Straight-chain Aldehydes Research Articles

Novel components from secretory hairs of azalea lace bugStephanitis pyrioides (Hemiptera: Tingidae)

The azalea lace bug secretes a clear fluid from secretory setae on the antennae and globulated spines on the dorsal and lateral aspects of the abdomen. The secretion contains 2-alkyl-5-hydroxychromones, the corresponding chromanones and diketones, and straight-chain aldehydes and ketones.

FLAVOR CHANGES IN WHOLE MILK POWDER DURING STORAGE

ABSTRACTThe kinetics of chemical changes are usually described as being zero order, first order, and so forth. A common and generally accepted description of fat oxidation in foods is that the reaction has an initial linear phase which gradually changes to an exponential phase. In the present investigation a generalized mathematical model was developed for the overall characterization of the formation of volatile fat oxidation products. The model is continuous, and describes the rate of the oxidation during both the linear phase (zero order) and the exponential phase (first order). The break point at which the oxidation changes from zero to first order was determined by a stepwise procedure. The zero order and first order models are special cases of the generalized model.Zero order, first order, and generalized mixed models were used to describe the formation of straight chain aldehydes, methyl ketones, Strecker aldehydes, alkyl furans, sulfur compounds, and hydrocarbons in spray dried, whole milk powder during storage. The milk powder was prepared without and with additions of either a mixture of the antioxidants BHA and BHT or an antioxidative mixture of Maillard reaction products. The milk powder was stored in either air or nitrogen for 84 weeks.The formation of volatile compounds was analyzed using gas chromatographic headspace methods. A static equilibrium sampling method was used for the most volatile compounds and a dynamic sampling method for the less volatile compounds.

Microbial oxidation of methanol: Purification and properties of formaldehyde dehydrogenase from a Pichia sp. NRRL-Y-11328

An NAD +-linked, reduced glutathione-dependent formaldehyde dehydrogenase was purified to homogeneity from soluble extracts of methanol-grown yeast, Pichia sp. Formaldehyde and methylglyoxal are oxidized in the presence of NAD + as an electron acceptor. NADP + could not replace NAD +. Other straight chain aldehydes (C 2–C 6 tested), branched-chain aldehydes (e.g., isobutyaldehyde), aromatic aldehydes (e.g., salicylal-dehyde, benzaldehyde), glutyraldehyde, glyceraldehyde, glycoaldehyde, and glyoxal-dehyde tested were not oxidized by the purified formaldehyde dehydrogenase. The product of formaldehyde oxidation by purified enzyme was demonstrated to be S-for-mylglutathione by measuring the absorption at 240 nm due to the formation of thioester of formaldehyde and reduced glutathione. The K m values for NAD +, formaldehyde, and reduced glutathione were 0.12, 0.31, and 0.16 m m, respectively, for the forward reaction at pH 8.0. The purified formaldehyde dehydrogenase also catalyzed the reduction of S-formylglutathione in the presence of NADH. Formate was not reduced by the purified enzyme. The K m values for S-formylglutathione and NADH were 0.60 and 0.25 m m, respectively, for the reverse reaction at pH 6.0. Formaldehyde dehydrogenase has a molecular weight of 84,000 as determined by gel filtration and subunit molecular weight of 41,000 as determined by sodium dodecyl sulfate-gel electrophoresis. S-Formylglutathione, a product of formaldehyde oxidation, was oxidized by the partially purified formate dehydrogenase from Pichia sp. Formate dehydrogenase has a higher affinity toward S-formylglutathione ( K m value 1.8 m m) than toward formate ( K m value 25 m m). Antiserum prepared against the purified formaldehyde dehydrogenase from Pichia sp. NRRL-Y-11328 forms strong precipitin bands with isofunctional enzymes from methanol-grown Pichia pastoris NRRL-Y-7556 and Torulopsis candida Y-11419 and weak precipitin bands with Hansenula polymorpha NRRL-Y-2214. No cross-reaction was observed with isofunctional enzyme derived from methanol-grown Kloeckera sp.

Soluble aldehyde dehydrogenase and metabolism of aldehydes by soybean bacteroids.

A soluble aldehyde dehydrogenase (EC 1.2.1.3) was partially purified from Rhizobium japonicum bacteroids and from free-living R. japonicum 61A76. The enzyme was activated by NAD+, NADH, and dithiothreitol, and it reduced NAD(P)+. Acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, and succinic semialdehyde were substrates. The Km for straight-chain aldehydes decreased with increasing carbon chain length. The aldehyde dehydrogenase was inhibited by 6-cyanopurine, but not by metronidazole. These compounds inhibited acetylene reduction, but not respiration, by isolated bacteroids.

Relaxation processes of some long chain aliphatic aldehydes

Abstract The dielectric absorption of seven aliphatic straight chain aldehydes has been examined in a polystyrene matrix between 80 and 325 K and in the 50 to 10 5 Hz region. For each solute two sets of absorption curves were found, one around 100 K and the other in approximately the 200 – 300 K region. The relaxation data for the 100 K region has been identified with segmental rotation and probably, with rotation about the C  CHO bond as well. The higher temperature process, which involves relaxation of appreciably larger units, may well be an overlap of molecular and larger segmental rotation. n-Nonanal was examined in a polystyrene and a polypropylene matrix and in both cases gave low and high temperaure absorption curves. The parameters for the former were almost independent of the medium whereas those for the latter process exhibited considerable variation.

Sex pheromone of the Asian corn borer moth

By 1975, insect sex pheromones had been identified from 60 species (1) of moths (Lepidoptera), and nearly all of the 40 compounds involved had been found to be mono- or di-unsaturated C 10 to C 18 straight-chain aldehydes, alcohols, or acetates, and the sites of olefinic unsaturation were, with one exception (2), at odd-numbered positions in the carbon chain. Since that time, many more lepidopteran pheromone components have been identified, and mono-unsaturated compounds with unsaturation at even-numbered positions in the carbon chain remain extremely rare (3–6). However, in females of Ostrinia furnacalis (Guenee), called the Asian corn borer, we have discovered another mono-olefinic lepidopteran sex pheromone that has the site of unsaturation at ab even carbon position. Females of this corn-pest species produce a ca . 1:1 geometric mixture of ( Z )- and ( E )- 12-tetradecen-1-o1 acetate to attract and sexually stimulate males. On the other hand, the nearest taxonomic relative (7) of the Asian corn borer, the European corn borer, Ostrinia nubilalis (Hübner), uses a mixture of ( Z )- and ( E )-11-tetradecen-1-o1 acetate as its sex pheromone (8). Biochemical explanation of the paucity of monounsaturated moth sex pheromones with olefinic sites at even numbered carbon positions remains to be elucidated.

Purification and properties of a heme-containing aldehyde dehydrogenase from Methylosinus trichosporium

Crude extracts of various methylotrophic bacteria contained a soluble phenazine methosulfate-linked aldehyde dehydrogenase. Procedures for the purification of an aldehyde dehydrogenase from extracts of the obligate methane-utilizing bacterium Methylosinus trichosporium are described. The purified enzyme is homogeneous as judged from polyacrylamide gel electrophoresis. The purified enzyme catalyzes the oxidation of straight-chain aldehydes (C 1-C 10 tested), aromatic aldehydes (benzaldehyde, salicylaldehyde), glyoxylate, and glyceraldehyde. Biological electron acceptors such as NAD +, NADP +, FAD, FMN, pyridoxal phosphate, and cytochrome c do not act as electron carriers. Sulfhydryl agents [ p-chloromercuribenzoate, N-ethylmaleimide, 5,5-dithiobis (2-nitrobenzoic acid), and thioacetamide], cuprous chloride, cupric sulfate, and thiourea inhibited enzyme activity. The molecular weight of the enzyme as estimated by gel filtration is approximately 43,000 and as estimated by sedimentation equilibrium analysis, 50,000. The sedimentation constant ( S 20, w) is 2.8. The subunit size determined by sodium dodecyl sulfate-gel electrophoresis is approximately 22,000. The purified enzyme is light brown and has an absorption peak at 410 nm. Reduction of the enzyme with sodium dithionite resulted in the appearance of peaks at 523 and 552 nm and a shift in the Soret peak from 410 to 412 nm was observed. These results suggest that the enzyme is a hemoprotein. There was no evidence that flavins were present as a prosthetic group. The amino acid composition of the enzyme is also presented. Antisera prepared against the purified enzyme are nonspecific; they cross-reacted with isofunctional enzyme from other methylotrophic bacteria on Ouchterlony double-diffusion plates.

Microbial oxidation of methane and methanol: purification and properties of a heme-containing aldehyde dehydrogenase from Methylomonas methylovora.

Procedures for the purification of an aldehyde dehydrogenase from extracts of the obligate methylotroph, Methylomonas methylovora are described. The purified enzyme is homogeneous as judged from polyacrylamide gel electrophoresis. In the presence of an artificial electron acceptor (phenazine methosulfate), the purified enzyme catalyzes the oxidation of straight chain aldehydes (C1--C10 tested), aromatic aldehydes (benzaldehyde, salicylaldehyde), glyoxylate, and glyceraldehyde. Biological electron acceptors such as NAD+, NADP+, FAD, FMN, pyridoxal phosphate, and cytochrome c cannot act as electron carriers. The activity of the enzyme is inhibited by sulfhydryl agents [p-chloromercuribenzoate, N-ethylmaleimide and 5,5-dithiobis (2-nitrobenzoic acid)], cuprous chloride, and ferrour nitrate. The molecular weight of the enzyme as estimated by gel filtration is approximately 45000 and the subunit size determined by sodium dodecyl sulfate-gel electrophoresis is approximately 23000. The purified enzyme is light brown and has an absorption peak at 410 nm. Reduction of enzyme with sodium dithionite or aldehyde substrate resulted in the appearance of peaks at 523 nm and 552nm. These results suggest that the enzyme is a hemoprotein. There was no evidence that flavins were present as prosthetic group. The amino acid composition of the enzyme is also presented.

Biosynthesis of the waxmoth sex attractants

The waxmoth, Galleria mellonella, was injected with radiolabelled acetate, propionate, and oleic acid to study the biosynthesis of n- nonanal and n- undecanal , its sex pheromones. The sex attractants were collected from the moths by condensation in a cold trap immersed in an acetone-dry ice bath, and then isolated by gas-liquid chromatography. The n- nonanal was found to contain 1.23% of the radiolabelled carbon from the 10- 14C-oleic acid, 0.13% from the 1- 14C-oleic acid, 0.20% from the 3- 14C-sodium propionate, and 0.30% from the 1,2- 14C-acetic acid. n- Undecanal contained 0.05% of the radiolabelled carbon from the 3- 14C-sodium propionate, 0.07% from the 1,2- 14C-acetic acid, and 0.09% from both the oleic acids injected. Both acetate and propionate are incorporated into the pheromone components but do not appear to be of primary importance. The incorporation of oleic acid suggests that α- and /or β-oxidation is involved in the biosynthesis of the pheromone fractions. The data show that odd numbered straight-chain aldehydes are synthesized from many different precursors much the same as other lipids.

The Origin ofn-Pentanol,n-Hexanol, andn-Heptanol in the Fusel Oil of Sulfite Waste-Liquor

The presence of n-hexanol and n-heptanol in sulfite fusel oils has been difficult to explain as the corresponding keto acid precursors of the fusel alcohols have not been identified in fermentation solutions. On analysis of the sulfite waste liquor utilized as raw material in sulfite spirit production, it has been found that the higher straight-chain aldehydes, pentanal, hexanal, heptanal, and octanal, appear in the sulfite waste liquor in concentrations that are sufficiently large to explain the formation of the corresponding alcohols.

Homogeneous hydroformylation of alkenes with hydridocarbonyltris-(triphenylphosphine)rhodium(I) as catalyst.

The compound hydridocarbonyltris(triphenylphosphine)rhodium(I), RhH(CO)(PPh3)3, is an efficient catalyst for hydroformylation of alkenes at 25 °C at 1 atm. From alk-1-enes high ratios of straight chain to branched chain aldehydes can be produced. The dependence of rates and products on catalyst and substrate concentration, partial pressures of hydrogen and carbon monoxide, temperature, and added excess of triphenylphosphine are described and the suggested mechanisms discussed in relation to these results. Studies at higher temperature and pressure show that rapid and effective conversion of both a liquid alkene and also propene to give high yields of straight chain aldehyde can be achieved particularly when molten triphenylphosphine provides the solvent phase.

Studies of the N-Oxides of N,N-Dialkylamino Acids. II. The Syntheses of N,N-Dialkylglycine and Corresponding N-Oxides

Abstract The reductive condensations of glycine with various aliphatic straight-chain aldehydes, such as acetaldehyde, propionaldehyde, and n-butyraldehyde, give the corresponding N,N-dialkyl derivatives. The N-monoalkyl derivative has not been obtained in any case. In another type of reactions, those with aliphatic branched-chain aldehydes, such as isobutyraldehyde and isovaleraldehyde, considerable N-monoalkylation takes place besides the dialkylation. The oxidations of N,N-dialkylglycine to the corresponding N-oxides have been successfully performed using an aqueous mixture of hydrogen peroxide and acetic acid except in the case of N,N-diisobutylglycine. Similar reductive condensations of sarcosine with various aliphatic aldehydes, such as acetaldehyde, propionaldehyde, n- and iso-butyraldehyde, and isovaleraldehyde, gave the corresponding N-alkylsarcosines. N-Isobutyl and N-isoamyl sarcosine were also obtained by the methylation of the corresponding N-monoalkylglycine. The N-oxides of N-alkylsarcosine were synthesized by a procedure similar to that described above.

THE RING STRUCTURE OF MANNOSE

For a long time the structure of the sugars has been the subject of considerable controversy. Originally the sugars were considered to be straight chain aldehydes, but they are now believed to have a cyclic or ring structure. The size of the ring may be determined experimentally by methylating the free hydroxyls and determining where the groups are located by degradation. Another method for determining ring structure has been devised by C. S. Hudson. This method depends upon the comparison of optical rotations. Those substances whose rotations conform to certain rules which he has developed are considered to have the same ring structure, while those which do not agree are considered to have different ring structures. Although there are other instances where the results from the two methods do not agree, the discussion today will be restricted to the ring structure of mannose. The sugar mannose differs from glucose in that the hydroxyl on the second carbon atom lies to the left rather than to the right as in glucose. The difference in the molecular rotations of like forms of glucose and mannose is presumably twice the rotation of the second carbon atom, which is