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In this survey magnesium sails in the form of solid dispersions were studied to examine the interaction of the drug and lecithin or Tego Betain L-7. The results of thermal analysis of solid dispersions containing magnesium adipate Mg[Adip] and compounds of this salt with glycine substituent, and the partition coefficient (logP) of this salts applied for solid dispersion, have been presented in this paper. Lecithin (45% phosphatidylcholine) or Tego Betain L-7 (30% solution of amide betaine) have been added to magnesium salts to obtain a solid dispersion. The influence of auxiliary substances: Tego Betain L-7 and lecithin on physicochemical properties of the examined preparations has been assessed. The results of thermal analysis (DTA, DSC, TG) of magnesium complexes indicated their good thermal resistance up to the temperature of 375 K.

Peroxidase hydrazides were prepared by conjugating horseradish peroxidase (HRP) to adipic acid dihydrazide (ADH) by carbodiimide or periodate oxidation method. The resulting HRP hydrazides (ADH-HRP) were conjugated to cortisol-21-hemisuccinate (cortisol-21-HS) by forming diimide bonds using the N-hydroxysuccinimide (NHS) carbodiimide mediated reaction. The prepared cortisol-21-HS-ADH-HRP enzyme conjugates were utilized for the development of an enzyme linked immunosorbent assay (ELISA) for direct estimation of cortisol. To the cortisol antibody coated microtiter wells, standard or serum sample (50 microL), along with 100 microL of cortisol-21-HS-ADH-HRP enzyme conjugate (ADH-HRP used is prepared by either carbodiimide or periodate oxidation method), was incubated for 1 hr at 37 degrees C. Bound enzyme activity was measured by using tetramethyl benzidine/hydrogen peroxide (TMB/H202) as substrate. The sensitivity, specificity, and recovery of the assays were found to be identical when ELISAs were employed with cortisol enzyme conjugates prepared by conjugating cortisol-21-HS to HRP hydrazide, made either by the carbodiimide method or periodate oxidation method.

Residue Phe375 of cephalosporin acylase has been identified as one of the residues that is involved in substrate specificity. A complete mutational analysis was performed by substituting Phe375 with the 19 other amino acids and characterising all purified mutant enzymes. Several mutations cause a substrate specificity shift from the preferred substrate of the enzyme, glutaryl-7-ACA, towards the desired substrate, adipyl-7-ADCA. The catalytic efficiency ( [Formula: see text] (cat)/ [Formula: see text] (m)) of mutant SY-77(F375C) towards adipyl-7-ADCA was increased 6-fold with respect to the wild-type enzyme, due to a strong decrease of [Formula: see text] (m). The [Formula: see text] (cat) of mutant SY-77(F375H) towards adipyl-7-ADCA was increased 2.4-fold. The mutational effects point at two possible mechanisms by which residue 375 accommodates the long side chain of adipyl-7-ADCA, either by a widening of a hydrophobic ring-like structure that positions the aliphatic part of the side chain of the substrate, or by hydrogen bonding to the carboxylate head of the side chain.

Aerobic metabolism of phenylalanine in most bacteria proceeds via oxidation to phenylacetate. Surprisingly, the further metabolism of phenylacetate has not been elucidated, even in well studied bacteria such as Escherichia coli. The only committed step is the conversion of phenylacetate into phenylacetyl-CoA. The paa operon of E. coli encodes 14 polypeptides involved in the catabolism of phenylacetate. We have found that E. coli K12 mutants with a deletion of the paaF, paaG, paaH, paaJ or paaZ gene are unable to grow with phenylacetate as carbon source. Incubation of a paaG mutant with [U-13C8]phenylacetate yielded ring-1,2-dihydroxy-1,2-dihydrophenylacetyl lactone as shown by NMR spectroscopy. Incubation of the paaF and paaH mutants with phenylacetate yielded delta3-dehydroadipate and 3-hydroxyadipate, respectively. The origin of the carbon atoms of these C6 compounds from the aromatic ring was shown using [ring-13C6]phenylacetate. The paaG and paaZ mutants also converted phenylacetate into ortho-hydroxyphenylacetate, which was previously identified as a dead end product of phenylacetate catabolism. These data, in conjunction with protein sequence data, suggest a novel catabolic pathway via CoA thioesters. According to this, phenylacetyl-CoA is attacked by a ring-oxygenase/reductase (PaaABCDE proteins), generating a hydroxylated and reduced derivative of phenylacetyl-CoA, which is not re-oxidized to a dihydroxylated aromatic intermediate, as in other known aromatic pathways. Rather, it is proposed that this nonaromatic intermediate CoA ester is further metabolized in a complex reaction sequence comprising enoyl-CoA isomerization/hydration, nonoxygenolytic ring opening, and dehydrogenation catalyzed by the PaaG and PaaZ proteins. The subsequent beta-oxidation-type degradation of the resulting CoA dicarboxylate via beta-ketoadipyl-CoA to succinyl-CoA and acetyl-CoA appears to be catalyzed by the PaaJ, PaaF and PaaH proteins.

An alternative liquid chromatographic (LC) method was developed and validated for the simultaneous determination of methoxyl and 2-hydroxypropoxyl substituents in hypromellose and hypromellose acetate succinate. The method uses the hydriodic acid cleavage reaction, catalyzed by adipic acid, of the substituted methoxyl and 2-hydroxypropoxyl groups, which are quantitatively converted to iodomethane and 2-iodopropane. The iodomethane and 2-iodopropane are extracted into xylene, the extract is diluted with methanol, and the analytes are separated and assayed by gradient elution using a reversed-phase C18 column. The method is selective and sensitive and has good linearity with values of 0.999 for R2 and 0.25% for the gamma-intercept bias from 1.39 to 5.55 mg/mL for iodomethane, and 0.999 for R2 and 0.52% for the gamma-intercept bias from 0.184 to 0.735 mg/mL for 2-iodopropane. The relative standard precisions for this LC method were found to be +/- 2.3% for determining methoxyl at the 23.1% (w/w) level, and +/- 3.5% for determining 2-hydroxypropoxyl at the 6.7% (w/w) level. Compared with the current gas chromatographic (GC) compendial (JPE) method, the LC assay method has equal or better precision. It was found that both the standard and sample solutions have limited stability (8 h) after preparation. This limited stability has not been reported previously in the literature and may have an impact on the reported accuracy/precision of the literature data for the GC method. The LC method was proven to be robust with respect to variation in derivatization time and temperature, flow rate, and column temperature. It is well suited for the quality control needed in today's fast-paced pharmaceutical laboratories.

Adipic acid (2) production currently entails use and generation of environmentally harmful materials: an efficient catalyst, consisting of nanoparticles of Ru10Pt2 anchored within the pores of mesoporous silica, facilitates the production of (2) by hydrogenating muconic acid, that may be derived biocatalytically from D-glucose.

The first step of enzyme linked immunosorbent assay (ELISA), namely, adsorption of antigen or antibody to the plastic microtiter well plate, was studied as a function of insolubility of IgG in water. Immobilization efficiency was assessed in terms of number of wells coated per milliliter of primary antiserum. We have compared different coating/immobilization protocols, i.e., direct and indirect immobilization of primary antibody to the plastic microtiter well plate using carbonate buffer and phosphate buffer with glutaraldehyde. We have observed efficient coating when the immobilization of primary antibody through an immunobridge technique was performed, where water was used as a coating medium. It gave a higher number of wells coated per milliliter of anti-serum (primary or secondary) than other compared coating protocols and it allowed the use of serum (non-immune) and anti-serum (primary and secondary antibody) dilutions, avoiding the need for gamma-globulin purification from normal and immunized serum.

Neurosteroids such as dehydroepiandrosterone (DHEA), pregnenolone and 17beta-estradiol are synthesized by cytochrome P450s from endogenous cholesterol. We previously reported a new cytochrome P450 enzyme, CYP7B, highly expressed in rat and mouse brain that metabolizes DHEA and related steroids by hydroxylation at the 7alpha position. Such 7-hydroxylation can enhance DHEA bioactivity in vivo. Here we show that the reaction is conserved across mammalian species: in addition to mouse and rat, DHEA hydroxylation activity was present in brain extracts from sheep, marmoset and human. Northern blotting using a human CYP7B complementary deoxyribonucleic acid (cDNA) probe confirmed the presence of CYP7B mRNA in marmoset and human hippocampus; CYP7B mRNA was present in marmoset cerebellum and brainstem, with lower levels in hypothalamus and cortex. In situ hybridization to human brain revealed higher levels of CYP7B mRNA in the hippocampus than in cerebellum, cortex, or other brain regions. We also measured CYP7B expression in Alzheimer's disease (AD). CYP7B mRNA was significantly decreased (approximately 50% decline; P<0.05) in dentate neurons from AD subjects compared with controls. A decline in CYP7B activity may contribute the loss of effects of DHEA with ageing and perhaps to the pathophysiology of AD.

One step competitive enzyme linked immunosorbent assay (ELISA) for direct estimation of testosterone in human serum is described. Testosterone-3-O-carboxymethyl-oxime-bovine serum albumin (testosterone-3-O-CMO-BSA), was used as immunogen and testosterone-3-O-carboxymethyl-oxime-adipic-acid dihydrazide-horseradish peroxidase (testosterone-3-O-CMO-ADH-HRP) was used as tracer. To the testosterone antibody coated microtiter wells, standard or serum samples (100 microL), along with testosterone-3-O-CMO-ADH-HRP conjugate (100 microL) were incubated for 1 h at 37 degrees C. Bound enzyme activity was measured by using tetra methyl benzidine/hydrogen peroxide (TMB/H2O2) as a substrate. In this new strategy, charcoal stripped pooled human serum spiked with non-cross reactive C18, C19, C21, and C27 steroids, used for preparing the standards and blocking the sex hormone binding globulin (SHBG)/and other steroid binding globulins (SBG). The sensitivity of the assay was 0.015 ng/mL. The intra-assay and inter-assay coefficients of variation (CVs) were ranged from 7.8 to 11.8 and 4.8 to 10.4, respectively. The serum testosterone values, obtained by this method, were correlated well with those obtained by radioimmunoassay r = .98 (n = 100).

Molecular mobility and phase structure of biodegradable poly(butylene succinate) (PBS) and poly(butylene succinate-co-20 mol % butylene adipate) [P(BS-co-20 mol % BA)] have been investigated by high-resolution solid-state (13)C NMR. For both samples, two components with different (13)C spin-lattice relaxation time (T(1C)) values have been observed in the crystalline region. The crystalline component with shorter T(1C) value is assignable to the interface near amorphous phase. The crystalline component with longer T(1C) value is ascribed to the inside of the crystalline region. On the basis of T(1C), it has been concluded that the BA units are not included in the crystalline region of P(BS-co-20 mol % BA). Molecular mobility and higher-ordered structure of amorphous phase have been also compared between the melt and solid state. Variable-temperature high-resolution (13)C NMR measurements for the amorphous phase have revealed the remarkable difference in dynamics and structure between the melt and solid state.

Commercially available proteases and lipases were screened for their ability to acylate regioselectively sucrose with divinyladipate either in pyridine or dimethylformamide (DMF). The protease (EC 3.4.21.62) from Bacillus subtilis (Proleather FG-F) exhibited the highest conversion (100% in 24 h of reaction in DMF) yielding sucrose 2-O-vinyladipate as main product. The enzyme preference for a secondary hydroxyl group is a distinct feature of this biocatalyst compared to others described in the literature. Two sets of chemically distinct silica supports were used for Proleather immobilization presenting terminal amino (S(APTES)) or hydroxyl groups (S(TESPM)(-)(pHEMA)). The percentage of immobilized enzyme was smaller in S(APTES) (7-17%) than in S(TESPM)(-)(pHEMA) (52-56%), yet Proleather immobilized into S(APTES) supports presented higher total and specific hydrolytic activity. The highest total and specific activities were obtained with S(TESPM)(-)(pHEMA) and S(APTES), respectively. Silicas with large pore (bimodal distribution of pores, 130/1200 A, denoted as S(1000)) presented higher specific activities relative to those with smaller pore sizes. Furthermore, the synthetic specific activity of S(1000)S(APTES) immobilized protease was ca. 10-fold higher than that of the free enzyme. In addition to sucrose, the immobilized protease was used to acylate methyl alpha-D-glucopyranoside, trehalose, and maltose in nearly anhydrous DMF. Finally, immobilized Proleather was reasonably stable, retaining ca. 55% activity after six reaction cycles.

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).

Adipic acid, upon catabolism, results in intermediates that bear a structural similarity to lysine degradation products. The objectives of this research were to determine whether adipic acid affects lysine concentrations in plasma and to evaluate whether adipic acid improves the efficiency of lysine utilization in pigs. In Exp. 1, nursery pigs (n = 14) were fed (for a period of 7 d) either a standard nursery diet or the same diet supplemented with 1% adipic acid to assess effects on plasma amino acid concentrations (plasma collected on d 7). In Exp. 2, nursery pigs (n = 56) were fed (for a period of 15 d) either a control diet or the same diet but deficient in either lysine, threonine, or tryptophan with or without supplemental adipic acid to assess the effects of adipic acid on the efficiency of amino acid utilization. The results from Exp. 1 showed that adipic acid increased plasma lysine (by 18%) but not alpha-amino adipic acid, an intermediate in lysine degradation. Experiment 2 demonstrated that adipic acid did not increase the efficiency of utilization of lysine, threonine, or tryptophan. The lack of effects on alpha-amino adipic acid in Exp. 1 and the lack of a positive effect on the efficiency of utilization of lysine, threonine, and tryptophan suggest that adipic acid does not inhibit the mitochondrial uptake of lysine and(or) its degradation in the mitochondrion. It is concluded that feeding adipic acid increases plasma lysine but does not improve the efficiency of lysine utilization.

Poly(tetramethylene succinate-co-tetramethylene adipate) (PBSA) and poly(tetramethylenesuccinate) (PBS) were hydrolyzed experimentally into water-soluble oligomers and monomers by Chromobacterium extracellular lipase. The oligomers were identified by high-performance liquid chromatography-mass spectrometry and 1H-nuclear magnetic resonance, which indicated that a total of 28 oligomer species were liberated from PBSA, and that 13 of them were identical to the hydrolysates from PBS. Moreover, 20 of the species were polyester-based compounds of monomer units, and the other 8 species were small amounts of diurethane compounds. Bis(hydroxybutyl) succinate (BSB) and bis(hydroxybutyl) hexamethylene dicarbamate (BHB) were the typical oligomers and were chemically synthesized. Biodegradability of BSB and BHB was examined for 28 d in the activated sludge, and analysis of the results of this study indicated that the final conversion rate of constituent carbon to carbon dioxide was estimated at 80 mol% for BSB and 10 mol% for BHB. The remaining amount of carbon in the undegraded BHB was 20 mol%. In the presence of BSB, the biodegradability of BHB was increased by about 1.5 times. The suggestion was made that BSB induced a growth of microorganisms and helped BHB degradation. This is consistent with the observation that the biodegradation of BHB in native soil for 60 d reached > 60%.

Stearamide DIBA-Stearate is a substituted dihydroxyisobutylamine (DIBA) that functions in cosmetic formulations as an opacifying agent, a surfactant-foam booster, and a viscosity increasing agent. Stearamide DIBA-Stearate was reportedly used in four cosmetic formulations, at concentrations of 1% to 3%. Few data on this ingredient were available. Data on related ingredients, including Dibutyl Adipate, Diisopropyl Adipate, Stearamide DEA, and Stearamide MEA, were considered in the assessment of safety. A formulation containing 1.3% Stearamide DIBA-Stearate (further diluted to 4% of the formulation) was mildly irritating but nonsensitizing in an repeated-insult patch test (RIPT). The same dilution was noncomedogenic. At a concentration of 20%, Dibutyl Adipate had an oral LD50 of 2 g/kg. Subchronic dermal exposure of rabbits (1.0 ml/kg/day) caused a reduction in weight gain that was not observed at a dose of 0.5 ml/kg/day. In studies using rabbits, undiluted Dibutyl Adipate caused mild to moderate skin irritation and minimal ocular irritation. When pregnant rats were treated intraperitoneally with approximately 1.75 ml/kg Dibutyl Adipate during gestation, the incidence of fetal gross abnormalities was increased. No effect was observed at smaller doses. Diisopropyl Adipate had low acute oral and percutaneous toxicity, and was only a very mild ocular irritant. In skin irritation studies using rabbits, 5.0% to 100% Diisopropyl Adipate caused minimal to mild irritation; these results were also seen in clinical testing with only moderate cumulative irritation, and no sensitization or photosensitization. A formulation containing 5.27% Stearamide MEA was not toxic to rats when applied topically daily for 13 weeks. In studies using rabbits, Stearamide DEA (35% to 40%) was not a skin or ocular irritant, and Stearamide MEA (5.27%) was not an ocular irritant. At 17%, Stearamide MEA was not irritating to the skin, but caused minimal to moderate irritation to the eyes of rabbits. Stearamide MEA (5.27%) did not cause sensitization during a clinical study. It was not possible, however, to determine the relevance of these data on related ingredients. Therefore, it was concluded that the available data are insufficient. Additional data needs are (1) method of manufacture; (2) chemical characterization, including impurities; (3) dermal absorption; if significantly absorbed, then a 28-day dermal toxicity study and a reproductive and developmental toxicity study may be needed; (4) two genotoxicity assays, at least one in a mammalian system; if positive, then a 2-year dermal carcinogenesis study using National Toxicology Program (NTP) methods may be needed; (5) ultraviolet (UV) absorption data; if significant absorption occurs in the UVA or UVB range, photosensitization data are needed. Absent these data, it was concluded that the available data are insufficient to support the safety of Stearamide DIBA-Stearate as used in cosmetic products.

Various microorganisms were screened for their ability to degrade poly(tetramethylene succinate)-co-(tetramethylene adipate) (PBSA). Strain BS-3, which was newly isolated from a soil sample, was selected as the best strain. From taxonomical studies, the strain was tentatively ascribed to belong to the genus Acidovorax, most probably to the species A. delafieldii. Strain BS-3 could degrade both solid and emulsified PBSA, and also emulsified poly(tetramethylene succinate). During the degradation, a lipase activity was observed in the culture broth. This lipase activity was induced more strongly by PBSA than by tributyrin or triolein which are typical substrates of lipase. These observations strongly suggest that this lipase was involved in the PBSA biodegradation in strain BS-3.

The variation in physical properties of crystals grown in the presence of additives or impurities have previously been attributed to lattice disorder developed during crystallization. Adipic acid crystallized in the presence of a variety of stereochemically related impurities typifies such behavior with disorder manifest in variations of dissolution rates and enthalpies of solution and fusion. In this case the most extreme habit, produced by the presence of added monoalkanoic acids, is a rounded dumbbell that was suggested previously to be a twinned crystal. In this contribution such crystals are fully characterized both through their external morphology and by means of single crystal X-ray diffraction. These techniques show that these particles are not twinned but rather are disordered single crystals comprising a small number of slightly misaligned domains. The interaction between additive and substrate is modeled and new additives selected that induce the formation of true mechanical twins in adipic acid.

The spraying of a paint formula (Acramin F system) had led to severe pulmonary disease in textile printing sprayers in Spain and Algeria (Ardystil syndrome). In order to elucidate the underlying mechanisms of the toxicity of this paint and its main polymeric components, Acramin FWR, Acramin FWN, Acrafix FHN, and Acramoll W, we have undertaken studies using a battery of different cell-types and assessing in vitro cytotoxicity by measuring LDH leakage. This study shows that, as in in vivo studies, the three polycationic paint components, Acramin FWR (a polyurea), Acramin FWN (a polyamide-amine), and Acrafix FHN (a polyamine) exhibited considerable cytotoxicity (LC50 generally below 100 microg/ml for an incubation of 20-24 h) in vitro, while Acramoll W, which is not a polycation, was almost non-toxic (in the concentration range tested). The cytotoxicity was comparable in primary cultures of rat and human type II pneumocytes and alveolar macrophages as well as in the pulmonary cell line A549 and the hepatic cell line HepG2. In human erythrocytes, the toxicity was less pronounced. We speculate that the multiple positive charges play an important role in the toxic mechanism. It is concluded that Acramin FWR and Acramin FWN have similar intrinsic toxicity and that these polymeric compounds, which have no irritant properties or systemic toxicity when given orally, exert a high, unexpected, degree of cytotoxicity.

The cross-linking effect of adipic acid dihydrazide (ADH) on polysaccharide derivatization can be evaluated by applying combination of elemental analysis and colorimetric assay. Elemental analysis is used for estimation of total ADH bound to polysaccharide and a colorimetric trinitrobenzene sulfonic acid assay is used to determine the part of ADH not involved in cross-linking. The difference of values expressed as molar ratios (per repeating unit) provides information on the amount of ADH involved in cross-linking the polysaccharides. Carboxymethylated polysaccharides were derivatized with different amounts of ADH to test the procedure. Analytical results showed that excess of ADH in the reaction only slightly decreased the cross-linking. The number of carboxyl groups remained unmodified even at high excess of ADH and high concentration of carbodiimide (EDC) coupling reagent.

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.

Guest molecules (impurities or additives), together with some crystallization solvent, are often incorporated into the host crystals during crystallization from solution. The guest molecules may be incorporated either in solid solution or in liquid inclusions, or by both mechanisms. The mechanism of guest incorporation has been examined by a simple calculation method which is based on the equality of the guest/solvent mole ratio in the initial crystallization medium and in the putative inclusions. Application of this calculation method to eight guest+host systems described in the literature has shown that a negligible amount (at most 0.2%) of the guest molecules is incorporated into the crystal lattice in liquid inclusions. Therefore, it is concluded that the vast majority of the guest molecules are incorporated into the crystals in solid solution, as previously suggested, but hitherto unproven, for these guest-host systems.

A study on the use of derivatized carbohydrates as C2-symmetric HIV-1 protease inhibitors has been undertaken. L-Mannaric acid (6) was bis-O-benzylated at C-2 and C-5 and subsequently coupled with amino acids and amines to give C2-symmetric products based on C-terminal duplication. Potent HIV protease inhibitors, 28 Ki = 0.4 nM and 43 Ki = 0.2 nM, have been discovered, and two synthetic methodologies have been developed, one whereby these inhibitors can be prepared in just three chemical steps from commercially available materials. A remarkable increase in potency going from IC50 = 5000 nM (23) to IC50 = 15 nM (28) was observed upon exchanging -COOMe for -CONHMe in the inhibitor, resulting in the net addition of one hydrogen bond interaction between each of the two -NH- groups and the HIV protease backbone (Gly 48/148). The X-ray crystal structures of 43 and of 48 have been determined (Figures 5 and 6), revealing the binding mode of these inhibitors which will aid further design.

The structure of WA8242B, a potent novel inhibitor against phospholipase A2, was fully characterized by spectroscopic methods and chemical degradation. The success of total synthesis of WA8242B confirmed the structure and allowed the pharmacological study of WA8242B. The structures of WA8242A1 and A2 were also described.

We evaluated the effects of pretreating rats intravenously with small aliphatic dicarboxylic acids on the renal disposition of injected inorganic mercury. Three different sets of experiments were carried out. When rats were pretreated with succinic acid, glutaric acid, or adipic acid 5 min prior to the injection of a 0.5-mumol/kg dose of mercuric chloride, there was a significant dose-dependent inhibitory effect on the renal disposition of mercury during the first hour after the administration of mercuric chloride. Both glutaric and adipic acid, at a dose of 1.0 mmol/kg, caused the greatest level of inhibition in the renal tubular uptake of inorganic mercury. By the end of the first hour after the injection of mercuric chloride, the renal burden of mercury in rats pretreated with either glutaric or adipic acid was 27-35% lower than in corresponding control rats. Malonic acid at a dose of 1.0 mmol/kg had no effect on the renal disposition of inorganic mercury. The inhibitory effect of succinic, glutaric, or adipic acid on the overall renal uptake of mercury was due to effects in both the cortex and outer stripe of the outer medulla. Findings from an experiment in which rats had their ureters ligated showed that the inhibitory effect of glutaric acid on the renal tubular uptake of mercury was due to inhibition of the uptake of mercury at the basolateral membrane. Our findings confirm that one of the mechanisms involved in the proximal tubular uptake of inorganic mercury is located on the basolateral membrane. According to findings from our previous studies, this mechanism appears to involve the activity of the organic anion transporter. The inhibitory effects of dicarboxylic acids on the renal tubular uptake of administered inorganic mercury, especially in rats whose ureters had been ligated, are consistent with the hypothesis that the organic anion transport system is involved in the basolateral uptake of inorganic mercury along the proximal tubule.

Spherical reservoir-type microcapsules fabricated using a water/oil/water (W/O/W) double emulsion technique with solvent evaporation and composed of poly(ethylene adipate) (PEAD) blended with 20% poly-epsilon-caprolactone (PCL II) containing a range of bovine serum albumin (BSA) loadings were incubated in Hank's buffer, pH 7.4, newborn calf serum, 1.5% pancreatin and synthetic gastric juice containing 10% pepsin A over 30 days and their percentage weight loss (PWL) and changes in ultrastructural morphology monitored by gravimetry and stereoscan electron microscopy (SEM) respectively. The greatest PWL from microcapsules was observed after incubation in newborn calf serum (NCS) and pancreatin and decreased in the order NCS > pancreatin > synthetic gastric juice > Hank's buffer. Only microcapsules theoretically loaded with 5-20% BSA and incubated in synthetic gastric juice showed a significant increase in PWL with increasing percentage BSA loading. The structural biodegradation of PEAD microcapsules in both Hank's buffer and synthetic gastric juice was minimal whilst the morphological changes observed during incubation in NCS involved pitting of the membrane, some surface erosion and reduction in diameter, followed by microcapsule membrane disruption and loss of reservoir contents. Biodegradation in pancreatin was associated with surface flaking and loss of large fragments of the microcapsule membrane. Only in NCS and pancreatin, where one would expect to see the effects of enzyme activity in addition to simple ester hydrolysis, did biodegradation proceed to the stage where there was a loss of spherical shape and almost total disruption of the microcapsule structure within 30 days.

Many additives used in plastics materials and articles intended for food contact are expected to be assigned specific migration limits (SMLs) in a future amendment to EC Directive 90/128/EEC. In order to demonstrate compliance with these restrictions, specific migration tests will need to be performed on the finished plastics packaging using foods or the appropriate EC food simulants. Owing to the involatile and lipophilic nature of many of these additives, their analysis in the conventional fatty food simulant, olive oil, presents technical difficulties. One way of overcoming these difficulties would be to use a simple solvent alternative to olive oil as has been proposed for overall migration testing. The objective of this work is to compare specific migration data obtained using olive oil with alternative fat simulants iso-octane and 95% ethanol, to find out if similar results are obtained and identify the most appropriate alternative simulant to use for future testing. Good agreement with the olive oil migration data was obtained using 95% ethanol (equivalent exposure conditions) for both of the additives studied in polyolefins. For the polystyrene materials studied it is unlikely that the SMLs for the two additives would be exceeded, and in these cases iso-octane (1.5 h at 60 degrees C) could be used as a rapid 'alternative test'.

The adipoyl- and suberoyl-linked bis(Ala) peptides have an extended backbone between the two C alpha atoms in each molecule. They self-assemble, through intermolecular hydrogen bonds and stacking of parallel strands, into highly ordered modified beta-sheet-like structures. Crystals data for adipoyl bis(Ala)diester are as follows: C14H24N2O6, monoclinic space group P2(1), a = 4.900(1), b = 29.093(10), c = 6.021(2) A, beta = 104.20(2) degrees, R = 0.053 for 1100 data > 3 sigma (F); for suberoyl bis(Ala)diester: C16H28N2O6, monoclinic space group P2(1), a = 4.887(2), b = 32.650(9), c = 6.004(2) A, beta = 103.79(3), R = 0.070 for 1065 data > 3 sigma (F).

A procedure for the assay of nitrile hydratase and amidase activity by high-performance liquid chromatography is described. The method can be used to assay the intermediate compounds resulting from the hydrolysis of adiponitrile into adipic acid, and to determine the kinetics of the hydrolysis of these compounds using whole cells and enzyme extracts. The precision of the method makes it suitable for the determination of the enzyme parameters: Km and Vm (nitrile hydratase and amidase). Using cyanovaleramide as substrate, Km and Vm were respectively 370 mM and 2060 U/mg for nitrile hydratase and 6.6 mM and 33 U/mg for amidase.

The possibility of producing slowly dissolving albuterol salts was investigated as a potential means of extending the duration of action of the drug following aerosol delivery to the lung. Albuterol adipate and stearate were precipitated from alcoholic solutions of albuterol and adipic or stearic acids, respectively. Differential scanning calorimetry and hot stage microscopy showed that albuterol adipate and stearate produced single melting endotherms at 182 and 116 degrees C, respectively, which were distinct from those of albuterol (158 degrees C), adipic acid (152 degrees C), and stearic acid (70 degrees C). The aqueous solubilities of albuterol free base, sulfate, adipate, and stearate were 15.7, 250, 353, and 0.6 mg . mL-1, respectively, at room temperature. Only the solubilities of the adipate and the stearate increased significantly when the temperature was elevated to 37 degrees C (452.5 and 1.4 mg . mL-1, respectively). With a rotating disk dissolution method, albuterol free base, sulfate, and adipate were found to have intrinsic dissolution rates of 1.1, 20.4, and 24.0 mg . min-1 . cm-2, respectively, in pH 7.4 phosphate buffer at 37 degrees C. Albuterol stearate dissolved much more slowly and in a nonlinear fashion; this was explained by the deposition of a stearate-rich layer on the dissolving surface of the compacted salt.

Four new binuclear complexes of formula [M2(bipy)2(BAA)]Cl2 (where M is Pt(II) or Pd(II), bipy is 2,2'-bipyridine, and BAA is a dianion of meso-alpha-alpha'-diaminoadipic acid (DAA) or meso-alpha,alpha'-diaminosuberic acid (DSA) have been synthesized. These complexes have been characterized by chemical analysis and ultraviolet-visible, infrared, and 1H NMR spectroscopy. The mode of binding of ligands in these complexes has been ascertained by infrared and detailed 1H NMR spectroscopy. These complexes are 1:2 electrolyte in conductivity water. They have also been tested against P388 lymphocytic leukemia cells and their target is DNA molecules. [Pt2(bipy)2(DSA)]Cl2, [Pd2(bipy)2(DSA)Cl2, and [Pd2(bipy)2(DAA)]Cl2 show I.D.50 values comparable or lower than cis-diamminedichloroplatinum(II) and [Pt(bipy)(Ala)]Cl. In addition, binding studies of [Pt2(bipy)2(DSA)]Cl2 and [Pd2(bipy)2(DAA)]Cl2 to calf thymus DNA have been carried out and the mode of binding seems to be hydrogen bonding, as suggested earlier for analogous mononuclear amino acid-DNA complexes.

Factors affecting the specific activity of immobilized antibodies and their biologically active fragments were studied with goat anti-mouse and goat anti-human immunoglobulin G. Antibodies were immobilized on HW 65 polymeric support matrix activated with carbonyldiimidazole, hydrazide and iodoacetic acid. The most significant factors influencing the specific activity of stochastic coupling of antibodies are multi-site attachment, multiple orientations and steric hindrance imposed by crowding of antibody and the size of the antigen. In oriented immobilization the specific activity is affected only by steric hindrance. The specific activity of immunosorbents prepared by immobilization of F(ab') fragments can be improved to almost 100% by limiting the amount of protein immobilization and the size of the antigen. The present study shows the protocols for optimizing immobilized antibody performance.

To assess the significance of migration of polymeric plasticizers into foods, chemical characterization and quantification of individual oligomeric species is required. This paper reports the identification of seven individual oligomers isolated from a poly(butylene adipate) plasticizer. Based on mass spectrometry, NMR and chemical degradation, the oligomers were identified as a series of diol-terminated units ranging from a trimer up to an 11-monomer unit, along with a cyclic tetramer, all in the molecular weight range of 300-1100. A study of the migration of polymeric plasticizer from PVC film into olive oil indicated preferential migration of low molecular weight species. These oligomers which comprised 24% of the parent plasticizer contributed more than 90% of the plasticizer migration with the smallest oligomers migrating 90-fold more readily than the bulk of the plasticizer. From a knowledge of total polymeric plasticizer migration from PVC films under actual conditions of food-use, the abundance of individual oligomers in the foods has been estimated.

The crystal structure of sodium hydrogen adipate-adipic acid (2/1) dihydrate, [Na2(C6H9O4)2(C6H10O4)].2H2O, Mr = 518.4, has been determined from neutron diffraction data collected at 220 and 295 K. Crystals are monoclinic, space group C2/m, with Z = 2. At 295 K, a = 9.378 (2), b = 13.379 (5), c = 10.247 (3) A, beta = 95.93 (3) degrees, V = 1278.8 (7) A3, Dn = 1.346, Dm = 1.348 (1) g cm-3 (in dibromomethane/bromobutane), lambda = 1.1588 (2) A, mu = 2.186 cm-1, F(000) = 176.4 fm, R(F2) = 0.108 for all 1995 nonequivalent reflections with sin theta/lambda less than 0.71 A-1. The crystal structure is similar at 220 K except for reduced nuclear mean-square displacements. Hydrogen adipate subunits (called A) are linked end-to-end in infinite chains by very short O...O (2.44 A) hydrogen bonds where the H nuclei are on centers of symmetry within the experimental error. The Na cation is octahedrally coordinated by O atoms from molecules A and also by non-ionized adipic acid molecules (called B). The B molecules have large mean-square nuclear displacements which are described in terms of anharmonicity and disorder.