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Research identifies two new genes encoding hydratase and aldolase that mediate biodegradation of tetralin by bacteria. Results demonstrate that these enzymes are similar to the enzymes involved in homoprotocatechuate degradation.

The authors review the publications on electolyte transfer entropies and enthalpies. The topics of interest include the standard molar Gibbs transfer energies of cations between water and mixed aqueous-organic solvents and the compensation which may occur between entropy and enthalpy.

Research has been conducted on the spheroidal molecular assemblies in polar organic media. The access to these assemblies has been developed and the results indicate that the assemblies are composed of building blocks based on ammonium cations and phosphonate anions.

Research has been conducted on the isodeltacyclyl cations. The feasibility of these cations as intermediates has been investigated via the preparation of deuterated and nondeuterated isodeltacyclanes and the details are reported.

Research has been conducted on the (S)-profen 2,2,2-triofluoroethyl thioesters. The racemization of these thioesters carried out in isooctane with the trioctylamine as base in investigating the substituents' electron-withdrawing effect to the alpha-phenyl thioester moiety is described.

Research has been conducted on the radiometal-containing dendrimers. The synthesis of different generations of the adamantane-terminated Frechet-type dendrimers consisting of the dendritic wedge ligands around the rhenium core has been carried out in organic solvents via the ReO(PPh (sub)3) (sub)2 Cl (sub)3 reaction and the results are discussed.

Research describes the existence of an additional multidrug efflux pump TtgGHI besides the two previously known TtgABC and TtgDEF, which mediate solvent resistance in Pseudomonas putida DOT-T1E. Results show that while TtgABC and TtgGHI pumps remove toluene, styrene, m-xylene, ethylbenzene, and propylbenzene, TtgDEF removes only toluene and styrene.

Research has been conducted on the InCl (sub)3, Yb(OTf) (sub)3 and Sc(OTf) (sub)3. The catalytic efficiency of these compounds in the alpha,beta-epoxycarboxylic acid azidolysis has been investigated in water and in organic solvents and the results are discussed.

Research has been conducted on the 4-alkoxycarbonyl-3-oxotetrahydroquinolizinium ylides. The solvolysis of these ylides in producing indolizine has been investigated and the study of Chichibabin indolizine formation reaction is presented.

Research has been conducted on the colicin E1 immunity protein, a membrane protein from Escherichia coli cytoplasmic membrane. The purification of this protein in 1-butanol extraction of isolated membranes has been performed to utilize its solubility in organic solvents.

Results suggest that the AcrAB-TolC efflux pump extrudes solvents in the range of 3.4 to 6.0 of log P(sub)OW and at higher than 4.4, the solvents are retarded. Data indicate that octane, heptane, and n-hexane are preferred substrates for the efflux system.

The participation of multidrug efflux systems of Pseudomonas aeruginosa in organic solvent tolerance was investigated using genetically defined efflux pump mutants. The findings demonstrated that the three efflux systems, namely MexE-MexF-OprN, MexC-MexD-OprJ and MexA-MexB-OprM, induce tolerance for such organic solvents as p-xylene and n-hexane. The expression of MexAB-OprM was associated with the maximum tolerance level and was a factor in the intrinsic solvent tolerance of the microorganism.

Overexpression of the soxS or robA gene have been found to induce in several Escherichia coli strains the acquisition of higher organic solvent tolerance and also enhanced resistance to a number of antibiotics. The marRAB genes were isolated from a Kohara lambda phage clone and cyclohexane-tolerant mutant strain OST3408. A substitution of serine for arginine at position 73 was observed in the coding region of marR of OST3408 and named marR08. marR08 was found to be responsible for the cyclohexane-tolerant phenotype.

The organic solvent tolerance of Escherichia coli was measured under conditions in which OmpF levels have been controlled. Genetically engineered E. coli mutants have previously been reported to tolerate high levels of organic solvents. It was speculated that the organic solvent molecules could pass through the OmpF porin protein. However, the results indicate that this hypothesis is not true. The solvent tolerance of E. coli has been found not to be dependent upon OmpF levels in the membrane.

Ethylene glycol monobutyl ether, also called 2-butoxyethanol (BE), is a solvent that is used in manufacturing lacquers, cleansing agents and paints. Large doses of BE are toxic to humans and can cause death. BE can be absorbed through the skin, it can be inhaled or it can be ingested. Once inside the body, BE is converted (metabolized) into butoxyacetic acid (BAA). BAA has been found in the urine of workers who were exposed to large amounts of BE and in hospital patients who ingested large amounts of BE. In rats, BE is toxic to red blood cells, and it is believed that BAA is responsible for the toxicity. In humans who have ingested large amounts of BE during suicide attempts, BE has been shown to reduce the number of red blood cells and the amount of hemoglobin (the protein responsible for carrying oxygen in the blood). Also, BAA can destroy red blood cells when it is added to samples of human blood. This article describes the results of a study designed to determine if BAA can be detected in the blood of humans after BE is inhaled. Five male volunteers inhaled BE, at a concentration of 20 parts per million in air, for two hours. Blood samples were taken and the amount of BAA was measured using a procedure called gas chromatography. The largest amounts of BAA were found in the blood between two and four hours after the BE was inhaled. However, the total amount of BAA present in the blood was not great enough to damage the red blood cells. It is concluded that BAA can be measured in the blood after BE is inhaled, and that inhaling BE at a concentration of 20 parts per million in air does not damage red blood cells. (Consumer Summary produced by Reliance Medical Information, Inc.)

Larvae of the nudibranch mollusc Phestilla sibogae metamorphosed when exposed to 10 of 14 organic solvents. The active solvents included five alcohols and ethanolamine, acetonitrile, acetone, dichloromethane, and toluene. Inactive solvents were ethylene glycol, DMSO, benzene, and hexane. These compounds span a wide range of polarities and contain a number of functional groups. Ethanol induced metamorphosis after 1-5 days of exposure at 0.5-0.001 M, and maximally induced about 65% of larvae to metamorphose in 3-5 days at 0.1 M. Ethanol was lethal to larvae above 0.75 M (ca. 4%). Methanol was lethal only above 1.75 M (ca. 7%), but produced less metamorphosis than ethanol at most concentrations. The natural inducer of metamorphosis in P. sibogae produced higher percentages of metamorphosis more rapidly than did any of the solvents. The mechanism of metamorphic induction by the solvents is not known, but they probably interfere with a wide range of neuronal activities and trigger an existing metamorphic pathway. Precompetent (young) larvae did not metamorphose in response to ethanol or methanol, but juveniles produced by exposure of competent (mature) larvae to ethanol or methanol survived to reproduce. Larvae of one other mollusc species also metamorphosed in response to ethanol, suggesting that larvae of other invertebrates may also be induced to metamorphose by organic solvents. Larval biologists should be aware of this possibility.