Activities of Individual Ions From Infinite Dilution to Saturated Solutions

A new procedure, which provides a closer approximation for the junction potentials than the Henderson equation, is tested to reduce new emf data for the chloride ion in CsCl solutions and previously measured data for individual ions in aqueous solutions of KCl, NaCl, and NaBr. The liquid junction potential is calculated from numerical integration of its basic equation without assuming constant mobility or using concentrations instead of activities. The mean ionic activity coefficients of the salts, obtained from the activity coefficients of the individual ions, show good agreement with values reported in the literature. The activity coefficients of the individual chloride ion at 25°C in aqueous solutions of CsCl up to 3 molal and in KCl solutions were measured using a chloride ion-selective electrode. It has been confirmed that the activity of the chloride ion is equal to the activity of the cation in CsCl solutions and, contrary to the prediction of hydration theory, it is higher than the activity of the cation in aqueous KCl solutions. The New Hydration Theory has been developed to overcome the shortcomings of the older hydration theory and has been used to smooth the experimental activity coefficients of the individual ions in aqueous solutions and to extrapolate them up to the saturated solution.     

Design,synthesis, biological activity evaluation and mechanism of action of myricetin derivatives containing thioether quinazolinone

Plant bacteria and viruses have a huge negative impact on food crops in the world. Therefore, it is important to create new and efficient green pesticides. In this paper, a series of myricetin derivatives containing quinazolinone sulfide were introduced. Good antibacterial and antiviral activities of the drug molecules 2-((3-((5,7-dimethoxy-4-oxo-2-(3,4,5-trimethoxyphenyl)-4H-chromen-3-yl)oxy)propyl)thio)-6-fluoro-3-phenylquinazolin-4(3H)-one (T5) and 2-((4-((5,7-dimethoxy-4-oxo-2-(3,4,5-trimethoxyphenyl)-4H-chromen-3-yl)oxy)butyl)thio)-6-methyl-3-phenylquinazolin-4(3H)-one (T15) respectively were found by biological activity screening. The value of dissociation constant (K_d) of compound T15 to TMV CP was 0.024 ± 0.006 μM, determined by Microscale thermophoresis (MST), which was far less than the value of 8.491 ± 2.027 μM of commercial drug ningnanmycin (NNM). The interaction between compound T15 and TMV CP was further verified by molecular docking. Compound T15 formed strong hydrogen bonds with residues SER:49 and SER:15 (1.92 Å, 2.20 Å, respectively), which were superior to the traditional hydrogen bonds formed by NNM with residue SER:215 (3.64 Å). In addition, the effects of compound T15 on the contents of chlorophyll and peroxidase (POD) in tobacco were studied, and the results indicated that compound T15 could enhance the disease resistance of tobacco plants to a certain extent.     

Thermodynamics of ionic solid solutions: II. Discontinuous series: A new treatment of existing distribution data

A method of finding the activity coefficients of salts, anhydrous or hydrated, in binary solid solutions, described in an earlier paper as it applies to continuous series, has been applied to discontinuous series. The salts must differ with respect to only one ion. The method requires isothermal distribution data for equilibria between liquid (aqueous) and solid solutions in the ternary system consisting of the two salts and water. The following salt pairs were used for illustration: K(I/Br) at 0, 15, 25, 35, and 50°C., (NH₄/K)SCN at 0, 30, 60, and 90°C., (K/Tl)C10₃ at 10°C., and (NH₄/K)SO₃NH₂, (NH₄/K)Br, (Mg/Co)SO₄-7H₂O, and (Mn/Cu) SO₄.n H₂O-all at 25°C. Two kinds of behavior were noted and treated differently: systems in which the two series have the same, and those in which they have different crystal lattices. For two salts, A and B, which have the same lattice, and whose rational activity coefficients, f _A and f _B , can be described by 2-suffix Margules equations (regular solutions), lnf _A =B_sx _B ² and lnf _B =B_sx _A ² to be partially miscible, B_s>2, but this requirement does not apply if the lattices are different. In each series, distribution constants for the equilibria were also determined. Where possible, the calculated activities of the salts or the Gibbs excess energies of the solid solutions were compared with values reported by others who determined them by other methods. All the salt pairs studied show slight or strong positive deviations from ideality.     

Recent developments in the chemistry of perhydroindoles and perhydrocinnolines

Recent synthetic routes to the tetrahydro, hexahydro and octahydro derivatives of indoles are reviewed. An interesting one is the formation of 3-amino-4-oxo-4,5,6,7-tetrahydroindoles in the reaction of 2-phenacyl cyclohexane-l,3-diones with 1,1-disubstituted hydrazines. Antifertility, cns depressant and antiinflammatory activities have been encountered for perhydroindoles besides other biological activities. Hexahydrocinnolines are obtained from the reaction of 2-phenacyl (acetonyl) cyclohexanones and cyclohexane-1,3-diones with hydrazines, while octahydrocinnolines are formed from cyclohexanone-2-acetic acids and hydrazines in two steps. 5-oxo-5,6,7,8-hexahydrocinnolines and their oximes undergo anomalous and interesting aromatisation reactions. Some hexahydrocinnolines are cns depressants while octahydrocinnolines are analgesics. More importantly, they are precursors for interesting azamorphinans. Contribution No. 736 from Research centre     

α-Tetralone glycosides from the green walnut husks of Juglans mandshurica Maxim. and their cytotoxic activities

Abstract

Five new α-tetralone glycosides, juglanbiosides A-E (1–5), together with an α-tetralone derivative (15) and nine known 1,4-naphthoquinones (6–14) were isolated from the 95% EtOH extract of green walnut husks of Juglans mandshurica Maxim. Their structures were elucidated by comprehensive spectroscopic methods (¹H, ¹³C NMR, DEPT, HSQC, HMBC, CD, HR-ESI-MS). In vitro cytotoxicities of all the isolated compounds were evaluated against BGC-823, HCT-15 and K562 cancer cell lines.

     

Ultrasound mediation for one-pot sonosynthesis and deposition of magnetite nanoparticles on cotton/polyester fabric as a novel magnetic,photocatalytic, sonocatalytic,antibacterial and antifungal textile

A magnetic cotton/polyester fabric with photocatalytic, sonocatalytic, antibacterial and antifungal activities was successfully prepared through in-situ sonosynthesis method under ultrasound irradiation. The process involved the oxidation of Fe²⁺ to Fe³⁺ via hydroxyl radicals generated through bubbles collapse in ultrasonic bath. The treated samples were analyzed by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and vibrating sample magnetometry. Photocatalytic and sonocatalytic activities of magnetite treated fabrics were also evaluated toward Reactive Blue 2 decoloration under sunlight and ultrasound irradiation. Central composite design based on response surface methodology was applied to study the influence of iron precursor, pH and surfactant concentration to obtain appropriate amount for the best magnetism. Findings suggested the potential of one-pot sonochemical method to synthesize and fabricate Fe₃O₄ nanoparticles on cotton/polyester fabric possessing appropriate saturation magnetization, 95% antibacterial efficiency against Staphylococcus aureus and 99% antifungal effect against Candida albicans, 87% and 70% dye photocatalytic and sonocatalytic decoloration along with enhanced mechanical properties using only one iron rich precursor at low temperature.     

Synthesis,spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases

New metal based triazoles (1–12) have been synthesized by the interaction of novel Schiff base ligands (L¹–L³) with the Co(II), Ni(II), Cu(II) and Zn(II) metal ions. The Schiff base ligands and their all metal(II) complexes have been thoroughly characterized using various physical, analytical and spectroscopic techniques. In vitro bacterial and fungal inhibition studies were carried out to examine the antibacterial and antifungal profile of the Schiff bases in comparison to their metal(II) complexes against two Gram‐positive, four Gram‐negative and six fungal strains. The bioactivity data showed the metal(II) complexes to have more potent antibacterial and antifungal activity than their uncomplexed parent Schiff bases against one or more bacterial and fungal species. Copyright © 2012 John Wiley & Sons, Ltd.     

SYNTHESIS AND FUNGICIDAL ACTIVITIES OF 2-BENZOTHIAZOLYLTHIO-SUBSTITUTED 4H-IMIDAZOL-4-ONES AND 4(3H)-QUINAZOLINONES

4H-Imidazol-4-ones 4 or 4(3H)-quinazolinones 8 were synthesized by base catalytic reactions of 2-mercaptobenzothiazole with carbodiimides 2 or 6, respectively, which were obtained via aza-Wittig reaction of iminophosphorane 1 or 5 with aromatic isocyanates. 4 and 8 exhibited fungicidal activity.     

Structure-Activity Relationship, Cytotoxicity and Mode of Action of 2-Ester-substituted 1,5-Benzothiazepines as Potent Antifungal Agents

Our studies examined the structural features responsible for the antifungal activity of 2-ethoxycarbonyl-1,5- benzothiazepine （7a）. Three series of 1,5-benzothiazepine derivatives were synthesized and screened for their antifungal activity. The results suggested that the ethoxycarbonyl group at the 2 position and the imine moiety on the seven-membered ring are essential for activity. The most potent of the synthesized analogues （7a, 7b） were further studied by evaluating their cytotoxicity and mode of action （for 7a）. The results showed that compounds 7a and 7b were relatively safe for BV2 cells, but compound 7a interfered with Cryptococcus neoformans cell wall integrity by increasing the chitinase activity. Therefore, compound 7a was considered safe as an antifungal agent for animal cells.     

The enhanced biological activities of three Zn (II) complexes based on different 1,2,4‐triazole fungicides

In order to screen effective fungicides, three Zn (II) complexes, [Zn L ¹ ₄ (NO₃)₂]·2H₂O·2EtOH ( 1 ), [Zn L ² ₄ (NO₃)₂] ( 2 ), and [Zn L ³ ₄ (DMF)₂](NO₃)₂ ( 3 ), ( L ¹  = paclobutrazol, L ²  = diniconazole, and L ³  = hexaconazole), were synthesized and characterized by elemental analysis, FT‐IR spectroscopy, and single‐crystal XRD. The antifungal activities of these complexes were then evaluated against four selected fungi using the mycelial growth rate method. The resulting data indicate that all the complexes show the enhanced antifungal activities than the corresponding ligand and mixtures. And, the interactions between the metal salt and ligands in the three complexes seem to be synergistic. According to the study of the influence of the structures on the activity, complex 2 with C=C linkage and 2,4‐dichlorophenyl moieties enhances the bioactivity significantly, especially against Wheat gibberellic ( II ). Density functional theory (DFT) calculations were carried out to help explain the enhanced bioactivity of the Zn (II) complexes. Meanwhile, all complexes are excellent grow‐regulators, especially complex 3 . The resulting data show that the complexes based on triazole fungicides have the potential applications in agriculture.