betadex and naphthalene

3-Naphthyl-1-phenyl-5-(5-fluoro-2-nitrophenyl)-2-pyrazoline (NPFP), a fluorogenic probe and its derivative NPFP-Phenylephrine were synthesized and their absorption and fluorescence properties were recorded in solvents of varying polarity. Spectroscopic studies reveal that, the solvatochromic behavior of the compounds depend not only on the polarity but also on the hydrogen-bonding properties of the solvents. The effects of β-cyclodextrin on the fluorescence properties of both compounds were studied. It was found that there is an enhancement in the fluorescence intensity of labeled drug (NPFP-Phenylephrine) in the presence of β-cyclodextrin. In the present study, the molecular motions of NPFP-Phenylephrine embedded in a β-cyclodextrin cavity have been investigated by fluorescence techniques in steady-state and time resolved modes.

Topics: Amines; beta-Cyclodextrins; Fluorescent Dyes; Halogenation; Models, Molecular; Naphthalenes; Phenylephrine; Pyrazoles; Solvents; Spectrometry, Fluorescence

Hazardous waste sites are commonly contaminated with both organic and metal pollutants. Many metal pollutants have been shown to inhibit organic pollutant biodegradation. We investigated the ability of a modified, polydentate cyclodextrin (carboxymethyl-beta-cyclodextrin, CMCD) to reduce the toxicity of 33.4 microM cadmium, cobalt or copper during naphthalene degradation by a Burkholderia sp. in 120 h aerobic, batch studies. The highest investigated concentration of CMCD, 3340 microM, reduced cadmium, cobalt, and copper toxicity. With each metal, the length of the lag phase was reduced (by as much as 108 h with cobalt or copper), the cell yield was increased (by as much as a factor of 16 with cobalt), and the growth rate was increased (by as much as a factor of 31 with cobalt). The degrader was unable to use CMCD as the sole source of carbon and energy. Our data suggest that the ability of CMCD to complex metals plays an important role in its ability to mitigate metal toxicity and that CMCD has the potential to enhance biodegradation in organic and metal co-contaminated environments.

Topics: Analysis of Variance; beta-Cyclodextrins; Biodegradation, Environmental; Bioreactors; Burkholderia; Cadmium; Cobalt; Copper; Environmental Pollution; Naphthalenes; Time Factors

UV-vis, circular dichroism (CD), fluorescence, and NMR spectral studies on the self-inclusion behavior of a newly synthesized sensitizing host, 6-(5-cyanonaphthyl-1-carboamido)-6-deoxy-beta-cyclodextrin (1), showed that the appended naphthalene moiety of 1 perches laterally on the cyclodextrin rim in aqueous methanol but is shallowly included and somewhat tilted in its own cavity in water. UV-vis and CD spectral examinations of the complexation of guest substrate 1,1-diphenylpropene (DPP) with host 1 revealed the formation of a stoichiometric 1:1 complex of DPP with 1. The naphthyl fluorescence of 1 was efficiently quenched by the addition of DPP in aqueous solutions of low methanol contents (or=50% methanol), where the fluorophore is not included in the cavity and allows the external attack of DPP to form an exciplex in the bulk solution. Upon irradiation in aqueous solutions of different methanol contents, competitive photoaddition of water and methanol to DPP occurred to give chiral water adduct 3 and methanol adduct 4, favoring the latter product by a factor of 2.5 due to the higher nucleophilicity of methanol. The enantiomeric excess (ee) values of the photoadducts were generally low in highly methanolic solutions, but was greatly improved by increasing the water content to reach 18% ee for 3 and 13% ee for 4 in 10% methanol solution at -10 degrees C. Interestingly, the ee of methanol adduct 4 was consistently lower than that of water adduct 3 particularly in water-rich solvents, revealing that the product's ee is not a simple thermodynamic function of the enantioface-selectivity upon complexation of DPP by chiral host 1 but also kinetically controlled by the subsequent photoinduced enantioface-differentiating nucleophilic attack of water and methanol to radical cationic DPP generated photochemically. Compatible with this mechanism, the compensation plot of the differential activation enthalpy versus entropy, which were obtained from the van't Hoff analysis of the temperature-dependent ee's obtained in aqueous solutions of varying methanol contents, gave an excellent straight line for water adduct 3 but an unprecedented bent plot for methanol adduct 4, indicating a switching of the mechanism in between 35 and 50% methanol solution. By using high pressure, low temperature, and/or added salt, the ee of water adduct 3 was further enhanced to 24-26%.

Topics: Alkenes; beta-Cyclodextrins; Chemistry, Organic; Cyclodextrins; Magnetic Resonance Spectroscopy; Methanol; Molecular Conformation; Molecular Structure; Naphthalenes; Photochemistry; Propane; Solvents; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Thermodynamics; Water

Electrokinetic soil remediation has been proven to remove heavy metals and polar organics from low hydraulic conductivity subsurface environment. In this study, carboxymethyl-beta-cyclodextrin (CMCD) was used as a carrier to assist electrokinetic treatment for removal of low polarity organic contaminants from soils (2.2% organic carbon content). Naphthalene and 2,4-dinitrotoluene (2,4-DNT) were selected as the test compounds. The results from columns experiments showed that 46 and 43% of naphthalene and 2,4-DNT, respectively, were removed using 0.01 N NaNO(3) flushing solution with 40 V electrical potential while 70 and 72% of naphthalene and 2,4-DNT were removed using 2 g/L CMCD solution. Naphthalene and 2,4-DNT removal was enhanced to 83 and 89%, respectively, by using 2 g/L CMCD with 40 V electrical potential. Findings from this study also demonstrated that cyclodextrin assisted electrokinetics can enhance the removal rate of naphthalene and 2,4-DNT. Electric potential applied has more influence on the contaminant removal than the amount of CMCD used. Higher voltage application caused increase in the removal rate of naphthalene and 2,4-DNT, and appeared to be one of the critical factors in obtaining higher contaminant removal while increasing CMCD solution concentration above 2 g/L appeared to have little effect on the contaminant removal.

Topics: beta-Cyclodextrins; Dinitrobenzenes; Electrochemistry; Kinetics; Naphthalenes; Soil Pollutants; Solutions

Naphthalene particles in a water slurry have been bioremediated in a sealed, roller bioreactor using a pure strain of Pseudomonas putida. High stripping losses of particles due to both splashing and aeration made the use of the traditional CSTR bioreactor unsuitable for bioremediation of naphthalene particles. The overall dissolution mass transfer coefficient of naphthalene particles in the roller bioreactor was low, 0.055 h(-1) at 50 RPM. The dissolution mass transfer rate was the limiting step for bioremediation. Although mass transfer was identified as the rate limiting step, the addition of hydroxypropyl-beta-cyclodextrin (a solubility enhancer) failed to improve naphthalene slurry bioremediation. In order to successfully bioremediate naphthalene particles at concentrations over 300 mg/L, intermittent aeration was applied in the sealed roller bioreactor on a daily basis. By operating in sequential batch mode with intermittent aeration, the roller bioreactor was successfully used to continuously bioremediate naphthalene particles at concentrations up to 1000 mg/L and at rates up to 10 mg/Lh.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Animals; beta-Cyclodextrins; Biodegradation, Environmental; Bioreactors; Catechols; Cyclodextrins; Kinetics; Naphthalenes; Oxygen; Propylene Glycol; Pseudomonas; Solubility; Water; Water Purification

Non-exhaustive extraction techniques (NEETs) have been shown to measure the putatively bioavailable fraction of hydrophobic compounds in soil. To date, these studies have only considered bioavailability in a single soil type. In this study, naphthalene was amended into five different soil types and mineralisation, bacterial biosensor response and the number of indigenous microbial naphthalene degraders were determined. Two NEETs were used to extract the naphthalene from soil; hydroxypropyl-beta-cyclodextrin (HPCD) and XAD-4. The HPCD extractable fraction correlated closely (R2 = 0.917) with the portion that was mineralised, but the XAD-4 extract did not (R2 = 0.044). HPCD may be ideal for the rapid assessment of the fraction of a hydrophobic organic contaminant that is available for biodegradation. A NEET that complements environmental microbial analysis will enhance our understanding of soil pollution interactions and equip us better in designing risk assessment models that integrate biological parameters. This application, although refined for soil samples, should be transferable to other environmental matrices.

Topics: Bacteriological Techniques; beta-Cyclodextrins; Biodegradation, Environmental; Biological Availability; Biosensing Techniques; Naphthalenes; Polystyrenes; Polyvinyls; Pseudomonas fluorescens; Soil; Soil Microbiology; Soil Pollutants

The solubility of the lipophilic carcinogens benzo[a]pyrene and aflatoxin B1 in water increases linearly and substantially with the concentration of hydroxypropyl beta-cyclodextrin present. Results of a kinetic study of naphthalene, a model for more potent carcinogens, indicate that the increase in the dissolution rate and in the transport through the aqueous phase into a nonpolar phase is on the same order of magnitude as the increase in solubility. Consequently, hydroxypropyl beta-cyclodextrin, when used in pharmaceutical formulations, has the potential to increase the absorption of carcinogens which enter the gastrointestinal tract either as food components or from air pollution through saliva. Only the above mechanism's simple proportionality needs be considered for estimating the increases in carcinogen absorption in the upper gastrointestinal tract and in the colon. In the presence of bile, however, additional factors are involved and the proportionality does not apply. Bile micelles, which themselves are effective solubilizers of lipophilic carcinogens, were disrupted by hydroxypropyl beta-cyclodextrin because of the formation of complexes with bile salts. Thus, in the presence of bile, two systems for delivery of carcinogens may coexist: that of cotransport with lipids and that of delivery through solubilization by hydroxypropyl beta-cyclodextrin.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Aflatoxin B1; Benzo(a)pyrene; beta-Cyclodextrins; Bile; Carcinogens; Chemical Phenomena; Chemistry, Physical; Cyclodextrins; Drug Synergism; Kinetics; Lipid Metabolism; Lipids; Mathematical Computing; Naphthalenes; Solubility; Water