• Toxicological Research
• /
• v.14 no.4
• /
• pp.557-562
• /
• 1998

Allyl alcohol is metabolized in the liver through two steps, first to reactive acrolein by alcohol dehydrogenase (ADH), subsequently to acrylic acid by aldehyde dehydrogenase (ALDH). Since ethanol could compete the same enzymes to be metabolized in the liver, we have determined the plasma concentrations of allyl alcohol and ethanol followed by combined treatment. Pretreatment of rats with 2g/kg ethanol followed by ip administration of 40mg/kg allyl alcohol increased the lethality significantly. Determination of in vivo blood concentrations revealed that ethanol pretreatment caused the apparent decrease in allyl alcohol clearance, whereas acetaldehyde level in blood increased significantly by allyl alcohol treatment, as determined by head space GC analysis. Treatment of 4-methylpyrazole, an inhibitor of ADH, delayed allyl alcohol elimination significantly and reduced its lethality. Collectively, these findings suggested that reduction of allyl alcohol clearance in the presence oj ethanol was mediated through ADH competitive inhibition.

• Molecules and Cells
• /
• v.28 no.5
• /
• pp.407-415
• /
• 2009

The sirtuins are a protein family named after the first identified member, S. cerevisiae Sir2p. Sirtuins are protein deacetylases whose activity is dependent on $NAD^+$ as a cosubstrate. They are structurally defined by two central domains that together form a highly conserved catalytic center, which catalyzes the transfer of an acetyl moiety from acetyllysine to $NAD^+$, yielding nicotinamide, the unique metabolite O-acetyl-ADP-ribose and deacetylated lysine. One or more sirtuins are present in virtually all species from bacteria to mammals. Here we describe a phylogenetic analysis of sirtuins. Based on their phylogenetic relationship, sirtuins can be grouped into over a dozen classes and subclasses. Humans, like most vertebrates, have seven sirtuins: SIRT1-SIRT7. These function in diverse cellular pathways, regulating transcriptional repression, aging, metabolism, DNA damage responses and apoptosis. We show that these seven sirtuins arose early during animal evolution. Conserved residues cluster around the catalytic center of known sirtuin family members.

• Bulletin of the Korean Chemical Society
• /
• v.19 no.1
• /
• pp.45-50
• /
• 1998

Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2 : 1 : 10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 ㎍/㎖ in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants.

• ALGAE
• /
• v.33 no.3
• /
• pp.205-214
• /
• 2018

Red algae in the genus Portieria produce secondary halogenated monoterpenes, which are effective deterrents against herbivores, as secondary metabolites. Portieria hornemannii samples from various sites contain different concentrations of these metabolites, suggesting the existence of genetic diversity and cryptic species. To evaluate the genetic diversity and species distribution of Portieria in the northwest Pacific, we analyzed rbcL sequences of samples collected from Korea, Japan, and Taiwan. The phylogenetic analysis revealed five distinct lineages at the species level. One was recognized as Portieria japonica and the others were cryptic lineages in P. hornemannii. The rbcL haplotypes of P. japonica were genetically fragmented into two subgroups of geographic origin; Korean and Japanese. The four cryptic lineages within P. hornemannii were also geographically structured at a much finer scale. These results suggest that different genetic lineages in Portieria evolved from variable microhabitats, consequently influencing secondary metabolites. Further study is required to resolve the relationships between genetic and secondary metabolite variations in Portieria.

• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.118.3-119
• /
• 2003

Diazepam (DZ) is one of the most frequently prescribed drugs as an antianxiety agent, muscle relaxant, and anticovulsant and sometimes causes intoxication due to accidental overdose, misuse or abuse. Screening or confirmation methods for DZ and NDZ in plasma are very important for clinical and toxicological studies and in forensic cases. GC/MS assay with SPE was developed for the determination of diazepam and its metabolite, nordiazepam in human plasma. Diazepam in plasma was extracted by a rapid and sensitive procedure based on C18 bonded-phase extraction. (omitted)

• Mass Spectrometry Letters
• /
• v.14 no.1
• /
• pp.1-8
• /
• 2023

Eutylone, dibutylone, and dimethylone are potential psychotropic designer drugs. The purpose of this study was to investigate the in vitro metabolic pathways of synthetic cathinones with methylenedioxy groups. The three methylenedioxy derivatives were incubated with human liver microsomes. The metabolites were characterized based on liquid chromatography and quadrupole-time-of-flight mass spectrometry. Eutylone, dibutylone, and dimethylone were metabolized to yield three, six, and four metabolites, respectively. Reduction and demethylenation were the major metabolic pathways for all three drugs tested. However, dibutylone and dimethylone showed an additional metabolite generated via N-oxidation. These results provide evidence for the in vivo metabolism of methylenedioxy synthetic cathinones, and could be applied to the analysis of synthetic cathinones and their relevant metabolites in biological samples.

• Korean Journal of Pharmacognosy
• /
• v.54 no.1
• /
• pp.16-20
• /
• 2023

KSM-2690 B (1), a peptide-polyketide hybrid compound, was discovered from an actinomycete strain (CJD 1) isolated from Dong-Baek hill on Jeju Island, Republic of Korea. The chemical structure of 1 was identified by using NMR, MS, and UV spectroscopic analyses. Careful analysis of 1D and 2D NMR data revealed that KSM-2690 (1) has an oxazole ring, a β-lactone-γ-lactam spirocycle ring, and both triene and diene structures. KSM-2690 B (1) showed inhibitory activities against E. coli at 200 ㎍/mL.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.59-59
• /
• 2017

Rice (Oryza sativa L.) is the most important crop and its yield must be improved to feed the increasing global population. Recently developed high-yielding varieties with extra-large sink capacity often have a problem in unstable grain-filling. Therefore, understanding limiting factors for improving grain-filling and controlling them are essential for further improvement of rice grain yield. However, since grain-filling rate was determined by complex sink-source balance, the ability of grain-filling was very difficult to evaluate. Source ability for 'grain' was not only determined by the ability of carbon assimilation in leaves, but also that of carbon translocation from leaves to panicles. Sink strength was determined by the complex carbon metabolism from sucrose degradation to starch synthesis. Hence, to evaluate the grain-filling ability and determine its regulatory steps, the whole picture of carbon flow from photosynthesis at leaves to starch synthesis at grains must be revealed in a metabolite level. In this study, the yield and grain growth rate of three high-yielding varieties, which show high sink capacity commonly, were compared. Momiroman showed lower grain filling rate and slower grain growth rate than the other varieties, Hokuriku 193 and Tequing. To clarify the limiting point in the carbon flow of Momiroman, $CO_2$ labeled by stable isotope ($^{13}C$) was fed to three varieties during ripening period. The ratio of $^{13}C$ left in the stem was higher in Momiroman 24 hours after feeding, suggesting inefficient carbon translocation of Momiroman. More interestingly, $^{13}C$ translocation from soluble fraction to insoluble one in the grain seemed to be slower in Momiroman. To get the further insight in a metabolite level, we are now trying the $^{13}C$ labeling metabolome analysis in the developing grains.

• Journal of Ginseng Research
• /
• v.45 no.4
• /
• pp.465-472
• /
• 2021

Background: Ginseng can help regulate brain excitability, promote learning and memory, and resist cerebral ischemia in the central nervous system. Ginsenosides are the major effective compounds of Ginseng, but their protein targets in the brain have not been determined. Methods: We screened proteins that interact with the main components of ginseng (ginsenosides) by affinity chromatography and identified the 14-3-3 ζ protein as a potential target of ginsenosides in brain tissues. Results: Biolayer interferometry (BLI) analysis showed that 20(S)-protopanaxadiol (PPD), a ginseng saponin metabolite, exhibited the highest direct interaction to the 14-3-3 ζ protein. Subsequently, BLI kinetics analysis and isothermal titration calorimetry (ITC) assay showed that PPD specifically bound to the 14-3-3 ζ protein. The cocrystal structure of the 14-3-3 ζ protein-PPD complex showed that the main interactions occurred between the residues R56, R127, and Y128 of the 14-3-3 ζ protein and a portion of PPD. Moreover, mutating any of the above residues resulted in a significant decrease of affinity between PPD and the 14-3-3 ζ protein. Conclusion: Our results indicate the 14-3-3 ζ protein is the target of PPD, a ginsenoside metabolite. Crystallographic and mutagenesis studies suggest a direct interaction between PPD and the 14-3-3 ζ protein. This finding can help in the development of small-molecular compounds that bind to the 14-3-3 ζ protein on the basis of the structure of dammarane-type triterpenoid.

• Journal of Ginseng Research
• /
• v.47 no.1
• /
• pp.44-53
• /
• 2023

Background: The genus Panax in the Araliaceae family has been used as traditional medicinal plants worldwide and is known to biosynthesize ginsenosides and phytosterols. However, genetic variation between Panax species has influenced their biosynthetic pathways is not fully understood. Methods: Simultaneous analysis of transcriptomes and metabolomes obtained from adventitious roots of two tetraploid species (Panax ginseng and P. quinquefolius) and two diploid species (P. notoginseng and P. vietnamensis) revealed the diversity of their metabolites and related gene expression profiles. Results: The transcriptome analysis showed that 2,3-OXIDOSQUALENE CYCLASEs (OSCs) involved in phytosterol biosynthesis are upregulated in the diploid species, while the expression of OSCs contributing to ginsenoside biosynthesis is higher in the tetraploid species. In agreement with these results, the contents of dammarenediol-type ginsenosides were higher in the tetraploid species relative to the diploid species. Conclusion: These results suggest that a whole-genome duplication event has influenced the triterpene biosynthesis pathway in tetraploid Panax species during their evolution or ecological adaptation. This study provides a basis for further efforts to explore the genetic variation of the Panax genus.