Acacia senegal gum attenuates systemic toxicity in CCl4-intoxicated rats via regulation of the ROS/NF-κB signaling pathway.

Acacia senegal (AS) gum (Gum Arabic) is a natural emulsifier exudate from the branches and trunk of Acacia trees and it is recognized by the Food and Drug Administration (FDA) agency as a secure dietary fiber. The present research evaluated the systemic oxidative and necroinflammatory stress induced by CCl4 administration and the alleviating effect of AS gum aqueous extract (ASE, 7.5 g/Kg b.w.). The results demonstrated the presence of certain phenolic compounds in ASE, as well as its in vitro potent scavenging ability against ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), NO, and lipid peroxide radicals. Also, the outcomes revealed an improvement in the CCl4-induced liver, lung, brain, and spleen toxicity by reducing the levels of ROS, lipid peroxidation, NO, and the gene expression of NF-κB and its relevant ROS-mediated inflammatory genes. In contrast, the total antioxidant capacity (TAC), as well as the enzymatic and non-enzymatic antioxidants, were significantly upregulated in these organs after the treatment with ASE. These results were confirmed by improving the morphological features of each organ. Therefore, ASE can ameliorate the systemic toxicity caused by CCl4 via regulation of the ROS/NF-κB signaling pathway in the rat organs, which is owed to its phytochemical composition.

Effects of losartan and l-serine in a mouse liver fibrosis model.

Hepatic fibrosis is a common liver disease caused by excessive collagen deposition in the liver. Since liver transplantation is the only current treatment for cirrhosis with worsened fibrosis, a new strategy to develop anti-fibrosis drugs with no adverse effects is necessary. In recent studies, amino acids have been applied as a type of therapy in various fields. l-serine plays a major role in antioxidant production via the maintenance of nicotinamide adenine dinucleotide phosphate hydride production in the mitochondria. l-serine may reduce fibrotic lesions in a mouse model of chronic liver injury. This study used 27 six-week-old C57BL/6 mice and injected them three times a week for eight weeks with carbon tetrachloride (CCl4) (1.5 mg/kg, 10% v/v CCl4 in olive oil) to create a hepatic fibrosis mouse model. The mice, which weighed approximately 20-30 g, were randomly classified into four groups: 1) the olive oil group, which received intraperitoneal injection of olive oil (1.5 mg/kg, 3 times per week for 8 weeks); 2) the CCl4-only group; 3) the CCl4 + losartan (10 mg/kg, PO, 5 days on, weekend off for 8 weeks) group; and 4) the CCl4 + l-serine (100 g/L, free access for 8 weeks) group. Hematoxylin and eosin staining and Masson's trichrome staining showed reduced inflammatory cell deposition and collagen deposition in the liver tissue in the l-serine supplemented group. l-serine was found to reduce the spread of hepatic fibrosis and has potential use in clinical settings. Based on these histopathological observations, l-serine is a potential anti-fibrosis drug.

Hepatoprotective effects of Psidium guajava on mitochondrial enzymes and inflammatory markers in carbon tetrachloride-induced hepatotoxicity.

OBJECTIVE: The present investigation was aimed to evaluate the hepatoprotective potential of ethanolic extract of Psidium guajava (P. guajva) and its isolated quercetin fraction on carbon tetrachloride (CCl4)-induced hepatotoxicity. MATERIALS AND METHODS: The rats were divided into 6 groups and each group contained 6 rats. CCl4 (1.5 ml/kg b.w.) was used to induce the hepatotoxicity. Ethanolic extract of P. guajava (300 mg/kg b.w.), isolated quercetin fraction (20 mg/kg b.w.) were used as a treatment and silymarin (25 mg/kg b.w.) was used as a standard drug. After the study period, the liver tissues were collected and evaluate the levels of liver functional markers, mitochondrial enzymes, histopathological analysis and the expressions of inflammatory markers. RESULTS: The levels of liver functional markers were increased and protein, albumin and A/G ratio levels were decreased and the decreased levels of mitochondrial enzymes were noted in CCl4-induced rats and the levels were restored near to normal significantly when the administration ethanolic extract of P. guajava, isolated quercetin fraction and silymarin. The normal architecture of liver tissues were altered and the mRNA expressions were up-regulated in CCl4-induced rats and the liver tissues were normalized and the mRNA and protein expressions were down-regulated near to normal significantly when the administration of ethanolic extract of P. guajava, isolated quercetin fraction and silymarin. CONCLUSION: From these results, the isolated quercetin fractions have better activity than that of the ethanolic extract of P. guajava leaves. Hence, the isolated quercetin may be used as the safest drug for hepatotoxicity in future.

Evaluation of carbon tetrachloride fraction of Actinodaphne angustifolia Nees (Lauraceae) leaf extract for antioxidant, cytotoxic, thrombolytic and antidiarrheal properties.

Actinodaphne angustifolia Nees (Family: Lauraceae) is commonly used in folk medicine against urinary disorder and diabetes. The objective of the present study was to evaluate the antioxidant, cytotoxic, thrombolytic, and antidiarrheal activities of carbon tetrachloride (CCl4) fraction of leaves of A. angustifolia (CTFAA) in different experimental models. Antioxidant activity was evaluated by using qualitative and quantitative assays, while antidiarrheal effects assessed with castor oil-induced diarrheal models in mice. The clot lysis and brine shrimp lethality bioassay were used to investigate the thrombolytic and cytotoxic activities, respectively. CTFAA showed antioxidant effects in all qualitative and quantitative procedures. The fraction produced dose-dependent and significant (P<0.05 and P<0.01) activities in castor oil-induced diarrheal models. Moreover, CTFAA significantly (P<0.05) demonstrated a 15.29% clot lysis effect in the thrombolytic test, and the brine shrimp lethality assay LC50 value was 424.16 µg/ml bioassay. In conclusion, the current study showed CTFAA has significant antidiarrheal effects along with modest antioxidant and thrombolytic effects, and these data warrant further experiment to justify and include CTFAA as a supplement to mitigate the onset of diarrheal and cardiovascular disease.

Hepatoprotective Activity of Linalool in Rats Against Liver Injury Induced by Carbon Tetrachloride.

This study aimed to investigate and compare hepatoprotective activity of Coriandrum sativum (Cs) and it is major component linalool (Ln) against experimentally induced hepatotoxicity in rats. Essential oil of Cs was isolated by hydrodistillation method and chemical composition was determined by GS-MS analysis. 42 male Wistar Albino rats were divited into 7 groups each containing 6. The experimental groups were designed as: Normal control group, 1 ml/kg CCl4 administirated group, 25 mg/kg Silymarin and CCl4 administirated group, 100 and 200 mg/kg Cs and CCl4 administirated groups, 100 and 200 mg/kg Ln and CCl4 administered groups. The protective activities were determined according to the results of liver biomarkers (AST, ALT, ALP), antioxidant parameters (GSH, GPx, CAT), lipid peroxidation (MDA) and histopathological examination. Linalool percentage of Cs was 81.6%. The groups treated with linalool (100 and 200 mg/kg) (p < 0.01) and coriander (200 mg/kg) (p < 0.05) had significantly reduced AST (262-375) and ALT (101-290) levels (U/L) compared to the CCl4 (600-622) group. The levels (nmol/g protein) of MDA (11-12) were significantly lower (p < 0.01), the levels of GSH (11-12) and the activities of CAT (23-24) were significantly higher (p < 0.01) in linalool groups (100 and 200 mg/kg) compared to the CCl4 (18-5-10 respectively) group. These results were also supported by histopathological findings and indicate that Cs and Ln shows hepatoprotective activity against liver damage. In this regard, evaluation of activities of major components are needed to compare to medicinal plants in experimental diseases models.

A Targeted Multiple Antigenic Peptide Vaccine Augments the Immune Response to Self TGF-ß1 and Suppresses Ongoing Hepatic Fibrosis.

Transforming growth factor (TGF)-ß1 expression is induced upon liver injury, and plays a critical role in hepatic fibrosis. Antibodies against TGF-ß1 represent a novel approach in the treatment of hepatic fibrosis. However, TGF-ß1 is not a suitable antigen due to immunological tolerance. In the current study, we synthesized a multiple antigenic peptide (MAP) vaccine against the dominant B-cell epitope of TGF-ß1. The immunogenicity and potential therapeutic effects of this vaccine were examined using a rat model of hepatic fibrosis. Dominant B-cell epitopes of TGF-ß1 were identified using bioinformatic program. An MAP vaccine corresponding to the 90-98 amino acid domain of TGF-ß1 and containing four dendritic arms was synthesized using a 9-fluorenylmethoxycarbonyl solid phase method. Hepatic fibrosis which was induced in male Sprague-Dawley rats received a high-fat diet and ethanol (1.8 g/kg). Starting from the third week, rats were exposed to 40 % carbon tetrachloride (CCl4; 150 µl/100 g body weight twice weekly, initially 200 µl/100 g) treatment for a duration of 8 weeks. Rats received the MAP vaccine (100 µg) or Freund's adjuvant at weeks 1, 3, 5. A group of rats receiving the fibrosis-inducing regimen alone and a group of healthy rats (receiving an olive oil vehicle alone) were included as controls. At the conclusion of the experiment, serum titre of TGF-ß1 antibody was measured using ELISA and a standard liver functional test panel was examined. The extent of hepatic fibrosis was determined by measuring hydroxyproline content in the liver as well as hematoxylin-eosin (HE) and van Gieson (VG) staining. The expression of TGF-ß1 and alpha-smooth muscle actin (α-SMA) was examined using immunohistochemistry, and presented as positive staining cells. The MAP purity was >90 % upon reverse phase high-performance liquid chromatography, with apparent molecular weight at 4.77 kDa. Serum TGF-ß1 antibody titre was 1:256. The fibrosis-inducing treatment produced significant liver damage, as reflected by increases in liver functional test, HE and VG staining. The MAP vaccine attenuated such damage, as reflected by decreased alanine aminotransferase, aspartate aminotransferase, total bilirubin, and hepatic hydroxyproline (116.78 ± 23.76 vs. 282.71 ± 136.94 IU/L; 319.78 ± 82.48 vs. 495.29 ± 137.13 IU/L; 2.02 ± 0.27 vs. 4.01 ± 0.52 µmol/L; 263.67 ± 41.18 vs. 439.14 ± 43.29 µg/g vs. in model rats, respectively; p < 0.01), as well as fibrosis extent by HE and VG staining. The MAP vaccine reduced TGF-ß1 and α-SMA expression in rats (0.325 ± 0.059 vs. 0.507 ± 0.044 IOD/area; 0.318 ± 0.058 vs. 0.489 ± 0.029 IOD/area vs. model rats, respectively; p < 0.05). The TGF-ß1 MAP vaccine could generate sufficient antibody that suppresses the development of hepatic fibrosis.

Combination of saponification and dispersive liquid-liquid microextraction for the determination of tocopherols and tocotrienols in cereals by reversed-phase high-performance liquid chromatography.

A simple sample preparation technique coupled with reversed-phase high-performance liquid chromatography was developed for the determination of tocopherols and tocotrienols in cereals. The sample preparation procedure involved a small-scale hydrolysis of 0.5g cereal sample by saponification, followed by the extraction and concentration of tocopherols and tocotrienols from saponified extract using dispersive liquid-liquid microextraction (DLLME). Parameters affecting the DLLME performance were optimized to achieve the highest extraction efficiency and the performance of the developed DLLME method was evaluated. Good linearity was observed over the range assayed (0.031-4.0µg/mL) with regression coefficients greater than 0.9989 for all tocopherols and tocotrienols. Limits of detection and enrichment factors ranged from 0.01 to 0.11µg/mL and 50 to 73, respectively. Intra- and inter-day precision were lower than 8.9% and the recoveries were around 85.5-116.6% for all tocopherols and tocotrienols. The developed DLLME method was successfully applied to cereals: rice, barley, oat, wheat, corn and millet. This new sample preparation approach represents an inexpensive, rapid, simple and precise sample cleanup and concentration method for the determination of tocopherols and tocotrienols in cereals.

Anti-nociceptive and anti-inflammatory activities of Azadirachta indica fruit skin extract and its isolated constituent azadiradione.

This study was carried out to evaluate the anti-nociceptive and anti-inflammatory activities of carbon tetrachloride extract (CTCE) of Azadirachta indica fruit skin and its isolated constituent azadiradione at two different dose levels (50 and 100 mg kg⁻¹ body weight). Anti-nociceptive screening by writhing test and hot-plate technique supported both peripheral and central mechanisms, respectively. Anti-inflammatory activity was observed using carrageenan-induced paw oedema model. The results concluded that the animals treated with 100 mg kg⁻¹ dose of CTCE and azadiradione exhibited significant anti-nociceptive and anti-inflammatory activities. This study had rationalised the ethnomedicinal use of the plant for wound, burns and injury by tribal people.

Double asynchronous orthogonal sample design scheme for probing intermolecular interactions.

This paper introduces a new approach called double asynchronous orthogonal sample design (DAOSD) to probe intermolecular interactions. A specifically designed concentration series is selected according to the mathematical analysis to generate useful 2D correlated spectra. As a result, the interfering portions are completely removed and a pair of complementary sub-2D asynchronous spectra can be obtained. A computer simulation is applied on a model system with two solutes to study the spectral behavior of cross peaks in 2D asynchronous spectra generated by using the DAOSD approach. Variations on different spectral parameters, such as peak position, bandwidth, and absorptivity, caused by intermolecular interactions can be estimated by the characteristic spectral patterns of cross peaks in the pair of complementary sub-2D asynchronous spectra. Intermolecular interactions between benzene and iodine in CCl(4) solutions were investigated using the DAOSD approach to prove the applicability of the DAOSD method in real chemical system.

Development and validation of a stability-indicating method for determination of free sterols in the Asian medicinal leech Hirudo manillensis.

A rapid, simple, sensitive, selective, precise and robust thin-layer chromatography densitometric method for the determination of free sterols in leech was developed and validated on silica gel layer using carbon tetrachloride-methanol-formic acid (9.5:1.5:0.55, v/v/v). Spectrodensitometric scanning was carried using a Camag TLC scanner III at 366 nm after spraying 2% methanolic sulphuric acid, which gave compact spots for cholesterol (R(F) = 0.35 ± 0.02). The regression analysis data for calibration plot implied a good linear relationship (r(2) = 0.99958) between response and concentration over the range 100-600 ng per spot with respect to peak area. The limits of detection and quantification were found to be 13.8 ± 0.51 and 45.01 ± 1.29 ng per spot, respectively. Validation was in accordance to the International Conference on Harmonization guidelines. Cholesterol was subjected to forced stress conditions of oxidation, hydrolysis and heat. Degradation products resulting from the forced stress did not interfere with detection because the degradant peaks were well separated from the cholesterol peak. The densitometric method can be regarded as stability-indicating and can be used for quality control assay of cholesterol in leech extract.

Gas chromatographic-ion trap mass spectrometric analysis of volatile organic compounds by ion-molecule reactions using the electron-deficient reagent ion CCl3(+).

When using tetrachloromethane as the reagent gas in gas chromatography-ion trap mass spectrometry equipped with hybrid ionization source, the cation CCl(3)(+) was generated in high abundance and further gas-phase experiments showed that such an electron-deficient reagent ion CCl(3)(+) could undergo interesting ion-molecule reactions with various volatile organic compounds, which not only present some informative gas-phase reactions, but also facilitate qualitative analysis of diverse volatile compounds by providing unique mass spectral data that are characteristic of particular chemical structures. The ion-molecule reactions of the reagent ion CCl(3)(+) with different types of compounds were studied, and results showed that such reactions could give rise to structurally diagnostic ions, such as [M+CCl(3) - HCl](+) for aromatic hydrocarbons, [M - OH](+) for saturated cyclic ether, ketone, and alcoholic compounds, [M - H](+) ion for monoterpenes, M(·+) for sesquiterpenes, [M - CH(3)CO](+) for esters, as well as the further fragment ions. The mechanisms of ion-molecule reactions of aromatic hydrocarbons, aliphatic ketones and alcoholic compounds with the reagent ion CCl(3)(+) were investigated and proposed according to the information provided by MS/MS experiments and theoretical calculations. Then, this method was applied to study volatile organic compounds in Dendranthema indicum var. aromaticum and 20 compounds, including monoterpenes and their oxygen-containing derivatives, aromatic hydrocarbon and sesquiterpenes were identified using such ion-molecule reactions. This study offers a perspective and an alternative tool for the analysis and identification of various volatile compounds.

Expansion of the sigma-hole concept.

The term "sigma-hole" originally referred to the electron-deficient outer lobe of a half-filled p (or nearly p) orbital involved in forming a covalent bond. If the electron deficiency is sufficient, there can result a region of positive electrostatic potential which can interact attractively (noncovalently) with negative sites on other molecules (sigma-hole bonding). The interaction is highly directional, along the extension of the covalent bond giving rise to the sigma-hole. Sigma-hole bonding has been observed, experimentally and computationally, for many covalently-bonded atoms of Groups V-VII. The positive character of the sigma-hole increases in going from the lighter to the heavier (more polarizable) atoms within a Group, and as the remainder of the molecule becomes more electron-withdrawing. In this paper, we show computationally that significantly positive sigma-holes, and subsequent noncovalent interactions, can also occur for atoms of Group IV. This observation, together with analogous ones for the molecules (H3C)2SO, (H3C)2SO2 and Cl3PO, demonstrates a need to expand the interpretation of the origins of sigma-holes: (1) While the bonding orbital does require considerable p character, in view of the well-established highly directional nature of sigma-hole bonding, a sizeable s contribution is not precluded. (2) It is possible for the bonding orbital to be doubly-occupied and forming a coordinate covalent bond.

Lisosan G, a powder of grain, does not interfere with the drug metabolizing enzymes and has a protective role on carbon tetrachloride-induced hepatotoxicity.

Lisosan G is a powder of grain registered as an alimentary integrator. The treatment of rats for 4 days with 0.5 g Lisosan G/kg had no effect on various drug metabolizing enzymes. Experiments in vitro showed that Lisosan G had radical scavenger activity. A confirmation of the antioxidative property of Lisosan G was also confirmed when it was administered in vivo to carbon tetrachloride (CCl(4))-intoxicated rats. The toxicity caused by CCl(4)-treatment of rats was restored to the control levels when the rats were given Lisosan G for 4 days before CCl(4). Lisosan G thus does not interfere with drug metabolizing system but has antioxidant properties and protects against CCl(4)-induced hepatotoxicity.

Effects of the extracts of Pycanthus angolensis against chemically induced acute hepatotoxicity.

The efficacy of the extract of Pycnanthus Angolensis (PA) against Carbon Tetra-chloride (CCl4) induced hepatotoxicity was studied in rat. The study highlights information on the protective effect of PA extract as ethnomedical treatment of induced hepatotoxic injury. The dried powder of PA extract was administered orally at a dose of 300 mg/3 mL solution while liver injury was induced by carbon tetrachloride administered intraperitoneally at a dose of 0.67 mg kg(-1). Estimating the protein concentrations, saponins, alkaloid, glutathione and cholesterol levels monitored the hepato-protective activity. The result shows evidence of non-toxic response of PA extract against chemically induced hepatic damage. The antioxidant activities in the extract indicated its ability to protect against CCl4 induced hepatic injury in rat. The saponins and bile acids may have interacted with cholesterol in the liver to form unabsorbed complexes, which are excreted via faeces resulting in decrease level of cholesterol in the experimental animals.

Análisis fitofarmacológico de los frutos de Luffa acutangula para determinar su actividad antihepatotóxica / Phytopharmacological screening of Luffa acutangula fruits for its antihepatotoxic activity

Se examinó el extracto acuoso y etanólico (100 mg/kg) de Luffa acutangula Linn (frutos) para determinar la actividadantihepatotóxica en ratas druckrey mediante la hepatotoxicidad inducida por tetracloruro de carbono (CCl4)y paracetamol (PCM). Se demostró que el extracto posee un efecto hepatoprotector signifi cativo, ya que reduce losniveles séricos de transaminasas (SGPT y SGOT), fosfatasa alcalina (ALP) y bilirrubina. La signifi cativa actividadhepatoprotectora de Luffa acutangula es comparable a la de la silimarina, agente hepatoprotector estándar, lo quejustifi ca su uso en afecciones del hígado

The ethanolic and aqueous extract (100mg/kg) of Luffa acutangula Linn(fruits) was examined for antihepatotoxic activityin druckrey rats by inducing hepatotoxicity with Carbon tetrachloride(CCl4) and Paracetamol(PCM). The extracthas shown to posses signifi cant hepatoprotective effect by lowering the serum level of transaminases (SGPT & SGOT),Alkaline phosphatase (ALP) and bilirubin. The signifi cant hepatoprotective activity of Luffa acutangula is comparableto that standard hepatoprotective agent silymarin, which justify its use in liver affection

Absolute configurations of brominated sesquiterpenes determined by vibrational circular dichroism.

Two brominated sesquiterpenes, majapolene B (1) and acetylmajapolene B (2), isolated from the red algal genus Laurencia were investigated using vibrational circular dichroism (VCD). The ab initio theoretical VCD and IR calculations of 1 and 2 were performed by density functional theory (DFT) using the B3PW91/6-31G(d,p) basis set. The experimental VCD spectra and corresponding population-weighted theoretical VCD spectra were found to be in excellent agreement in CCl(4) solution in the 1800-850 cm(-1) region, which allowed unambiguous determination of the absolute configurations of (-)-1 and (-)-2 as 7S,10S and 7S,10S, respectively.

Enhanced anaerobic biotransformation of carbon tetrachloride with precursors of vitamin B(12) biosynthesis.

Relatively low concentrations of Vitamin B(12) are known to accelerate the anaerobic biotransformation of carbon tetrachloride (CT) and chloroform (CF). However, the addition of vitamin B(12) for field-scale bioremediation is expected to be costly. The present study considered a strategy to generate vitamin B(12) by addition of biosynthetic precursors. One of the precursors, porphobilinogen (PB) involved in the formation of the corrin ring, significantly increased the CT biotransformation rates by 2.7-, 8.8- and 10.9-fold when supplemented at 160, 500 and 900 microM, respectively. A positive control with 10 microM of vitamin B(12) resulted in a 5.9-fold increase in the CT-bioconversion rate. PB additions provided high molar yields of inorganic chloride (57% of CT organochlorine), comparable to that obtained with vitamin B(12) supplemented cultures. The primary substrate, methanol, known to induce vitamin B(12) production in methanogens and acetogens, was required for PB to have a significant impact on CT conversion. The observation suggests that PB's role was due to stimulating vitamin B(12) biosynthesis. The present study therefore provides insights on how to achieve vitamin B(12) enhanced rates of CT bioremediation through the use of less complex compounds that are precursors of vitamin B(12). Although PB is a costly chemical, its large impact points to corrin ring formation as the rate-limiting step.

Interactions of alpha-tocopherol with biomembrane models: binding to dry lecithin reversed micelles.

The state of alpha-tocopherol (Vitamin E) in solutions of dry lecithin reversed micelles dispersed in an apolar medium has been investigated as a function of the Vitamin E to surfactant molar ratio (RVE) at fixed surfactant concentration by FT-IR, 1H NMR and SAXS with the aim to emphasize the role played by anisotropic intermolecular interactions and confinement effects as driving forces of its partitioning between apolar bulk solvent and polar nanodomains and of mutual Vitamin E/reversed micelle effects. It has been found that its binding strength to reversed micelles, triggered by steric and orientational constrains, is mainly regulated by specific interactions between the hydrophilic groups both of Vitamin E and surfactant. Moreover, the RVE dependence of the Vitamin E distribution constant and of the micellar size suggest that the inclusion of increasing amounts of Vitamin E in reversed micelles involves substantial changes in the structural and dynamical properties of the micellar aggregates. The occurrence of mutual effects and the partitioning of Vitamin E between hydrophilic/hydrophobic interfaces and apolar domains allow to infer some important biological implications concerning the capacity of Vitamin E to scavenge free radicals arising from hydrophilic and/or hydrophobic domains, possible variations of its local reactivity respect to that observed in bulk as well as its significant influence on the stability of biomembranes.

An infrared spectroscopic method for quantitative analysis of fatty alcohols and fatty acid esters in machinery oils.

A new infrared spectroscopic method suitable for determining total fatty alcohol and fatty acid ester concentrations in industrial oils has been developed. Oil samples were diluted with toluene (1:3 w/w), the toxicity and volatility of which are relatively low compared with more commonly used IR solvents, like carbon tetrachloride or carbon disulfide. Mixture standards were prepared from dodecanol, tetradecanol, octadecanol, methyl stearate and methyl palmitate. Some analytical and statistical tests were performed on the developed method. The recoveries and the repeatability of the method proved to be sufficient for the quantitative determination of fatty alcohol and fatty acid ester additives in industrial oils. Reproducibility testing in another laboratory also produced satisfactory results. The developed method also proved to be relatively quick and simple. This method was developed to satisfy industry's need to determine the concentrations of these oil additives, and it has already been applied successfully in machinery oil analysis.

Transformation of chlorinated methanes by zero-valent aluminum coupled with Pd/Al2O3.

The transformation of chlorinated methanes by zero-valent aluminum under various pH conditions has been examined in the presence and absence of Pd/Al2O3. In the absence of Pd/Al2O3, carbon tetrachloride was primarily transferred to chloroform (65%) and dichloromethane (15.3%) at pH 2.5 while little of the hydrodehalogenation intermediates (approximately 5%) was found at pH 10.8. This indicates that carbon tetrachloride undergoes hydrodehalogenation at low pH but not at high pH. The low production of hydrodehalogenation intermediates at high pH could be attributed to the base-catalyzed hydrolysis of carbon tetrachloride resulting in the formation of products that can not be detected by the provided analytic methods. In the presence of Pd/Al2O3, degradation rates were increased by a factor of 10-43 compared to the system without Pd/Al2O3, suggesting Pd/Al2O3, serves as a catalyst. Further, complete degradation of carbon tetrachloride by zero-valent aluminum with Pd/Al2O3 led directly to methane (86.4%) without formation and accumulation of dichloromethane at pH 9.0. The direct transformation of carbon tetrachloride to methane can be rationalized by the catalytic hydrodehalogenation occurring at the palladium surface. The study indicates aluminum coupled with Pd/Al2O3 is an environmentally-friendly technology for treatment of chlorinated organic contaminants.