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PubMed1977

[Studies on sulfhemoglobin formation by various drugs (2) (author's transl)].

Sulfhemoglobin (SHb) and methemoglobin (MHb) formations by various aniline erivatives were examined by a single and three consecutive intraperitoneal administrations to mice. It was found that with a single administraion, methemoglobinemia was induced by aniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 3-trifluoromethylaniline (3-TFMA), 4-trifluoromethylaniline (4-TFMA), 2, 3-dichloroaniline, 2-aminopehnol, acetanilide (AA), 2-hydroxyacetanilide, N-methylaniline (NMA), N,N-dimethylaniline (NDMA), N-ethylaniline (NEA) and N,N-diethylaniline, and was not observed with 2, 3-dimethylanilnie, 2-trifluoromethylaniline, 3-aminophenol, 4-aminophenol, 2. 6-dichloroaniline, 3-hydroxyacetanilide (3-HAA), 4-hydroxyacetanilide (4-HAA), 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid and 4-chloro-2-aminobenzoic acid. On the other hand, sulfhemoglobinemia which appeared much more delayed than MHb, with a single administration, was found to be induced by 3-TFMA, 4-TFMA and NMA. Furthermore, with three consecutive administrations, such was induced by AA, 3-HAA, NDMA and NEA even though SHb was not demonstrated with a single administration. Structure-SHb and MHb forming property relationships were discussed.

Aniline Compounds↗
PubMed2001

Enhanced biodegradation of petrochemical wastewater using ozonation and BAC advanced treatment system.

The characteristics of degradation/conversion of bio-refractory and the growth of a biofilm are investigated in laboratory-scale pre-ozonation and lifted moving-bed biological activated carbon (BAC) advanced treatment processes treating phenol, benzoic acid, aminobenzoic acid and petrochemical industry wastewater which contains acrylonitrile butadiene styrene (ABS). The optimal reaction time and ozone dosage of pre-ozonation for bio-refractory conversion were determined to be 30 min and 100-200 mg O3/hr, respectively. After pre-ozonation of 30 min treatment, BOD5/COD ratio of influent and effluent increased apparently from 20 to 35%, approximately. However, the change of pH in pre-ozonation was inconspicuous. The optimal flow rate of influent and air were controlled at 1.6 l/h and 120-150 nl/min in lifted moving-bed BAC advanced treatment reactor. A COD removal efficiency of 85-95% and 70-90% may be maintained by using an organic loading of 3.2-6.3 kg COD/m3 day and 0.6-1.6 kg-COD/m3 day with an HRT of 6.0 h as secondary and advanced treatment system, respectively. The time required for the BAC bed is be regenerated by a thermal regeneration is prolonged 4-5 times more than that of GAC system. It can be estimated that the enhanced COD removal capability of the biofilm was not only due to the increase in the COD removal capability of acclimated bacteria, but also due to species succession of bacteria in bio-film ecosystem.

Adsorption↗
PubMed1998

Highly polar metabolites of nitroaromatic compounds in ammunition wastewater.

Transformation processes of nitroaromatic compounds (NAC) are described that lead to polar and highly hydrophilic metabolites in ammunition waste water. For the identification of proposed metabolites, several analytical methods for the separation and determination of these compounds were developed and applied to the investigation of a former ammunition plant and its surroundings. The compound classes which were investigated include nitro and amino substituted toluenesulfonic acids, nitrobenzoic acids, aminobenzoic acids and nitromethylphenols. Method development was usually done with high performance liquid chromatography and ion pairing or ion suppression techniques. In the leachate water of a disposal site of a former ammunition plant in Stadtallendorf, Germany, 15 compounds from the above-mentioned categories have been found to be present in concentrations up to a few hundred microgram/L. The presence of so many polar compounds suggest that current and future surveying programs should include representative analytes of the investigated categories.

Biotransformation↗
PubMed2005

Characterization and purification of polyphenol oxidase from artichoke (Cynara scolymus L.).

In this study, the polyphenol oxidase (PPO) of artichoke (Cynara scolymus L.) was first purified by a combination of (NH(4))(2)SO(4) precipitation, dialysis, and a Sepharose 4B-L-tyrosine-p-aminobenzoic acid affinity column. At the end of purification, 43-fold purification was achieved. The purified enzyme migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Polyacrylamide gel electrophoresis indicated that PPO had a 57 kDa molecular mass. Second, the contents of total phenolic and protein of artichoke head extracts were determined. The total phenolic content of artichoke head was determined spectrophotometrically according to the Folin-Ciocalteu procedure and was found to be 425 mg 100 g(-1) on a fresh weight basis. Protein content was determined according to Bradford method. Third, the effects of substrate specificity, pH, temperature, and heat inactivation were investigated on the activity of PPO purified from artichoke. The enzyme showed activity to 4-methylcatechol, pyrogallol, catechol, and L-dopa. No activity was detected toward L-tyrosine, resorsinol, and p-cresol. According to V(max)/K(m) values, 4-methylcatechol (1393 EU min(-1) mM(-1)) was the best substrate, followed by pyrogallol (1220 EU min(-1) mM(-1)), catechol (697 EU min(-1) mM(-1)), and L-dopa (102 EU min(-1) mM(-1)). The optimum pH values for PPO were 5.0, 8.0, and 7.0 using 4-methylcatechol, pyrogallol, and catechol as substrate, respectively. It was found that optimum temperatures were dependent on the substrates studied. The enzyme activity decreased due to heat denaturation of the enzyme with increasing temperature and inactivation time for 4-methylcatechol and pyrogallol substrates. However, all inactivation experiments for catechol showed that the activity of artichoke PPO increased with mild heating, reached a maximum, and then decreased with time. Finally, inhibition of artichoke PPO was investigated with inhibitors such as L-cysteine, EDTA, ascorbic acid, gallic acid, d,L-dithiothreitol, tropolone, glutathione, sodium azide, benzoic acid, salicylic acid, and 4-aminobenzoic acid using 4-methylcatechol, pyrogallol, and catechol as substrate. The presence of EDTA, 4-aminobenzoic acid, salicylic acid, gallic acid, and benzoic acid did not cause the inhibition of artichoke PPO. A competitive-type inhibition was obtained with sodium azide, L-cysteine, and d,L-dithiothreitol inhibitors using 4-methylcatechol as substrate; with L-cysteine, tropolone, d,L-dithiothreitol, ascorbic acid, and sodium azide inhibitors using pyrogallol as substrate; and with L-cysteine, tropolone, d,L-dithiotreitol, and ascorbic acid inhibitors using catechol as a substrate. A mixed-type inhibition was obtained with glutathione inhibitor using 4-methylcatechol as a substrate. A noncompetitive inhibition was obtained with tropolone and ascorbic acid inhibitors using 4-methylcatechol as substrate, with glutathione inhibitor using pyrogallol as substrate, and with glutathione and sodium azide inhibitors using catechol as substrate. From these results, it can be said that the most effective inhibitor for artichoke PPO is tropolone. Furthermore, it was found that the type of inhibition depended on the origin of the PPO studied and also on the substrate used.

Catechol Oxidase↗
PubMed1994

Lipoamidase and biotinidase activities in the rat: tissue distribution and intracellular localization.

Lipoamidase (not yet given an EC number) activity was measured in various rat tissues using two different substrates, one natural, lipoyllysine (epsilon-N-(D,L-lipoyl)L-lysine) and one artificial, lipoyl-p-aminobenzoic acid (N-D,L-lipoyl-p-aminobenzoic acid). Biotinidase, EC 3.5.1.12, was measured in the same tissue with the artificial substrate, biotinyl-p-aminobenzoic acid (N-D-biotinyl-p-aminobenzoic acid). Lipoamidase measured as lipoyl-p-aminobenzoic acid hydrolase activity had two pH optima, at pH 6.0 and pH 9.5, in liver homogenate, but only one pH optimum at pH 6.0 in rat plasma. Lipoamidase measured as lipoyllysine hydrolase activity had a pH optimum at pH 5.5 both in liver homogenate and plasma. Similarly, biotinidase shows a single pH optimum at pH 6.0 in liver homogenate and plasma. The properties of lipoyllysine hydrolase and biotinidase were similar with respect to thermostability, pH stability and inhibition pattern, and their properties differed from those of lipoyl-p-aminobenzoic acid hydrolase. Lipoyllysine hydrolase and biotinidase activities were highest in kidney, liver and blood plasma, whereas lipoyl-p-aminobenzoic acid hydrolase activities were highest in liver, brain and kidney. Lipoyllysine hydrolase and biotinidase activities were found mainly in the liver microsomal fraction, and lipoyl-p-aminobenzoic acid hydrolase was recovered from the microsomal fraction and to a small extent from the mitochondrial fraction. These results indicate that liver lipoyl-p-aminobenzoic acid hydrolase is an enzyme protein which differs from lipoyllysine hydrolase, and the data also indicate that liver lipoyllysine hydrolase and biotinidase are the same enzyme protein.

Amidohydrolases↗
PubMed1977

Black lipid membranes as a model for intestinal absorption of drugs.

Black lipid membranes were generated in isotonic buffer (pH 4-5 and pH 6-5) from egg phosphatidylcholine and intestinal lipid, and the permeability to salicylamide, salicylic acid, p-aminobenzoic acid and tryptophan of these membranes was studied. Electrical resistance of intestinal lipid membranes was higher than that of phosphatidylcholine membranes. The presence of cholesterol produced an increase in the electrical resistance of black lipid membranes and a small decrease in the permeability of membranes to drugs. The permeability coefficient of salicylamide, an uncharged drug, was much larger than the coefficients of the charged drugs examined. The values for salicylic acid and p-aminobenzoic acid were much larger than comparable values predicted from their partition coefficients. Intestinal lipid membranes were more permeable to acidic drugs than phosphatidylcholine membranes. It is suggested that phospholipids and other lipid components of the small intestine may play an important role in the membrane permeability to acidic drugs. This method may be of interest in studying the complex processes of drug absorption from intestine.

4-Aminobenzoic Acid↗
PubMed1996

Application of stripping voltammetry to trace lead analysis in intermediates and final products of syntheses of pharmaceuticals.

Applications of differential pulse anodic stripping voltammetry using a new pen-type renewed hanging mercury electrode have been investigated for trace analysis of lead in pharmaceutical substances and intermediates of their syntheses, such as procaine hydrochloride, 4-aminobenzoic acid, methyl 4-aminobenzoate, 2-(4-chlor-3-aminobenzoyl) benzoic acid, benzyl 2-naphthyl ether, 5-aminoisophthalic acid, 3-aminobenzoic acid, 5-hydroxyisophthalic acid, and N, N'-dibenzylethylenediamine diacetate. Samples were dissolved in 1 M HCI or 1 M NaOH and the electrochemical scan was carried out. No sample mineralization was necessary. The method showed a good linearity up to 50-100 ppm Pb with a detection limit less than 100 ppb. The results agreed well, but were more precise than those obtained by atomic absorption spectrometry using air/acetylene flame atomisation.

4-Aminobenzoic Acid↗