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At least 19 recordsLinked to original sources
PubMed1991

Crystal structure of cholestanyl caprylate and binary phase behavior with cholesteryl caprylate.

The crystal structure of cholestanyl n-octanoate (caprylate) (C35H62O2) is monoclinic with space group A2 and cell dimensions a = 10.103(7), b = 7.646(7), c = 87.63(7) A, beta = 90.51(6) degrees; Z = 8 [two molecules (A, B) in asymmetric unit], V = 6769 A3, Dc = 1.010 g cm-3. Integrated X-ray intensities for 3798 reflections with I greater than 2 sigma (I) were measured with a rotating anode diffractometer at room temperature. The structure was determined using direct methods. Block diagonal least squares refinement gave R = 0.111. Molecules A and B have almost fully extended conformations, but differ significantly in the rotation about the ester bond and in the C17 chains. The molecular packing in the crystal structure of cholestanyl caprylate consists of stacked bilayers each having d002 = 43.8 A in thickness and within each bilayer, cholestanols pack with cholestanols and caprylate chains pack with caprylate chains. The crystal structure is very similar to that of cholesteryl myristate but is quite different from that of cholesteryl caprylate. The phase equilibria of the cholestanyl caprylate/cholesteryl caprylate binary system have been shown to involve limited mutual solubility of the two components and to have a eutectic point at 73% cholestanyl caprylate. The cholesteric mesophase is monotropic at all compositions except for a narrow range near the eutectic point where it is enantiotropic.

Cholesterol Esters↗
PubMed1990

Cellular mechanism of caprylic acid-induced growth hormone suppression.

To determine the dynamic secretory pattern of growth hormone (GH) in the presence of free fatty acids (FFA), we studied the effect of caprylic acid on basal and rGRF(1-29)NH2 (GRF)-induced GH secretion in acutely dispersed and perifused rat pituitary cells. At a concentration of 3.0 mmol/L, caprylic acid inhibited both basal (P less than .05) and GRF-stimulated GH secretions (P less than .01), except when the maximal (near the EC100) GRF concentration of 100 pmol/L was used. Lower concentrations of caprylic acid such as 0.3 and 1.0 mmol/L significantly inhibited, in a concentration-dependent manner, GH secretion induced by a 6.25-pmol/L GRF. However, at a GRF concentration of 25 pmol/L, this inhibitory effect was abolished. The time-course of GH response to GRF was similar in both control and caprylic acid-treated cells. To elucidate the mechanism(s) of action of the caprylic acid-induced blockade of GH secretion, in 3-day cultured rat pituitary cells, the effect of caprylic acid on basal and GRF-stimulated GH and 3',5'-cyclic adenosine monophosphate (cAMP) release. We also tested its effect on the Ca2+ ionophore, A23187-induced GH release. Caprylic acid (0.3 to 3.0 mmol/L) significantly inhibited basal GH release and GRF- or A23187-induced GH secretion. Furthermore, it decreased both basal and GRF-stimulated cAMP release (P less than .05). In addition, the effect of caprylic acid on rGRF(1-29)NH2 affinity to GRF pituitary binding sites was determined using [125I-Tyr10]hGRF(1-44)NH2 as radioligand.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Experimental induction of caprylate-dependent albumin antibodies.

To provide evidence for the immune nature of the albumin agglutination phenomenon or caprylate dependent albumin agglutinins (CDAA), rabbits were injected with native serum that had been incubated in a solution of sodium caprylate. Two of three rabbits responded with the production of CDAA, which in vitro behaved identical to human antisera. Human cells were agglutinated only when caprylate stabilized albumin was added to the cell/serum mixture or when caprylate free albumin plus sodium caprylate were used. The CDAA failed to agglutinate rabbit cells, although, both human adult and cord cells were agglutinated. These experiments indicate that the CDAA represent an immune response to native albumin that had been altered by caprylate.

Agglutination↗
PubMed1989

Purification of murine IgG monoclonal antibodies by precipitation with caprylic acid: comparison with other methods of purification.

Purification of murine IgG monoclonal antibodies from ascitic fluid by precipitation with caprylic acid was compared to that: 1) by sequential precipitation with caprylic acid and (NH4)2SO4; 2) by affinity chromatography on either antiidiotypic monoclonal antibodies or antimouse IgG xenoantibodies; and 3) by sequential (NH4)2SO4 precipitation, ion exchange chromatography and high pressure liquid chromatography (referred to as HPLC). In terms of yield of antibodies, precipitation with caprylic acid is comparable to sequential precipitation with caprylic acid and (NH4)2SO4, but superior to affinity chromatography on antibodies and to HPLC. In terms of purity of antibodies, precipitation with caprylic acid is less efficient than the other three methods. It should also be noted that precipitation with caprylic acid is associated with a reduction in the affinity of some antibodies and is not suitable to purify murine IgA and IgG3.

Animals↗
PubMed1988

Fluorescence study of the membrane-perturbing action of sodium caprylate as related to promotion of drug absorption.

The medium-chain fatty acid sodium caprylate released 6-carboxyfluorescein (CF), a model compound of water-soluble drugs, from the rat small intestinal brush border membrane (BBM) vesicles and liposomes containing CF. Caprylate caused a decrease in the fluorescence polarization of dansyl chloride, fluorescein isothiocyanate, and eosin maleimide covalently labeled to BBM. This indicates a perturbation of the BBM. However, no change in the fluorescence polarization of lipid-soluble fluorescent probes (2-(9-anthroyloxy) stearic acid, 12-(9-anthroyloxy) stearic acid, and 1,6-diphenyl-1,3,5-hexatriene) labeled to BBM was produced by caprylate. These findings indicate that caprylate can increase the permeability of the plasma membranes through the perturbation of the membranes. These actions of caprylate on membranes are considered one possible mechanism by which it promotes the absorption of water-soluble and poorly absorbed drugs.

Animals↗
PubMed1991

Inactivation of lipid-enveloped viruses in proteins by caprylate.

The use of caprylate for the inactivation of lipid-enveloped viruses in biologically active proteins both plasma derived and produced by cell culture was evaluated. Viruses consisted of herpes simplex virus type I, vesicular stomatitis virus, vaccinia virus, and Sindbis virus. Utilizing the dissociation reaction and varying the concentration of the ionized form of caprylate, a specific amount of the nonionized form of caprylate was maintained over a wide pH range. Virus-spiked protein solutions contacted with caprylate provide rapid virus inactivation under a variety of conditions while maintaining the integrity of the respective protein or activity. With the exception of coagulation factor AHF, protein and biological activity yield were essentially quantitative. Caprylate is removed after treatment by size exclusion chromatography or anion/cation exchange adsorption of the protein, followed by buffer wash.

Antiviral Agents↗
PubMed1975

Platelet reactivity ex vivo and in vivo after acute and chronic treatment with sodium caprylate.

The effect of sodium caprylate on platelet function and other hematological parameters was studied, using rabbits as experimental animals. Intravenous administration of caprylate resulted in a pronounced, although transient, inhibition of platelet reactivity as measured by the laser technique. A single oral dose of caprylate had no effect on platelet adhesiveness. Long-term oral administration of caprylate (2 and 3 weeks) to rabbits resulted in a progressive and significant decrease in platelet adhesiveness in these animals compared to that in a control group receiving saline. However, the platelet reactivity to laser damage was not changed after administration of caprylate for 3 weeks. Other hematological parameters such as hematocrit, plasma cholesterol, triglycerides, and ketone body concentrations were not altered by the treatment.

Acetoacetates↗
PubMed1976

Experimental induction of caprylate-dependent albumin antibodies.

A normal donor with the caprylate-dependent albumin agglutinins volunteered to receive 50 ml. of 25% caprylate-stabilized human albumin to determine the clinical significance of the antibodies. The donor manifested no clinical sign of a reaction. Samples of blood and urine collected before, during and after administration of albumin were subjected to extensive laboratory investigation. Biochemical, immunologic, hematologic, hemostatic and immunohematologic variables investigated showed only insignificant variations in all blood and urine samples. Results indicated that the infusion of albumin was safe, for the donor showed no sign of a hemolytic, febrile, allergic or anaphylactic transfusion reaction. However, since this is the first and only reported experiment of its kind, it is deemed advisable to exercise caution when administering albumin to patients who have caprylate-dependent albumin agglutinins until sufficient supportive data attesting to the complete safety of this procedure have accumulated.

Albumins↗
PubMed1989

Purification of F(ab')2 anti-snake venom by caprylic acid: a fast method for obtaining IgG fragments with high neutralization activity, purity and yield.

Pooled horse plasma containing antibodies against Crotalus durissus terrificus whole venom were digested with pepsin at an enzyme-substrate ratio of 8:1, pH 3.1, for 40 min and the F(ab')2M fragments purified by adding 8.7% caprylic acid (pH 5.0). For comparison, F(ab')2B purified by precipitation with ammonium sulphate and uncleaved IgG purified with caprylic acid were also prepared. Fab' fragments were obtained by reduction and alkylation of F(ab')2B. The anti-whole C.d. terrificus venom titers, determined by Dot-Blot were 12,800 (IgG), 6400 [F(ab')2B], 4800 [F(ab')2M] and 3200 (Fab'B). Immunochemical analysis of these fragments by SDS gel electrophoresis, Western blot and by double immunodiffusion revealed that the solution containing F(ab')2M was free of IgG and of other plasma proteins, whereas that containing F(ab')2B was not. One milligram of either F(ab')2B, F(ab')2M or Fab'B was able to neutralize respectively 20.7 micrograms, 20.2 micrograms and 13.8 micrograms of C.d. terrificus venom.

Animals↗
PubMed1986

Determination of sodium caprylate in plasma volume expanders by gas chromatography.

A quantitative gas chromatographic method for the determination of the sodium (caprylate) octanoate, antimicrobial in the plasma volume expanders hydroxyethyl starch and human serum albumin, has been developed. The sodium caprylate and the internal standard were converted to pentafluorobenzyl derivatives. The reaction mixture was extracted with methylene chloride and chromatographed on a 1.8-m OV-17 column at 170 degrees C with flame ionization detection. The method is linear over the concentration range studied (40-700 micrograms/ml). The method is precise (coefficient of variation less than 2%).

Caprylates↗
PubMed1977

Caprylate-dependent auto-anti-e.

A caprylate-dependent autoantibody with specificity for the e antigen of red cells is described. The antibody was completely inactivated by 2-mercaptoethanol and was probably of the IgM immunoglobulin class. The antibody had no apparent specificity for albumin. Reactivity of the described antibody may depend upon conformational change of red cell Rh antigen by caprylate.

Adult↗
PubMed1976

Caprylate-thallous agar medium for selectively isolating Serratia and its utility in the clinical laboratory.

A defined agar medium (hereinafter designated caprylate-thallous [CT5 agar) containing 0.01% yeast extract, 0.1% caprylic (n-octanoic) acid, and 0.025% thallous sulfate is highly selective for all Serratia species and effectively discriminates against most non-Serratia strains likely to be in the same habitats. The selectivity of CT agar is demonstrated by the very high efficiency of colony formation (mean, 80.7% of that on a nonselective complex medium) on CT agar by known Serratia strains and the very low efficiency of colony formation (close to zero) on CT agar by bacterial strains known not to be Serratia. The utility of this medium in actual clinical laboratory practice is demonstrated by the more rapid and higher recovery of Serratia on this selective medium as compared to conventional procedures of in-tandem runs of 513 consecutive urine, feces, and sputum specimens. Pigmented and nonpigmented Serratia strains deliberately added to fecal specimens can be selectively and quantitatively recovered on CT agar. CT agar compares favorably with, or in some cases is an improvement over, other selective media which have been recommended for isolating Serratia. This selective CT agar medium could be quite useful in ecological surveys, especially those related to hospital-acquired infections.

Agar↗
PubMed1976

The binding of 1-anilino-8-naphthalenesulfonate, heparin, salicylate and caprylate by human antithrombin III.

The binding of 1-anilino-8-naphthalenesulfonate to human antithrombin III was studied by fluorescence enhancement of the fluorophor and fluorescence quenching of the protein emission. Two molecules of 1-anilino-8-naphthalenesulfonate were found to bind per antithrombin molecule with an average dissociation constant of 4.4-10(-5) M. The binding of heparin to antithrombin was studied by ultraviolet difference spectroscopy. The stoichiometry of the heparin binding indicated 1.8 binding sites with an average dissociation constant of 4.3 - 10(-6) M. Further the fluorometric competition experiments with 1-anilino-8-naphthalenesulfonate, heparin, salicylate and caprylate indicated two different classes of anion binding sites on the antithrombin molecule.

Anilino Naphthalenesulfonates↗
PubMed1990

Purification of human immunoglobulins by sequential precipitation with caprylic acid and ammonium sulphate.

We have tested the usefulness of sequential precipitation with caprylic acid and ammonium sulfate to purify human monoclonal and polyclonal immunoglobulins from sera of 11 patients with monoclonal gammapathy (4 IgG kappa, 2 IgG lambda, 2 IgM kappa, 1 IgA kappa, 2 IgA lambda), four patients with autoimmune diseases and four healthy donors. In terms of purity and activity of Ig as well as execution time and cost, this two-step non-chromatographic procedure is highly efficient for the purification of IgG, IgA and IgM, thus offering several advantages over other methods of purification. Therefore, this procedure may have useful application in the preparation of human Ig for structural studies and therapeutic purposes.

Ammonium Sulfate↗
PubMed1989

Purification of IgG from serum with caprylic acid and ammonium sulphate precipitation is not superior to ammonium sulphate precipitation alone.

Immunoglobulin G (IgG) from bovine serum raised against Aeromonas Salmonicida was purified by ammonium sulphate precipitation (ASP) or caprylic acid treatment followed by ammonium sulphate precipitation (CAAS). Purity of IgG samples prepared by both methods were examined by High Performance Gel Permeation Chromatography, electrophoresis and antibody activity assay. Results suggest that IgG prepared by ASP is better than that obtained by CAAS method in terms of the yield of the IgG monomers and the recovery of the antibody activity.

Aeromonas↗
PubMed1986

A rapid colorimetric assay for the extracellular lipase of Pseudomonas fluorescens B52 using beta-naphthyl caprylate.

Conditions necessary for the determination of crude extracellular lipase activity from Pseudomonas fluorescens B52 using beta-naphthyl caprylate (beta-NC), an 8-carbon ester, as the substrate were examined. Maximum enzyme synthesis occurred at 20 degrees C in pyruvate mineral salts medium containing 1 mM-CaCl2. Bile salts were necessary for enzyme activity; 6 mM-Na taurocholate or Na deoxycholate gave maximum activity but the latter compound was inhibitory at higher concentrations. Activity was optimal in N-Tris[hydroxymethyl]methyl-2-aminoethane sulphonic acid buffer pH 8.0 at 40 degrees C. A comparison of beta-NC with beta-naphthyl butyrate (a 4-carbon ester) and beta-naphthyl myristate (a 14-carbon ester) showed that beta-NC was the best substrate; Km values of 0.0415, 0.141 and 0.200 mM and Vmax values of 67.2, 20.1 and 5.28 mumol ml-1 h-1 were obtained for those substrates respectively. The enzyme was inhibited 50% in its activity against beta-NC by 0.009 mM-EDTA, 0.0007% (w/v) mixed alkyltrimethylammonium bromide and 0.00275% (w/v) Triton X-100. The biochemical properties determined using beta-NC as substrate are consistent with those reported for the lipases of other strains of Ps. fluorescens using natural substrates.

Bile Acids and Salts↗
PubMed1986

Determination of the extracellular lipases of Pseudomonas fluorescens spp. in skim milk with the beta-naphthyl caprylate assay.

A method based on the hydrolysis of beta-naphthyl caprylate (beta-NC) has been developed for quantitating extracellular lipase from Pseudomonas fluorescens. The assay was extremely sensitive to skim milk (SM); as little as 0.02 ml raw SM in a 2.0 ml reaction mixture resulted in an apparent loss of 50% of the lipase activity. Activity improved 3-fold when trypsin (50 micrograms/ml) was included in the reaction mixture. When super-simplex optimization was used to determine the optimum levels of beta-NC, Na taurocholate (NaTC), SM/lipase mixture and trypsin for maximum activity, NaTC was found to be unnecessary for activity. Subsequent addition of 15 mM-NaTC resulted in 80% loss of activity. On the other hand, NaTC was required for native lipase activity in the presence of SM. Native lipase was completely inhibited by heating at 70 degrees C for 2 min, while B52 lipase retained 75% of its activity under the same conditions. The assay was able to detect lipase produced by Ps. fluorescens B52 in SM at 5 degrees C when the cell density exceeded 10(8) colony forming units/ml. The presence of butterfat (3.5%) in the SM assay inhibited B52 lipase by 97%. The beta-NC assay gave results comparable to the tributyrin agar diffusion assay using cell-free extracts of ten strains of common dairy psychrotrophs. The results suggest that the beta-NC assay may be useful for determining lipase activity in raw SM.

Animals↗
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↗