• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.156-164
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• 1996

Benzidine is recognized as a urinary bladder carcinogen in humans. The use of benzidine in industries was prohibited because of its carcinogenecity, but, production and usage of benzidine-based dye was still permitted in most countries. This study was performed to compare the excretory patterns of urinary metabolites between benzidine-based dye(Direct Black 38) and benzidine in rats Benzidine-based dye was administered orally at the doses of 0.3, 0.5, 0.7 mmol/kg and benzidine was administered orally at the doses of 0.2, 0.4, 0.6 mmol/kg into Sprague-Dawley rats. To analyze benzidine and its metabolites, the high performance liquid chromatography with an electric chemical and ultraviolet detector were used. N-acetylbenzidine, N,N'-diacetylbenzidine and 4-aminobiphenyl were identified in the urine of the rats receiving dye and benzidine. The excreted amount of the urinary benzidine from dye was almost 1/10 of that from benzidine. Excretion rates of metabolites were more prolonged in the dye receiving group than those of the benzidine group. Peak concentration time of urinary N,N'-diacetylbenzidine was more prolonged than other metabolites in both groups. The excreted amount of N-acetylbenzidine was more than the others in both group. These results suggested that N-acetylbenzidine may be an useful Biological exposure index for benzidine-based dye.

• Journal of Environmental Health Sciences
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• v.28 no.4
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• pp.6-11
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• 2002

3.3'-Dichlorobenzidine(DCB) has be shown carcinogenic in several animals, and the development of non-invasive biomonitoring method in workers exposed with it is a very important subject. DNA adduct is a good biomarker for biomonitoring about carcinogens exposure, and lymphocytes is a good non-invasive samples. So we studied to analyze metabolites in blood lymphocytes of female Sprague-Dawley rats exposed orally with DCB(20, 30, and 40 mg/kg wt.) for 3 weeks. For analysis of them, we isolated DNA adducts from blood lymphocytes by using the enzymes method in /sup 32/P-postlabeling, and measured them by using gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM). 4-aminobiphenyl and phenanthrene-d/sub 10/ were added as internal standard for blank sample. Standard metabolites of DCB were synthesized with using pyridine and acetic acid which were promoter and controller in acetylation of DCB. And they were used for calibration curve. Our results showed two kinds of metabolites in DNA adducts of blood lymphocytes. They were N-acetyl 3,3'-dichlorobenzidine(acDCB) and N,N'-diacetyl 3,3'-dichiorobenzidine(di-acDCB ). They were combined with DNA at the same time as an acetyl of it was removed. So we measured DCB and acDCB for two kinds of metabolites in DNA adducts of blood lymphocytes. Our results showed the levels of DCB were 1.46∼2.26 times more than that of acDCB. And also the levels of metabolites in 20, 30 and 40 mg/kg wt. were gradually increased with going days from 1st to 3rd week. They are 1.66, 1.38 and 0.90 times in total metabolites, 1.76, 1.49 and 1.02 times in DCB, and 1.51, 1.22 and 1.28 times in acDCB. In conclusion, the results of this study showed DCB exposed to rats formed DNA adduct in blood lymphocytes after acetylated to N-acetyl 3.3'-dichloro benzidine(acDCB) and N,N'-diacetyl 3,3'-dichlorobenzidine(di-acDCB), and they could be analyzed by us ing gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM).

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.168-180
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• 2016

Various researches on the effects of fertilization levels on functional metabolites in crop have been conducted. This review summarizes the previous studies on the relation between fertilization supply and accumulation of metabolites (phenolics, carotenoids, ascorbic acid and glucosinolates) which function as antioxidants in crop. The accumulation of phenolic compounds is related to the activation of phenylalanine ammonia lyase (PAL) in phenylpropanoid pathway. Most of the previous studies discuss that low nitrogen (N) supply activates PAL, thereby increasing the synthesis of phenolics. Similarly, high N supply leads to a decrease in ascorbic acid because of the shading effect derived from the accelerated vegetative growth under high N level. Unlike the phenolics and ascorbic acid, carotenoids are accumulated with increasing N supply. In this regard, the previous studies explain that N is a main element closely associated with formation of key enzyme for the synthesis of carotenoids. Glucosinolates are generally increased under decreasing N supply and increasing S supply. Although the previous studies show similar trends about the accumulation of metabolites by nutrient level, they also suggest that many other factors including crop types, cultivars, cultural environment (water, temperature, light, etc.) influence the accumulation of functional metabolites in crop.

• Biomolecules & Therapeutics
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• v.4 no.3
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• pp.251-256
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• 1996

The metabolism of carbinoxamine, 2-[(4-chlorophenyl)-2-pyridinyl-methoxy]-N, N-dimethylethaneamine, was studied in adult male volunteers after an oral dose of 15 mg. Solvent extracts of urine obtained with or without enzyme hydrolysis were analyzed by gas chromatography-mass spectrometry after derivatization with MSTFA/TMSCl (N-methyl-N-trimethylsilyltrifluoroacetamide/trimethyl chlorosilane). The structures of metabolites were determined based on the electron impact (EI) and chemical ionization (CI) mass spectra. Nonconjugated metabolites identified in the urine were carbinoxamine, nor-carbinoxamine, and bits-nor-carbinoxamine. Parent drug, nor-carbinoxamine, and bits-nor-carbinoxamine were also detected as conjugated forms. These metabolites observed in human urine were different from those previously reported in the rat. Urinary excretions of carbinoxamine were reached to maxima in 4 hours after drug administration with 4.9%-8.1% and 2.5-4.2% of the dose excreted during 24 h as carbinoxamine and its glucuronide, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.689-698
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• 2016

Specific metabolic network responses to mineral starvation are not well-defined. We examined a detailed broad-scale identification of metabolic responses of tomato leaf and root to N, P or K starvation. Tomato plants were grown hydroponically under optimal (5 mM N, 0.5 mM P, or 5 mM K) and starved (0.5 mM N, 0.05 mM P, or 0.5 mM K) conditions and metabolites were measured by LC-MS and GC-MS. Overall, the levels of metabolites (lipids, nucleotides, peptides and secondary metabolites) presented in this paper largely showed mineral- and tissue-specific responses. Most strikingly, G3P (glycerol-3-P), GPC (glycerol-P-choline) and choline phosphate responded differently to a type of mineral; an increase in N or K starvation and a decrease in P starvation. A dramatic increase in the levels of secondary metabolites, in particular, rutin and chlorogenate in both tomato tissues during N starvation were observed. Based on these data, it is necessary to clearly elucidate an unknown event taking place in a variety of abiotic impacts, and we are now studying to expand our knowledge on metabolic- and proteomic-responses using GS-MS and LC-MS.

• Journal of Microbiology and Biotechnology
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• v.31 no.4
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• pp.540-549
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• 2021

The Wnt/β-catenin signaling pathway is involved in breast cancer and Myxococcus fulvus KYC4048 is a myxobacterial strain that can produce a variety of bioactive secondary metabolites. Although a previous study revealed that KYC4048 metabolites exhibit anti-proliferative effects on breast cancer, the biochemical mechanism involved in their effects remains unclear. In the present study, KYC4048 metabolites were separated into polar and non-polar (ethyl acetate and n-hexane) fractions via liquid-liquid extraction. The effects of these polar and non-polar KYC4048 metabolites on the viability of breast cancer cells were then determined by MTT assay. Expression levels of Wnt/β-catenin pathway proteins were determined by Western blot analysis. Cell cycle and apoptosis were measured via fluorescence-activated cell sorting (FACS). The results revealed that non-polar KYC4048 metabolites induced cell death of breast cancer cells and decreased expression levels of WNT2B, β-catenin, and Wnt target genes (c-Myc and cyclin D1). Moreover, the n-hexane fraction of non-polar KYC4048 metabolites was found most effective in inducing apoptosis, necrosis, and cell cycle arrest, leading us to conclude that it can induce apoptosis of breast cancer cells through the Wnt/β-catenin pathway. These findings provide evidence that the n-hexane fraction of non-polar KYC4048 metabolites can be developed as a potential therapeutic agent for breast cancer via inhibition of the Wnt/β-catenin pathway.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.28-37
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• 1996

Benzidine, an aromatic amine used primarily in the manufacture of azo dyes, is recognized as a urinary bladder carcinogen in humans. In rats, mice, and hamsters, chronic exposure to benzidine resulted in tumors of the liver. The present study was undertaken to suggest analyzing the metabolites of benzidine with the optimal condition, identify the metabolites of benzidine, and observe time variance of the metabolites in the isolated perfusated rat liver. N-acetylbenzidine was synthesized by acetylation of benzidine with acetic anhydride and separated by thin layer chromatography(TLC) and high performance liquid chromatography(HPLC). To analysis benzidine and the metabolites of benzidine, HPLC operating condition has been optimized by means of preliminary experiment. The mobile phase consisted of acetonitrile(37%) in phosphate buffer, flow rate maintained at 1.0 ml/min. Optimal detective conditions were electrochemicaldetector(ECD) at 0.75 V for benzidine and N-acetylbenzidine and ultravioletdetector(UVD) at 287 nm for N,N'-diacetylbenzidine. The separation system was composed of a guard column and a separation column(Polymer C18, $4.6{\times}250cm$) at a temparature of $40^{\circ}C$. The perfusion system was equilibrated for 30 minutes before addition of benzidine to the perfusate. Samples of the perfusate were collected at time intervals(0, 10, 20, 30, 60, 90, 120 min) during the 2 hour perfusion. Before analyzing samples by HPLC/ECD/UVD, samples had been treated with sep-pak. Samples of perfusate analyzed by HPLC/ECD/UVD and the metabolites of benzidine in the isolated perfused rat liver were N-acetylbenzidine and N,N'-diacetylbenzidine. Benzidine metabolized over 60% during the initial 30 minutes of perfusion, extensively by 1 hour, and was undetectable in the perfusate. N-acetylbenzidine increased by 30 minutes of perfusion, declined. N,N'-diacetylbenzidine increased the 0-90 minutes period, remained constant during the 90-120 minutes period.

• Journal of Microbiology
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• v.43 no.3
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• pp.313-318
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• 2005

In this study, we demonstrate the use of a PCR-based method for the detection of the specific genes involved in natural-product biosynthesis. This method was applied, using specifically designed PCR primers, to the amplification of a gene segment encoding for sedo-heptulose 7-phosphate cyclase, which appears to be involved in the biosynthetic pathways of $C_7N$ aminoacyclitol or its keto analogue-containing metabolites, in a variety of actinomycetes species. The sequences of DNA fragments (about 540 bp) obtained from three out of 39 actinomycete strains exhibited a high degree of homology with the sedo-heptulose 7-phosphate cyclase gene, which has been implicated in acarbose biosynthesis. The selective cultivation conditions of this experiment induced the expression of these loci, indicating that the range of $C_7N$ aminoacyclitol or its keto analogue-group natural products might be far greater than was previously imagined. Considering that a total of approximately 20 $C_7N$ aminoacyclitol metabolites, or its keto analogue-containing metabolites, have been described to date, it appears likely that some of the unknown loci described herein might constitute new classes of $C_7N$ aminoacyclitol, or of its keto analogue-containing metabolites. As these metabolites, some of which contain valienamine, are among the most potent antidiabetic agents thus far discovered, the molecular detection of specific metabolite-producing actinomycetes may prove a crucial step in current attempts to expand the scope and diversity of natural-product discovery.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1232-1235
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• 2004

In order to investigate the effect of recombinant bovine somatotropin (rbST) on blood metabolites and milk yield of lactating buffaloes, 30 lactating buffaloes after acclimatization for 30 days were divided into 2 groups as control (n=10) and experimental (n=20). Animals were injected 250mg of rbST (Boostin-250) on 0, $14^{th}$ and $28^{th}$ day subcutaneously at ischiorectal fosse, where as control animals were given placebo of 2 ml normal saline. Fortnightly blood samples were collected from 15 days prior to 60 days post injection to estimate different blood metabolites. Daily milk yield was recorded and weekly average yield of each animal was calculated. From this study, it was found that blood metabolites such as glucose, triglycerides, total proteins, albumin, globulin and electrolytes like sodium and potassium were not altered by rbST injection. However, there was a significant (p<0.05) decrease in blood urea nitrogen (BUN) concentration in experimental group as compared to that of control group. The weekly average milk yield was significantly (p<0.001) higher (25%) in rbST injected group over the control group.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.809-816
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• 2010

Microbial biotransformations can be used to predict mammalian drug metabolism. The present investigation deals with microbial biotransformation of valdecoxib using microbial cultures. Thirty-nine bacterial, fungal, and yeast cultures were used to elucidate the biotransformation pathway of valdecoxib. A number of microorganisms metabolized valdecoxib to various levels to yield nine metabolites, which were identified by HPLC-DAD and LC-MS-MS analyses. HPLC analysis of biotransformed products indicated that a majority of the metabolites are more polar than the substrate valdecoxib. Basing on LC-MS-MS analysis, the major metabolite was identified as a hydroxymethyl metabolite of valdecoxib, whereas the remaining metabolites were produced by carboxylation, demethylation, ring hydroxylation, N-acetylation, or a combination of these reactions. The hydroxymethyl and carboxylic acid metabolites were known to be produced in metabolism by mammals. From the results, it can be concluded that microbial cultures, particularly fungi, can be used to predict mammalian drug metabolism.