Gas phase equilibria for dibenzo‐p‐dioxin,dibenzo‐p‐furan and biphenyl in the C‐H‐O system

The gas phase equilibrium calculation for the C‐H‐O system at atmospheric pressure and temperature from 773 to 1773 K at intervals of 250 K was performed to understand the generation and decomposition behavior of dibenzo‐p‐dioxin (DD), dibenzo‐p‐furan (DF) and biphenyl (BP) in relation to the existing oxygen potential. It is possible to categorize these results into three regions from the viewpoint of this potential: region (A), region (B) and region (C) are that of the higher, modest and lower oxygen potential, respectively. In region (A), the equilibrium amounts of DD, DF and BP are nearly zero. In region (B), they increase once and then decrease with rise in temperature. In the most characteristic region (C), they increase uniformly with rise in temperature.     

New O,O‐dimethyl (2,2,2‐trichloro‐1‐carbamoyloxy)‐ethyl phosphonates and their biological activity

A series of fifteen carbamoyl derivatives of O,O‐dimethyl (2,2,2‐trichloro‐l‐hydroxy) ethyl phosphonate (trichlorphon) was synthesized. A number of them showed higher insecticidal activity, having at the same time lower toxicity than the starting biologically active structure. A waste‐free technology for the production of the more promising representatives of this series could possibly be developed in the future.     

Concentrations of polychlorinated dibenzo‐p‐dioxins and dibenzofurans in outdoor air of North‐Rhine‐Westphalia,Germany

Measurements of polychlorinated dibenzo‐p‐dioxins (PCDD) and dibenzofurans (PCDF) in outdoor air of North‐Rhine‐Westphalia were carried out. Fifty‐six samples were taken at different sites in areas of different land use and emission structures. A special filter system allowed analysis of the gas and particle phases separately. It was found that higher chlorinated PCDD/PCDF (7 or 8 chlorine atoms) are collected on glass fiber filter and lower chlorinated PCDD/PCDF (tetra‐ and penta‐CDD/CDF) are absorbed on polyurethane foam. The following isomers were determined: OCDD, OCDF and 11 isomers with chlorine substitution in 2,3,7,8‐position as well as the sum of TCDD, PeCDD, HxCDD, HpCDD, TCDF, PeCDF, HxCDF, HpCDF and the sum of PCDD (4–8) and PCDF (4–8). No 2,3,7,8‐TCDD could be detected but 2,3,7,8‐TCDF was found at 15 sites. Mean concentration in the Rhine‐Ruhr‐District for the sum of PCDD (4–8) and PCDF (4–8) was 3.2pg/m³ and 5.5pg/m³ respectively. Detection limit for TCDD and PCDD/PCDF (5–8) was 0.1–0.2 pg/m³ and 0.005–0.015 pg/m³ respectively. There is no significant indication that 2,3,7,8‐chlorinated isomers of PCDD/PCDF are predominantly decomposed by photochemical reactions in outdoor air.     

Synthesis of 2,5‐diaryl‐2,4‐pentadienenitriles and their spectral,fluorescence and mutagenic properties

The condensation of substituted cinnamaldehydes and arylacetonitriles using sodium ethoxide in ethanol at room temperature afforded 2,5‐diaryl‐2,4‐pentadienenitriles in good yield. The structure of the reaction products was established on the basis of their infrared, nuclear magnetic resonance and elemental analysis data. Two representative compounds were studied for their mutagenic activity. One of them showed a weak mutagenicity while the second showed a high mutagenic activity in TA97a Salmonella strain. Both were negative in TA100. Some of these pentadienenitriles showed fluorescence in solutions.     

Synthesis and antithyroid activity of 6‐n‐propyl‐5‐arylazo‐2‐thiouracils †

The synthesis of several 6‐n‐propyl‐5‐arylazo‐2‐thiouracil derivatives was achieved. The antithyroid activity of these derivatives has been determined using iodine‐125‐thiocyanate discharge technique in rats, and 6‐n‐propyl‐2‐thiouracil (PTU) as a standard. None of the 5‐arylazo‐2‐thiouracil analogs showed antithyroid activity as compared to PTU. The structure‐activity relationships (SAR) of position 5 in the PTU molecule and the requirements for better binding to the proposed receptor are discussed.     

Photodecomposition of Isofenphos (O‐ethyl‐O(2‐isopropoxycarbonyl)‐phenyl)‐Isopropylphos‐Phoramidothioate)

Photodecomposition of the organophosphorus insecticide isofenphos (O‐ethyl‐O‐(2‐isopropoxy‐carbonyl)‐phenyl)‐N‐isopropylphosphoremidothioate) has been studied in solution, on glass and soil surfaces. Isofenphos underwent oxidation from P = S to the P = O group and deesterification on irradiation in hexane and methanol. Photoproducts were isolated and identified by spectroscopic methods.     

Photolysis of 3‐(3,4‐dichlorophenyl)‐1, 1 ‐Dimethylurea (Diuron) in dilute aqueous solution

Diuron samples at 40mg/L concentration were photolyzed with ultraviolet lamps and with natural sunlight to determine if data from ultraviolet lamp photolysis could be used to predict results from sunlight photolysis. Seven photoproducts were identified from the photolysis experiments. The identified photoproducts and the photoproduct yields were essentially the same for the two light sources.     

Crystallization and X‐ray structure of 3,3’,4‐trichlorobiphenyl (PCB 35)∗

A method for the preparation of single crystals of PCB 35 suitable for single crystal X‐ray structure determination was developed. This method has already been proven suitable for 2,4'‐dichlorobiphenyl and may prove useful for other PCBs or related compounds. The crystals of PCB 35 are orthorhombic, spacegroup P2₁22₁ (a= 10.665(8), 6 = 3.825(3), c= 14.086(9) Å) and the structure was refined to R = 0.094 for 156 unique observed reflections and 43 parameters. Although the crystals were of poor quality, the structure determination unequivocally confirmed the substitution pattern of the biphenyl moiety by Cl atoms inferred previously from spectroscopic methods. The dihedral angle between the planes of the two phenyl rings is 33(2)°.     

Relationships between octan‐1‐ol/water partition coefficients,aqueous activity coefficients and reversed phase HPLC capacity factors of alkylbenzenes,chlorobenzenes, chloronaphthalenes and chlorobiphenyls

Linear relationships between logarithms of octan‐1‐ol/water partition coefficients (K_d,oct), aqueous activity coefficients (y_aq) and extrapolated RP HPLC capacity factors (k‘_w) are found for four types of aromatic hydrocarbons (alkylbenzenes and poly‐chlorinated benzenes, ‐naphthalenes and ‐biphenyls).

Both log K,_d,oct and logk‘_w increase with the increasing number of chlorine or methyl‐ene substituents. These increases of log K,_d,oct and log k‘_w are proportional and almost independent of the parent compound. In addition, these increases are linear to increases of logy_aq. The slopes of logk‘_w‐logy_aq and log K,_d,oct‐logv_aq relationships deviate significantly from 1.0. This suggests that the activity coefficients of the test compounds in both octan‐1‐ol and in the stationary phase of the RP column increase after substitution of aromatic compounds with methylene or chlorine.     

Metal binding capacity of soft acid,organic‐rich waters

Organic carbon from one stream and two ponds in South Carolina was fractionated into five nominal molecular diameter fractions by ultrafiltration. The concentrations associated with and binding capacity for Ca, Cd, Cu and Pb were determined for each fraction. The distribution of organic carbon among ultrafilter fractions varied from water to water, with the largest percentage occurring in the smaller fractions. Calcium was associated with each of the fractions isolated from each of the three waters, indicating Ca is bound to organics in all fractions, however, more than 99% of the Ca which passed the smallest ultrafilter was removed by cationic exchange resin. Each fraction bound more Ca than Cd, Cu or Pb except in a few cases where Pb binding was greater. All of the organic fractions had their Ca++ binding sites saturated. Calcium was not an effective competitive ion against Cd, Cu or Pb for organic binding sites. The total Cu binding capacity was less than that of Ca or Pb but similar to that of Cd. Naturally occurring organics bound more Pb than Cd or Cu but less than Ca. Saturation of Cu binding sites was less than 20% in most ultrafilter fractions except that with a nominal molecular weight of between 10,000 and 300,000 where the percent of saturation was as much as 60%. Approximately 50% of the Cu was removed onto anionic exchange resin in two waters while more than 90% was removed from water with a high organic content. Percent saturation of Cd and Pb binding sites ranged from 0.091% to 5.4% and 0.059% to 1.5%, respectively. All ions tested effectively competed with Cd, Cu or Pb for some but not all binding sites, indicating that organic binding sites were heterogeneous. A generalized order of metal‐organic stabilities based on competition for binding sites is Al>Cd>Pb>Cu>Ni = Mg=Zn = Mn>Ca. Both Cd+2 and Al+3 effectively out competed Pb++ and Cd and Pb out competed Cu for most organic binding sites.     

Toxicity of 3‐Amino‐1: 2: 4‐Triazole to Activated Sludge Biomass

3‐amino‐1: 2: 4‐triazole (AT), a potent weed killer, added to activated sludge, caused immediate and drastic reduction in oxygen uptake by biomass. AT, a known specific inhibitor of catalases of animal and plant sources, did not appreciably alter catalase of activated sludge biomass.     

Constitutive and herbivore‐induced volatiles in pear,alder and hawthorn trees

Summary. Qualitative and quantitative differences among pear cultivars were found in constitutive and Cacopsylla-induced volatiles, depending on experimental treatment of the trees (i.e., uninfested and partly or completely infested by psyllids). Blend differences were also found between pear cultivars and wild-type pear, alder and hawthorn–the latter trees are frequently present in pear orchard hedgerows. ?Interesting differences were found in the presence of methyl salicylate and (E,E)-α-farnesene, two compounds previously found to mediate attraction of predatory bugs towards psyllid-infested pear trees. Methyl salicylate is expressed constitutively and is induced systemically by infestation in the whole plant of all four cultivars. (E,E)-α-farnesene on the other hand showed also systemic induction in Bartlett, NY10355 and Beurré Hardy, but in partially infested Conference trees it was induced locally, only in herbivore-damaged leaves. No methyl salicylate or (E,E)-α-farnesene were identified in honeydew. In field collected headspace samples of alder leaves infested by aphids and leaf beetles we found methyl salicylate but no (E,E)-α-farnesene, whereas in uninfested hawthorn neither were identified. Insight in the variability of damage-related pear volatiles will have important implications for integrated pest management in the field. Received 27 August 2002; accepted 28 November 2002 R1D=" Correspondence to: Petru Scutareanu, e-mail:scuterea@science.uva.nl     

Photolytic decomposition of uc‐54229, a Proinsecticide of the Carbamate group

Phototransformation of UC‐54229 (1) [2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl‐N‐(trimethylamino acetyl)‐N‐methyl carbamate chloride] was studied under UV and visible light conditions. Photoirradiation of 1 with UV‐light resulted in the formation of five degradation products which on the basis of their mass and ¹H Nmr spectral analysis were characterised as 2, 3, 4, 5 and 6. It was observed that under the influence of light, UC‐54229 was degraded to acetyl‐carbofuran which under similar conditions underwent further transformation to the actual toxicant carbofuran. The degradation products or impurities present in 100% water soluble powder formulation were identified as carbofuran phenol and triethylamine hydrochloride.     

Presence of Cd‐binding proteins in pre‐exposed and not pre‐exposed cadmium brine shrimp Artemia

The presence of metal binding proteins has been variously suggested as indicating involvement in uptake, storage, transport and elimination of toxic metals and in the routine metabolism of metals in mammals and a variety of marine invertebrates. This report describes results on the characterization of Cd‐BPs obtained from cadmium pre‐exposed and not pre‐exposed Anemia. The effect of pre‐exposure in the Cd‐binding protein induction in Artemia is discussed.     

Light‐induced changes in rabbit pineal gland n‐acetyltransferase activity

N‐acetyltransferase (NAT) activity was determined in different ages of New Zealand White rabbit pineal gland using 2‐aminofluorene and p‐aminobenzoic acid as substrates and it was assayed by high pressure liquid chromatography. Rabbits of different ages were either sacrificed during the light phase, exposed to darkness or light for 1 min during the dark phase of the lighting cycle, returned to their cages in darkness for 30 min and then sacrificed. Pineal gland NAT activity in animal nocturnally exposed to 1 min of light was inhibited in animals 1 ‐day‐old of age. Nocturnal light exposure did not inhibit enzyme activity in 1‐day‐old rabbit, even though these animal displayed clear light : dark differences in pineal gland NAT activity. Nocturnal light exposure also did not inhibit night time levels of NAT activity in 1‐day‐old animals who had been bilaterally enucleated. The result suggested that this effect is retinally mediated. Pre‐treatment of 1‐day‐old and 60‐day‐old animals with the isoproterenol (beta‐noradrenoreceptor agonist drug), prevented the nocturnal light‐induced inhibition of NAT activity. The different sensitivity of 60‐day‐old and 1‐day‐old animals to different illuminances or durations of nocturnal light exposure, was that the duration or intensity of light exposure was enable to inhibit nocturnal NAT activity. The NAT activity was at least 3.2‐ to 4.6‐fold greater in 1‐day‐old rabbits compared to 60‐day‐old rabbits. Kinetic constants for arylamine NAT activity in pineal gland from rabbits were determined. K_m and F_max values for 2‐aminofluorene were 2.6‐fold higher for light exposure than for no light exposure rabbits. This is the first demonstration of the retina‐pineal gland pathway appears light‐induced changes in pineal glands of animals in 1‐day‐old of ages or older; but this pathway does not function in 60‐day‐old rabbits like manner in 1‐day‐old rabbits.     

Polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/Fs) in dated environmental samples,and their connection to known sources

This article investigates available environmental data from measurements of the everywhere present contaminants polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/F) in dated trends in sediment, soil and herbage from locales in Europe and North America. The PCDD/F data are examined in relation to potential major PCDD/F sources based on volume: wood and coal, example of natural combustion; pentachlorophenol (PnCP), example of chlorinated aro‐matics; and polyvinyl chloride (PVC) pyrolysis, example of chlorinated aliphatic. Collected PCDD/F data of congener sums and 2, 3, 7, 8‐substituted congener (PCDD/F profiles) have been investigated with multivariate methods: principal component analysis (PCA) and partial least squares projection to latent structures model (PLS). The results show that PCDD/F data from 12 locales can be separated in one to three independent profiles. Normally one profile is related to the PCDD/F found in PnCP and another to combustion. A subtype of the ‘PnCP’ and ‘combustion’ profiles indicates PCDD/F contributions from PVC‐related combustions. The environmental profiles exhibit some differences from the suggested sources. The relatively unprotected PCDD/F related to PnCP is suggested to have passed photolytic and/or thermal dechlorinations. Lower‐chlorinated congeners in environmental profiles related to combustion appear to have been influenced by environmental distribution processes. PCDD/F data before industrial production of chlorinated organics have only limited similarity to PCDD/F in technical PnCP profiles; an average 4.6% of the PCDD/F is related to PnCP. This suggests that PnCP similarity in recent deposition profiles cannot be a result of environmental transformation. The average proportion of PnCP‐related PCDD/F profile in recent depositions is 35% with North America high (average 57%) and Europe low (average 24%).     

Photolysis of chlorimuron‐ethyl

To examine the photostability of the herbicide chlorimuron‐ethyl (ethyl‐2‐[[[[(4‐methoxy‐6‐chloro‐pyrimidin‐2‐yl)amino]carbonyl]amino]sulfonyl]benzoate) in the field, model experiment with organic solvent was performed. Photolysis of chlorimuron‐ethyl in methanol solution resulted in the formation of seven major and five minor photoproducts, isolated and identified by spectroscopic methods. Major photoproducts reported were formed by the cleavage of sulfonylurea bridge, contraction of sulfonylurea bridge, methylation of urea nitrogen and cyclisation, whereas minor products by dechlorination.     

Regression models for octanol‐water partition coefficients,and for bioconcentration in fish

Octanol‐water partition coefficients (P) of a number of organochlorine insecticides (OCs) are presented. The merits of log‐log regressions between experimental ? values and calculated estimates of P, solute activity coefficients in water, solute molecular surface area data, and reversed‐phase liquid‐chromatographic net retention data, are critically evaluated for several classes of pollutants: polycyclic aromatic hydrocarbons (PAHs), chlorinated benzenes, chlorinated biphenyls and OCs. Special attention is paid to the predictive accuracy of such semi‐empirical regressions in connection with possible effects of solute molecular shape and polarity.

Finally, bioconcentration and ‐accumulation of hydrophobic pollutants in fish are briefly discussed.     

Antimutagenic and bacteriostatic activities of Schiff‐base compounds derived from aminoguanidine,semicarbazone and thiosemicarbazone and a copper(II)‐coordination complex

The Schiff‐base aminoguanidine compounds including a resorcylidene aminoguanidine copper(II) complex that were synthesized at our laboratory posses non‐mutagenic properties when tested with Ames test using Salmonella typhimurium TA97, TA100 and TA102 bacterial strains. These compounds were tested as possible pharmacological agents in preventing a wide array of illnesses. Additionally, some of these compounds exhibit strong antimutagenic and bacteriostatic activity. Nitrovin, a known mutagen, was used in the antimutagenicity tests as the inducer. A three‐dimensional projection of the copper(II) complex was derived by the semi‐empirical method ZINDO/1 to obtain additional information about its structure, and to help elucidate a possible mechanism of action.     

Patterns of serum calcium fractions,magnesium, phosphates and albumin in non‐insulin dependent diabetics (Nidd)

Blood level of calcium fractions (ionized and bound), phosphates, magnesium and albumin were measured in non‐insulin dependent diabetic patients (NIDD). Results were compared with healthy controls to elucidate the pathogenesis of probable changes of these elements. Total ionized calcium and magnesium showed significant decrease (p<0.001, p<0.05 and p<0.05) respectively. Phosphates showed non‐significant decrease while albumin reported nearly similar results. Positive correlation between inorganic phosphates and ionized calcium (r = 0.48, p<0.05) was observed only in healthy control group, not in diabetics. This may be attributed to alteration of ions excretions under diabetic condition through unknown mechanism. Additive increase of heparin sodium units in vitro to normal blood resulted in progressive fall in ionized calcium. Significant decrease was only observed upon addition of higher unit (5IU/ml). This must be taken into consideration biochemically for plasma determination of ionized calcium.