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PubMed1991

Role of paracellular pathway in nonelectrolyte permeation across rat colon epithelium enhanced by sodium caprate and sodium caprylate.

The enhancing effects of 0.25% sodium caprate (C10) and sodium caprylate (C8) on the paracellular permeation of seven water-soluble nonelectrolytes (inulin, polyethylene glycol 900, mannitol, erythritol, glycerol, thiourea, and urea) across the isolated rat colonic epithelium were examined using the Ussing-type chamber technique. The paracellular changes were also measured by impedance analysis. In both the presence and the absence of enhancers, the permeation clearances (Pm) for inulin (12-15 A in molecular radius) to erythritol (3.2 A) increased linearly with the increase in their free diffusion coefficients (Dfr), showing the existence of a paracellular shunt pathway unrestricted to any molecular size. Glycerol (2.9 A), thiourea (2.6 A), and urea (2.3 A) had higher clearances than the expected linear values, showing the existence of a restricted paracellular or transcellular pathway. Both C10 and C8 increased the permeabilities in the two pathways, but C10 was more effective than C8. The increase in the permeabilities via the shunt pathway caused by the enhancers was greater than that via the restricted pathway, and thus, the two-phase pattern in the relationship of Pm and Dfr was similar to that in the absence of enhancers. The transcellular permeabilities for urea and thiourea, which were obtained from the efflux experiments, were increased by the enhancers. However, the relative increase caused by C10 was smaller than that of the paracellular-restricted permeabilities. The paracellular changes probably were due to the increase in pore area per unit diffusive path length.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2002

Pathway of oral absorption of heparin with sodium N-[8-(2-hydroxybenzoyl)amino] caprylate.

PURPOSE: The oral bioavailability of heparin is negligible. Recent studies, however, have shown that sodium N-[8-(2-hydroxybenzoyl) amino]caprylate (SNAC) and other N-acylated amino acids enable oral heparin absorption. To investigate the mechanism by which heparin crosses the intestinal epithelium in the presence of SNAC, we have used fluorescence microscopy to follow the transport of heparin across Caco-2 cell monolayers. METHODS: The experiments were carried out on Caco-2 monolayers and Caco-2 cells grown to confluence on culture dishes, using different concentrations of SNAC. The localization of fluorescently labeled heparin was determined using epi-fluorescence and confocal microscopy. DNA dyes were used to determine the effect of SNAC on the plasma membrane integrity. F-actin was labeled with fluorescent phalloidin to investigate the stability of perijunctional actin rings in the presence of SNAC. RESULTS: Heparin was detected in the cytoplasm only after incubation of the cells with heparin and SNAC. No DNA staining was observed in cells incubated with a DNA dye in the presence of SNAC concentrations at which heparin transport occurred. In addition, no signs of actin redistribution or perijunctional ring disbandment were observed during the transport of heparin. CONCLUSIONS: The results indicate that SNAC enables heparin transport across Caco-2 monolayers via the transcellular pathway. Heparin transport in the presence of SNAC is selective and does not involve permeabilization of the plasma membrane or tight junction disruption.

Administration, Oral↗
PubMed1984

Preparation of human immunoglobulin by caprylic acid precipitation.

Caprylic acid was used to precipitate nonimmunoglobulin proteins from human plasma. The crude IgG present in the supernatant (which contained 26-29% of the total protein in terms of absorbance units or 78-87% of IgG by weight) was fractionated on DEAE-cellulose, to yield pure IgG as shown by disc electrophoresis, immunoelectrophoresis and gel filtration. Pure IgG was free of plasmin and plasminogen and did not exhibit any fragmentation or aggregation during storage for periods up to 4 weeks at 40 degrees C, and its anticomplementary activity was low. Antibodies to viral agents were recovered unchanged.

Antibodies↗
PubMed2006

Comparison between therapeutic antitoxin F(ab)2 fractionated with ammonium sulfate and caprylic acid.

To date, animal derived therapeutic antibodies represent the best and only choice source of antitoxins, especially in developing countries. Furthermore, this industry needs to develop a production protocol to achieve safer products. Recently, several laboratories changed their production protocol from ammonium sulfate (AS) protocol to caprylic acid (CA) fractionation. Our results showed that using the CA protocol leads to improvement in the product quality, as assessed by the albumin and protein content decrease (from 4.75 to 3.54 g/dL and 0.64 to 0.18 g/dL, respectively), which yielded a purer antitoxin product. The F(ab)2 protein aggregate formation and turbidity have been significantly reduced, 4.60 versus 2.55 and 0.046 versus 0.021 (p < 0.01), respectively. However, the anti-complementary activity was also reduced, from 42 to 33. The total IgG content was higher in CA fractionated products than AS materials. The endotoxin content was worrisome in some F(ab)2 products.

Ammonium Sulfate↗
PubMed1975

Dietary effects of the esters of butyric, caproic, caprylic, capric, lauric, myristic, palmitic, and stearic acids on food intake, weight gain, plasma glucose, and tissue lipid in the male white rat.

Eight saturated fatty acid esters were fed to male white rats for 30 days in a 1/81 fractional factorial experiment in which diets contained 12-38% of their total energy as lipid. Marked increases in food intake, feed efficiency, and weight gain were achieved when lipid provided 36% of diet energy, and when that lipid was more than half caproate, caprate, myristate, and/or stearate. Caproate was the only saturated fatty acid to increase plasma glucose levels. The feeding of stearate or caprylate decreased plasma and liver cholesterol. Caprate increased liver fat. The short-chain fatty acids (butyrate to myristate) increased the concentration of fat in the carcass.

Animal Nutritional Physiological Phenomena↗
PubMed1984

Stabilization of human albumin by caprylate and acetyltryptophanate.

The thermal stabilization of human albumin by caprylate (CA) and acetyltryptophanate (AT) was studied by monitoring the formation of albumin polymer (defined as species larger than dimer) on the basis of its molecular size as well as its characteristic migration as alpha-globulin. Heating 5% protein solutions of purified albumin monomer, cohn fraction V, and fraction IV-4 + V at 60 degrees C in 0.1 M sodium phosphate or 145 mM sodium chloride, pH 7.0, established the following order of stabilizer effectiveness: 4 mM CA + 4 mM AT approximately 4 mM CA greater than 8 mM AT greater than or equal to 2 mM CA greater than 4 mM AT. However, albumin was more thermally stable in the chloride medium. Raising the CA concentration above 4 mM provided little additional stabilization. The D- and L-enantiomers of AT were equally effective, but 16 mM AT was needed to equal the effect of 4 mM CA. L-Tryptophanate exerted only slight stabilization, even at 32 mM; D-tryptophanate was even less effective. The albumin polymer level increased progressively with time at 60 degrees C in 2 mM CA or 4 mM AT, whereas in 4 mM CA it reached a plateau in 4-6 h. Acetone drying of albumin-rich fractions was shown to remove nearly all endogenous fatty acid, rendering the protein thermally labile unless sufficient exogenous stabilizer(s) was added. Even in the presence of 145 mM sodium chloride and 4 mM CA + 4 mM AT or 4 mM CA, the stabilizing effect of endogenous fatty acid was still detectable.

Anions↗
PubMed1999

[One simple and efficient method for purification of IgG McAb from mice ascites: caprylic acid/ammonium sulfate precipitation].

Several ascitic IgG McAbs were purificated by caprylic acid/ammonium sulfate precipitation (CA-AS), ammonium sulfate precipitation (AS) and SPA affinity chromatography. Purity of IgG purificated by CA-AS ranged from 87% to 91%, higher than that obtained by CA (65%-70%), lower than that obtained by SPA affinity chromatography (100%). The yield of IgG purificated by CA-AS ranged from 4.8 g/L to 5.5 g/L, lower than that obtained by CA (7.0-7.9 g/L), more higher than that obtained by SPA affinity chromatography (0.6 g/L). The recovery of IgG purificatied by CA-AS ranged from 39.0% to 44.4%, lower than that obtained by CA (56.0%-65.0%), more higher than that obtained by SPA affinity chromatography (7.4%). The ELISA titer of 4E2 or H6McAb was not impaired by purification of CA-AS. The above results suggested that CA-AS is one simple, efficient, rapid and low-cost method for purification of IgG McAb from ascitic fluid.

Ammonium Sulfate↗
PubMed2003

[Studies on gastrointestinal absorption enhancement effect and mechanism of sodium N-[8-(2-hydroxybenzyl)amino] caprylate to insulin solution].

AIM: To study the enhancement effect and mechanism of sodium N-[8-(2-hydroxybenzyl) amino] caprylate (SNAC--a kind of synthetic enhancer) to insulin (INS) solution in gastrointestine. METHODS: To determine the enhancement effect of SNAC on INS absorption by oral administration to rats and mice; To study the enhancement mechanism of SNAC by three kinds of methods: Delivering SNAC and INS solution to different parts of rats' intestines, adding energy inhibitor 2,4-dinitrophenol (DNP) or P-glycoprotein (P-gp) inhibitor verapamil (Ver) into SNAC and INS solution. RESULTS: SNAC was shown to enhance the gastrointestinal absorption of INS, the intensity of absorption enhancement corresponded to the doses of SNAC. The enhancement of SNAC to INS in different parts of the rat intestine was different (jejunum > colon > ileum). The effect of SNAC on INS absorption increased accordingly. CONCLUSION: The enhancement of SNAC to INS absorption presented dose dependence on SNAC; the absorption process needed energy and related to P-gp efflux.

2,4-Dinitrophenol↗
PubMed1989

Rectal absorption enhancement of gentamicin in rabbits from hollow type suppositories by sodium salicylate or sodium caprylate.

The absorption of gentamicin (GM) from the rectum of rabbits after coadministration of GM (60 mg) and sodium salicylate (SA) or sodium caprylate (CA) as absorption-enhancing agents was investigated. Two types of hollow type suppositories were used--a conventional type (Type I) and a release-restricted type (Type II). Without SA or CA, GM was not absorbed. However, GM absorption was marked when 90 mg of solid SA or CA was added (the bioavailability of GM was 58% with SA, and 59% with CA). The enhancing effect of SA or CA (30 mg) in solid or aqueous solution form on GM absorption was evaluated using the Type I suppository. In the case of SA, the highest plasma GM level (Cmax 15.3 +/- 1.7 micrograms/ml, AUC0-4 27.3 +/- 3.9 h.micrograms/ml) was obtained following coadministration of powdered GM and SA; the plasma GM level (Cmax 1.5 +/- 0.6 micrograms/ml, AUC0-4 3.0 +/- 1.3 h.micrograms/ml) following the administration of a solution of GM and SA was significantly decreased as compared with the results using the powdered form. In the case of CA, the plasma GM level (Cmax 14.8 +/- 4.5 micrograms/ml, AUC0-4 25.4 +/- 8.7 h.micrograms/ml) following administration of the solution form was not significantly decreased in comparison with the results obtained using the powdered form. A marked increase in the enhancing effect of SA on the rectal GM absorption was found following use of Type II suppositories when GM and SA were coadministered in solution form. However, the GM absorption after coadministration of GM and CA using Type II suppositories was not significantly different from the absorption resulting from use of Type I suppositories. Our results suggest that the form and concentration of drug should not be ignored in evaluating the enhancing effects of SA or CA on the rectal absorption of poorly absorbed drugs such as GM.

Administration, Rectal↗
PubMed2004

Effects of structured lipids containing eicosapentaenoic or docosahexaenoic acid and caprylic acid on serum and liver lipid profiles in rats.

The physiological activity and effect on lipid metabolism of four types of structured lipids (SLs), that contain caprylic acid (C8) and either eicosapentaenoic (EPA) or docosahesaenoic acid (DHA), were evaluated in male Wistar rats fed experimental diets containing 7% (wt %) of each SL and 3% (wt %) soybean oil for 28 days. Control rats were fed a diet containing 10% (wt %) soybean oil. The relative perirenal adipose tissue weights of rats fed D-8-8 and 8-D-8 diets were significantly lower than those of other groups. We observed significantly lower serum cholesterol concentrations in rats fed SLs than those of control group over experimental period. The serum lipids concentrations in rats fed diets containing SLs were significantly lower P < 0.05) than those of soybean oil group. The fatty acid compositions of WAT did not reflect the structural differences in the triglyceride. These results suggest that the physiological effects of the SLs used in this study were due to the fatty acids rather than the structural specificity. Therefore, further study will be needed to ascertain the most desirable structural configuration.

Adipose Tissue↗
PubMedDate not supplied

[IgG4 levels in polyvalent immunoglobulins and immunoglobulins prepared by precipitation with caprylic acid].

Levels of IgG4 in immunoglobulin preparations obtained either by conventional ethanol fractionation or by ethanol and caprylic acid fractionation (Allergam) were measured by an enzyme-immunoassay (competitive Elisa). In 9 ethanol preparations, the mean percentage of IgG4 was 2.1% +/- 0.5. In 10 preparations of Allergam, the mean percentage of IgG4 was 4.6% +/- 1. The concentration of IgG4 in Allergam preparations is about twice the concentration found in conventional ethanol preparations.

Enzyme-Linked Immunosorbent Assay↗
PubMed2001

Paralogous gene analysis reveals a highly enantioselective 1,2-O-isopropylideneglycerol caprylate esterase of Bacillus subtilis.

Carboxylesterase NP of Bacillus subtilis Thai I-8, characterized in 1992 as a very enantioselective (S)-naproxen esterase, was found to show no enantiopreference towards (S)-1,2-O-isopropylideneglycerol (IPG) esters. The ybfK gene was identified by the B. subtilis genome project as an unknown gene with homology to carboxylesterase NP. The purpose of the present study was to characterize the ybfK gene product in order to determine whether this paralogue of carboxylesterase NP had an altered or enhanced stereospecificity. The ybfK gene was cloned and expressed in B. subtilis using a combination of two strong promoters in a multicopy vector. The enzyme was purified from the cytoplasm of B. subtilis by means of anion exchange and hydrophobic interaction chromatography. The purified YbfK is an enzyme of 296 amino acids and shows an apparent molecular mass of 32 kDa (SDS/PAGE). Comparison of the activities of YbfK and carboxylesterase NP towards caprylate esters of IPG revealed that YbfK produces (S)-IPG with 99.9% enantioselectivity. Therefore, we conclude that we have isolated a paralogue of carboxylesterase NP that can be used for the enantioselective production of (S)-IPG.

Bacillus subtilis↗
PubMed2005

Miniaturization of the structure elucidation of novel natural products--two trace antibacterial acylated caprylic alcohol glycosides from Arctostaphylos pumila.

High-throughput isolation, purification and analysis methods applied to natural products libraries from plants gave rise to the discovery of two novel acylated caprylic alcohol glycosides (1, 2) produced by Arctostaphylos pumila. The NMR spectra were acquired using the CapNMR probe and performed on mass-limited samples, which enabled us to elucidate the structures of 2,6-diacetyl-3,4-diisobutyl-1- O-octylglucopyranoside (1, 200 microg) and 2,6-diacetyl-3,4-dimethylbutyl-1- O-octylglucopyranosid (2, 70 microg). Compounds 1 and 2 exhibited antibacterial activity against Gram-positive methicillin-resistant Staphylococcus aureus with an MIC of 128 microg/mL and 64 microg/mL, respectively.

Anti-Bacterial Agents↗
PubMed2002

Final report on the safety assessment of sorbitan caprylate, sorbitan cocoate, sorbitan diisostearate, sorbitan dioleate, sorbitan distearate, sorbitan isostearate, sorbitan olivate, sorbitan sesquiisostearate, sorbitan sesquistearate, and sorbitan triisostearate.

Sorbitan fatty acid esters are mono-, di-, and triesters of fatty acids and sorbitol-derived hexitol anhydrides. They function as surfactants in cosmetic formulations. Previously, the Cosmetic Ingredient Review (CIR) Expert Panel had reviewed the safety of several of these sorbitan fatty acid esters (Sorbitan Laurate, Sorbitan Oleate, Sorbitan Palmitate, Sorbitan Sesquioleate, Sorbitan Stearate, Sorbitan Trioleate, and Sorbitan Tristearate). This safety assessment is an addendum to that report that includes Sorbitan Caprylate, Sorbitan Cocoate, Sorbitan Diisostearate, Sorbitan Dioleate, Sorbitan Distearate, Sorbitan Isostearate, Sorbitan Olivate, Sorbitan Sesquiisostearate, Sorbitan Sesquistearate, and Sorbitan Triisostearate. Although concentrations of these ingredients up to 25% have been reported to be used, most commonly they are used at less than 10%. These esters may be hydrolyzed to the fatty acid and anhydrides of Sorbitol. Fatty Acids are absorbed and metabolized. Sorbitan fatty acid esters were relatively nontoxic via ingestion in acute and long-term studies. They were generally minimal to mild skin irritants in animal studies, except that Sorbitan Isostearate applied to the skin was a moderate irritant in one rabbit study and when injected intradermally caused mild to severe irritation in guinea pigs. Sorbitan fatty acid esters did not sensitize guinea pigs. The fatty acid component, tested alone, typically caused only slight irritation and sensitization, and was not photosensitizing. Sorbitan fatty acid esters were not ocular irritants. Fatty acids are normal components of diet for which no data were available concerning reproductive or developmental toxicity, but Sorbitol had no adverse effects on the reproduction of CD rats during a multigeneration feeding study and was not a reproductive toxin at doses of 3000 to 7000 mg/kg/day for 2 years. Overall these esters and their corresponding fatty acids were not mutagenic, but Sorbitan Oleate was reported to reduce DNA repair following ultraviolet radiation exposure in human lymphocytes in culture. Sorbitan Laurate and Sorbitan Trioleate were cocarcinogens in one mouse study, but Sorbitan Trioleate and Sorbitan Oleate were not tumor promoters in another study. In clinical tests, Sorbitan fatty acid esters were generally minimal to mild skin irritants and were nonsensitizing, but Sorbitan Sesquioleate did produce an allergic reaction in fewer than 1% of patients with suspected contact dermatitis and addition of Sorbitan Sesquioleate to the components of a fragrance mix used in patch testing increased both irritant and allergic reactions to the fragrance mix. Careful consideration was made of the data on the cocarcinogenesis of Sorbitan Laurate and Sorbitan Trioleate, but the high exposure levels, high frequency of exposure, and absence of a dose-response led to the conclusion that there was not a cocarcinogenesis risk with the use of these ingredients in cosmetic formulations. Accordingly, these ingredients were considered safe for use in cosmetic formulations under the present practices of use.

Animals↗
PubMed2004

Final report of the amended safety assessment of Glyceryl Laurate, Glyceryl Laurate SE, Glyceryl Laurate/Oleate, Glyceryl Adipate, Glyceryl Alginate, Glyceryl Arachidate, Glyceryl Arachidonate, Glyceryl Behenate, Glyceryl Caprate, Glyceryl Caprylate, Glyceryl Caprylate/Caprate, Glyceryl Citrate/Lactate/Linoleate/Oleate, Glyceryl Cocoate, Glyceryl Collagenate, Glyceryl Erucate, Glyceryl Hydrogenated Rosinate, Glyceryl Hydrogenated Soyate, Glyceryl Hydroxystearate, Glyceryl Isopalmitate, Glyceryl Isostearate, Glyceryl Isostearate/Myristate, Glyceryl Isostearates, Glyceryl Lanolate, Glyceryl Linoleate, Glyceryl Linolenate, Glyceryl Montanate, Glyceryl Myristate, Glyceryl Isotridecanoate/Stearate/Adipate, Glyceryl Oleate SE, Glyceryl Oleate/Elaidate, Glyceryl Palmitate, Glyceryl Palmitate/Stearate, Glyceryl Palmitoleate, Glyceryl Pentadecanoate, Glyceryl Polyacrylate, Glyceryl Rosinate, Glyceryl Sesquioleate, Glyceryl/Sorbitol Oleate/Hydroxystearate, Glyceryl Stearate/Acetate, Glyceryl Stearate/Maleate, Glyceryl Tallowate, Glyceryl Thiopropionate, and Glyceryl Undecylenate.

The safety of 43 glyceryl monoesters listed as cosmetic ingredients was reviewed in a safety assessment completed in 2000. Additional safety test data pertaining to Glyceryl Rosinate and Glyceryl Hydrogenated Rosinate were received and served as the basis for this amended report. Glyceryl monoesters are used mostly as skin-conditioning agents--emollients and/or surfactant--emulsifying agents in cosmetics. The following 20 glyceryl monoesters are currently reported to be used in cosmetics: Glyceryl Laurate, Glyceryl Alginate, Glyceryl Arachidonate, Glyceryl Behenate, Glyceryl Caprylate, Glyceryl Caprylate/Caprate, Glyceryl Cocoate, Glyceryl Erucate, Glyceryl Hydroxystearate, Glyceryl Isostearate, Glyceryl Lanolate, Glyceryl Linoleate, Glyceryl Linolenate, Glyceryl Myristate, Glyceryl Oleate/Elaidate, Glyceryl Palmitate, Glyceryl Polyacrylate, Glyceryl Rosinate, Glyceryl Stearate/Acetate, and Glyceryl Undecylenate. Concentration of use data received from the cosmetics industry in 1999 indicate that Glyceryl Monoesters are used at concentrations up to 12% in cosmetic products. Glyceryl Monoesters are not pure monoesters, but are mostly mixtures with mono-, di-, and tri-esters. The purity of commercial and conventional Monoglyceride (Glyceryl Monoester) is a minimum of 90%. Glyceryl Monoesters (monoglycerides) are metabolized to free fatty acids and glycerol, both of which are available for the resynthesis of triglycerides. Glyceryl Laurate enhanced the penetration of drugs through cadaverous skin and hairless rat skin in vitro and has been described as having a wide spectrum of antimicrobial activity. A low-grade irritant response was observed following inhalation of an aerosol containing 10% Glyceryl Laurate by test animals. Glyceryl monoesters have little acute or short-term toxicity in animals, and no toxicity was noted following chronic administration of a mixture consisting mostly of glyceryl di- and mono- esters. Glyceryl Laurate did have strong hemolytic activity in an in vitro assay using sheep erythrocytes. Glyceryl Laurate, Glyceryl Isostearate, or Glyceryl Citrate/Lactate/Linoleate/Oleate were not classified as ocular irritants in rabbits. Undiluted glyceryl monoesters may produce minor skin irritation, especially in abraded skin, but in general these ingredients are not irritating at concentrations used in cosmetics. Glyceryl monoesters are not sensitizers, except that Glyceryl Rosinate and Hydrogenated Glyceryl Rosinate may contain residual rosin, which can cause allergic reactions. These ingredients are not photosensitizers. Glyceryl Citrate/Lactate/Linoleate/Oleate was not mutagenic in the Ames test system. Glyceryl Laurate exhibited antitumor activity and Glyceryl Stearate was negative in a tumor promotion assay. At concentrations higher than used in cosmetics, Glyceryl Laurate did cause moderate erythema in human repeat-insult patch test (RIPT) studies, but the other glyceryl monoesters tested failed to produce any significant positive reactions. Glyceryl Rosinate was irritating to animal skin at 50%, but did not produce sensitization in clinical tests at concentrations up to 10% and covered with semioccluded patches. There is reported use of Glyceryl Rosinate at 12%in mascara, which is somewhat higher than the concentration in the clinical testing. It was reasoned that the available data do support the safety of this use because there would be minimal contact with the skin and no occlusion. The safety of Arachidonic Acid was not documented and substantiated for cosmetic product use in an earlier safety assessment and those same safety questions apply to Glyceryl Arachidonate. Based on these data, the Cosmetic Ingredient Review (CIR) Expert Panel found that these glyceryl monoesters are safe as cosmetic ingredients in the present practices of use and concentration: except that the available data are insufficient to support the safety of Glyceryl Arachidonate. Additional data needed to support the safety of Glyceryl Arachidonate include (1) dermal absorption data; and, based on the results of the absorption studies, there may be a need for (2) immunomodulatory data; (3) carcinogenicity and photocarcinogenicity data; and (4) human irritation, sensitization, and photosensitization data.

Animals↗
PubMed1994

Identification of Salmonella spp. with Rambach agar in conjunction with the 4-methylumbelliferyl caprylate (MUCAP) fluorescence test.

The utility of Rambach agar to identify Salmonella spp. was examined relative to its usefulness in clinical microbiology. Forty-four of 54 (82%) salmonella organisms isolated from faecal cultures and 66 of 82 (84%) salmonella stock cultures produced bright red colour colonies after 24 h incubation at 37 degrees C, whereas 48 of 54 (89%) salmonellae isolated from faecal cultures, and 74 of 82 (90%) salmonella stock cultures, yielded the bright red colour when the incubation time was extended to 48 h. Apart from Salmonella typhi and Salmonella paratyphi A the sensitivity of Rambach agar to detect salmonella strains belonging to five serogroups was 83% and 92% after 24 and 48 h of incubation, respectively. In contrast, other members of the family Enterobacteriaceae tested failed to give the bright red colour, except for one strain of Pseudomonas aeruginosa and another of Acinetobacter baumannii. The non-salmonella strains either gave a different colour--blue, green or orange--or were colourless. To supplement the use of Rambach agar in the detection of Salm. typhi and Salm. paratyphi A and other late or negative acid-producing salmonella species on this medium, the 4-methylumbelliferyl caprylate fluorescence (MUCAP) test was carried out, and this showed positive results with all the salmonella strains tested. These results suggest that while Rambach agar can not pre-identify Salm. typhi and Salm. paratyphi A, the use of a simple and rapid (MUCAP) test in combination would make it very useful to identify all Salmonella spp. after 24 h incubation.

Agar↗
PubMed1996

Differential scanning calorimetry study of the influence of phospholipid analogs with a carbonyl-terminated sn-2 chain on the interdigitated phases formed by 1-stearoyl-2-capryl-sn-glycero-3-phosphatidylcholine (C18:C10-PC).

Synthetic glycerophosphocholines with highly asymmetric chain lengths form interdigitated bilayers in the gel phase. In nature, phospholipids with one hydrocarbon chain approximately twice as long as the other can arise from the autooxidation of unsaturated linkages in the acyl chain, and thus the oxidation products would contain a carbonyl group at the chain terminus. In this study, we have investigated the thermotropic behavior of bilayers prepared from mixtures of the well-studied, mixed-chain phospholipid, 1-stearoyl-2-capryl-sn-glycero-3-phosphocholine (C18:C10-PC, 1), with synthetic 1-stearoyl-2-acyl-sn-glycero-3-phosphocholines in which the sn-2 chain is approximately one-half the length of the sn-1 chain and contains a C==O group near the omega terminus. Phase diagrams of binary mixtures of 1 with a chain-terminal ketone-PC analog (2) or with a chain-terminal ester-PC analog (3) in excess water exhibited gel-phase immiscibility over a wide compositional range, but miscibility in the liquid-crystalline phase. However, 1 was completely miscible with C18:C10:1 delta 10-PC (compound 4), which bears a chain-terminal carbon-carbon double bond, in both the gel and liquid-crystalline phases. The calorimetric data suggest that phosphatidylcholines (PC) with carbonyl-terminated chains, which can be produced by autooxidation of naturally abundant 1-saturated-2-unsaturated phospholipids such as 1-stearoyl-2-oleoyl-PC, may not form the normal triple-chain mixed interdigitated structure characteristic of hydrocarbon-terminated PCs in gel-phase bilayers.

Calorimetry, Differential Scanning↗