Non-acid Components Research Articles

Efficient Medium-Scale Chromatographic Group Separation of Anacardic Acids from Solvent-Extracted Cashew Nut (Anacardium occidentale) Shell Liquid

Biologically active anacardic acids as a group have been separated from the toxic phenolic constituents (cardols and cardanols) of the solvent-extracted cashew nut shell liquid (CNSL) by a novel two-stage chromatographic method. Advantage was taken of the difference in acidity of the two groups of compounds, namely, the carboxylic acids and the phenolics, and the ability of silica gel to selectively retain amines and amine salts. CNSL (1 part) was loaded onto a silica gel bed (5 parts), prepared in a solvent system comprising ethyl acetate-hexane (25 :75) and an organic base (triethylamine, 0.5%). Continued irrigation of the bed with the same eluent resulted in the elution of all the non-acid components. The anacardic acids were subsequently eluted by changing the basic eluent to acidic by replacing the triethylamine with acetic acid (1%). This procedure was shown to be of general applicability for group separation of carboxylic acids.

Defective transcriptional activation by diverse VP16 mutants associated with a common inability to form open promoter complexes.

Three different types of VP16 mutants were assayed in vitro. These included deletion of the C-terminal activation subdomain and alterations in either the acidic or non-acidic components of the minimal activation domain. The mutant GAL4-VP16 proteins were found to be transcriptionally defective using a HeLa cell nuclear extract. In all three cases the loss of transcription activity was accompanied by a commensurate loss in ability to form open transcription complexes. The comparison implies that the diverse components of GAL4-VP16 activate transcription by the common facilitation of steps required for open complex formation. The results further imply that open complex formation may be a common target for mammalian transcriptional activation, as known previously to be the case in bacterial systems.

Modulatory action of adenosine on gastric function and ethanol-induced mucosal damage in rats

This study examines the gastric effects of adenosine and its antagonist, theophylline, on secretory function, mucosal blood flow, and on ethanol-induced glandular mucosal damage in rats that were fasted for 24 hr before experimentation. The animals were anesthetized with sodium pentobarbitone (50 mg/kg intraperitoneal) and their tracheae cannulated. An ex vivo stomach chamber then was prepared. The luminal bathing solution was collected every 15 min and the concentrations of H+ and Na+ were determined by a pH autotitrator and an ionmeter, respectively. The glandular mucosal blood flow was measured by a laser Doppler flowmeter and the severity of lesions was determined by measuring the hemorrhagic areas. Adenosine administration (2.5 or 7.5 mg/kg, subcutaneous) markedly lowered the H+ and Na+ output but increased the secretory volume and mucosal blood flow in a dose-dependent manner. The same doses of the nucleoside also prevented ethanol-induced mucosal damage. These effects were prevented by pretreatment with theophylline (30 or 60 mg/kg, subcutaneous). Ethanol given alone significantly depressed the H+ and Na+ secretion. Both effects were not modified by adenosine treatment. However, the depressive action of ethanol on mucosal blood flow was prevented by adenosine. These findings indicate that adenosine modulates the physiological function of the stomach. It also directly activates the defensive mechanism of the stomach, which is partially mediated by the improvement of the gastric mucosal blood flow and an increase in the nonacid component of gastric secretion.

Separation of male goat pheromones responsible for stimulating ovulatory activity in ewes

Abstract Ether washings of hair clipped from the sebacious gland areas of sexually active mature male goats were fractionated into acid and non-acid components. Testing for pheromonal activity using anovular ewes showed that both acid and non-acid fractions were active but that the individual fatty acids, 4-ethyl octanoic acid and 4-methyl octanoic acid which possess intense goaty odour, did not stimulate the ewes to ovulate. The free fatty acid fraction was analysed by gas chromatography and combined gas chromatography - mass spectrometry and found to contain predominantly 4-ethyl branched fatty acids. Minor components tentatively identified included 2-ethyl, 4-butyl, or 6-ethyl branched structures.

Glycolipids of human large intestine: difference in glycolipid expression related to anatomical localization, epithelial/non-epithelial tissue and the ABO, Le and Se phenotypes of the donors

Human large intestine specimens were obtained during elective surgery from donors of known blood group ABO, Lewis and secretor phenotypes. The intestinal epithelial cells were isolated from the non-epithelial tissue in one case and in another case mucosa tissue was obtained by scraping. Total non-acid glycolipid and ganglioside fractions were isolated from the tissue specimens, analyzed by thin-layer chromatography and detected by chemical reagents and autoradiography after staining the plate with various blood group monoclonal antibodies and bacterial toxins. The amount of non-acid glycolipids present in the large intestine epithelial cells was 3.9 μg/mg of cell protein and in the non-epithelial tissue 0.39 mg/g dry tissue weight. The epithelial cells contained monoglycosylceramides and blood group Le a pentaglycosylceramides as major compounds together with small amounts of diglycosylceramides. In addition, trace amounts of tri- and tetra-glycosylceramides together with more complex glycolipids were present. The non-epithelial tissue contained mopno-, di-, tri- and tetra-glycosylceramides as major non-acid components. Blood group ABH glycolipids were present in trace amounts in the non-epithelial part of the large intestine. Le a pentaglycosylceramide was the major blood group glycolipid present in all Le-positive individuals independent of the secretor status. Le b glycolipids were present in trace amounts in secretor individuals but completely lacking in non-secretors. Trace amounts of X antigens were found in all individuals, while Y antigens were only present in secretor individuals. The Le a, Le b, X and Y glycolipids were located in the epithelial cells. The gangliosides were present mainly in the non-epithelial tissue (65–350 nmol of sialic acid/g dry weight) and only trace amounts (less than 0.014 nmol/mg of cell protein) were found in the epithelial cells. The major gangliosides of the non-epithelial tissue were identified as GM 3, GM 1, GD 3, GD 1a, GD 1b, GT 1b and GQ 1b. In addition, several minor gangliosides were also present. Binding of cholera toxin to the thin-layer plate revealed trace amounts of the GM 1 ganglioside in the epithelial cell ganglioside fraction.

The relation between the rate of production of gastric juice and its electrolyte concentrations.

1. Repeated 15-min collections of gastric juice were made during the plateau of response to an intravenous infusion of histamine diphosphate 0·01 mg h−1 kg−1 and the samples measured and their electrolyte concentrations estimated. A linear relationship was found between chloride output and the volume-rate of overall secretion and between hydrogen ion output and the same rate of secretion, while a multivariate linear relationship was also found between all three variables. 2. A mathematical analysis of these results suggests that if gastric secretion consists of an acid and a non-acid component, each of fixed composition, then the acid component has the composition H = 143 mEq/l, K = 16 mEq/l, Cl = 169 mEq/l, and the non-acid component is secreted at the same rate in different subjects under these circumstances. 3. The data enable gross sampling and analytical errors to be detected; in particular, the volume-rate of secretion can be predicted from hydrogen ion concentration, better from chloride ion concentration, and best from the concentrations of both ions. 4. For single samples such predictions appear to be superior to the direct measurement of volume.

Bloat in cattle

Abstract Apparatus for foam separation, and its application to the isolation of surface active components of rumen liquor, are described in detail. Preliminary results demonstrate that foam fractions of rumen liquor drawn prior to bloating, and non-bloating feeds of red clover, show differences in concentrations of non-acid lipid, fatty acid, and carbohydrate components that are not reflected in the rumen liquor samples themselves. Foam separation has been used to isolate saponins from rumen liquor Yellow bubbles containing more than 30% lipid were found present in the leading fraction of foam separated from rumen liquor drawn prior to feeding. There were more present when bloat resulted from the following feed than when no bloat occurred. Yellow bubbles were also observed in foam obtained from bloated cattle.

EFFECT OF IMIDAZOLES ON ACTIVE TRANSPORT BY GASTRIC MUCOSA AND URINARY BLADDER.

Studies were undertaken to determine whether the stimulatory effect of histamine and the methyl xanthines on the frog gastric mucosa in vitro could be ascribed to the imidazole component of these compounds. The actively transported ions of gastric secretion appear in the form of hydrochloric acid and of a nonacid chloride component that is responsible for the short-circuit current (Isc). At 10–2 m, imidazole reduced acid secretion (Jh) by 80%, which was somewhat greater than the reduction produced by thiocyanate. N-methylimidazole, 2-methylimidazole, 4(5)-methylimidazole, and benzimidazole abolished Jh. The Isc tended to rise as Jh fell. In stimulated mucosae, imidazole and N-methylimidazole promptly reduced oxygen consumption (qO2) by 25%; thiocyanate had a delayed and lesser effect. Pyrazole, 4-hydroxymethylimidazole, and tris had little or no effect on Jh, Isc, or qO2. Imidazole and N-methylimidazole reduced active sodium transport by the toad urinary bladder by 50%. The results indicate that the inhibitory effects of the imidazoles cannot be ascribed to their buffering capacity or to competitive inhibition of histamine. Instead the effects may result from depletion of tissue content of adenosine-3',5'-phosphate or from interference with protein-bound phosphohistidine in oxidative phosphorylation.