N-caproic Acid Research Articles

ADDITIONAL CONSTITUENTS OF HOPS

Gas chromatograms of the isopropyl esters of the acids obtained from α and β acids by oxidation or pyrolysis indicate the presence of small amounts of some additional analogues of humulone and lupulone; countercurrent distribution of the α acid group has provided fractions which are greatly enriched in these minor analogues. The countercurrent distribution fraction conforming to prehumulone yields isocaproic and n-caproic acids on oxidation, and the β acid group likewise contains two corresponding analogues of lupulone; prehumulone and prelupulone are therefore almost certainly mixtures of isocaproyl and n-caproyl analogues of humulone and lupulone. The β acid group yields a small amount of n-propionic acid, indicating the presence of postlupulone, corresponding to the presence of posthumulone in the α acid group reported by Verzele and also confirmed here; small amounts of humulone and lupulone analogues bearing n-butyryl side chains appear to be present also. Evidence has been obtained also which supports the existence of 4-desoxycohumulone and 4-desoxyadhumulone and indicates, in addition, the presence of other additional analogues corresponding to those now found in the α and β acid groups.

Liquid scintillation counting of nickel-63

Liquid scintillation systems based on gels, ether, and toluene are investigated for counting nickel-63. A nickel complex of n-caproic acid dissolved in a solution of toluene containing 1,4-bis(2-(5-phenloxazolyl)- benzene(POPOP) and 2,5-diphenyloxazole (PPO) is found to be prefterable with respect to reproducibility, ease of preparation, and interpretation. The addition of a small quantity of ethyl alcohol produces a slight loss of efficiency but stabilizes the solution in the presence of residual water. The method for preparing the sample is described. The results show that count rate increases with decreasing temperature. (N.W.R.)

The pathway of formation of n-butyl and n-amyl alcohols by a mutant strain of Saccharomyces cerevisiae

A mutant strain of Saccharomyces cerevisiae was found which produces relatively large amounts of n-propyl and n-butyl alcohols but none of the other higher alcohols usually associated with alcoholic fermentation by yeasts. Tracer studies with this mutant are reported which are consistent with the hypothesis that n-butyl alcohol is formed by the familiar Ehrlich-Neubauer-Fromherz pathway from α-keto- n-valeric acid which in turn is synthesized from α-ketobutyric acid by a pathway analogous to the pathway by which α-ketoisocaproic acid is synthesized from α-ketoisovaleric acid in the synthesis of leucine; i.e., it is proposed that α-ketobutyric acid condenses with acetyl-CoA to form α-aceto-α-hydroxybutyric acid which, after dehydration, rehydration, oxidation, and decarboxylation, yields α-keto- n-valeric acid. If norvaline is added as a source of α-keto- n-valeric acid to the wild type, n-butyl alcohol is formed. If the same compound is added to a fermentation by the mutant, the formation of n-butyl alcohol is slightly stimulated and, in addition, a new alcohol is formed, namely, n-amyl alcohol. Tracer studies indicate that this alcohol is formed from α-ketovaleric acid by a pathway analogous to the pathway of formation of n-butyl alcohol from α-ketobutyric acid. The addition of norleucine, as a source of α-keto- n-caproic acid, to a fermentation by the mutant, stimulates the formation of n-amyl alcohol but does not cause detectable amounts of n-hexyl alcohol to be formed. The several acetotransferase activities of yeasts are discussed.

Volatile fatty acids from axenic Ascaris lumbricoides

1. 1. The investigations in this study have been concerned with the separation and identification by gas-liquid chromatography of the methyl esters of volatile fatty acids excreted from axenic Ascaris lumbricoides. 2. 2. Ten methyl ester peaks, of which three were major components and seven minor components, were detected. All but one were tentatively identified by comparison with the relative retention times of comparable standards under the same conditions. 3. 3. The three major components were positively identified by infrared spectroscopy and preparation of amide derivatives as α-methyl n-butyric, n-valeric, and isocaproic acids. The minor components were acetic, propionic, isobutyric and/or trimethylacetic, n-butyric, trans-α-niethyl crotonic (tiglic), and n-caproic acids, plus an unknown branched C 7 or C 8 acid. 4. 4. The total mole percentages of the methyl esters of different carbon numbers were: C 2, 0.27%; C 3, 0.77%; C 4, 1.14%; C 5, 38.0%; C 6, 56.2%; and C 7–8 3.56%. The most abundant individual acids found were isocaproic, 55.1 mole %, and α-methyl- n-butryic, 31.8 mole %.

Some Volatile Acids and Esters of Cigarette Smoke

The isolation and identification of volatile organic acids and esters contained in the cigarette smoke, which was produced in constant volume continuous smoking by an artificial smoking device, have been studied. Acetic, propionic, n-butyric, isovaleric and β-methyl valeric acid as their p-bromophenacyl esters, and benzoic acid as the crystal of itself, were isolated and identified by mixed examinations, paper chromatographic techniques, infrared spectra and elementary analyses; and the presence of n-caproic acid was estimated. By paper chromatography, ethyl esters of acetic and propionic acid were qualitatively identified, and ethyl esters of n-butyric, isovaleric, and n-caproic and/or β-methylvaleric acid were estimated. Among these compounds, β-methylvaleric acid and all of the esters have not yet been reported in the literature concerning tobacco smoke.

醤油香気成分に関する研究

The flavorous substances in the steam distillate of Soy-cake (bp 185_??_325°) were investigated by means of hydrolysis and oxidation. Acetic acid, benzoic acid, isovaleric acid, n-caproic acid, vanillic acid, vanillic acid ethylester, 1-hydroxy-2-methoxy-4-ethylbenzene, acetovanillon (uncertain), isoacetovanillon (uncertain) and two more unknown phenolic substances were obtained as the decomposed products of hydrolysis. Of those substances, acetic acid, benzoic acid, vanillic acid, vanillic acid ethyl ester, 1-hydroxy-2-methoxy-4-ethylbenzene were obtained by considerablly light hydrolysis, and these were proved in the oxidized products of the neutral fraction by means of KMnO4 at room temperature and in this case isovaleric acid or n-caproic acid were not obtained. So it comes to this conclusion that the flavorous substances in the sample are the esters and phenol esters of these acidic or phenolic substances and as the easily decomposable phenol esters the following four substances are considerable:_??_

醤油香氣成分に関する研究

The flavorous substances in the steam distillate of Soy-cake (bp 185_??_325°) were investigated by means of hydrolysis and oxidation. Acetic acid, benzoic acid, isovaleric acid, n-caproic acid, vanillic acid, vanillic acid ethylester, 1-hydroxy-2-methoxy-4-ethylbenzene, acetovanillon (uncertain), isoacetovanillon (uncertain) and two more unknown phenolic substances were obtained as the decomposed products of hydrolysis. Of those substances, acetic acid, benzoic acid, vanillic acid, vanillic acid ethyl ester, 1-hydroxy-2-methoxy-4-ethylbenzene were obtained by considerablly light hydrolysis, and these were proved in the oxidized products of the neutral fraction by means of KMnO4 at room temperature and in this case isovaleric acid or n-caproic acid were not obtained. So it comes to this conclusion that the flavorous substances in the sample are the esters and phenol esters of these acidic or phenolic substances and as the easily decomposable phenol esters the following four substances are considerable:_??_

The biochemistry of the ustilaginales. III. The degradation products and proof of the chemical heterogeneity of ustilagic acid.

The D-glucolipid designated as ustilagic acid was shown to be a mixture of partially acylated derivatives of a di-D-glucosyl-dihydroxyhexadecanoic acid. The dihydroxyhexadecanoic acid was named "ustilic acid" and its di-D-glucosyl derivative was termed "glucoustilic acid". Alkaline hydrolysis of ustilagic acid yielded glucoustilic acid, acetic acid, dextro-β-hydroxy-n-caproic acid, dextro-β-hydroxy-n-caprylic acid and a small amount of n-caproic acid. The β-hydroxy-acids were characterized as dextro-β-hydroxy-n-caprohydrazide, m.p. 131–132°C., [α]D + 15.9° (water), and dextro-β-hydroxy-n-caprylhydrazide, m.p. 127–128°C., [α]D + 12° (water). Ustilic acid, m.p. 114–115°C., [α]D − 6.3° (methanol), yielded a methyl ester, m.p. 80−81.8°C, [α]D − 0.2 (chloroform). The methyl ustilate formed a di-phenylurethane derivative, m.p. 76–77°C. The infrared spectra of crystalline and amorphous samples of ustilagic acid are given. The specific rotation of glucoustilic acid, [α]D − 11° (methanol) was that expected of β-D-glucosides and the infrared spectrum of this substance showed a marked resemblance to that of methyl-β-D-glucopyranoside.

Effect of Fatty Acids on Acetylcholine Synthesis.

Summary1. The effect of fatty acids and related substances on the synthesis of acetylcholine was investigated. 2. The synthesis was not modified in the presence of glycerol, acetic-, palmitic-, and stearic acid, acetone, and acetoacetic acid. 3. The synthesis increased in the presence of butyric-, propionic-, valeric-, and n-caproic acid. 4. The synthesis decreased in the presence of formic-, n-caprylic-, capric-, lauric-, oleic-, linoleic acid, glyceraldehyde, acetylaldehyde, and β-hydroxy butyric acid.