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Abstract By employing a synergistic blend of experimental and theoretical methodologies, we investigated the corrosion inhibition efficacy of a synthesized pyrazole derivative (BM-01) in a solution of hydrochloric acid (1 M). We utilized molecular dynamics (MD) simulations, scanning electron microscopy (SEM), density functional theory (DFT), complexation, plus electrochemical impedance spectroscopy (EIS). We conducted weight loss (WL) measurements from 298 to 328 K. Inhibition efficacy reached a maximum at a BM-01 concentration of 10−3 M, achieving 90.0% (EIS), 90.40% (WL), and 90.38% (potentiodynamic polarization (PDP)). SEM unveiled the shielding of the carbon-steel surface from acid-induced damage by BM-01. The Langmuir adsorption isotherm exhibited a robust fit with a low sum of squares, standard deviation, and a high correlation coefficient. PDP findings indicated that BM-01 acted as a mixed-type inhibitor, predominantly favoring the cathodic process, suggesting potential corrosion-mitigation properties. Theoretical analyses involving DFT, MD simulations, and radial distribution function were conducted to postulate a mechanism and identify an inhibitory layer. Theoretical outcomes aligned closely with experimental data, thereby reinforcing the validity of our findings.

Abstract Within the context of Molecular Electronic Density Theory (MEDT), this study investigates the Diels–Alder reaction among isoprene (2) and R-carvone (1R) applying DFT simulations, with and without Lewis acid (LA) catalysis. The results show that carvone (1R) acts as an electrophile and isoprene (2) as a nucleophile in a polar process. LA catalysis increases the electrophilicity of carvone, thereby improving the reactivity and selectivity of the reaction by reducing the activation Gibbs free energy. Parr functions reveal that the C5=C6 double bond is more reactive than the C9=C10 double bond, indicating chemoselectivity. The examination of the Electron Localization Function (ELF) reveals high regio- and stereoselectivity, indicating an asynchronous mechanism for the LA-catalyzed DA reaction. Furthermore, it is suggested that cycloadduct 3 has great anti-HIV potential because it exhibits lower binding energies than azidothymidine (AZT) in the docking studies of cycloadducts 3 and 4 amongst a primary HIV-1protein (1A8O plus 5W4Q).

Rubus ellipticus Smith is an evergreen shrub in the Rosaceae family, commonly known as yellow Himalayan raspberry. The objective of this study is to determine the morphological analysis, minerals, proximate, ascorbic acid, anthocyanins, and carotenoids content in R. ellipticus fruits. The fruit samples were collected from four different sites with different altitudes [500 m (District Bilaspur), 1,000 m (District Hamirpur), 1,500 m (District Solan) and 2,000 m (District Shimla)] of Himachal Pradesh for the two consecutive years (2018 and 2019). The fruit morphological investigation revealed that the maximum length (7.71 ± 0.08 mm), width (8.71 ± 0.03 mm), and weight (0.80 ± 0.01 g) of fruits is achieved at higher altitudes (2,000 m) in the year 2018 as compared to 2019. The mineral content (0.05–36.6 mg/g DW), ascorbic acid content (14.59–23.64 mg/g DW), proteins (95.20–131 mg/g DW), and crude fibers (5.6–11.5%) were also higher in fruits grown at 2,000 m altitude, whereas carbohydrates (210–398 mg/g DW), crude fat (2.4–4.1%), and anthocyanins (0.42–1.35 mg/100 g FW) contents were higher in fruits collected from 500 m altitude. According to the results, R. ellipticus fruits were rich in crude fiber, moisture, carbohydrates, protein, ash, and crude fat, as well as in micronutrients, and displayed significant variation with altitude in nutrient content. This could be due to the different environmental, geographical, and weather conditions. The high nutrient content of R. ellipticus suggests its future potential applications for the food and pharmaceutical industry.

Thymol (THY), as the natural monoterpene phenol, acts against oxidative stress and inflammatory processes. This study aimed to evaluate the anti-inflammatory effects and possible molecular mechanisms of THY via formalin-induced mouse and egg albumin-induced chick models alongside molecular docking and molecular dynamic (MD) simulations. THY (7.5, 15, and 30 mg/kg) was investigated, compared to celecoxib and ketoprofen (42 mg/kg), as anti-inflammatory standards. THY dose-dependently and significantly (p < 0.05) decreased paw-licking and edema diameter parameters in formalin (phases I and II) and egg albumin-induced models. Moreover, THY (15 mg/kg) exerted better anti-inflammatory effects in combination with the standard drug ketoprofen than alone and with celecoxib. In silico studies demonstrated elevated binding affinities of THY with cyclooxygenase-2 (COX-2) than the COX-1 enzyme, and the ligand binds at a similar location where ketoprofen and celecoxib interact. The results of MD simulations confirmed the stability of the test ligand. THY exerted anti-inflammatory effects on Swiss mice and young chicks, possibly by interacting with COX-2. As a conclusion, THY might be a hopeful drug candidate for the management of inflammatory disorders.

Recently, nanotechnology has emerged as an extensively growing field. Several important fabricated products including Carbon nanotubes (CNTs) are of great importance and hold significance in several industrial sectors, mainly food industry. Recent developments have come up with methodologies for the prevention of health complications like lack of adequate nutrition in our diet. This review delves deeper into the details of the food supplementation techniques and how CNTs function in this regard. This review includes the challenges in using CNTs for food applications and their future prospects in the industry. Food shortage has become a global issue and limiting food resources put an additional burden on the farmers for growing crops. Apart from quantity, quality should also be taken into consideration and new ways should be developed for increasing nutritional value of food items. Food supplementation has several complications due to the biologically active compounds and reaction in the in vivo environment, CNTs can play a crucial role in countering this problem through the supplementation of food by various processes including; nanoencapsulation and nanobiofortification thus stimulating crop growth and seed germination rates. CNTs also hold a key position in biosensing and diagnostic application for either the quality control of the food supplements or the detection of contagions like toxins, chemicals, dyes, pesticides, pathogens, additives, and preservatives. Detection such pathogens can help in attaining global food security goal and better production and provision of food resources. The data used in the current review was collected up to date as of March 31, 2024 and contains the best of our knowledge. Data collection was performed from various reliable and authentic literatures comprising PubMed database, Springer Link, Scopus, Wiley Online, Web of Science, ScienceDirect, and Google Scholar. Research related to commercially available CNTs has been added for the readers seeking additional information on the use of CNTs in various economic sectors.

Introduction:Cheilanthes tenuifolia is an evergreen ornamental small fern, belonging to the family Pteridaceae, that grows in warm and rocky regions worldwide. Many species of Cheilanthes genus are evidently endowed with important phytochemicals and bioactivities. This study aimed to perform a preliminary phytochemical analysis of Cheilanthes tenuifolia leaves alongside an evaluation of free radical scavenging, anti-inflammatory, antimicrobial, and clot lysis activities of extract fractions.Materials and methods: A preliminary phytochemical analysis was done after fractionation of ethanolic extract (ECT) with n-hexane (HCT) and chloroform (CCT). Then, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, egg albumin and RBC membrane stabilization tests, disc diffusion, and human blood clot lysis assays were performed.Results: Phytochemical investigations suggested that the plant is rich in alkaloids, glycosides, tannins, and flavonoids. All obtained fractions exhibited concentration-dependent radical scavenging, inhibition of egg protein denaturation and RBC membrane lysis capacities. Except for antifungal tests, ECT exhibited better DPPH radical scavenging, anti-inflammatory, antibacterial, and clot lysis capacities than HCT and CCT fractions. However, all fractions exhibited a mild anti-inflammatory activity.Conclusion:C. tenuifolia might be a good source of antioxidant, anti-microbial, and anti-atherothrombotic agents. Further studies are required to isolate and characterize the active principles liable for each bioactivity, along with possible molecular interactions.

Abstract Luminescent solids exhibit unique optical and electronic properties, and it is important to develop a simple experimental procedure to reduce the mass of weakly emissive hybrid inorganic–organic solids. The instant mixing of (1‐cyano‐2‐[α‐terthiophen‐2‐yl]‐vinyl)carboxylic acid (3TCC) and a metal–organic framework (MOF‐177; ZnO4(BTB)2; BTB = 1,3,5‐benzenetribenzoate) in an organic solvent, followed by evaporation of the solvent, produces solids with distinct photoluminescence (PL) properties, turning over the PL quantum yields (PLQY) of the generated 3TCC@MOF‐177 solids by 2‐ to 40‐fold compared to the 3TCC solution is demonstrated. The new solids are characterized by various methods and optical measurements. Contrarily to the trend in the photophysical results of 3TCC solutions, the anisotropic rotational times of 3TCC@MOF‐177 solids inversely correlate with the corresponding PLQY values depending on the protic solvent used in the initial preparation step in the following order: methanol>ethanol>butanol. This behavior is attributed to the complexation of 3TCC dye with metal clusters within the pores of MOF‐177 and hydrogen bonding of the CN group in the dye with the OH group in the linkers. These factors interplay with the kinetics of dye twisting. These observations reflect the potential of new solid luminescent architectures with remarkable PLQY that can be easily manufactured.

Introduction: D-pinitol, a naturally occurring inositol, has diverse biological activities like antioxidant, antimicrobial and anticancer activities. This study aimed to evaluate anti-inflammatory effect of d-pinitol in a chick model. Additionally, in silico studies were performed to evaluate the molecular interactions with cyclooxygenase-2 (COX-2).Methods: The tested groups received d-pinitol (12.5, 25, and 50 mg/kg) and the standard drugs celecoxib and ketoprofen (42 mg/kg) via oral gavage prior to formalin injection. Then, the number of licks was counted for the first 10 min, and the paw edema diameter was measured at 60, 90, and 120 min.Results and Discussion: The d-pinitol groups significantly (p < 0.05) reduced the number of paw licks and paw edema diameters, compared to negative control. When d-pinitol was combined with celecoxib, it reduced inflammatory parameters more effectively than the individual groups. The in silico study showed a promising binding capacity of d-pinitol with COX-2. Taken together, d-pinitol exerted anti-inflammatory effects in a dose-dependent manner, possibly through COX-2 interaction pathway.

Background:The most frequent lesion in the blood vessels feeding the myocardium is vascular stenosis, a condition that develops slowly but can prove to be deadly in a long run. Non-invasive biomarkers could play a significant role in timely diagnosis, detection and management for vascular stenosis events associated with cardiovascular disorders.Aims:The study aimed to investigate high sensitivity troponin I (hs-TnI), cardiac troponin I (c-TnI) and high sensitivity C-reactive protein (hs-CRP) that may be used solely or in combination in detecting the extent of vascular stenosis in CVD patients.Methodology:274 patients with dyspnea/orthopnea complaints visiting the cardiologists were enrolled in this study. Angiographic study was conducted on the enrolled patients to examine the extent of stenosis in the five prominent vessels (LDA, LCX, PDA/PLV, RCA, and OM) connected to the myocardium. Samples from all the cases suspected to be having coronary artery stenosis were collected, and subjected to biochemical evaluation of certain cardiac inflammatory biomarkers (c-TnI, hsTn-I and hs-CRP) to check their sensitivity with the level of vascular stenosis. The extent of mild and culprit stenosis was detected during angiographic examination and the same was reported in the form significant (≥50% stenosis in the vessels) and non-significant (

Abstract 2-Thienylbenzimidazole (TBI)/cucurbit[7]uril (CB7) host–guest complex was used as a motif to significantly improve the turnover of γ-Fe3O4 magnetic nanoparticles for potential application in the separation of toxic mercuric ions in polluted water samples. The mechanism of restoring the original solid materials is based on applying the pH-controlled preferential binding of the CB7 host to the TBI guest. The analytical application of this concept has not been realized in the literature. The pH-controlled stimuli-responsive abilities were confirmed in aqueous solution by the three-order of magnitudes higher stability constant of the protonated TBIH + /CB7 complex (e.g., K = 4.8 × 108 M−1) when compared to neutral TBI/CB7 complex (e.g., K = 2.4 × 105 M−1), also manifested in an increase in pK a values by ~ 3.3 units in the ground state. The supramolecular interaction and adsorption on iron oxide nanoparticles (NPs) were also spectroscopically confirmed in the solid state. The excited-state lifetime values of TBI/CB7NPs increased upon lowering the pH values (e.g., from 0.6 to 1.3 ns) with a concomitant blue shift of ~ 25 nm because of polarity effects. The time-resolved photoluminescent behaviors of the final solids in the presence of CB7 ensured pH-driven reusable systems for capturing toxic mercuric ions. The study offers a unique approach for the controllable separation of mercury ions using an external magnet and in response to pH through preferential binding of the host to guest molecules on the top of magnetic surfaces.

Abstract Controlling the number of molecular switches and their relative positioning within porous materials is critical to their functionality and properties. The proximity of many molecular switches to one another can hinder or completely suppress their response. Herein, a synthetic strategy involving mixed linkers is used to control the distribution of spiropyran-functionalized linkers in a covalent organic framework (COF). The COF contains a spiropyran in each pore which exhibits excellent reversible photoswitching behavior to its merocyanine form in the solid state in response to UV/Vis light. The spiro-COF possesses an urchin-shaped morphology and exhibits a morphological transition to 2D nanosheets and vesicles in solution upon UV light irradiation. The merocyanine-equipped COFs are extremely stable and possess a more ordered structure with enhanced photoluminescence. This approach to modulating structural isomerization in the solid state is used to develop inkless printing media, while the photomediated polarity change is used for water harvesting applications.

Abstract The cellular uptake of drug carriers to the cytosol of a specific cell remains challenging, and a non‐classical supramolecular strategy is motivated. Here, we select a model host–guest complex in which a diamino‐viologen (1,1′‐bis(4‐aminophenyl)‐[4,4′‐bipyridine]−1,1′‐diium dichloride [VG]) fluorescent tag was engulfed by cucurbit[8]uril (CB8) and covalently linked to alginate polysaccharides (alginic acid [ALG]) as the modified drug vehicle. When adsorbed on the ALG surface, the encapsulation of VG was first confirmed utilizing Fourier transform infrared and nuclear magnetic resonance spectroscopic methods. Solid optical measurements (diffuse reflectance spectroscopy, photoluminescence, and time‐resolved photoluminescence) revealed emissive materials at around 650 nm and that CB8 enhanced the rigidity of the modified hydrogel. The molar composition of 2:1 for the complexation of VG to CB8 on the alginate surface and the thermal stabilities were also confirmed using thermogravimetric analysis and differential scanning calorimetry techniques. CB8 induced a dramatic decrease in the average size of the VGALG polysaccharides from 485 to 165 nm and a turnover in their charge from –19.8 to +14.4 mV. Flow cytometry with inhibitors of various endocytosis pathways was employed to track the cellular uptake across different blood cell types: human T‐cell leukemia 1301 and peripheral blood mononuclear cells. Noticeably, complexation of VG with the CB8 host on top of the sugar platform dramatically enhanced the internalization into 1301 cells (viz. from 1% to 99%) at a concentration of 1.8 mg/mL via caveolae‐mediated endocytosis because of the size reduction, turnover in the charge from negative to positive, and rigidity induction. These observations reveal a more profound understanding of the macrocyclic effects on drug delivery.

Abstract Two lanthanide metal–organic frameworks [Ln-MOFs, Ln = Eu(III), Tb(III)] composed of oxalic acid and Ln building units were hydrothermally synthesized and fully characterized by powder X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, and energy-dispersive X-ray spectroscopy. Furthermore, their magnetic susceptibility measurements were obtained using SQUID based vibrating sample magnetometer (MPMS 3, Quantum Design). Both Ln-MOFs exhibited highly efficient luminescent property. Solid-state photoluminescence (PL) measurements revealed phosphorescence emission bands of Eu-MOF and Tb-MOF centered at 618 nm (red emission) and 550 nm (green emission) upon excitation at 396 nm and 285 nm, respectively. Eu-MOF and Tb-MOF displayed a phosphorescence quantum yield of 53% and 40%, respectively. Time-resolved PL analyses showed very long lifetime values, at 600 and 1065 ± 1 µs for Eu-MOF and Tb-MOF, respectively. Calculations performed by density functional theory indicated a charge transfer form metal centres to the ligand which was in good agreement with the experimental studies. Therefore, this new mode of highly photoluminescent MOF materials is studied for the first time which paves the way for better understanding of these systems for potential applications.

Ionic covalent organic frameworks (iCOFs) are new examples of porous materials and show great potential for various applications. Here, the authors demonstrate functionalization of an iCOFs with suitable emission sites and application as chemosensor for amine detection with high sensitivity which can be used to monitor meat spoilage.

Cucurbiturils are a family of macrocyclic oligomers capable of forming host–guest complexes with various molecules. Due to noncovalent binding to drug molecules and low toxicity, cucurbiturils has been extensively investigated as potential carriers for drug delivery. However, the immune system’s interactions with different drug carriers, including cucurbiturils, are still under investigation. In this study, we focused on cucurbiturils’ immunosafety and immunomodulation properties in vivo. We measured blood counts and lymphocyte subpopulations in blood, spleen, and bone marrow, and assessed the in vivo toxicity to spleen and bone marrow cells after intraperitoneal administration to BALB/c mice. When assessing the effect of cucurbit[6]uril on blood parameters after three intraperitoneal injections within a week in laboratory animals, a decrease in white blood cells was found in mice after injections of cucurbit[6]util, but the observed decrease in the number of white blood cells was within the normal range. At the same time, cucurbit[7]uril and cucurbit[8]uril did not affect the leukocyte counts of mice after three injections. Changes in the number of platelets, erythrocytes, and monocytes, as well as in several other indicators, such as hematocrit or erythrocyte volumetric dispersion, were not detected. We show that cucurbiturils do not have immunotoxicity in vivo, with the exception of a cytotoxic effect on spleen cells after сucurbit[7]uril administration at a high dosage. We also evaluated the effect of cucurbiturils on cellular and humoral immune responses. We founded that cucurbiturils in high concentrations affect the immune system in vivo, and the action of various cucurbiturils differs in different homologues, which is apparently associated with different interactions in the internal environment of the body.

Sensitive spectrofluorometric and liquid chromatography with fluorescence detection methods have been developed for detection and determination of naproxen drug in the presence of cucurbit7uril (CB7). Fluorescence signals have been improved with the addition of CB7 to the drug aqueous solution. Fluorescence spectroscopy, mass spectrometry, 1H-NMR, and liquid chromatography with fluorescence detection were used to investigate the guest-host interaction of naproxen drug and cucurbiturils. Naproxen was found to form a supramolecular complex with CB7 that had a high formation constant. The optimal conditions for the interaction were discovered using spectroflurometry to be 0.2 mg/ml of CB7, 2.4 μg/ml of naproxen drug, and pH10. A 1:1 complex between naproxen and CB7 is revealed by proton NMR and tandem mass spectrometry. Using the standard addition calibration method, an HPLC with a fluorescence detector was used to detect naproxen in influent and effluent wastewater samples. Finally, it was discovered that the measured concentrations of naproxen in the influent and the effluent wastewater were 1.87 × 10−4 ppb and 2.1 × 10−5 ppb, respectively. This was done by sample enrichment, which reduced the 1000 mL into 1 ml.

Abstract Organic‐inorganic halide perovskite solar cells (PSCs) have drawn tremendous attention as their power conversion efficiency (PCE) has soared to 25.2%. Yet the most efficient halide perovskite materials all contain the toxic element lead (Pb). The search for an alternative element is a crucial research direction. Among all candidates, tin (Sn) appears to be the most promising one for its nontoxicity and physical similarity to lead (Pb). Herein, we review and summarize recent advancements in this emerging research area of Sn‐based perovskites. First, we discuss the photophysical dynamics of the Sn‐based perovskites and the relatively high efficiency of corresponding PSCs and other applications. Then, the attention is focused on the fabrication process and methods to improve the performance of Sn‐based photovoltaic devices. Despite the fact that the stabilities of the materials and related devices are far from perfect, the Sn‐based perovskites are still the best candidates with vast potential among all the Pb‐free perovskites for PSC application.

In this study, we aimed to elucidate the effects of temperature on the photoluminescence from ZnO–SiO2 nanocomposite and to describe the preparation of SiO2-coated ZnO nanocrystals using a chemical precipitation method, as confirmed by Fourier transform infrared (FTIR) and powder X-ray diffraction analysis (XRD) techniques. Analyses using high-resolution transmission microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), and electrophoretic light scattering (ELS) techniques showed that the new nanocomposite has an average size of 70 nm and 90% silica. Diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and photoluminescence-excitation (PLE) measurements at different temperatures revealed two emission bands at 385 and 590 nm when the nanomaterials were excited at 325 nm. The UV and yellow emission bands were attributed to the radiative recombination and surface defects. The variable-temperature, time-resolved photoluminescence (VT-TRPL) measurements in the presence of SiO2 revealed the increase in the exciton lifetime values and the interplay of the thermally induced nonradiative recombination transfer of the excited-state population of the yellow emission via deep centers (DC). The results pave the way for more applications in photocatalysis and biomedical technology.

Microcystis aeruginosa is a cyanobacterium that produces a variety of cyclic heptapeptide toxins in freshwater. The protective effects of the macromolecular container cucurbit[7]uril (CB7) were evaluated using mouse models of cyanotoxin-induced liver damage. Biochemical analysis of liver function was performed to gauge the extent of liver damage after exposure to cyanobacterial crude extract [CCE; LD50 = 35 mg/kg body weight; intraperitoneal (i.p.)] in the absence or presence of CB7 (35 mg/kg body weight, i.p.). CCE injection resulted in liver enlargement, potentiated the activities of alanine aminotransferase (ALT) and glutathione S-transferase (GST), increased lipid peroxidation (LPO), and reduced protein phosphatase 1 (PP1) activity. CCE-induced liver enlargement, ALT and GST activities, and LPO were significantly reduced when CB7 was coadministered. Moreover, the CCE-induced decline of PP1 activity was also ameliorated in the presence of CB7. Treatment with CB7 alone did not affect liver function, which exhibited a dose tolerance of 100 mg/kg body wt. Overall, our results illustrated that the addition of CB7 significantly reduced CCE-induced hepatotoxicity (P < 0.05).

A dye-sensitized solar cell was constructed on the basis of encapsulating the ruthenium polypyridyl photosensitizer Z907 in the macrocycle cucurbit[7]uril (CB7). The work focuses on the photophysical properties of the new host-guest complexes in acetonitrile and water (volume ratio 1:9) and on the top of nanocrystalline titanium dioxide (TiO2) electrode prior to the addition of poly(3-hexylthiophene) polymer and gold electrode. Complexation to CB7 in aqueous solutions has decreased the emission intensity and excited-state lifetime for metal-to-ligand charge transfer (MLCT) state at 650 nm by twofold because of collisional quenching, which opens a non-radiative deactivation channel. Similarly, a twofold decrease in the emission intensity and excited-state lifetime of MLCT at 750 nm on the top of TiO2 electrodes was observed with the addition of CB7. Encapsulation of Z907 dye to CB7 host has, also, led to fourfold enhancement in the short circuit current and power conversion efficiency of the final solar cell. The results support the premise that host-guest complexation of CB7 facilitates faster electron injection from Z907 dye into the conduction band of TiO2 electrodes.

Cis- or Z-configuration is required for the plant growth-promoting activity of cinnamic acid (CA), whereas the E-form is inactive. Herein, we describe the encapsulation of E-CA by cucurbit[7]uril (CB7) and show that photoisomerization reactions can be more efficiently controlled in aqueous solutions by utilizing this supramolecular approach. Measurements of UV–visible absorption and proton NMR spectra at different pH values confirm that E-CA and its methyl ester, methyl-E-cinnamate (MC), form stronger 1:1 host–guest complexes with CB7 compared to cucurbit[8]uril (CB8) or three cyclodextrins (α-, β-, and γ-CD). Irradiation of (300 nm) UV light to an aqueous solution of the CB7-bound E isomers induces E to Z photoisomerization and the dissociation of the complex. When the same solution is irradiated by (254 nm) UV light, Z to E conformational changes of the unbound Z isomers are observed and are accompanied by restoring the host–guest complex formation.

Eighteen structurally-related Schiff base derivatives, which belong to salicylidenebenzylamine and 2-hydroxy-1-naphthylidenebenzylamine families were prepared and characterized by spectroscopic techniques. All the synthesized compounds were screened in vitro for their antibacterial and antifungal activities. Human pathogenic gram-negative (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Serratia marcescens), gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus and Bacillus subtilis), and fungi (Alternaria alternata, Aspergillus niger, Penicillium roqueforti, and Saccharomyces cerevisiae) were evaluated based on their toxicity to different concentrations of Schiff base compounds. For assessment of toxicity to pathogens, a disc diffusion assay was used to test the antimicrobial properties. The results revealed some antimicrobial activities of some of the synthesized compounds. Among the tested pathogens, the synthesized salicylidinaniline derivatives show highly potent action towards Alternaria alternata. Interestingly, a compound which contains the –Cl group is only effective against gram negative bacteria, but not gram positive bacteria. No remarkable antibacterial or antifungal activities were observed in the presence of –CH3 or –Br group. Furthermore, most of the naphthalene-containing compounds show no growth retardation towards bacterial or fungal pathogens. On the other hand, the presence of –OH or –SH group at para or ortho position, respectively, on the aniline site is correlated with an increased inhibitory drug effect on all pathogens. The importance of our findings to the drug research and developments is discussed in the context of finding a correlation between the structural properties of the new drugs and their biological activities.

The excited-state lifetimes of the anticoagulant drug warfarin (W) in water and in the absence and presence of methyl-β-cyclodextrins (Me-β-CD) were recorded using time-resolved fluorescence measurements. Selective excitation of the open and cyclic protonated isomers of W were acquired with laser emitting diodes (LED) producing 320 and 280 nm excitation pulses, respectively. Formation of the inclusion complex was checked by UV-visible absorption spectroscopy, and the values of binding constants (2.9 × 103 M–1 and 4.2 × 102 M−1 for protonated and deprotonated forms, respectively) were extracted from the spectrophotometric data. Both absorption and time-resolved fluorescence results established that the interior of the macromolecular host binds preferentially the open protonated form, red shifts the maximum of its absorption of light at ~305 nm, extends its excited-state lifetime, and decreases its emission quantum yield (ФF). Collectively, sequestration of the open guest molecules decreases markedly their radiative rate constants (kr), likely due to formation of hydrogen-bonded complexes in both the ground and excited states. Due to lack of interactions, no change was observed in the excited-state lifetime of the cyclic form in the presence of Me-β-CD. The host also increases the excited-state lifetime and ФF of the drug deprotonated form (W−). These later findings could be attributed to the increased rigidity inside the cavity of Me-β-CD. The pKa values extracted from the variations of the UV-visible absorption spectra of W versus the pH of aqueous solution showed that the open isomer is more acidic in both ground and excited states. The positive shifts in pKa values induced by three derivatives of cyclodextrins: HE-β-CD, Ac-β-CD, and Me-β-CD supported the preferential binding of these hosts to open isomers over cyclic.