Aldehydes Of Chain Lengths Research Articles

Performance of glyoxal-resorcinol-based aqua gel and its activated carbon for the production of environmental-friendly bagasse composites

This work deals with the evaluation of the ability of resorcinol-glyoxal based aqua-gel (AG) and its activated carbon (ACAG), as new formaldehyde scavenger, to provide low toxic urea formaldehyde(UF)-bagasse composite. Preliminary studies were carried out to evaluate the adsorption capacity of ACAG, via determining its texture parameters and adsorption of formaldehyde. The performance of the investigated scavenger-UF adhesive systems was evaluated in comparison with previously synthesized activated carbons based on gels from different chain length aldehydes. Further, the quality of final bagasse composites was evaluated by mechanical, water resistance and free-HCHO tests. The results show that the investigated ACAG has a promising effect towards HCHO adsorption (149 mg/g) compared to that obtained from previously published gel-activated carbons (max. 109 mg/g). Both AG and ACAG provide improvement in properties of the resulted bagasse composites. The greatest improvement in static bending was noticed by applying AG-UF adhesive system (MOR: 32.2 MPa and MOE: 2026 MPa); these values exceed the ANSI standard requirements for grade H-3, while the internal bond strength (0.51 MPa) exceeds the M-2 grade. Applying the ACAG-UF adhesive system provides greater reduction in free-HCHO of the produced boards (~ 47%) than the AG-UF adhesive system (27.3%).

Comparative study on the performance of carbon nanotubes prepared from agro- and xerogels as carbon supports

The role of natural and synthetic polymers on performance of the prepared carbon nanotubes (CNTs) is compared. In this respect rice straw (RS) and organic xerogels (OXG) are used as carbon supports; while camphor and tri-metal oxides (Fe-Ni-Cu) are performed as carbon precursor and catalyst to produce CNTs. Two chain length aldehydes (formaldehyde and butyraldehyde) are used in preparing OXG from their reaction with resorcinol. The evaluation of CNTs is carried out by SEM, TEM and FT-IR, as well as adsorption performance (e.g., nitrogen gas, iodine value and methylene blue adsorption capacity). The results show that, the xerogels prepared from two aliphatic aldehydes are more efficient as carbon supporting materials of CNTs than RS, where they provide yields of CNTs over the carbonized xerogels varying from 85 to 320% (based on starting weight of support carbon+catalyst); while the yield becomes 20% in case of rice straw (RS) carbon support. Moreover, the produced CNTs from xerogels possess relatively higher surface area ( >100m2/g) than that obtained from rice straw (8m2/g). The formaldehyde-resorcinol xerogel and tri-metallic catalysts (Fe-Ni-Cu) are recommended as efficient support and catalyst toward synthesis of CNT possessing high yield, large surface area, reasonable morphology, as well as high adsorption capacity both toward iodine (117mg/g) and methylene blue (88mg/g).

An Apoptosis-Associated Mammary Protein Deficiency Leads to Enhanced Production of IgM Antibodies against Multiple Damage-Associated Molecules

Milk fat globule epidermal growth factor 8 (MFG-E8) is a protein that binds to apoptotic cells by recognizing phosphatidylserine and enhances the engulfment of apoptotic cells by macrophages. Many apoptotic cells are left unengulfed in the germinal centers of the spleen in the MFG-E8-deficient (MFG-E8−/−) mice, and these mice develop an autoimmune disease resembling human systemic lupus erythematosus. We found that the MFG-E8 deficiency was accompanied by the increased production of immunoglobulins. Further Western blot and ELISA analyses validated the increase in the IgM levels in the MFG-E8−/− mice. It was also revealed that the sera from the MFG-E8−/− mice cross-reacted with oxidation-specific epitopes generated upon incubation of serum albumin with the peroxidized lipids. Among the modified proteins with several unsaturated aldehydes of chain lengths varying from three to nine carbons, the MFG-E8−/− mice sera exclusively cross-reacted with the protein-bound 4-oxo-2-nonenal (ONE), a highly reactive aldehyde originating from the peroxidation of ω6 polyunsaturated fatty acids. In addition, the IgM monoclonal antibodies (mAbs) that selectively cross-reacted with the ONE-modified proteins were generated from the MFG-E8−/− mice. A subset of the ONE-specific IgM mAbs significantly recognized the late apoptotic and necrotic cells and enhanced the phagocytosis by macrophages. These data demonstrate that the impairment of the phagocytic clearance of apoptotic cells through MFG-E8 can lead to the generation of natural antibodies, which may play a critical role in removing multiple damage-associated molecules, including oxidation-specific epitopes and late apoptotic/necrotic cells.

A Sex Attractant for the Siberian Moth Dendrolimus superans sibiricus (Lepidoptera: Lasiocampidae)

Field trapping experiments were conducted against the Siberian moth, Dendrolimus superans sibiricus Butler, in Siberia, Russia, using traps baited with a virgin female moth or 100 μg synthetic mixtures of C12 straight chain-length aldehydes, alcohols, and acetates alone or in combinations on rubber septa. Traps baited with a 1:1 blend of aldehydes and alcohols captured many males. The capture rate was similar to the rate of capture seen in traps baited with virgin females. The mixture of aldehydes and alcohols (64% Z,E-5,7-dodecadienal, 10% Z-5-dodecenal, 18% E-7-dodecenal, 8% E-6-dodecenal) and (64% Z,E-5,7-dodecadien-1-ol, 10% Z-5-dodecen-1-ol, 18% E-7-dodecen-1-ol, 8% E-6-dodecen-1-ol) can be used as a sex attractant to monitor endemic Siberian moth populations in Asia, and for surveillance and detection of the moth in countries where the insect might be accidentally introduced.

Microtox EC 50 values for drinking water by-products produced by ozonolysis

The aim was to determine the Microtox EC 50 values of some aliphatic aldehydes and carboxylic acids of normal chain length with 1–14 carbon atoms since these compounds have been detected as ozonolysis by-products in drinking water. The aqueous EC 50 values decreased with increasing chain length except for formaldehyde and for the C1–C7 acids. At chain lengths above C7, where methanolic saline solutions were utilized to promote solubility, the aldehydes were more toxic than their corresponding carboxylic acids. Below a chain length of C7, the reverse situation applied. More precise and sensitive EC 50 values were reserved at 15 and 25 min than at 5 min. Both C14 aldehyde and acid as well as palmitoleic acid showed luminescence in methanolic saline solutions. The C14 compounds are known natural substrates for bacterial luciferase, and the present findings confirm this for Photobacterium phosphoreum. The concentrations of the aldehyde and/or carboxylic acid ozonolysis by-products reported in drinking water could not be detected by the Microtox test. This is the first report of Microtox EC 50 values for these carboxylic acids and for aldehydes of chain lengths > C4.

Purification and characterization of human liver “high Km” aldehyde dehydrogenase and its identification as glutamic gamma-semialdehyde dehydrogenase.

The enzyme previously considered as an isozyme (E4, ALDH IV) of human liver aldehyde dehydrogenase (NAD+) (EC 1.2.1.3) has been purified to homogeneity by the use of ion exchange chromatography on CM-Sephadex and affinity chromatography on Blue Sepharose CL-6B and 5'-AMP Sepharose 4B and identified as glutamic gamma-semialdehyde dehydrogenase, or more precisely 1-pyrroline-5-carboxylate dehydrogenase (EC 1.5.1.12). Glutamic gamma-semialdehyde dehydrogenase was never previously purified to homogeneity from any mammalian species. The homogeneous enzyme is seen on isoelectric focusing gels as two fine bands separated by 0.12 pH units: pI = 6.89 and 6.77. In addition, the enzyme also appears as two bands in gradient gels; however, in polyacrylamide gels containing sodium dodecyl sulfate the enzyme migrates as one band, indicating that its subunits are of identical size. Because the enzyme molecule is considerably smaller (Mr approximately 142,000-170,000) than that of aldehyde dehydrogenases (EC 1.2.1.3) (Greenfield, N. J., and Pietruszko, R. (1977) Biochim. Biophys. Acta 483, 35-45; Mr approximately 220,000) and its subunit weight is different (70,600 versus approximately 54,000 for E1 and E2 isozymes), the enzyme is not an isozyme of aldehyde dehydrogenase previously described. The Michaelis constants for glutamic gamma-semialdehyde dehydrogenase with acetaldehyde and propionaldehyde are in the millimolar range. Its substrate specificity within the straight chain aliphatic aldehyde series is essentially confined to that of acetaldehyde and propionaldehyde with butyraldehyde and longer chain length aldehydes being considerably less active. Other substrates include succinic, glutaric, and adipic semialdehydes in addition to glutamic gamma-semialdehyde. The reaction velocity with glutamic gamma-semialdehyde is at least an order of magnitude larger than with carboxylic acid semialdehydes. Aspartic beta-semialdehyde is not a substrate. The reaction catalyzed appears to be irreversible. Although NADP can be used, NAD is the preferred coenzyme. The enzyme also exhibits an unusual property of being subject to substrate inhibition by NAD.

Reversible steps in the reaction of aldehydes with bacterial luciferase intermediates

Aliphatic aldehydes of different chain lengths were found to differ in their reaction at 22 °C with the B. harveyi luciferase peroxyflavin intermediate. Although similar quantum yields were obtained in the luciferase reaction with the different chain-length aldehydes, the catalytic turnover rates differed. The kinetics of a reaction utilizing two aldehydes of different chain lengths can thus indicate the degree to which the aldehyde reaction is reversible. By such criteria the reactions of octanal and decanal were found to be readily reversible, while that of dodecanal was not. This conclusion was supported both by the effects of long-chain alcohols, which are competitive inhibitors, and by the secondary addition of hydroxylamine, an aldehyde trapping agent. The results are consistent with a model in which there are many intermediates along the reaction path. Since the reactions are monitored by decay of luminescence intensity, it is difficult to determine the position of the rate-determining step. For octanal and decanal the rate-limiting step could be at an early reversible stage of the reaction, but later for dodecanal, subsequent to a less reversible step, but still prior to the final irreversible step which populates the excited state.

Partial purification and characterization of a reduced nicotinamide adenine dinucleotide phosphate-linked aldehyde reductase from heart

The presence of a nonspecific NADPH-linked aldehyde reductase (alcohol-NADP oxidoreductase, EC 1.1.1.2) from heart was observed in the soluble portion of tissue homogcnates. The reductase activity was present in at least two forms. The enzyme which accounted for the major portion of activity was purified some 800-fold over the crude homogenate. The enzyme was capable of reducing a number of aromatic and medium chain length aldehydes in the presence of NADPH. No ketones were utilized as substrates and the enzyme was inactive with NADH. The enzyme was shown to have a pH optimum at 6.4 for the reduction of aldehydes. Oxidation of alcohols occurred optimally at pH 9.6 with NADP as cofactor. although the reaction proceeded at less than 10 per cent of the rate observed in the forward direction. A molecular weight of 29,000 was estimated by gel filtration on Sephadex G-75. Biogenic aldehydes prepared from β-hydroxylated phenylethylamines were actively reduced. The K m values for 3,4-dihydroxyphenylglycolaldehyde, 4-hydroxy-3-methoxyphenylglycolaldehyde and 4-hydroxyphenylglycolaldehyde were: 0.53, 0.50 and 0.03 mM respectively. The aldehydes of non-β-hydroxylated phenylethylamines were not efficiently utilized as substrates. The K m for NADPH was determined to be 0.013 mM in the presence of ρ-nitrobenzaldehyde. Inhibitor studies show the enzyme to be different from “classical” alcohol dehydrogenase. Various anticonvulsants and diuretics were inhibitory at concentrations of 0.01 mM. The enzyme is postulated to be responsible for the reduction of biogenic aldehydes in heart in vivo.