• 제목/요약/키워드: LC-MS-MS

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Synthesis and Fragmentation Behavior Study of n-alkyl/benzyl Isatin Derivatives Present in Small/Complex Molecules: Precursor for the Preparation of Biological Active Heterocycles

  • Kadi, Adnan A.;Al-Shakliah, Nasser S.;Motiur Rahman, A. F. M.
    • Mass Spectrometry Letters
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    • 제6권3호
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    • pp.65-70
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    • 2015
  • N-Alkyl/benzyl substituted isatin derivatives are intermediates and synthetic precursors for the preparation of biological active heterocycles. N-alkyl/benzyl isatins have showed various biological activities, such as cytotoxicity, antiviral, caspase inhibition, cannabinoid receptor 2 agonists for the treatment of neuropathic pain, etc. In this study, N-alkyl/benzyl isatin derivatives were synthesized from isatin and alkyl/benzyl halides in presence of K2CO3 in DMF and excellent to quantitative yields (~95%) were obtained. Isatins and benzyl-isatins were condensed with fluorescein hydrazide to form fluorescein hydrazone. All the compounds were subjected to their fragmentation behavior study using LC/MSn. N-Alkyl substituted isatin derivatives fragmented at nitrogen-carbon (N-C) bond, hence gave daughter ion as [RN+H]+. Whereas, N-benzyl substituted isatin derivatives fragmented at carbon-carbon (C-C) bond of alkyl chain which linked with nitrogen molecules, therefore gave N-methyl fragments [RNCH2]+. This study demonstrated that, isatin moiety present in a small/large molecule or in a matrix of reaction mixture with/without N-alkyl/benzyl substituents can be identified by mass spectroscopic fragmentation behavior study.

Hepatotoxic Effect of 1-Bromopropane and Its Conjugation with Glutathione in Male ICR Mice

  • Lee Sang Kyu;Jo Sang Wook;Jeon Tae Won;Jun In Hye;Jin Chun Hua;Kim Ghee Hwan;Lee Dong Ju;Kim Tae-Oh;Lee Eung-Seok;Jeong Tae Cheon
    • Archives of Pharmacal Research
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    • 제28권10호
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    • pp.1177-1182
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    • 2005
  • The hepatotoxic effects of 1-bromopropane (1-BP) and its conjugation with glutathione were investigated in male ICR mice. A single dose (1000 mg/kg, po) of 1-BP in corn oil to mice significantly increased serum activities of alanine aminotransferase and aspartate aminotransferase. Glutathione (GSH) content was dose-dependently reduced in liver homogenates 12 h after 1-BP treatment. In addition, 1-BP treatment dose-dependently increased levels of S-pro-pyl GSH conjugate at 12 h after treatment, as measured by liquid chromatography-electro-spray ionization tandem mass spectrometry. The GSH conjugate was maximally increased in liver at 6 h after 1-BP treatment (1000 mg/kg), with a parallel depletion of hepatic GSH content. Finally, 1-BP induced the production of malondialdehyde in liver. The present results suggest that 1-BP might cause hepatotoxicity, including lipid peroxidation via the depletion of GSH, due to the formation of GSH conjugates in male ICR mice.

Deadenylation of Adenine Based-Nucleosides and Calf thymus DNA Induced by Halogenated Alkanes at the Physiological Condition

  • Sherchan, Jyoti;Yun, Min-Ho;Lee, Eung-Seok
    • Bulletin of the Korean Chemical Society
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    • 제30권10호
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    • pp.2318-2328
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    • 2009
  • Massive deadenylation of adenine based-nucleosides induced by halogenated alkanes at the physiological condition have been observed. For the study of deadenylation effects by the different substituents and/or functionality in halogenated alkanes, diverse kinds of halogenated alkanes were incubated with adenine based-nucleosides (ddA, dA and adenosine) for 48 h at the physiological condition (pH 7.4, $37\;{^{\circ}C}$), which were analyzed by HPLC and further confirmed by LC-MS. Among the sixteen different halogenated alkanes, we observed massive deadenylation of nucleosides by 2-bromo-2-methylpropane, 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane. The order of deadenylation rate was highest in 2-bromo-2-methylpropane followed by 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane. In addition, time and dose response relationship of deadenylation in adenine based-nucleosides induced by 2-bromo-2-methylpropane, 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane at the physiological condition were investigated. In addition, deadenylation of calf thymus DNA induced by halogenated alkanes was also investigated. These results suggest that the toxic effect of certain halogenated alkanes might be from the depurination of nucleosides.

Substance P and Neuropeptide Y as Potential Biomarkers for Diagnosis of Acute Myocardial Infarction in Korean Patients

  • Han, Hyojeong;Seo, Hong Seog;Jung, Byung Hwa;Woo, Kyoungja;Yoo, Young Sook;Kang, Min-Jung
    • Bulletin of the Korean Chemical Society
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    • 제35권1호
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    • pp.158-164
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    • 2014
  • Substance P and neuropeptide Y were discovered as early diagnostic biomarkers of acute myocardial infarction in Korean patients and confirmed using enzyme-linked immunosorbent assay (ELISA). We screened 12 peptides from the sera of Korean acute myocardial infarction (AMI) patients and detected 3 peptides (neuropeptide Y, substance P, and N-terminal pro-B-type natriuretic peptide) to be elevated from patients' sera by liquid chromatography mass/mass spectrometry. The elevated concentration of 3 peptides was confirmed by ELISA. The screening results revealed the substance P, neuropeptide Y, and pro-B-type natriuretic peptide (47-76) concentrations were higher in patients' sera than in healthy controls. The sensitivity and specificity of substance P for AMI diagnostic marker were 80% and 83%, respectively, and those of neuropeptide Y were 87% and 90%, respectively compared to healthy controls. These results suggest that substance P and neuropeptide Y could be used as early diagnostic biomarkers in patients with AMI.

Residual determination of Ceftiofur in Raw Bovine Milk by Liquid Chromatography-Electrospray Mass Spectrometry

  • Lim, Jong-hwan;Park, Byung-kwon;Kim, Myoung-seok;Jang, Beom-Su;Kim, Doo;Yun, Hyo-in
    • 대한수의학회지
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    • 제44권3호
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    • pp.367-371
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    • 2004
  • This report describes the determination of ceftiofur residues in milk from treatment of lactating dairy cattle by intramuscular injection of three consecutive daily doses of about 1 mg /kg BW, the recommended label dosing. The separation of ceftiofur was achieved on $C_1_8$ reverse phase column. The mobile phase consisted of 0.1% trifluoracetic acid in water (A) and 0.05% acetic acid in acetonitrile (B) and grediently flowed at the flow rate of 0.4 mL/min. As a result of analysis of blank raw bovine milk samples, matrix interference was not shown. Limit of detection and limit of quantitaion was 0.5 ng/mL and 1 ng/mL, respectively. The values of precision and recovery satisfied the guideline of National Veterinary Research and Quarantine Service (NVRQS, Korea). The mean residual concentration of ceftiofur in milk did not exceed 3.71 ng/mL when ceftiofur was administered intramuscularly to lactating dairy cattle for 3 consecutive days at 1 mg/kg of BW per day. It is much lower than the proposed MRL (100 ng/mL) of ceftiofur in milk.

Deguanylation of Guanine Based-Nucleosides and Calf Thymus DNA Induced by Halogenated Alkanes at the Physiological Condition

  • Sherchan, Jyoti;Lee, Eung-Seok
    • Bulletin of the Korean Chemical Society
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    • 제30권12호
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    • pp.2949-2958
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    • 2009
  • Massive deguanylation of guanine based-nucleosides induced by halogenated alkanes at the physiological condition have been observed. For the study of deguanylation effects by the different substituents and/or functionality in halogenated alkanes, diverse kinds of halogenated alkanes were incubated with guanine based-nucleosides (ddG, dG and guanosine) for 48 h at the physiological condition (pH 7.4, 37$^{\circ}C$), which were analyzed by HPLC and further confirmed by LC-MS. Among the sixteen different halogenated alkanes, we observed massive deguanylation of nucleosides by 2-bromo-2-methylpropane, 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane. The order of deguanylation rate was highest in 2-bromo-2-methylpropane followed by 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane. In addition, time and dose response relationship of deguanylation in guanine basednucleosides induced by 2-bromo-2-methylpropane, 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane at the physiological condition were investigated. Deguanylation of calf thymus DNA induced by halogenated alkanes was also investigated. These results suggest that the toxic effect of certain halogenated alkanes might be from the depurination of nucleosides.

Photocatalytic and Sonophotocatalytic degradation of alachlor using different photocatalyst

  • Bagal, Manisha V.;Gogate, Parag R.
    • Advances in environmental research
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    • 제2권4호
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    • pp.261-277
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    • 2013
  • The degradation of alachlor has been investigated using sonolysis (US), photocatalysis (UV) and sonophotocatalysis (US/UV) using three photocatalyst viz. $TiO_2$ (mixture of anatase and rutile), $TiO_2$ (anatase) and ZnO. The effect of photocatalyst loading on the extent of degradation of alachlor has been investigated by varying $TiO_2$ (both types) loading over the range of 0.01 g/L to 0.1 g/L and ZnO loading over the range of 0.05 g/L to 0.3 g/L. The optimum loading of the catalyst was found to be dependent on the type of operation i.e., photocatalysis alone or the combined operation of sonolysis and photocatalysis. All the combined processes gave complete degradation of alachlor with maximum rate of degradation being obtained in the case of sonophotocatalytic process also showing synergistic effect at optimized loading of photocatalyst. About 50% to 60% reduction in TOC has been obtained using the combined process of sonophotocatalysis depending on the operating conditions. The alachlor degradation fitted first order kinetics for all the processes under investigation. It has been observed that the $TiO_2$ (mixtrure of anatase and rutile) is the most active photocatalyst among the three photocatalysts studied in the current work. The effect of addition of radical enhancers and scavengers on sonophotocatalytic degradation of alachlor has been investigated in order to decipher the controlling mechanism. The alachlor degradation products have been identified using LC-MS method.

HPLC 법에 의한 국산 고추에 함유되어 있는 Nonivamide의 신규 분석법 개발 (Improved High-Performance Liquid Chromatographic Method for the Determination of N-vanillyl-n-nonivamide(nonivamide) in Korean Hot Peppers)

  • 최석현
    • 동아시아식생활학회지
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    • 제16권5호
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    • pp.585-591
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    • 2006
  • We report a novel HPLC method for analyzing the capsaicinoids and nonivamide. The following conditions were used: a total column and column temperature of $3^{\circ}C$, a detection wavelength of 280 nm, an eluent containing acetonitrile : 0.5% formic acid(31:69, v/v). The experimental data was compared with standard nonivamide and capsaicin. The results showed that nonivamide was eluted in 96.7 minutes with a recovery ratio of 96.5% after adding known nonivamide. In addition, the detection limit for nonivamide was 18.6 ng. The capsaicinoids from Korean pepper were extracted (after blooming 60th) from 3 breeds cultivated in Korea, Buchon, Chungyang and Hanbando. and crisis it analyzed sympathizes the nonivamide in the result nonivamide from the Buchon and the Chungyang which are not detected from the Hanbando $0.16{\sim}0.24{\mu}g/g$ it detects with very small amount it contains it confirmed the each capsaicinoid with the HPLC and the LC-MS. These results are expected contribute to the quality control of various product processes, which includes product delivery inspection as well as examining the capsaicinoids present in the product for possible medicine manufacture and various foodstuff, and the nonivamide content, which may be a feed for various manufacturing processes involving chemical synthesis.

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Identification of 1-Furan-2-yl-3-pyridin-2-yl-propenone, an Anti-inflammatory Agent, and Its Metabolites in Rat Liver Subcellular Fractions

  • Lee, Sang-Kyu;Jeon, Tae-Won;Basnet, Arjun;Jeong, Hye-Gwang;Lee, Eung-Seok;Jeong, Tae-Cheon
    • Archives of Pharmacal Research
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    • 제29권11호
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    • pp.984-989
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    • 2006
  • 1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) has been characterized to have an anti-inflammatory activity through the inhibition of the production of nitric oxide and tumor necrosis $factor-{\alpha}$. In the present studies, the phase 1 metabolism of FPP-3 was investigated in rat liver microsomes and cytosols. When FPP-3 was incubated with rat liver microsomes and cytosols in the presence of NADPH. 2 major peaks were detected on a liquid chromatography/electrospray ionization-mass spectrometry. Two metabolites (i.e., M1 and M2) were characterized as reduced forms on propenone: M1 (1-furan-2-yl-3-pyridin-2-yl-propan-1-one) was the initial metabolite and M2 (1-furan-2-yl-3-pyridin-2-yl-propan-1-ol) was a secondary alcohol believed to be formed from M1.

Comparison of Heavy Metal Contents in Eyeliner Products -Focused on Domestic and Foreign Cosmetic Brands-

  • Lee, Kee-Young;Kim, Jeong-hee
    • 패션비즈니스
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    • 제19권3호
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    • pp.113-120
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    • 2015
  • Heavy metal ingredients of eyeliner product could cause side effect ranging from simple irritation, keratitis, corneal epithelium inflammation, eyelid dermatitis and dry eye symptoms have been reported. This study was conducted in order to prepare fundamental data for acceptable quality level heavy metal ingredients in the domestic and foreign cosmetic brand eyeliner products and to assess theirs the heavy metal concentrations. We measured the concentration of 5 heavy metals in 10 eyeliner products using ICP/MS-LC. According to the results, the average metal concentrations were as follows.; In case of domestic eyeliner products, 289.4 ppm for aluminium(Al), 304 ppm for manganese(Mn), 44 ppm for nickel(Ni), 0.58 ppm for arsenic(As) and 0.35 ppm for lead(Pb). In case of Foreign eyeliner products, 11337.8 ppm for aluminium(Al), 1678.8 ppm for manganese(Mn), 74.2 ppm for nickel(Ni), 1 ppm for arsenic(As) and 0.8 ppm for lead(Pb). Foreign products contained higher amounts of the two elements(Pb, As) compared to domestic ones. Also, greater concentrations of arsenic(As) were detected from waterproof products than non-waterproof ones. In conclusion, for safety reasons we suggested the amounts of heavy metals from the domestic and foreign eyeliner products. This finding will be helpful to provide the fundamental data which is standard of toxicological heavy metals acceptable on eyeliner products.