic molecules were examined in this study. we have synthesized a novel series of 1,3,4-thiadiazole hybrids (5a-o) based on 3,4-dihydropyrimidines. After an effective synthesis, the compounds' structure was confirmed by using spectrum techniques like IR, 1H NMR, 13C NMR, and mass spectrometry. Elemental analyses were performed on a Perkin-Elmer 2400 CHN analyzer and the resulting data were within the accepted range (± 0.40) of the calculated values. The in vitro antimicrobial activity of the compounds against a range of bacterial and fungal species. Compound 5i showed potent inhibitory effects against P. aeruginosa with MIC values of 12.5 μg/ml S. aureus and A.niger were positively affected by compound 5k with MIC values of 12.5 μg/ml and 50 μg/ml, respectively. Based on the results, compounds 5a and 5o have moderate activity against C.albicans and E. coli with MIC values of 50 μg/ml and 62.5 μg/ml respectively. Furthermore, molecular docking and molecular dynamics simulations were used to identify the most stable conformation of newly discovered inhibitors. Thermo-acoustical properties of derivatives 5k and 5l in DMSO and DMF solvent have been determined at three different atmospheric pressure temperatures (298.15, 308.15, and 318.15)K. The components of the liquid mixture's molecular interactions have been taken into account to explain these results. The acquired results are interpreted in terms of interactions between solutes and solvents, providing insight into the compounds' potential to form or disrupt structures in DMSO and DMF solutions.

Synthesis, experimental and computational studies of new (trifluorosilyl)propyl derivatives of cyclic imides of dicarboxylic acids

New (trifluorosilyl)propyl derivatives of cyclic dicarboxylic acid imides 1-[3-(trifluorosilyl)propyl]pyrrolidine-2,5‑dione, 1-[3-(trifluorosilyl)propyl]piperidine-2,6‑dione and 2-[3-(trifluorosilyl)propyl]-1H-isoindole-1,3(2H)‑dione were synthesized and structurally characterized by FTIR, NMR spectroscopy, mass spectrometry and elemental analysis. Intramolecular coordination interaction O→Si and the influence of the hydrocarbon chain length on the strength of the coordination interaction in Si-fluoroethyl and Si-fluoropropyl derivatives of cyclic imides of dicarboxylic acids were characterized by DFT calculations. The geometric, energetic and electronic characteristics of the investigated molecules were also determined. The intramolecular O→Si coordination bond, closing the six-membered chelate cycle SiCCN(C=O), is observed in the (trifluorosilyl)ethyl derivative phthalimide in the gas, and in the (trifluorosilyl)ethyl derivative succinimide the O→Si coordination bond is observed both in the gas phase and in DMSO solution. The coordination bond O→Si, closing the seven-membered chelate cycle SiCCCN(C=O), is found in the (trifluorosilyl)propyl derivative succinimide in the gas phase. Quantum chemical calculations were carried out at the M06/6–311G** and MP2/6–311++G**//M06/6–311G** levels with the 6–311G** basis set.

Cryopreservation of canine ovarian tissue by slow freezing and vitrification: Evaluation of follicular morphology and apoptosis rate

In this study, we aimed to evaluate the efficacy of cryopreserving canine ovarian tissue using vitrification and slow freezing methods while investigating potential differences in cryotolerance based on follicular type and cryopreservation technique. Twenty-eight ovaries were collected from 14 anoestrus bitches of various breeds, aged between 2 and 5 years, and undergoing elective ovariohysterectomy. The ovaries were sectioned into small fragments and randomly assigned to three groups: vitrification, slow freezing, and a control group (fresh tissue). Vitrification was performed using cryotubes containing DAP 213 solution (2M DMSO, 1M acetamide, 3M propylene glycol) in two stages, while slow freezing involved cryotubes with 1.5M DMSO solution inserted into a programmable machine. The effects of cryopreservation were evaluated by histology and immunohistochemistry (cleaved caspase-3), to determine the percentage of cells undergoing apoptosis. Histological examination revealed that the slow freezing group exhibited a significantly higher percentage of intact follicles (45.75 %) compared to those subjected to vitrification (38.17 %; P = 0.01). Immunohistochemical evaluation further indicated that 84.21 % of the follicles in the slow freezing group did not express caspase-3, suggesting the absence of apoptosis. Conversely, vitrified samples exhibited significantly more apoptotic cells compared to other groups (P < 0.001). Furthermore, early antral follicles displayed a higher susceptibility to degeneration regardless of the cryopreservation method employed. Nevertheless, when comparing the cryopreserved groups, early antral follicles showed greater degeneration in slow freezing group, while preantral follicles were the most affected in the vitrification group. In conclusion, slow freezing demonstrated superior preservation of viable follicles compared to vitrification and emerged as the preferred technique for cryopreserving canine ovarian tissue. These findings contribute valuable insights into optimizing cryopreservation methods for canine ovarian tissue, potentially benefiting reproductive technologies and fertility preservation in canines.

Engineered CoS/Ni3S2 Heterointerface Catalysts Grown Directly on Carbon Paper as an Efficient Electrocatalyst for Urea Oxidation

Developing highly efficient and stable electrocatalysts for urea electro-oxidation reactions (UORs) will improve wastewater treatment and energy conversion. A low-cost cobalt sulfide-anchored nickel sulfide electrode (CoS/Ni3S2@CP) was synthesized by electrodeposition in DMSO solutions and found to be highly effective and long-lasting. The morphology and composition of catalyst surfaces were examined using comprehensive physicochemical and electrochemical characterization. Specifically, CoS/Ni3S2@CP electrodes require a potential of 1.52 volts for a 50 mA/cm2 current, confirming CoS in the heterointerface CoS/Ni3S2@CP catalyst. Further, the optimized CoS/Ni3S2@CP catalyst shows a decrease of 100 mV in the onset potential (1.32 VRHE) for UORs compared to bare Ni3S2@CP catalysts (1.42 VRHE), demonstrating much greater performance of UORs. As compared to Ni3S2@CP, CoS/Ni3S2@CP exhibits twofold greater UOR efficiency as a result of a larger electroactive surface area. The results obtained indicate that the synthetic CoS/Ni3S2@CP catalyst may be a favorable electrode material for managing urea-rich wastewater and generating H2.

Achieving Inkjet‐Printed 2D Tin Iodide Perovskites: Excitonic and Electro‐Optical Properties

AbstractCurrently, there is a great demand for non‐toxic lead‐free halide perovskites as active materials for solar cells, light‐emitting diodes and other optoelectronic devices. Although an essential progress has been made using tin(II) halide perovskites, still greater efforts are needed to improve their stability and manufacture films and devices under a scalable technology. The first goal of the work is to achieve suitable physical properties of 2D Sn(II) polycrystalline perovskite films obtained by the industrially scalable inkjet printing deposition technique. In the present work, inks of 2D tin(II) halide perovskite 2‐thiopheneethylammonium tin(II) iodide, TEA2SnI4, have been successfully formulated in DMF (toxic) and DMSO (non‐toxic) solutions and using appropriate additives (SnF2 and reducing agents) for improving the stability of the inks and the resulting films. Room‐ and low‐temperature excitonic photoluminescence (PL), charge carrier recombination dynamics and µ‐PL is used to explain the observed two excitonic bands, which are associated to the bulk and edges of perovskite grains nanoplatelet‐like composing the polycrystalline films. Promising electro‐optical properties are also obtained in the TEA2SnI4 films inkjet‐printed from DMSO formulations onto ITO‐interdigitated electrodes, such as low dark currents, ≈10 – 20 nA at 10 V of bias voltage, and high responsivities ≈1–20 A/W.

Precipitation of advanced nanomedicines (curcumin) using supercritical processing; experimental study, design and optimizing operating conditions

Curcumin is a known herbal medicine with numerous therapeutic effects and low bioavailability. Reducing the particle size of this medicine is a confirmed solution to increase its dissolution rate and bioavailability. To do so, Curcumin nanoparticles were produced in the present work by the supercritical gas anti-solvent (GAS) method. First, the minimum GAS operating pressure (Pmin) required to precipitate fine Curcumin particles from two solvents DMSO and ethanol was estimated using Peng-Robinson equation of state (PR-EoS). Then, Curcumin nanoparticles were precipitated from these two solvents under different operating conditions, specified by the Box–Behnken design method. Given the desired operating variables including pressure (120, 180, and 240 bar), temperature (308, 328, and 348 K), initial concentration (5, 35, and 65 mg/ml), flow rate of the supercritical carbon dioxide (scCO2) (10, 50, and 90 ml/min), and stirring rate (500, 1500, and 2500 rpm), their influence on the particle size of Curcumin was investigated, and optimum conditions were determined. At 240 bar and 328 K, nano Curcumin particles with the size of 230 nm and 81 nm were precipitated from DMSO and ethanol solutions with the initial concentration of 5 mg/ml and stirring rate of 1500 rpm, respectively. Results show that scCO2 flow rate is not a significant parameter.The remarkable reduction in the particle size of Curcumin from 28 ± 10 μm of the original sample to nano-scale confirms GAS efficiency. Also, the dissolution rate of the nanoparticles, produced in the optimal condition is much higher than the original sample, which can be due to their nano-metric size and lower degree of crystallinity.

Femtosecond to Microsecond Observation of Photochemical Pathways in Nitroaromatic Phototriggers Using Transient Absorption Spectroscopy.

The synthetic accessibility and tolerance to structural modification of phototriggered compounds (PTs) based on the ortho- nitrobenzene (ONB) protecting group have encouraged a myriad of applications including optimization of biological activity, and supramolecular polymerization. Here, a combination of ultrafast transient absorption spectroscopy techniques is used to study the multistep photochemistry of two nitroaromatic phototriggers based on the ONB chromophore, O-(4,5-dimethoxy-2-nitrobenzyl)-l-serine (DMNB-Ser) and O-[(2-nitrophenyl)methyl]-l-tyrosine hydrochloride (NB-Tyr), in DMSO solutions on femtosecond to microsecond time scales following the absorption of UV light. From a common nitro-S1 excited state, the PTs can either undergo excited state intramolecular hydrogen transfer (ESIHT) to an aci-S1 isomer within the singlet state manifold, leading to direct S1 → S0 internal conversion through a conical intersection, or competitive intersystem crossing (ISC) to access the triplet state manifold on time scales of (1.93 ± 0.03) ps and (13.9 ± 1.2) ps for DMNB-Ser and NB-Tyr, respectively. Deprotonation of aci-T1 species to yield triplet anions is proposed to occur in both PTs, with an illustrative time constant of (9.4 ± 0.7) ns for DMNB-Ser. More than 75% of the photoexcited molecules return to their electronic ground states within 8 μs, either by direct S1 → S0 relaxation or anion reprotonation. Hence, upper limits to the quantum yields of photoproduct formation are estimated to be in the range of 13-25%. Mixed DMSO/H2O solvents show the influence of the environment on the observed photochemistry, for example, revealing two nitro-S1 lifetimes for DMNB-Ser in a 10:1 DMSO/H2O mixture of 1.95 ps and (10.1 ± 1.2) ps, which are attributed to different microsolvation environments.

Self-assembly variation of glycyrrhetinic acid epimers: Assembly mechanism and antibacterial efficacy between 18 α-GA and 18 β-GA

Studies have confirmed that the spatial arrangement of chiral molecules has a decisive influence on supramolecular assembly. However, the effect of epimerization caused by the change of a single chiral center on the self-assembly of chiral molecules has not been reported. Herein, we explored a pair of epimers 18 α-glycyrrhetinic acid and 18 β-glycyrrhetinic acid from Glycyrrhiza uralensis Fisch, which had completely different medicinal activities. In this study, we found that these epimers of glycyrrhetinic acid showed distinct self-assembly properties under the condition of the deionized water and a small amount of DMSO solution. Interestingly, the cis-configured 18 β-GA could form a 'head-to-tail' interlaced structure and further self-assembled to form nanoparticles, while trans-configured 18 α-GA was connected in a “head-to-head” manner, and due to the excessive steric hindrance that made it difficult to assemble. This work not only clearly demonstrates the impact of epimerization due to changes in a single chiral center on the self-assembly of chiral molecules as well as biological activity, but also provides new insights into the self-assembly of natural organic molecules in the development of nanomedicines and biofunctional materials.

Arsenate Stabilization via Dynamic Covalent Chemistry

AbstractWe report the synthesis of arsenic heterocycles derived from saccharides 2–4 and AsCl3. Compounds 5 and 6 are stable in aqueous solutions, DMSO, or methanolic solutions. However, NMR and HPLC studies revealed that intramolecular trans‐esterification processes leads to dynamic equilibria. Theoretical studies revealed that three arsenates and two arsoranes participate in these intramolecular equilibria and account for the experimental spectroscopy and HPLC results. Through the correlation between the experimental and theoretical 13C NMR spectra, we proposed the speciation of arsenic Compounds 5 and 6. Moreover, experimental and theoretical IR spectra demonstrated that arsenates 5 A and 6 A predominate in the solid state. QTAIM studies were performed to explain the chemical shifts in the 13C NMR spectra. Biological studies suggest that the structural flexibility of Compounds 5 and 6 increase the cytotoxic and antiproliferative activities of these compounds.

Novel pyrene-based Schiff base ligand as a fluorescent sensor for Al3+ and colorimetric sensor for Ni2+ ions detection: Synthesis, photo-physical and cell imaging studies

A simple fluorescent and colorimetric pyrene-based ((Z)-4-hydroxy-3-((pyren-1-ylmethylene)amino)benzoic acid (HPMB) chemosensor was synthesized through the condensation reaction between pyrene-1-carboxaldehyde and 3-amino-4-hydroxybenzoic acid. The structure of HPMB was elucidated using 1H NMR, MS, and UV–Visible spectroscopic techniques. The receptor HPMB displayed a detectable, colorimetric colour shift in the presence of Ni2+ and the colour of the solution was observed to be light brown. On the other hand, it also exhibited a fluorescent “turn on” response when Al3+ ions were added in DMSO solution (HEPES 0.01 M, pH = 7.4) at room temperature. Job’s plot showed that HPMB binding ratio to Ni2+ and Al3+ ions was in 1:1 ratio. The detection limit for Ni2+ and Al3+ ions was found to be 0.33 × 10-6 M and 0.26 × 10-6 M, respectively. In addition, HPMB was utilised to create a molecular logic gate, and the fluorescence imaging of HeLa cells was investigated because of HPMB’s low cytotoxicity, indicating that it could be used to detect Al3+ and Ni2+ in living cells.

Viability of Methicillin-Resistant Staphylococcus aureus (MRSA) Bacteria Preserved at Different Temperature and Time

The bacteria Staphylococcus aureus, a normal component of human flora, is easily mutated and antibiotic-resistant, leading to the creation of Methicillin-Resistant Staphylococcus aureus (MRSA). This bacterium is a difficult-to-control nosocomial infection in healthcare settings, so it must be stored using specialized preservation agents, like DMSO, to investigate the nature and characteristics of these bacteria for prevention, control, and therapy. The purpose of this study was to evaluate the survival of MRSA bacteria that had been kept in a DMSO solution at various temperatures and periods. This study was carried out between July and October2022 using a one-shot study case research design, data analysis, and quantitative descriptive analysis. According to the findings, MRSA bacteria held in 15% DMSO solution lost viability over time and at various storage temperatures. Among various bacterial species held at various storage temperatures, MRSA bacteria had the lowest colony loss rate (-20 °C). Based on the findings of this study, it can be said that the preservation of MRSA bacteria at freezing temperature (-20 °C) and storage length of one month resulted in the greatest survivability of the bacteria when stored in 15% DMSO solution.