Benzoyl Ring Research Articles

β-Cyclodextrin-Tethered Butein, a Greener Redox-Active Biomaterial for Electrochemical Enzymatic Sensing of Sialic Acid.

Biocompatible, industrially scalable, and opto/electrochemically active biomaterials are promising for biosensor platform design and application. Herein, cyclic oligosaccharide, β-cyclodextrin (BCD), is conjugated with Butein, a chalcone-type polyphenol, via dehydration reaction of the hydroxyl groups of BCD and the benzoyl ring of Butein. Functional group changes in the conjugated BCD-Butein were comprehensively studied using UV-visible absorbance, Fourier transform-infrared, and X-ray photoelectron spectroscopic techniques. The electrochemical characteristics of BCD-Butein were explored using cyclic voltammetry, showing the reversible redox behavior (2e-/2H+) attributed to the catecholic OH group of Butein. The BCD-Butein-modified electrode exhibits a surface-confined redox process (R2 = 0.99, Ipa and Ipc) at the interface, suitable for external mediatorless sensor studies. An enzymatic biomolecular sensor has been constructed using BCD-Butein-modified glassy carbon and a screen-printed electrode targeting sialic acid as the model clinical biomarker. With the enzyme sialic acid aldolase, BCD-Butein-modified substrate exhibited a selective conversion of sialic acid to N-acetyl-d-mannosamine and pyruvate, with a wide linear detection range (1-100 nM), the lowest detection limit of 0.2 nM, and a quantification limit of 0.69 nM, convenient for clinical threshold diagnosis.

Effect of liposomal complexes of quercetin-rich flavonoids from French Marigold (Tagetes patula L.) on Jurkat cell viability

Background: Natural polyphenols are naturally used in traditional medicine to treat various diseases. Despite their healthful properties, ingesting phenolic compounds in food form does not provide a sufficient concentration for systemic therapeutic effects due to their low solubility in water, poor absorption, and fast metabolism. This problem has been solved by creating various composite pharmaceuticals from phenolic compounds using different methods to stabilize polyphenols. Objective: The purpose of this study was to assess the effects of the DPPA (1,2-palmitoyl phosphatidic acid) and DPPC (dipalmitoyl phosphatidylcholine) liposomes on the protective effects of a quercetin-rich flavonoid fraction extracted from French Marigold (Tagetes patula L.) on the viability of Jurkat cells. The study will examine both intact cells and cells that have been incubated under oxidative stress conditions. Materials and Methods: Quercetin-rich flavonoid fraction was extracted from a French Marigold (Tagetes patula L.) by thin-layer chromatography (TLC), High-pressure liquid chromatography (HPLC), and Liquid Chromatography-Mass Spectrometry (LC-MS) methods. Extract alone and in complex with dipalmitoyl phosphatidylcholine (DPPC) and 1,2- dipalmitoyl phosphatidic acid (DPPA) liposomes were added to the Jurkat cells culture at a rate of 2 mg/mL−1.The 3-(4,5-dimethylthiazol-2)-2,5-diphenyltetrazolium bromide (MTT) test assayed Cell viability by evaluating cellular dehydrogenase activity. Results: Flavonoids were separated and identified in the marigold extracts by TLC, HPLC, and LC-MS methods. The spectrophotometric absorption spectrum of the quercetin-rich flavonoid fraction extracted from French Marigold (Tagetes patula L.) shows two peaks corresponding to benzoyl (254nm) and cinnamyl (375nm) aromatic rings. In the complex of quercetin-rich flavonoid fraction with DPPC and DPPA liposomes, the spectrophotometric absorption peak at 254nm was not detected, while the absorption intensity of the peak at 375nm was sharply reduced. The quercetin-rich flavonoid fraction alone and in combination with DPPC liposome increased intact and incubated under low- and high-intensity oxidative stress conditions Jurkat cells’ viability but did not reveal effect in combination with DPPA liposome. Conclusions: The quercetin-rich flavonoid fraction extracted from French Marigold (Tagetes patula L.) forms stable complexes with DPPC and DPPA liposomes that allow the storage of high content of phenolic compounds in lipid nanocapsules. The use of the liposomal system in the pharmaceutical and food industry allows for carried and controlled bioactive-compound release, which is considered one of the main strategies to improve and enhance the quality of food, providing preventative healthcare for the population and decreasing the risk of disease. Keywords: bioactive-compound, polyphenols, Quercetin, Liposomes, Jurkat cells, therapeutic effects, pharmaceuticals

Essential Oil of Origanum vulgare as a Green Corrosion Inhibitor for Carbon Steel in Acidic Medium

In this study, Oregano (Origanum vulgare) leaf essential oil was studied as an environmental-friendly anticorrosion agent for carbon steel in aggressive hydrochloric acid. The corrosion inhibition of O. vulgare was characterized by surface morphology, electrochemical, weight loss, theoretical and computational methods. It was found that the highest inhibition performance of O. vulgare was 85.64% at 2 g/l in 1 M HCl. The results of Langmuir isotherm and adsorption thermodynamics investigation demonstrated that the O. vulgare inhibitor adsorbed on the metal surface by the formation of rigid covalent bonds. The adsorption and inhibition centers of the selected inhibitor were studied by the computational methods, resulting in that the hydroxyl functional groups and benzoyl rings are mainly responsible for the high inhibition efficiency.

Synthesis, analgesic, anti-inflammatory, ulcerogenic evaluation, and docking study of (benzoylphenoxy)-N-{5-[2-methylphenyl-6-chlorobenzoxazole]} acetamides as COX/5-LOX inhibitor

The COX and 5-LOX inhibitors with analgesic and anti-inflammatory effectiveness and very less gastrointestinal toxicity have been recognized as constructive and sustainable agents for inflammatory treatment. In this approach, a series of titled compounds (10a-j) were developed, synthesized, and evaluated in terms of in-vitro COX and LOX enzyme inhibition followed by analgesic, anti-inflammatory, and the ulcerogenic activity. The anti-inflammatory evaluation was conducted on those compounds 10a-c, 10e, and 10g-10i that displayed potential analgesic activity and later, validated for the ulcerogenic effect of potent anti-inflammatory compounds. The compound 10b with ortho substitution of methyl and para substitution of chloro groups on the phenyl ring and meta substitution of chloro group on benzoyl ring of benzophenone appended to benzoxazole was observed to have good inhibitory potency. Furthermore, Autodock tools docking software was used to carry out the in silico studies.

Synthesis, analgesic, anti-inflammatory, COX/5-LOX inhibition, ulcerogenic evaluation, and docking study of benzimidazole bearing indole and benzophenone analogs

Inflammation therapy is particularly focused on the development of safer non-steroidal anti-inflammatory drugs (NSAIDs), administered to control inflammation. It is typically considered that dual-inhibition of COX/5-LOX, which improves efficacy and has fewer side effects, is an effective technique for combating inflammation. In this perspective, the series of titled compounds (10a-j) were designed, synthesized, and characterized following with the anti-inflammatory, analgesic, and ulcerogenic evaluation. The investigation of the potentiality of the titled compounds (10a-j) displayed a high degree of anti-inflammatory activity. The compounds displaying potential analgesic activity were identified and validated further for evaluation of analgesic, anti-inflammatory activity, and subsequent ulcerogenic evaluation. In addition, the COX-1, COX-2, and 5-LOX analyses were carried out in vitro. Among (10a-j) series, compound 10c with para substitution of fluoro group on the benzoyl ring and two chloro groups at ortho position in phenyl ring of benzophenone was observed to have good inhibitory potency. Furthermore, the in silico docking study was performed by using AutoDock tools docking software.

Cholinesterase Inhibition Activity and Molecular Docking Study of Eugenol Derivatives

The study was conducted to explore the anticholinesterase inhibition property of eugenol derived molecules. Ten eugenol derivatives were synthesized and evaluated for the inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) by Ellman’s method. Most of the tested derivatives showed higher inhibition on BChE than AChE, however, their overall inhibitory activity was weak. In contrast, three derivatives (compounds 3,6,9) showed higher and good AChE inhibitory activity of more than 50% inhibition at 10 μg/mL. Among them, compound 9bearing a ethyl substituent at para position of the benzoyl ring showed the most potent AChE inhibition, with IC50 of 5.64 μg/mL. Ligand-protein docking simulation was also performed for the most active derived molecules (compounds 3,6,9).

Crystal structure of (E)-1-(3-benzyl-5-phenyl-1,3-thia-zol-2-yl-idene)-2-[(E)-1,2,3,4-tetra-hydro-naphthalen-1-yl-idene]hydrazin-1-ium bromide.

In the title mol-ecular salt, C26H24N3S+·Br-, the dihedral angles between the thia-zole ring and its attached phenyl and benzoyl rings are 54.81 (7) and 85.51 (7)°, respectively. In the crystal, ion pairs are linked by C-H⋯Br and N-H⋯Br hydrogen bonds and are connected into helical chains extending along the c-axis direction by weak, electrostatic S⋯Br- inter-actions. A Hirshfeld surface analysis was performed, which showed the dominant role of H⋯H contacts (51.3%).

Anti-tubercular activity and molecular docking studies of indolizine derivatives targeting mycobacterial InhA enzyme

A series of 1,2,3-trisubstituted indolizines (2a–2f, 3a–3d, and 4a–4c) were screened for in vitro whole-cell anti-tubercular activity against the susceptible H37Rv and multidrug-resistant (MDR) Mycobacterium tuberculosis (MTB) strains. Compounds 2b–2d, 3a–3d, and 4a–4c were active against the H37Rv-MTB strain with minimum inhibitory concentration (MIC) ranging from 4 to 32 µg/mL, whereas the indolizines 4a–4c, with ethyl ester group at the 4-position of the benzoyl ring also exhibited anti-MDR-MTB activity (MIC = 16–64 µg/mL). In silico docking study revealed the enoyl-acyl carrier protein reductase (InhA) and anthranilate phosphoribosyltransferase as potential molecular targets for the indolizines. The X-ray diffraction analysis of the compound 4b was also carried out. Further, a safety study (in silico and in vitro) demonstrated no toxicity for these compounds. Thus, the indolizines warrant further development and may represent a novel promising class of InhA inhibitors and multi-targeting agents to combat drug-sensitive and drug-resistant MTB strains.

Design and synthesis of novel 1-substituted -3-(4-oxo-2-phenylquinazolin-3(4H)-yl) urea and thiourea analogues targeting on TACE, as potent anticancer agents

1-substituted phenyl quinazolinones analogues were designed by performing molecular modelling studies against tumour necrosis factor alpha converting enzyme (TACE PDB Id: 2A8H) and in-silico Lipinski properties for drug likeness. From QSAR studies, it could be concluded that the urea and thiourea groups play a crucial role in enhancing cytotoxic effects of compounds. Substitution of halogens like trifluoromethyl, chloro and allylic functional group may enhance the cytotoxic effect of urea and thiourea analogues. Substitution of phenyl and benzoyl ring were not found effective against cancer. Also, the presence of substituted aromatic ring at position 3 and methyl or thiol group at position 2 are essential for antimicrobial activities of quinazolinone. The synthesized compounds were characterized by TLC, MP, IR, NMR and Mass spectral data and were screened for their anticancer activity. The in vitro anticancer studies were performed on six selected compounds using MTT assay against MDA MB-231 cell line using paclitaxel as a standard. The synthesized 1-substituted -3-(4-oxo-2-phenylquinazolin-3(4h)-yl) urea and thiourea derivatives exhibited significant anticancer activities.

Lipoxygenase Inhibition Activity of Coumarin Derivatives-QSAR and Molecular Docking Study.

Lipoxygenases (LOXs) are a family of enzymes found in plants, mammals, and microorganisms. In animals and plants, the enzyme has the capability for the peroxidation of unsaturated fatty acids. Although LOXs participate in the plant defense system, the enzyme’s metabolites can have numerous negative effects on human health. Therefore, many types of research are searching for compounds that can inhibit LOXs. The best quantitative structure–activity relationship (QSAR) model was obtained using a Genetic Algorithm (GA). Molecular docking was performed with iGEMDOCK. The inhibition of lipoxygenase was in the range of 7.1 to 96.6%, and the inhibition of lipid peroxidation was 7.0–91.0%. Among the synthesized compounds, the strongest inhibitor of soybean LOX-3 (96.6%) was found to be 3-benzoyl-7-(benzyloxy)-2H-chromen-2-one. A lipid peroxidation inhibition of 91.0% was achieved with ethyl 7-methoxy-2-oxo-2H-chromene-3-carboxylate. The docking scores for the soybean LOX-3 and human 5-LOX also indicated that this compound has the best affinity for these LOX enzymes. The best multiple linear QSAR model contains the atom-centered fragment descriptors C-06, RDF035p, and HATS8p. QSAR and molecular docking studies elucidated the structural features important for the enhanced inhibitory activity of the most active compounds, such as the presence of the benzoyl ring at the 3-position of coumarin’s core. Compounds with benzoyl substituents are promising candidates as potent lipoxygenase inhibitors.

Synthesis, growth and structural characterization of 1-(furan-2-yl)-3-(2,4,6-trimethoxyphenyl) prop-2-en-1-one crystal

The compound 1-(furan-2-yl)-3-(2, 4, 6-trimethoxyphenyl) prop-2-en-1-one (FT2MP) was synthesized using solution growth method and UV–Visible, FT-IR and FT-Raman spectroscopy studies were carried out. In addition, thermal and optical studies have also been carried out. Thermal studies indicate that acetyl furan substituted chalcone crystal FT2MP is thermally stable. It was also observed that chalcone derivatives substituted with multiple methoxy group show better crystallizability. In case of chalcone derivative such as FT2MP, methoxy group linked on benzoyl ring at one end acts as an electron donor and a methyl furan ring at the other end acts as strong electron acceptor thereby enhancing nonlinearity. Third order nonlinear optical studies have been carried out using both open and closed aperture Z-scan experiments. Third order nonlinear optical properties such as absorption coefficient, refractive index, and susceptibilities have been extensively studied and the results show that the high third order optical nonlinearities of the crystal may lead to important applications in optical devices.

Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors.

The development of multidrug resistance (MDR) is a major cause of failure in cancer chemotherapy. Several abietane diterpenes with antitumoral activities have been isolated from Plectranthus spp. such as 6,7-dehydroroyleanone (DHR, 1) and 7α-acetoxy-6β-hydroxyroyleanone (AHR, 2). Several royleanone derivatives were prepared through hemisynthesis from natural compounds 1 and 2 to achieve a small library of products with enhanced anti-P-glycoprotein activity. Nonetheless, some derivatives tend to be unstable. Therefore, to reason such lack of stability, the electron density based local reactivity descriptors condensed Fukui functions and dual descriptor were calculated for several derivatives of DHR. Additionally, molecular docking and molecular dynamics studies were performed on several other derivatives to clarify the molecular mechanisms by which they may exert their inhibitory effect in P-gp activity. The analysis on local reactivity descriptors was important to understand possible degradation pathways and to guide further synthetic approaches toward new royleanone derivatives. A molecular docking study suggested that the presence of aromatic moieties increases the binding affinity of royleanone derivatives toward P-gp. It further suggests that one royleanone benzoylated derivative may act as a noncompetitive efflux modulator when bound to the M-site. The future generation of novel royleanone derivatives will involve (i) a selective modification of position C-12 with chemical moieties smaller than unsubstituted benzoyl rings and (ii) the modification of the substitution pattern of the benzoyloxy moiety at position C-6.

Benzoylthioureas: Design, Synthesis and Antimycobacterial Evaluation.

New drugs and strategies to treat tuberculosis (TB) are urgently needed. In this context, thiourea derivatives have a wide range of biological activities, including anti-TB. This fact can be illustrated with the structure of isoxyl, an old anti-TB drug, which has a thiourea as a pharmacophore group. The aim of this study is to describe the synthesis and the antimycobacterial activity of fifty-nine benzoylthioureas derivatives. Benzoylthiourea derivatives have been synthesized and evaluated for their activity against Mycobacterium tuberculosis using the MABA assay. After that, a structure-activity relationship study of this series of compounds has been performed. Nineteen compounds exhibited antimycobacterial activity between 423.1 and 9.6 μM. In general, we observed that the presence of bromine, chlorine and t-Bu group at the para-position in benzene ring plays an important role in the antitubercular activity of Series A. These substituents were fixed at this position in benzene ring and other groups such as Cl, Br, NO2 and OMe were introduced in the benzoyl ring, leading to the derivatives of Series B. In general, Series B was less cytotoxic than Series A, which indicates that the presence of a substituent at benzoyl ring contributes to an improvement in both antimycobacterial activity and toxicity profiles. Compound 4c could be considered a good prototype to be submitted to further structural modifications in the search for new anti-TB drugs, since it is 1.8 times more active than the first line anti-TB drug ethambutol and 0.65 times less active than isoxyl.

Synthesis of novel disperse dyes based on curcumin for the creation of antibacterial polyester fabrics

Purpose This study aims to synthesize some new curcumin containing Aroyl derivatives dyestuffs and study their application in dyeing polyester fabrics, rendering to their antibacterial evaluation. Design/methodology/approach Modification of curcumin dye was carried out by introducing benzoyl rings through coupling with curcumin. All newly synthesized dyes were characterized by elemental analyses and spectral data (IR, 1 H-NMR and MS). Moreover, the optimal dyeing condition was assigned. Antibacterial activities of the dyed samples at different concentrations of both dyes were studied against gram positive (Staph aureus) and gram-negative (Salmonellatyphimurium) bacteria. Findings Synthesized curcumin containing benzoyl dyes were applied on polyester fabrics. Meanwhile, these synthesized dyes showed reasonable results towards fastness properties at optimal conditions matching the curcumin dye. In addition to their good fastness assets, synthesized dyes displayed antibacterial efficacy towards both gram positive and gram-negative bacteria. The dyed polyester fabrics showed higher antibacterial efficacy after multiple events of washing. Research limitations/implications The synthesized benzoyl containing curcumin moiety was not described before. Practical implications Disperse dyes derived from curcumin were prepared via coupling of various diazonium salts of p-aminobenzaldhyde, p-aminoacetopheneone, p-aminobenzoic acid and p-aminobenzoyl chloride with curcumin. The resulting disperse dyes were applied on polyester fabrics at optimal conditions, and antibacterial efficacy of dyed fabrics were evaluated. Originality/value Curcumin being was used in food colouration and was effective for dyeing and antimicrobial finishing on textile fabrics. Novel antibacterial dyestuff containing curcumin moieties with benzoyl amine coupling components showed interesting colourant for polyester fabrics. This work introduced innovative disperse dyes for medical textile applications.

Design, synthesis and SAR bioevaluation of benzophenone-mercaptooxadiazole analogs

Two novel series of the benzophenone tagged oxadiazoles were synthesized by cyclization of benzophenone hydrazide, followed by the nucleophillic alkylation of heterocyclic scaffold. Synthesized title compounds were characterized by the FT-IR, LCMS and NMR spectral techniques and were screened for the antibacterial, antifingal and anti-tuberculosis (anti-TB) activities. Biological screening of the synthesized target compounds reveals that, compound 7h was the potent cytotoxicant with lengthened activity against tubercular, bacterial and fungal agents. Compound 7h has morpholine group (six membered ring) attached to oxadiazole through two CH2 groups, methyl substituent at ortho-position and chlorine group at ortho-position of benzoyl ring. Compound 7h interacted through Vander Waal's interactions into the hydrophobic binding pocket, surrounded by the portions of Phe 41, Ile 122, Val 65, Phe 97, Ile 95, Gly 14, Asp 64, Ile 21, Phe 149, Asp 148, Met 147, Ser 94 and Ala 22. MIC value of the compounds for in-vitro anti-TB activity was 1.6 μg/ml.

Design, synthesis and molecular docking of benzophenone conjugated with oxadiazole sulphur bridge pyrazole pharmacophores as anti inflammatory and analgesic agents

The prostaglandins (PG) a group of physiologically active lipid compounds having diverse hormone like effects are important mediators of the body’s response to pain and inflammation, and are formed from essential fatty acids found in cell membranes. This reaction is catalyzed by cyclooxygenase, a membrane associated enzyme occurring in two isoforms, COX-1 and COX-2. Nonsteroidal anti-inflammatory drugs (NSAIDs) act by inhibiting the activity of COX. In view of this, a series of novel benzophenones conjugated with oxadiazole sulphur bridge pyrazole moiety 8a-l were designed, synthesized, characterized and subsequently evaluated for anti-inflammatory and analgesic property. The investigation of novel analogues 8a-l for potential anti-inflammatory activity showed high levels of COX-1 and COX-2 inhibitory activity. Among the series, compound 8i with electron withdrawing fluoro group at the para position of the benzoyl ring of benzophenone was characterized by highest IC50 values for both COX-1 and COX-2 inhibition, which is comparable to the standard drug. Further, molecular docking studies have been performed for the potent compound.

Dissecting the Conformational and Interaction Topological Landscape of N-ethynylphenylbenzamide by the Device of Polymorphic Diversity

The modern day crystal engineering approach aims at the exploration of the structural landscape of a molecule to perceive the phenomenon of the crystallization event for that molecule. The present study focuses on thorough experimental and computational investigations of the crystal landscape in the conformationally flexible N-ethynylphenylbenzamide molecule. We have performed the chemical modification of the parent unsubstituted N-ethynylphenylbenzamide molecule on the benzoyl ring by different halogen substitutions (monofluoro/difluoro/trifluoromethyl/chloro/bromo) at ortho/meta/para positions and employed the device of the polymorphophore concept to access a large number of experimentally viable structures in the landscape. In a total of 11 substituents as variants in molecules, the parent molecule displays monomorphic behavior, and in the remaining 10 molecules, each exists in several polymorphic forms resulting in a total of 28 single-component crystal structures. Through the systematic analysis of their conformational preferences in the conformational landscape and classification of the prevalent supramolecular recognition patterns, the interaction topologies of all substituent modified polymorphic structures have been mapped by the quantification of interaction energies of supramolecular synthons followed by a crystal structure prediction study. The combination of all studies demonstrates the robustness of primary synthon topology (formed by N–H···O═C/ π···π stacking interaction) and local variation of structures by different secondary interaction preferences (weak C–H···O, C–H···π, C–H···F/Cl/Br, and π···π interactions) to construct a nearly similar global interaction topology of molecules in all crystal structures and represents a general interaction topological landscape.

Peculiarities of tyrosine metabolism in the rat liver under the condition of protein deficiency

In the present study, a tyrosine content in liver and enzymatic activities of its metabolism: tyrosine aminotransferase, 4-hydroxyphenylpyruvate dioxygenase, aldehyde dehydrogenase (ALDH3A1) were investigated under the conditions of alimentary protein deprivation. The experiments were performed on white rats with a body weight of 100-150 g aging 2.5-3 months. The animals were divided into two experimental groups: I – animals receiving a full-value semi-synthetic ration (C); II – animals receiving a low-protein ration (LPR). In order to simulate the low-protein diet, the animals received a diet containing 4.7% protein, 10% fat and 85.3% carbohydrates for 28 days, calculated according to the American Institute of Nutrition's recommendations. Determination of tyrosine in deproteinized by 6% sulfosalicylic acid extracts of the liver tissue was performed using the automatic analyzer of amino acids T-339 (Microtechnology, Czech Republic). The enzyme activity was determined by spectrophotometric method – tyrosine aminotransferase by the amount of 4-hydroxybenzaldehyde, which has a maximum absorption at 331 nm, 4-hydroxyphenylpyruvate dioxygenase – by the intensity of colored product formation at λ 336 nm, ALDH3A1 activity was measured at 340 nm wavelength. It was established a 5-fold depletion of the tyrosine pool and a 2-fold reduction of the tyrosine aminotransferase activity, which catalyzes the formation of the first transformation of the tyrosine – 4-hydroxyphenylpyruvate transformation in the liver tissue under the condition of protein deficiency. Determination of the key enzymes activity of two possible ways of further 4-hydroxyphenylpyruvate transformation has shown that the activity of 4-hydroxyphenylpyruvate dioxygenase, as an enzyme of the homogentisin pathway of tyrosine metabolism, remains at the control level, while the aldehyde dehydrogenase, as the key enzyme of the synthesis pathway of the benzoyl ring of ubiquinone molecule, is by half reduced. The obtained results allow us to conclude that under the conditions of an alimentary protein deficiency tyrosine is predominantly metabolized in the liver by the homogenetistic pathway, which can be considered as a compensatory reaction directed at the maintaining energy metabolism while simultaneously affecting the use of tyrosine as a precursor in ubiquinone synthesis. Key words: alimentary protein deficiency, liver, mitochondria, tyrosine, ubiquinone, tyrosine aminotransferase, 4-hydroxyphenylpyruvate dioxygenase, aldehyde dehydrogenase

Influence of peripheral substituents on the stability of sandwich-type complexes of crown ether-containing anthraquinoneimines

ABSTRACTBenzo-15-crown-5 ether derivatives of 1-hydroxy-9,10-anthraquinone-9-imine bearing a substituted benzoylamino group, NHCO(p-C6H4NO2) or NHCOC6F5, in position 2 were synthesized by a photochemical method. The structure of the fluorine-containing compound was determined by single-crystal X-ray diffraction. Both synthesized dyes, as well as their analogue without substituents on the benzoyl ring, are capable of binding Sr2+ and Ba2+ to form sandwich-type 2:1 (ligand:metal) complexes. In MeCN, these complexes exhibit higher stability constants (K2:1) than the corresponding 1:1 complexes (K1:1). The para-substitution of the benzoyl ring with a nitro group leads to a significant increase in both the K2:1 constant and the K2:1/K1:1 ratio. The fluorination of the benzoyl ring insignificantly affects the stability of sandwich complexes. Density functional theory calculations showed that this is related to steric interactions in the benzoylamino group. The calculated structures of the dyes and their sandwich complexes with Ba2+ are consistent with the 2D NOESY data.

Statistical Analysis of Antimicrobial Data of 2-[2-(Aroyl)aroyloxy]methyl1, 3, 4 Oxadiazoles analogues Using ANOVA

Heterocyclic chemistry has become one of the most important fields of research in pharmaceutical industry due to their many fold applications. Amongst all, heterocyclic molecules containing nitrogen and oxygen (like oxadiazole ring system) have shown most potent biological activities. Microorganisms are strictly attendant with the fitness and well-being of human beings. The present treatments of bacterial and fungal infections are a bit unsatisfactory, owing to rapidly developing drug resistance and side effects. The improved of antibacterial and antifungal agents results in resistant to drugs. A series of substituted Oxadiazoles analogues 4a-jwere synthesized and screened for their antibacterial and antifungal activities to evaluate zone of inhibition. The significant effect ofin-vitroantimicrobial and antifungal activities of compounds 4a-jwere studied using one way ANOVA. It was shown that the variables 4a-j series weresignificant. Further pairwise comparison of significant differences between the variables were analyzed using Tukey HSD. The data revels that compound 4a with 2-methyl and 3chloro group in phenyl and benzoyl ring respectively, have shown excellent activity and more potent among the 4a-j series.