Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Adipates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed2006

Protein concentration and adsorption time effects on fibrinogen adsorption at heparinized silica interfaces.

Heparin was modified with adipic dihydrazide and covalently linked to surface-activated silica wafers. X-ray photoelectron spectroscopy was used at each stage of derivatization and showed that successful immobilization had taken place. Surfaces were imaged with atomic force microscopy to determine the uniformity of the heparin layer as well as its thickness. In situ ellipsometry was used to estimate layer thickness as well, and to study protein concentration and adsorption time effects on the adsorption and elution kinetics exhibited by human plasma fibrinogen. The adsorbed amount of fibrinogen increased with time and concentration on each type of surface. Under all experimental conditions, fibrinogen adsorbed at a lower rate and to a lower extent on heparinized as compared to unheparinized silica. In addition, buffer elution experiments showed that fibrinogen was less tightly bound to heparinized silica. In order to examine behavior relative to fibrinogen mobility at these interfaces, the sequential adsorption of fibrinogen was recorded. The difference in adsorption rates between the first and second adsorption cycles, evaluated at identical mass density, indicated that post-adsorptive molecular rearrangements had taken place. In general, higher solution concentration and longer adsorption time in the first adsorption step led to more rearrangement, and these history dependent effects were more pronounced on the heparinized silica. These rearrangements are suggested to involve clustering of adsorbed fibrinogen, in this way increasing the amount of unoccupied area at the interface. These rearrangements were presumably facilitated on the heparinized silica by enhanced lateral mobility of fibrinogen at this negatively charged, highly hydrophilic interface.

Adipates↗
PubMed2006

Synthesis and degradation test of hyaluronic acid hydrogels.

Hyaluronic acid (HA) hydrogels prepared with three different crosslinking reagents were assessed by in vitro and in vivo degradation tests for various tissue engineering applications. Adipic acid dihydrazide grafted HA (HA-ADH) was synthesized and used for the preparation of methacrylated HA (HA-MA) with methacrylic anhydride and thiolated HA (HA-SH) with Traut's reagent (imminothiolane). (1)H NMR analysis showed that the degrees of HA-ADH, HA-MA, and HA-SH modification were 69, 29, and 56 mol%, respectively. HA-ADH hydrogel was prepared by the crosslinking with bis(sulfosuccinimidyl) suberate (BS(3)), HA-MA hydrogel with dithiothreitol (DTT) by Michael addition, and HA-SH hydrogel with sodium tetrathionate by disulfide bond formation. According to in vitro degradation tests, HA-SH hydrogel was degraded very fast, compared to HA-ADH and HA-MA hydrogels. HA-ADH hydrogel was degraded slightly faster than HA-MA hydrogel. Based on these results, HA-MA hydrogels and HA-SH hydrogels were implanted in the back of SD rats and their degradation was assessed according to the pre-determined time schedule. As expected from the in vitro degradation test results, HA-SH hydrogel was in vivo degraded completely only in 2 weeks, whereas HA-MA hydrogels were degraded only partially even in 29 days. The degradation rate of HA hydrogels were thought to be controlled by changing the crosslinking reagents and the functional group of HA derivatives. In addition, the state of HA hydrogel was another factor in controlling the degradation rate. Dried HA hydrogel at 37 degrees C for a day resulted in relatively slow degradation compared to the bulk HA hydrogel. There was no adverse effect during the in vivo tests.

Adipates↗
PubMed2005

Amodiaquine polymeric membrane electrode.

The construction and electrochemical response characteristics of two types of poly(vinyl chloride) (PVC) membrane sensors for the determination of amodiaquine hydrochloride (ADQ.2HCl) are described. The sensing membrane comprised an ion-pair formed between the cationic drug and sodium tetraphenyl borate (NaTPB) or potassium tetrakis(4-chlorophenyl) borate (KTCPB) in a plasticized PVC matrix. Eight PVC membrane ion-selective electrodes were fabricated and studied. Several plasticizers were studied namely, dioctyl phthalate (DOP), 2-nitrophenyl octyl ether (NPOE), dioctyl phenylphosphonate (DOPP) and bis(2-ethylhexyl)adipate (EHA). The sensors display a fast, stable and near-Nernstian response over a relative wide ADQ concentration range (3.2 x 10(-6) to 2.0 x 10(-2) M), with slopes comprised between 28.5 and 31.4 mV dec(-1) in a pH range comprised between pH 3.7 and 5.5. The assay of amodiaquine hydrochloride in pharmaceutical dosage forms using one of the proposed sensors gave average recoveries of 104.3 and 99.9 with R.S.D. of 0.3 and 0.6% for tablets (Malaritab) and a reconstituted powder containing ADQ.2HCl, respectively. The sensor was also used for dissolution profile studies of two drug formulations. The sensor proved to have a good selectivity for ADQ.2HCl over some inorganic and organic compounds, however, berberine chloride interfered significantly. The results were validated by comparison with a spectrophotometric assay according to the USP pharmacopoeia.

Adipates↗
PubMedDate not supplied

Steroidogenesis in fetal male rats is reduced by DEHP and DINP, but endocrine effects of DEHP are not modulated by DEHA in fetal, prepubertal and adult male rats.

The plasticizer di(2-ethylhexyl)phthalate (DEHP) exhibits antiandrogenic effects in perinatally exposed male rats. Di(2-ethylhexyl) adipate (DEHA) and diisononyl phthalate (DINP) are currently being evaluated as potential substitutes for DEHP, but similarities in structure and metabolism of DEHP with DEHA and DINP have led to the hypothesis that similarities in action may also exist. Pregnant Wistar rats were gavaged during gestation and lactation with vehicle, DEHP (300 or 750 mg/kg bodyweight per day), DINP (750 mg/kg bodyweight per day), DEHP (750 mg/kg bodyweight per day) in combination with DEHA (400 mg/kg bodyweight per day), or DEHP (300 mg/kg bodyweight per day) in combination with DINP (750 mg/kg bodyweight per day). DINP and DEHP were both shown to reduce testicular testosterone production ex vivo and testosterone levels in testes and plasma of male fetuses at gestation day 21, indicating a similar mechanism of action for DINP and DEHP. Additionally, plasma LH levels in male fetuses were elevated. Neonatal anogenital distance was reduced and the number of nipples at postnatal day 13 increased in DEHP-exposed male offspring. Serum inhibin B levels were significantly reduced in DEHP-exposed prepubertal male offspring, and in a few adult males. No modulating effects of DEHA on the endocrine effects of DEHP were detected, but a tendency towards an accumulating effect of DEHP and DINP in combination on suppression of testosterone synthesis was seen.

Adipates↗
PubMedDate not supplied

Early testicular effects in rats perinatally exposed to DEHP in combination with DEHA--apoptosis assessment and immunohistochemical studies.

This study aimed to characterize the effects of di(2-ethylhexyl) phthalate (DEHP) on the fetal rat testes and relate them to the effects seen in adults. Histopathological effects in fetal testes were examined with immunohistochemistry for anti-Mullerian hormone (AMH), 3beta-hydroxysteroid dehydrogenase, smooth muscle actin (SMA), proliferating cell nuclear antigen (PCNA), histone H3 and vimentin. Additionally, testicular apoptosis levels were assessed in fetal, prepubertal and adult rats. As the plasticizer di(2-ethylhexyl) adipate (DEHA) has similarities with DEHP in chemical structure and metabolism, we investigated if the testicular effects of DEHP were modulated by co-administration with DEHA. Wistar rats were gavaged during gestation and lactation with vehicle, DEHP (300 or 750 mg/kg/day), or DEHP (750 mg/kg/day) in combination with DEHA (400mg/kg/day), and male offspring were examined at gestation day (GD) 21, postnatal day (PND) 22, 26 and 190. In fetal testes, Leydig cells were found in large clusters containing AMH positive Sertoli cells. At GD 21, seminiferous chords appeared enlarged with an apparently increased number of gonocytes. However, proliferation of gonocytes did not appear increased. A few animals had a high number of TUNEL positive apoptotic cells in degenerating seminiferous tubules at PND 22 and 190, whereas most exposed animals had low levels of germ cell apoptosis at GD 21, PND 22 or PND 26, as evaluated by DNA laddering, TUNEL staining, Caspase-3 immunohistochemistry and Caspase-3 activity measurement. No differences between DEHP and DEHP+DEHA exposed groups were observed.

Adipates↗
PubMed2005

Testicular toxicity of DEHP, but not DEHA, is elevated under conditions of thioacetamide-induced liver damage.

As part of an investigation of possible enhancement by liver disease of testicular toxicity caused by phthalates, we tested the effects of di(2-ethylhexyl)phthalate (DEHP) and di(2-ethylhexyl)adipate (DEHA) in a thioacetamide (TAA)-induced rat liver damage model. Male, 6-week-old, F344 rats (n=60) were divided into ten groups. Animals of groups 1-5 received TAA (200 mg/kg, intraperitoneal, three times per week) for 4 weeks, and groups 6-10 served as controls without TAA. After a 1 week interval, at week 5, powder diet containing DEHP or DEHA was provided to the animals of groups 1 and 6 (DEHP 25000 ppm), groups 2 and 7 (DEHP 6000 ppm), groups 3 and 8 (DEHA 25000 ppm) and groups 4 and 9 (DEHA 6000 ppm), while groups 5 and 10 received basal diet. All animals were sacrificed at week 9. Significant decrease in sperm numbers and motility and increase in morphology abnormalities were evident in group 1 as compared to groups 5 and 6 (p<0.01). However, DEHA treatment was not associated with any apparent testicular toxicity in either TAA- or vehicle-treated animals. Histopathological examination of the testes revealed severe atrophy and degeneration of testicular tubules in all animals given TAA and DEHP at high dose, only mild to moderate lesions being found with DEHP alone. We conclude that liver toxicity induced by TAA is associated with the enhancement of testicular toxicity of DEHP, but not DEHA, in rats.

Adipates↗
PubMed2005

Metabolites from the biodegradation of di-ester plasticizers by Rhodococcus rhodochrous.

The plasticizers di-2-ethylhexyl phthalate (DEHP) and di-2-ethylhexyl adipate (DEHA) are ubiquitous in the environment and undergo partial biodegradation in the presence of soil micro-organisms. The validity of a proposed pathway for the degradation of these plasticizers by Rhodococcus rhodochrous has been confirmed by the identification of 2-ethylhexanal in gas phase emissions. Complete analyses of the aqueous and gas phases were able to account for more than 98% of the 2-ethylhexanol component of the DEHA added at the beginning of a growth study. Of this, 25% was either 2-ethylhexanol or 2-ethylhexanal that had been stripped into the gas phase and, at most, only 2% of the 2-ethylhexanol component could have been removed by mineralization. It is concluded that plasticizers are of significant environmental concern due to the resistance of the metabolites to biodegradation and their known health impacts. Two of the metabolites are of added concern due to their volatility and their potential impact on indoor air quality.

Adipates↗
PubMed1999

A GC/MS/MS screening method for multiple organic acidemias from urine specimens.

A gas chromatography tandem mass spectrometry method using an ion trap GC/MS system was developed to quickly screen urine samples for 14 organic acids associated with multiple organic acidemias. The following organic acids are used as diagnostic markers: methylmalonic acid, glutaric acid, 2-ketoisocaproic acid, succinylacetone, 3-methylcrotonylglycine, tiglylglycine, isovalerylglycine, fumaric acid, butyrylglycine, propionylglycine, hexanoylglycine, adipic acid, suberic acid, and sebacic acid. 2-ketocaproic acid is used as an internal standard. The samples are prepared using a solid-phase extraction and converted to trimethylsilyl derivatives. The extraction efficiency for the 14 compounds is between 57 and 106%. A derivatized standard mixture of the 14 markers is run prior to the patient samples to determine the accurate absolute and relative retention times. The samples are then injected and the product ion spectra monitored. For data analysis, one characteristic product ion plot is extracted for each of the 14 marker compounds, and the presence of a peak with the expected retention time is determined. The areas of the product ion peaks are compared with the reference range determined from 30 normal controls. Ten samples of patients with known organic acidemias were measured. For all patients, diagnostic peaks at the expected retention times of at least five times the upper limit of the reference range were detected. The method, with its relatively fast sample preparation, short 10.0 min run time and simple data analysis, is suitable for use as a quick metabolic screen of very sick patients in whom there is concern regarding the possibility of a treatable inborn error.

Acids↗
PubMed1976

An improved technique for the gas-liquid chromatographic separation of the N-trifluoroacetyl n-butyl derivatives of amino acids.

A complete separation of the twenty protein amino acids and two internal standards in 35 min has been made possible by analyzing their N-trifluoroacetyl n-butyl (TAB) derivatives simultaneously on an ethylene glycol adipate (EGA) column and on an OV-17 column using the same temperature programme. The detector signal from the EGA column is recorded up to the point just after the elution of TAB-aspartic acid; thereafter, the signal from the effluent of the OV-17 column is recorded. The TAB derivative of norleucine is poorly resolved from TAB-leucine and TAB-proline. Therefore, alpha-aminocaprylic acid has been used as the internal standard instead of noreleucine. TAB-alpha-aminocaprylic acid appears as a separate peak between TAB-serine and TAB-cysteine.

Adipates↗
PubMed2002

Slow-stir water solubility measurements of selected alcohols and diesters.

Experimental data are presented for 11 C8-C15 aliphatic alcohols and 12 phthalate and adipate diesters using a slow-stir water solubility test method. The slow stirring method provides more reliable water solubility measurements for these liquid substances than previous studies since the formation of emulsions is avoided. Because the solubility of these chemicals spanned a range of more than six orders of magnitude, several different analytical procedures were employed. The water solubility data reported in this work agree well with other recently reported slow-stir measurements and with structure-property model predictions (SPARC and WSKOWWIN).

Adipates↗
PubMed2004

Effect of conjugation methodology on the immunogenicity and protective efficacy of meningococcal group C polysaccharide-P64k protein conjugates.

Neisseria meningitidis serogroup C polysaccharide (CCPS) was conjugated to the carrier protein P64k using two different conjugation procedures, condensation mediated by carbodiimide with adipic acid dihydrazide as spacer and the reductive amination method. BALB/c mice were immunized with the resultant polysaccharide-protein conjugates and the immune response was evaluated. All conjugates assayed generated at least 10-fold higher antibody titers than the free polysaccharide. The reductive amination method rendered the best conjugate (CCPS-P64kR) that was able to elicit antibody titers statistically higher than the titer elicited by the plain CCPS (P<0.001). The sera of the group immunized with CCPS-P64kR showed a three-fold higher bactericidal response than the sera of the group immunized with the plain CCPS and they were able to protect against challenge with meningococci in the infant rat protection model. In addition, three different conjugates were obtained from polysaccharides with molecular relative sizes of 2000-4000 Da, 4000-10,000 Da or 10,000-50,000 Da, but no differences were detected in the immune response obtained against the three conjugates. Our experiments demonstrate that it is possible to generate a protective, T-cell-dependent response against CCPS using the P64k protein as carrier.

Adipates↗
PubMed1975

New inhibitors of methane production by rumen micro-organisms. Experiments with animals and other practical possibilities.

1. Two inhibitors of rumen methane production were given to sheep and their effects were measured using an in vitro technique. 2. The substances used were trichloroethyl pivalate (TCE-P) and trichloroethyl adipate (TCE-A). In one experiment with two sheep TCE-P was injected into the rumen and in another experiment with two sheep the same inhibitor was mixed with the food just before feeding. In another experiment, TCE-A was given to two sheep at two dose levels, and in an experiment with four sheep two levels of inhibitor and two levels of diet were used. 3. In general the inhibition of methane production was greater with samples of rumen contents taken after feeding than with those taken before feeding. When sheep were given 120--300 mg TCE-P/d the inhibition of methane production ranged from 21 to 81%. When sheep given maintenance rations were given 125-300 mg TCE-A/d there was 28--90% inhibition of methane production. When sheep were given twice maintenance rations 150 mg TCE-A/d gave no inhibition and 300 mg TCE-A/d gave very low inhibition of methane production (about 16%). 4. In most experiments there was a significant increase in the propionic acid:acetic acid concentration ratio in the rumen when methane production was inhibited. 5. The possible practical use of inhibitors is discussed.

Adipates↗
PubMedDate not supplied

Synthesis and biological activity of ribose-5'-carbamate derivatives of vitamin B(12).

Twelve biologically active derivatives of vitamin B(12) (cyanocobalamin) have been synthesized in which spacers were attached to the ribose-5'-hydroxyl group of vitamin B(12). Their potential to act as oral delivery agents for proteins, nanospheres, or immunogens using the vitamin B(12) uptake system was evaluated by determining their affinity for intrinsic factor (IF) and non-IF. The ribose-5'-hydroxyl group of vitamin B(12) was activated through the use of 1,1'-carbonyldiimidazole (CDI), 1,1'-carbonyldi(1,2, 4-triazole) (CDT), or di(1-benzotriazolyl) carbonate (DBTC). Subsequent addition of an aminoalkane, diaminoalkane, or alkane diacid dihydrazide gave rise to vitamin B(12) derivatives suitable for attachment to various proteins, peptides, or nanospheres to enable oral delivery utilizing the vitamin B(12) uptake system. The ribose-5'-carbamate derivatives were found to possess similar affinity for intrinsic factor as that of the e-monocarboxylic acid of vitamin B(12). The affinity for non-IF was similar to cyanocobalamin or even higher for some of the smaller derivatives. Polysciences nanoparticles derivatized with vitamin B(12) 5'-carbamate adipic dihydrazide into CaCo-2 cells showed significantly higher levels of transport of the particles, when compared to unmodified particles.

Adipates↗
PubMed2001

Effect of a novel chemical mixture on senescence processes and plant--fungus interaction in Solanaceae plants.

The effects of exogenous application of a chemical mixture consisting of adipic acid monoethyl ester, furfurylamine, and 1,2,3,4-tetra-O-acetyl-beta-D-glucopyranose (FGA) on various metabolic pathways and the plant-fungus interaction have been studied in Solanaceae plants. Tomato and pepper plants were sprayed with the FGA mixture, and different biochemical parameters such as gas exchange, chlorophyll concentration, protein, cell wall sugar and phenolics contents, and peroxidase and phenylalanine ammonia lyase (PAL) activities were measured. FGA-treated plants showed, in general, an increase in cell wall sugar content and decreases in the chlorophyll degrading rate and the peroxidase activity. These results suggest that FGA (a possible synthetic regulator) could act as a retardant--antisenescence agent in Solanaceae plants. The FGA mixture increased the PAL activity and promoted an overall rise in the concentration of flavonoids and phenolic compounds. Therefore, FGA induced the synthesis of compounds that could give protection to plants against pathogens or insects. To further verify this putative protection, several fungi were inoculated in intact plants. Exogenous FGA applications on intact plants delayed fungus-provoked lesion development. In addition, data also showed that applications of 1,2,3,4-tetra-O-acetyl-beta-D-glucopyranose inhibited fungal growth in vitro. These results confirm that FGA can activate protective mechanisms in plants upon contact with invaders such as fungi.

Adipates↗
PubMed2000

Evaluation of synthetic schemes to prepare immunogenic conjugates of Vibrio cholerae O139 capsular polysaccharide with chicken serum albumin.

Vibrio cholerae serotype O139 is a new etiologic agent of epidemic cholera. There is no vaccine available against cholera caused by this serotype. V. cholerae O139 is an encapsulated bacterium, and its polysaccharide capsule is an essential virulent factor and likely protective antigen. This study evaluated several synthetic schemes for preparation of conjugates of V. cholerae O139 capsular polysaccharide (CPS) with chicken serum albumin as the carrier protein (CSA) using 1-ethyl-3(3-dimethylaminopropyl)carbodiimide (EDC) or 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) as activating agents. Four conjugates described here as representative of many experiments were synthesized in 2 steps: 1) preparation of adipic acid hydrazide derivative of CPS (CPS(AH)) or of CSA (CSA(AH)), and 2) binding of CPS(AH) to CSA or of CPS to CSA(AH). Although all conjugates induced CPS antibodies, the conjugate prepared by EDC-mediated binding of CPS and CSA(AH) (EDC:CPS-CSA(AH)) was statistically significantly less immunogenic than the other three conjugates. Representative sera from mice injected with these three conjugates contained antibodies that mediated the lysis of V. cholerae O139 inoculum. Evaluation of the different synthetic schemes and reaction conditions in relation to the immunogenicity of the resultant conjugates provided the basis for the preparation of a V. cholerae O139 conjugate vaccine with a medically useful carrier protein such as diphtheria toxin mutant.

Adipates↗
PubMed2002

Degradation of aliphatic polyester films by commercially available lipases with special reference to rapid and complete degradation of poly(L-lactide) film by lipase PL derived from Alcaligenes sp.

Commercial lipases were examined for their degradation efficiency of aliphatic polyester films. In 100 days immersion of polyester films in lipase solutions at 37 degrees C at pH 7.0, Lipase Asahi derived from Chromobacterium viscosum degraded polybutylene succinate-co-adipate (PBSA), poly (e-caprolactone) (PCL) and polybutylene succinate (PBS), and Lipase F derived from Rhizopus niveus degraded PBSA and PCL during 4-17 days. Lipase F-AP15 derived from Rhizopus orizae could degrade PBSA in 22 days. In these cases, PBS and PBSA were mainly degraded to dimers, whereas PCL was mainly degraded to monomers. Only poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB/V) and poly (L-lactide) (PLA) were not degraded in the experiments. However, PLA degraded completely at 55 degrees C, pH 8.5 with Lipase PL during 20 days. This result could be explained with the sequential reactions of the chemical hydrolysis of the polymer to oligomers at higher pH and temperature, and the succeeding enzymatic hydrolysis of oligomers to the monomers.

Adipates↗
PubMed2003

Isolation and characterization of a bacterium that degrades various polyester-based biodegradable plastics.

Microorganisms isolated from soil samples were screened for their ability to degrade various biodegradable polyester-based plastics. The most active strain, designated as strain TB-13, was selected as the best strain for degrading these plastics. From its phenotypic and genetic characteristics, strain TB-13 was closely related to Paenibacillus amyloyticus. It could degrade poly(lactic acid), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(caprolactone) and poly(ethylene succinate) but not poly(hydroxybutylate-co-valerate). However, it could not utilize these plastics as sole carbon sources. Both protease and esterase activities, which may be involved in the degradation of plastic, were constitutively detected in the culture broth.

Adipates↗
PubMed2004

Enzymatic transesterification of purine nucleoside having a low solubility in organic medium.

Enzymatic transesterification of guanosine having low solubility against organic solvent was examined. For the transesterification between guanosine and divinyl adipate catalyzed by alkaline protease from Bacillus (Bioprase), DMSO was added to DMF to increase the solublility of the nucleoside, and the conversion rate of guanosine to the vinyl guanosine ester was less than 30%. To overcome the reversible inactivation of enzyme by hydrophilic organic solvents, the reaction was carried out with 10% (v/v) water. The transesterification reaction was effectively catalyzed in DMF/DMSO in the presence of water and the conversion rate increased ca. 70% after 7 d reaction. The result shows that the water effect of Bioprase would be a useful method for the synthesis of low solublility nucleoside esters.

Adipates↗