Chromatogram Profiles Research Articles

Effect of the synthesized mycolic acid on the biodegradation of diesel oil by Gordonia nitida strain LE31

The dynamics of diesel oil biodegradation were previously investigated at initial substrate concentrations of 1000 to 20,000 ppm using Gordonia nitida isolated from wastewater. Following the gas chromatogram profiles of diesel oil degradation, diesel oil with concentrations of up to 15,000 ppm was efficiently degraded by this strain. At a concentrations of 20,000 ppm, however, the degradation by this strain was not effective. The enhancement of the biodegradation of diesel oi1 (at 15,000 and 20,000 ppm) by a synthetic mycolic acid biosurfactant (at 9, 90 and 900 ppm) was also investigated. In G. nitida inoculated cultures, the degradation of diesel oil was enhanced by the biosurfactant. For comparison, diesel oil degradation in batch incubations was measured after the addition of rhamnolipid and other surfactants. Synthetic mycolic acid enhanced the degradation to a greater extent than any other surfactant tested. Additionally, it was demonstrated that the degradation-enhancing property of synthetic mycolic acid was similar to that of rhamnolipid and Tween 80.

Thermoplastic starch–lignosulfonate blends. 1. Factorial planning as a tool for elucidating new data from high performance size-exclusion chromatography and mechanical tests

Blends of cornstarch, glycerol and lignosulfonate were prepared in variable-speed batch mixer at 150–160 °C, with the glycerol in various proportions from 20 to 40% and lignosulfonate from 10 to 40%. Alterations in HPSEC chromatogram profiles after the thermal processing were analyzed. The results showed that an increase in glycerol preserves the starch chains from degradation, which occurs to a smaller extent in samples without both lignosulfonate and modified lignosulfonate. Researchers have attributed the degradation of the starch compounds to shear-induced fragmentation, which increases the viscosity of the starch–glycerol matrices. Applying factorial planning at two levels, it was possible to obtain equations that better represent the effects caused by the presence of glycerol and lignosulfonate in the thermoplastic matrices. The effect of using hydroxymethylated lignosulfonate on the mechanical properties of starch was also investigated.

TOXICITY TEST OF MAKUTADEWA (Phaleria macrocarpa (Scheff.)Boerl.) BARK AGAINST Artemia salina Leach AND THIN LAYER CHROMATOGRAPHY PROFILE OF THE ACTIVE FRACTION

Makutadewa (Phaleria macrocarpa (Scheff) Boerl.) is one of the herbal medicines used against cancer, however, the scientific basis of the activity still void. Daphne mezereum, the same family (Thymelaeaceae) to makutadewa has been proved to contain cytotoxic substances in its bark. Therefore, the aims of this research were to investigate the toxic effect of makutadewa bark against Artemia salina Leach. as the primary step to identify an anticancer activity and find out substances responsible to this activity. The material powder was extracted using Soxhlet apparatus with chloroform, followed by methanol and finally by distilled water. The toxicity of chloroform, methanolic and aqueous extracts were assayed against A.salina Leach. The chloroform extract (most active) with the LC50 of 29.6  0.14 g/ml was fractionated by vacuum liquid chromatography using wash benzene 100 % (a); wash benzene-ethyl acetate =20:1 (b); 15:1 (c); 10:1 (d); 5:1 (e); 2:1 (f) and chloroform-methanol 1:1 (g) as mobile phases. The active fractions against A.salina were E {combination of (e) and (f)} with LC50 of 106,9 g/ml and F (g) with the LC50 of 131,53 g/ml, hence less toxic than the original extract. The thin layer chromatogram profiles showed that E and F fractions contained terpenoid and alkaloid substances. Key words : toxicity test , (Phaleria macrocarpa (Scheff)Boerl.), bark

Characterization of microorganisms by thermogravimetric analysis–mass spectrometry

A thermogravimetric analysis (TGA) system was interfaced to a mass spectrometry (MS) detector to investigate the thermal evolution of decomposition products from microorganisms. Traditionally, TGA–MS has been used to investigate the thermal parameters and chemical composition of materials such as the coal and lignin energy producing compounds and a wide range of technical organic polymers. The relative weight loss of biochemical species and compounds in bacteria from the TGA system allowed a comparison to the relative amounts of the same substances in bacteria from conventional microbiological extraction and isolation techniques. MS is shown to produce information rich total ion chromatogram profiles of thermal products from biochemical standards and microorganisms. The TGA thermal weight loss chromatogram (TWC) provides a degree of resolution, because the bacterial biochemical substances and components partition in a temporal fashion. Standard biochemical substances such as dipicolinic acid, polyhydroxybutyric acid, and peptidoglycan are produced in the same general temperature region in the TWC profile, and the compounds have similar mass spectra compared to those from microorganisms. Characterization of microorganisms was possible by the relation of their thermal events and extracted mass spectra to those of low and high mass model biochemical compounds.

Detection of Genistein as an Estrogenic Contaminant of River Water in Osaka

The estrogenic activity in water at various localities on Lake Biwa-Yodo River, a representative watershed in Japan, was measured using a recombinant yeast that expresses the human estrogen receptor. The yeast bioassay revealed that the activities of 13 water samples had an average value of 14 pmol/L (3.8 ng/L) (17beta-estradiol equivalent) with a very wide range from 0 to 72 pmol/L (0-19.6 ng/ L), and two of the samples had prominent levels of activity (72 pmol/L (19.6 ng/L) and 56 pmol/L (15.2 ng/L)). We analyzed these two samples with instrumental approaches. A high-performance liquid chromatogram profile showed that the strong activity in one sample, which was collected just downstream of a sewage-treatment plant, would be due to 17beta-estradiol and estrone, whose source is considered to be human urine contained in the effluent of the plant. The activity in the other sample, which was obtained from a tributary river in a primarily residential area with some industrial development (i.e., Osaka City), however, did not correspond to 17beta-estradiol, estrone, or synthetic chemicals known as estrogenic. Analysis of a fraction with estrogenic activity by liquid chromatography-mass spectrometry (LC-MS) provided evidence that the activity in the water sample resulted from the presence of genistein, an isoflavone compound of plant origin.

Chromatographic multivariate quality control of pharmaceuticals giving strongly overlapped peaks based on the chromatogram profile

In the present paper, the simultaneous quantification of two analytes showing strongly overlapped chromatographic peaks ( α=1.02), under the assumption that both available equipment and training of the laboratory staff are basic, is studied. A pharmaceutical preparation (Mutabase) containing two drugs of similar physicochemical properties (amitriptyline and perphenazine) is selected as case of study. The assays are carried out under realistic working conditions (i.e. routine testing laboratories). Uncertainty considerations are introduced in the study. A partial least squares model is directly applied to the chromatographic data (with no previous signal transformation) to perform quality control of the pharmaceutical formulation. Under the adequate protocol, the relative error in prediction of analytes is within the tolerances found in the pharmacopeia (10%). For spiked samples simulating formulation mistakes, the errors found have the same magnitude and sign to those provoked.

Some kinetic parameters of the degradation of natural rubber induced by chloranil and iron (III) chloride, in solution

The degradation of natural rubber (NR) induced by chloranil and FeCl 3, in solution, was investigated by efflux time measurements and by FTIR and 1H NMR spectroscopies. GC–MS was used to investigate the influence of chloranil on residues generated during thermal degradation of NR. 2-Methyl-2-butene (MB) was used as a model compound for the reactions. The results show that the reaction occurs by the scission of the double bond. The reactions were characterised by second-order kinetics, independent of the catalyst. The rate constants determined from efflux time data show a strong contribution of the physical entanglements: if the reactants are diluted 10-fold the value of the rate constant decreases significantly. Thus, the rate constants were more realistically calculated from the changes in the CC concentration measured by 1H NMR. The rate constants for the reaction of MB and chloranil (or FeCl 3) are lower than for the corresponding NR degradation. The presence of chloranil does not alter the chromatogram profile obtained by GC–MS for the thermal degradation of NR. It is concluded that chloranil decreases the activation parameters for the degradation because the degradation products are the same as those obtained thermally in absence of chloranil. Activation parameters such as energy, enthalpy, entropy and Gibbs energy were determined. Activation energies (in kJ mol −1) for the degradation of NR are 60.1 for NR/chloranil and 41.9 for NR/FeCl 3. From the values of activation parameters, it was suggested that the activation step of the reaction induced by chloranil is more thermally dependent than the reaction induced by FeCl 3 that, otherwise, is more entropically dependent.

Volatile compounds of selected strawberry varieties analyzed by purge-and-trap headspace GC-MS.

Six strawberry (Fragaria x ananassa Duch.) varieties, Senga Sengana, Jonsok, Polka, Korona, Bounty, and Honeoye, were studied in relation to composition of their volatile headspace compounds collected by dynamic purge-and-trap concentration. Also, the influence of cultivation technique on the volatile compounds was tested by comparing conventionally and organically cultivated strawberry varieties. In addition, the effect of geographical origin on strawberry volatiles was investigated. The emphasis of this study was lay in the industrial utilization of strawberry. A total of 52 different volatile compounds were determined from frozen strawberries grown in 1997 and 1998. In addition to individual compounds, total areas of chromatogram profiles were compared. The major esters were found to be methyl butanoate, ethyl butanoate, methyl hexanoate, and ethyl hexanoate. With the application of principal component analysis and analysis of variance to the data matrix, the varieties were classified into three groups. Var. Honeoye was most different from the others. Organic cultivation had no effect on strawberry volatiles.

Comparison of three analytical methods for 1-hydroxypyrene glucuronide in urine after non-occupational exposure to polycyclic aromatic hydrocarbons

Urinary pyrene metabolites, 1-OHP and 1-OHPG, have been used as biomarkers for the assessment of occupational and environmental exposure to PAHs. This study compares the sensitivity and applicability of the different analytical methods of 1-OHPG for human biomonitoring of low level exposure to PAHs. Three analytical methods were compared: (1) HPLC method from that reported by Singh et al. (Singh, R., Tucek, M., Maxa, K., Tenglerova, J., Weyand, E.H., 1995. A rapid and simple method for the analysis of 1-hydroxypyrene glucuronide: a potential biomarker for polycyclic aromatic hydrocarbon exposure. Carcinogenesis 16, 2909–2915); (2) IAC-SFS method: the rapid and simple assay using IAC purification using monoclonal antibody specific for PAH-DNA adduct and PAH metabolites and SFS quantitation; and (3) IAC-HPLC method: IAC and HPLC separation and quantitation. The correlation between the IAC-SFS method, HPLC method, and the IAC-SFS method was determined in 20 first year-grade junior high school students (age 12–13) from Yochon, Korea who participated in a nationwide survey for the environmental disease surveillance projects in Korea. Chromatograms obtained by the IAC purification and HPLC quantitation method were clear with no interfering peaks adjacent to 1-OHPG, thus 1-OHPG could be easily quantitated. However, the HPLC method produced chromatogram profiles with many interfering peaks adjacent to 1-OHPG peak. The concentrations of 1-OHPG in 20 urine samples were similar when analyzed by all three analytical methods. The correlation coefficient between the IAC-HPLC and IAC-SFS methods was 0.915, and between the IAC-HPLC and HPLC methods was 0.844, and between the IAC-SFS and HPLC methods was 0.805. The analytical methods for 1-OHPG compared in this study showed a good correlation with one another. These results suggest that any of the methods can be applied to human biomonitoring of PAH exposure. However, SFS quantitation after IAC purification is rapid and simple because this method does not need HPLC separation of 1-OHPG.

β-casomorphin 4 from milk fermented by a mutant of Lactobacillus helveticus

Abstract Hydrophobic peptides were isolated from milk fermented by a wild-type strain and a mutant strain of Lactobacillus helveticus L89 deficient in X-prolyl-dipeptidyl aminopeptidase (X-PDAP, EC.3.4.14.5) which is specific for peptide bonds on the carboxyl side of proline residues. Peptides were fractionated by RP-HPLC. Chromatogram profiles showed differences in peptide elution time, concentration and number. An opioid peptide, β-casomorphin 1–4 (60–63), was detected in a peptide extract derived from milk fermented with an X-PDAP-deficient mutant of L. helveticus . The molecular weight of this tetrapeptide was confirmed by mass spectrometry. A tetradecapeptide present in the wild-type culture (β-cas 106–119) was absent in the mutant strain culture after 24 h of fermentation with the pH controlled at 6.

DMSO resolves certain compressions and signal dropouts in fluorescent dye labeled primer-based DNA sequencing reactions

Automated base calling algorithms are more sensitive to the quality of the DNA sequencing data than are the labor intensive visual methods of base calling. To improve this quality, data from DNA sequencing reactions have been compared in order to determine the effects of the inclusion of dimethyl sulfoxide (DMSO). Inclusion of 10% DMSO into the reaction cocktail resolves at least one type of sequence compression. This compression may be due to the lack of ability in T7 DNA polymerase to read through certain sequences correctly. The poor quality of these data is seen as radioactive bands or fluorescent signal peaks that have an abnormal alignment, either in the wrong order or as single bands/peaks. The inclusion of DMSO also resolves sequences where the peak signal is absent or severely diminished, leading to a "gap" in the chromatogram profile. DMSO is better than deaza-dITP for resolving certain compressions. Addition of DMSO is a cheaper and more efficient method for high-throughput DNA sequencing than repeating reactions with base analogs.

A recirculating system for concentrating volatile samples

A recirculating system powered by a diaphragm pump which may be readily dismantled for cleaning, is described. The results of operating this system for dynamic headspace sampling in the closed or open mode to load volatiles onto a Tenax trap over a range of temperatures and loading volumes are shown. The system was designed to facilitate the analysis of volatiles in natural products and tested using an equimolar solution of 7 esters of boiling points ranging from 120°C to 299°C. The results showed that compounds in the boiling point range 120–200°C could be loaded onto the trap at 30°C by passing 1–21 of carrier gas through. In order to trap compounds of boiling points approaching 300°C, a temperature of 50–70°C and a loading volume of 2.5–3 1 was necessary. Using the apparatus, human sweat was analysed to show the degree of concentration possible with a natural sample and the variation in the chromatogram profiles of successive trapping from the same sample. Twelve chromatograms from the sweat of two pairs of identical twins were pattern matched to show the high degree of reproducibility possible using this apparatus to trap biological volatiles.

Urinary 1-hydroxypyrene as an indicator of human exposure to ambient polycyclic aromatic hydrocarbons in a coal-burning environment

Urinary 1-hydroxypyrene of residents of Beijing, Shenyang and Taiyuan, and workers at two coke plants, a steel plant and control groups was determined using high pressure liquid chromatography. Polycyclic aromatic hydrocarbons (PAHs) of airborne particulates from these cities and coke plants were analyzed using GC-MS; chromatogram profiles, from which 15 chemical compounds were quantified, were similar. The percentage of pyrene and benzo[ a]pyrene in PAHs was fairly constant. Statistical analysis showed significant correlation of urinary 1-hydroxypyrene with the concentration of pyrene and benzo[ a]pyrene in the ambient PAHs; the correlation coefficient was 0.978 and 0.959, respectively. It is suggested that urinary 1-hydroxypyrene can be used as a biological monitoring index for human exposure to genotoxic PAHs from the burning of coal.

Biotoxicity and persistence of nonylphenol during incubation in a compost-sandstone mixture

The persistence and biotoxicity of nonylphenol, a mixture of monoalkyl phenols that is found in relatively high concentrations in sewage sludge, were studied in an incubation experiment with a reconstituted soil system (compost + sandstone). The effect of nonylphenol (100 and 1000 ppm) on CO2 evolution and biomass ATP were monitored. Nonylphenol depressed CO2 production significantly only at high concentrations [1000 ppm 4-nonylphenol (4-NP)]. Biomass ATP declined progressively after the 5th day. At 100 ppm no toxic effects were detected. After a lag phase, nonylphenol disappeared readily upon incubation at the lower concentration (100 ppm), but persisted at high levels (1000 ppm). The persistence of 4-nonylphenol increased under aseptic conditions. The chromatogram profile of 4-NP changed over time, indicating that some of the isomers are more easily degraded than others.

In vivo and in vitro metabolism of the new anticancer drug bisantrene

The metabolism of bisantrene, a new anthracene anticancer agent active in the treatment of disseminated breast cancer, was studied in vitro using rat liver S9 preparations and in vivo in patients receiving the drug as treatment for their cancers. 14C-ring labeled bisantrene (248 mCi/40 mg) plus cold bisantrene were administered IV to cancer patients (260-340 mg/m2). Fractional urine samples were collected at various time intervals up to 120 h after drug administration and analyzed by HPLC. The percent of total 14C excreted as unchanged parent drug per ml urine ranged from 37 to 79% in the 0 to 24 h samples. The remainder of the radioactivity appeared chromatographically just prior to the bisantrene peak, indicating that compounds more polar than the parent were present as transformation products. Metabolism of bisantrene was also studied in vitro under oxic (O2) and hypoxic (N2) conditions, using commercially available Aroclor 1254 induced rat liver S9 preparations. Following N2 incubation at 37 degrees C for 1 h there was no evidence of metabolism, whereas there was more than 50% decrease in parent drug within 1 h following O2 incubation in the presence of NADPH generating system, suggesting that the metabolic process involves an oxidative reduction. HPLC chromatogram profiles of the mixtures exposed to the activated S9 system indicated that there were at least 3 polar metabolites. In vitro human tumor clonogenic assay showed that the biological activity of bisantrene decreased greater than 4-fold when the drug was incubated with S9 preparations in the presence of NADPH and O2, indicating that the transformation process leads to relatively inactive bisantrene metabolites.

Cluster analysis of chromatographic profiles of urine proteins

A method to examine and classify the chromatograms of urinary proteins, separated on a fast protein liquid chromatography system, is presented. For the analyses a measure of similarity between chromatogram profiles is defined and this is used to implement a statistical cluster analysis technique for the identification of a system of classification. The resulting classification can be related to a clinical assessment of the proteinuria of the sample urines, which are from patients with various renal disorders.