Oxidation of 2,6-di-tert-butylphenol with tert-butyl hydroperoxide catalyzed by iron porphyrin tetrasulfonate, iron porphyrin tetracarboxylate and their supported analogues in a water-methanol mixture.

In this study, two water-soluble iron porphyrins bearing sulfonate and carboxylate functionalities (FePTS and FePTC, respectively) and their supported analogues were used as catalysts for the oxidation of 2,6-di-tert-butylphenol (DTBP) in a water-methanol mixture. tert-Butyl hydroperoxide (TBHP) was the oxidant and the volume ratio of water to methanol in the mixture was 1-8. The major products of the DTBP oxidation were 3,3',5,5'-tetra-tert-butyl-4,4'-diphenoquinone (DPQ) and 4,4'-dihydroxy-3,3',5,5'-tetra-tert- butylbiphenyl (H2DPQ). Also 2,6-di-tert-butyl-1,4-benzoquinone (BQ) was the minor product of the oxidation. The results showed that FePTC was more catalytically active than FePTS in the oxidation and gave the highest TON and TOF values in comparison to those for metalloporphyrin and metallophthalocyanine based catalysts in the DTBP oxidation given in the literature. In addition, the ecotoxicity tests of the DTBP oxidation mixtures before and after oxidative catalytic treatment toward Artemia salina were performed. It was found that the toxicity of the catalytically treated DTBP mixture containing residual DTBP and products was lower than the catalytically untreated DTBP mixture.

Antimicrobial activity of extracts of the lichen Xanthoparmelia pokornyi and its gyrophoric and stenosporic acid constituents.

The antimicrobial activity of the diethyl ether, acetone, chloroform, petroleum ether, and ethanol extracts of the lichen Xanthoparmelia pokornyi and its gyrophoric acid and stenosporic acid constituents has been screened against some foodborne bacteria and fungi. Both the extracts and the acids showed antimicrobial activity against Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Proteus vulgaris, Staphylococcus aureus, Streptococcus faecalis, Yersinia enterocolitica, Candida albicans and Candida glabrata. The extracts were inactive against the tested filamentous fungi. The MIC values of the extracts and the acids for the bacteria have also been determined.

Antimicrobial activity of extracts of chemical races of the lichen Pseudevernia furfuracea and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents.

The antimicrobial activity and the MIC values of the ethanol, chloroform, diethyl ether, and acetone extracts of the chemical races of Pseudevernia furfuracea (var. furfuracea and var. ceratea) and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents have been investigated against some microorganisms. Nearly all extracts of both chemical races showed antimicrobial activity against Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Proteus vulgaris, Staphylococcus aureus, Streptococcus faecalis, Yersinia enterocolitica, Candida albicans, Candida glabrata, Alternaria alternata, Ascochyta rabiei, Aspergillus niger, Fusarium culmorum, Fusarium moniliforme, Fusarium oxysporum, Fusarium solani, and Penicillium notatum. There was no antimicrobial activity of the extracts against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Pseudomonas syringae, Salmonella typhimurium, Alternaria citri, Alternaria tenuissima, and Gaeumannomyces graminis. Chloroatranorin and olivetoric acid were active against the same microorganisms with few exceptions. Physodic acid was active against about the same bacteria and yeasts and inactive against all of the filamentous fungi tested. Also no activity of atranorin against the filamentous fungi was observed.

Electrochemical Determination of Bisphenol A with Pencil Graphite Electrodes Modified with Co(II), Ni(II), Cu(II) and Fe(II) Phthalocyaninetetrasulfonates.

Pencil graphite electrodes modified with Co(II), Ni(II), Cu(II) and Fe(II) metallophthalocyaninetetrasulfonates (MePcTSs) were investigated for an electrochemical determination of bisphenol A (BPA). The electrochemical performances of the modified electrodes for different pH values in phosphate and the Britton-Robinson buffers were determined by cyclic voltammetry; the electrode performances were better in the Britton-Robinson buffer. NiPcTS and CoPcTS modifications of the electrodes had remarkable enhancements on their performances. The differential pulse voltammetry parameters for the electrodes were optimized, and we found that the electrochemical response versus the concentration of BPA is linear from 5.0 × 10(-7) to 1.0 × 10(-5) M for the NiPcTS and CoPcTS modified electrodes. The detection limits of these modified electrodes are 2.9 × 10(-7) and 4.3 × 10(-7) M, respectively, and the effects of interfering species are less than 5%. The results show that NiPcTS and CoPcTS modified pencil graphite electrodes could be used for electrochemical determinations of BPA for analytical purposes.

The antimicrobial activity of extracts of the lichen Hypogymnia tubulosa and its 3-hydroxyphysodic acid constituent.

The antimicrobial activity and the MIC values of the diethyl ether, acetone, chloroform, petroleum ether, and ethanol extracts of the lichen Hypogymnia tubulosa and its 3-hydroxyphysodic acid constituent have been investigated against some microorganisms. At least one of the extracts or 3-hydroxyphysodic acid showed antimicrobial activity against Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Proteus vulgaris, Salmonella typhimurium, Staphylococcus aureus, Streptococcus faecalis, and Candida albicans. No antifungal activity of the extracts has been observed against ten filamentous fungi.

Evaluation of the antimicrobial activity of the acetone extract of the lichen Ramalina farinacea and its (+)-usnic acid, norstictic acid, and protocetraric acid constituents.

The acetone extract of the lichen Ramalina farinacea and its (+)-usnic acid constituent showed antimicrobial activity against Bacillus subtilis, Listeria monocytogenes, Proteus vulgaris, Staphylococcus aureus, Streptococcus faecalis, Yersinia enterocolitica, Candida albicans, and Candida glabrata. Norstictic acid was active against Aeromonas hydrophila as well as the above microorganisms except Yersinia enterocolitica. Protocetraric acid showed activity only against the tested yeasts Candida albicans and Candida glabrata. The MIC values of the extract as well as of the three substances were determined. No antifungal activity of the acetone extract has been observed against ten filamentous fungi.

The antimicrobial activity of extracts of the lichen Cetraria aculeata and its protolichesterinic acid constituent.

In this study, the antimicrobial activity of the acetone, diethyl ether and ethanol extracts of the lichen Cetraria aculeata has been investigated. The extracts were tested against twelve bacteria and eight fungi and found active against Escherichia coli, Staphylococcus aureus, Aeromonas hydrophila, Proteus vulgaris, Streptococcus faecalis, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Listeria monocytogenes. No antimicrobial activity against the fungi was detected. It was determined that only one substance in the extracts has antimicrobial activity and it was characterized as protolichesterinic acid. The MICs of the extracts and protolichesterinic acid were also determined.

Synthesis of novel methacrylate based adsorbents and their sorptive properties towards p-nitrophenol from aqueous solutions.

The polymeric adsorbents were synthesized from 2-dimethylaminoethyl methacrylate (DMA) and [2-(methacryloyloxy)ethyl]dimethylhexadecylammonium bromide (DMAC(16)) monomers in the presence of ethylene glycol dimethacrylate (EDMA) cross-linking monomer using suspension polymerization technique and their adsorption efficiencies in the removal of p-nitrophenol from aqueous solutions were investigated. DMAC(16) monomer was prepared by means of modification of DMA monomer with 1-bromohexadecane. Adsorption experiments were carried out in a batch system and the experimental parameters were evaluated with respect to pH, agitation time, temperature and initial p-nitrophenol concentration. It was observed that the adsorbent poly[2-(methacryloyloxy)ethyl]dimethylhexadecylammonium bromide (p-DMAC(16)) prepared from DMAC(16) monomer was more effective in the removal of p-nitrophenol than the adsorbent poly(2-dimethylaminoethyl methacrylate) (p-DMA) prepared from DMA monomer. The effective pH ranges for the adsorption of p-nitrophenol onto p-DMAC(16) and p-DMA were 2-12 and 3-9, respectively. Langmuir and Freundlich adsorption models were used to describe the isotherms and find isotherm constants. The Langmuir model was well agreed with experimental data for both adsorbents. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetic models were used to understand the mechanism of the adsorption process and it fitted very well the pseudo-second-order kinetic model for each adsorbent. Thermodynamic parameters such as activation energy and changes of free energy, enthalpy, and entropy were also evaluated for the adsorption of p-nitrophenol onto each adsorbent. Additionally, reusability of the adsorbents was investigated and the results showed that both adsorbents can be employed many times without a significant loss in their adsorption capacities for the removal of p-nitrophenol from water.

Non-enzymatic glucose biosensor based on overoxidized polypyrrole nanofiber electrode modified with cobalt(II) phthalocyanine tetrasulfonate.

An enzymeless biosensor, based on electrodeposition of overoxidized polypyrrole nanofiber onto pencil graphite electrode and modified with cobalt(II) phthalocyanine tetrasulfonate (CoPcTS), was investigated in this study. CoPcTS showed electrocatalytic activity for the oxidation of glucose in alkaline solution. The electrochemical performance of the modified electrodes was investigated by differential pulse voltammetric (DPV) method. The resulting biosensor exhibited excellent performance for glucose determination with a wide linear range (0.25-20mM), a highly reproducible response (R.S.D. of 2.7%), low percentage of the interferences and long-term stability. The calculated detection limit was 0.1mM at 3sigma. In order to verify the reliability of the biosensor, it was applied to the determination of glucose in serum samples. The results were satisfactory and agreed closely with those measured in a hospital.