• Title/Summary/Keyword: $MS^n$

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염기성 용액에서 마젠타 아조메틴 색소의 퇴색 반응속도와 메커니즘

  • Lee, Jung-Ho;Kim, Jeong-Seong;Kim, Chang-Su
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2005.05a
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    • pp.301-305
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    • 2005
  • 3-메틸-1-페닐-2-피라졸린-5-은과 N,N-디에틸-1,4-페닐렌디아민의 반응에서 마젠타 아조메틴색소(M)를 합성하였다. 마젠타 아조메틴 색소는 에탄올, 아세톤, 그리고 클로로포름에 잘 녹는다. 원소분석, 핵자기공명스펙트럼, 적외선 홉수 스펙트럼, 그리고 GC/MS 스펙트럼에서부터 마젠타 아·조메틴 색소임을 확인하였다. 마젠타 아조메틴 색소는 염기성용액에서 분해된다. 에탄을 수용액에서 염기에 의한 마젠타 아조메틴 색소의 퇴색반응을 분광학적인 방법으로 540 nm에서 측정하였다. 그리고 OH$^-$와 H$_{2}$O(11${\sim}$40 M의 범위)의 농도가 증가함에 따라 퇴색반응속도는 증가하였다. 이 반응에 대한 실험속도 식은 다음과 같다. -d[D]/dt = {k$_{OH}$[OH$^-$][H$_{2}$O]}[D] 이 속도식과 일치하는 메커니즘을 제시하였다.

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Anti-microbial and Anti-inflammatory Activity of New 4-methoxy-3-(methoxymethyl) Phenol and (E)-N'-(5-bromo-2-methoxybenzylidene)-4-methoxy Benzohydrazide Isolated from Calotropis gigantean white

  • Manivannan, R.;Shopna, R.
    • Natural Product Sciences
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    • v.23 no.1
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    • pp.69-74
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    • 2017
  • A new phenol and hydrazide derivatives were obtained for the first time from the C. giganteawhite by silica gel column chromatography. The structure of the isolated compounds was identified by UV, IR NMR and MS. C. gigantea was scientifically reported for several medicinal properties viz. analgesic, antimicrobial and cytotoxic. In this screening work, anti-microbial activity of test compounds was found to be active against all organisms. Additionally, anti-inflammatory activity of the test groups has reduced the thickness of edema of the hind paw compared to the control group.

N fractional frequency synthesizer for 800 MHz frequency hopping (800 MHz 주파수도약 시스템을 위한 분수분주 방식 주파수 합성기의 설계 및 제작)

  • 박종문;이승대;방성일;진연강
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.526-533
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    • 1996
  • In this paper, the 800 MHz band N fractional frquency synthesizer having 677 channel with 30 kHz channel bandwidth is designed on the based on the theory which is dervied in terms of the relation between reference freqiency and the number of channels, loop bandwidth and acquistion time. The experimental resuls show 10 Hz deviation from the bandwidth and acquisition time. The experimental results show 10 Hz deviation from the bandwidth, the spurious suppression of aroud -45 dBc and the acqusition time of 1.44 ms. The results satisfy the given specification, but don't achieve thebesired spurious -60 dBc suppression. It is found that 500 hop per second will be possible over the range from 800 to 820 MHz.

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Regio- and Diastereoselective 1,3-Dipolar Cycloaddition between Perfluoro-2-methyl-2-pentene and Nitrones: A Facile Approach to Partially-Fluorinated Isoxazolidines

  • Moon, Mi-Eun;Park, Joo-Yeon;Jeong, Eun-Ha;Vajpayee, Vaishali;Kim, Hyun-Uk;Chi, Ki-Whan
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1515-1518
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    • 2010
  • Regio- and diastereoselective 1,3-dipolar cycloaddition reactions of nitrones {(Z)-${\alpha}$-phenyl-N-methylnitrone (1a) and (Z)-${\alpha}$-propyl-N-butylnitrone (1b)} with electron-deficient perfluoro-2-methyl-2-pentene (2) lead to novel isoxazolidines {5-fluoro-5-pentafluoroethyl-4,4-bis-trifluoromethyl-2-methyl-3-phenyl-isoxazolidine (3a) and 2-butyl-5-fluoro-5-pentafluoroethyl-4,4-bis-trifluoromethyl-3-propyl-isoxazolidines (3b) respectively} as major constituents. These derivatives were characterized by IR, $^1H$ and $^{19}F$ NMR, GC-MS and NOE measurements, and the absolute structure of 3a was confirmed by X-ray crystallography.

Inhibitory Effect of Continentalic Acid from Aralia continentalis on Streptococcus mutans Biofilm

  • Jeong, Seung-Il;Lee, Sang-Bong;Moon, Hae-Dalma;Ra, Ji-Young;Lee, Kwang-Hee;You, Yong-Ouk
    • International Journal of Oral Biology
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    • v.35 no.4
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    • pp.177-184
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    • 2010
  • In our present study, we investigated the effects of continentalic acid on Streptococcus mutans (S. mutans) biofilm. Methanol extract of Aralia continentalis (A. continentalis) was suspended in water and sequentially partitioned with CHCl3, ethyl acetate (EtOAc), and n-butanol (n-BuOH). The CHCl3 fraction showed the highest activity and an antibacterial compound against S. mutans was isolated from this preparation through various chromatography methods by bioassay guided fractionation. MS, $^1H-NMR$ and $^{13}C-NMR$ analysis showed that the active principle was continentalic acid which was confirmed to show significant inhibitory effects against S. mutans biofilm. These results may provide some scientific rationale for the traditional use these extracts for the treatment of dental diseases.

Biotransformation of Tranylcypromine in Rat Liver Microsomes

  • Kang, Gun-Il;Hong, Suk-Kil
    • Archives of Pharmacal Research
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    • v.11 no.4
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    • pp.292-300
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    • 1988
  • Metabolism of tranylcypromine (TCP) in rat liver microsomes was studied in vitro using fortified microsomal preparations. As well as unlabeled TCP, two deuterium labeled analogs, TCP-phenyl-$d_{5}$ and TCP-cyclopropyl-$d_{2}$ were used and GC/MS employed which was then metabolized to cinnamaldehyde and hydrocinnamyl alcohol. Schiff bases of TCP with hydrocinnamaldehyde and acetaldehyde were detected and possibility of the metabolic formation of N-ethylidene TCP was proposed. In addition, acetophenone (benzoylacetic acid), benzaldehyde, benzoic acid, and benzyl alcohol were detected as the metabolites. Chemical decomposition studies suggested that parts of the oxidized products might be derived by air oxidation processes. A potential metabolite assumed to be N-ethylidene-1, 2-dihydroxy-3-phenylpropanamine oxide was also detected.

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Cytogenetic and Histological Characteristics of Ginseng Hairy Root Transformed by Agrobacterium rhizogenes (Agrobacterium rhizogenes에 의하여 형질전환된 인삼 모상근의 세포 유전학적 및 조직학적 특성)

  • 고경민
    • Journal of Plant Biology
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    • v.36 no.1
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    • pp.75-81
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    • 1993
  • Ginseng (Panax ginseng C.A. Meyer) hairy root transformed with Agrobacterium rhizogenes (strain A4) was examined cytogenetically and histologically to assess its characteristics. The optimum growth of hairy root obtained in hormone-free MS medium (sucrose 30 g/L, pH5-6) for long period cultures. All hairy root strains (HB1, HB2, HB3) had the 2n diploid number (2n=48) of chromosomes in root tip cells. There were no alteration in chromosome structure except in one cell of HB3 strain. Results of SDS-PAGE showed a few difference in pattern and number of bands between normal and hairy root of ginseng. The root anatomy of normal root and hairy root differed each other. The hairy root had a clearly defined vascular strand, and the morphology of cortical cells were disorganised with large intercellular spaces.

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Photodegradation of Phosphamidon and Profenofos (Phosphamidon과 Profenofos의 광분해성)

  • 민경진;차춘근
    • Journal of Environmental Health Sciences
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    • v.26 no.2
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    • pp.49-58
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    • 2000
  • The present study was performed to investigate photodegradation rate constants and degradation products of phosphamidon and profenofos by the USEPA method. The two pesticides were very stable in 16 days exposure of sunlight from September 3 to 22, 1999 and humic acid had no sensitizing effect on the photolysis of each pesticide in sunlight. In the UV irradiation test, phosphamidon was rapidly degraded as increasing UV intensity. In case of UV irradiation with TiO2 and with TiO2 powder amount, degradation of profenofos showed no significant difference with UV irradiation. Photodegradation rate of profenofos was slower than that of phosphamidon. In order to identify photolysis products, the extracts of degradation products were analyzed by GC/MS. The mass spectra of photolysis products of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the photolysis products of phosphamidon were 0, 0-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and 0-ethyl-S-propyl phosphate.

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Chemical Composition of Clausena lansium (Lour.) Skeels Leaves and Antifungal Activity

  • Vu, Duc Nam;Teruhisa, Fujimatsu;Hirofumi, Takigawa;Hiroshi, Kusuoku;Nguyen, Minh Khoi;Le, Viet Dung;Do, Thi Ha;Hiroshi, Hashimoto
    • Natural Product Sciences
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    • v.22 no.1
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    • pp.35-40
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    • 2016
  • The first study on chemical constituents and biological activities of Clausena lansium (Lour.) Skeels (Rutaceae) growing in Vietnam has been done. Phytochemical investigation of n-hexane extract led to the isolation of five compounds: dihydroindicolactone (1), 8-geranyloxy psoralen (2), imperatorin (3), heraclenol (4) and indicolactone (5), in which this is the first report on the presence of dihydroindicolactone (1). Their structures were elucidated based on LC/MS/NMR hyphenated techniques as well as comparison with those of literature data. The n-hexane extract and its subfractions, ethanol 95% extract and several isolated compounds were evaluated for antifungal activity.

Thiolactomide: A New Homocysteine Thiolactone Derivative from Streptomyces sp. with Neuroprotective Activity

  • Jang, Jun-Pil;Kwon, Min Cheol;Nogawa, Toshihiko;Takahashi, Shunji;Osada, Hiroyuki;Ahn, Jong Seog;Ko, Sung-Kyun;Jang, Jae-Hyuk
    • Journal of Microbiology and Biotechnology
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    • v.31 no.12
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    • pp.1667-1671
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    • 2021
  • A new homocysteine thiolactone derivative, thiolactomide (1), was isolated along with a known compound, N-acetyl homocysteine thiolactone (2), from a culture extract of soil-derived Streptomyces sp. RK88-1441. The structures of these compounds were elucidated by detailed NMR and MS spectroscopic analyses with literature study. In addition, biological evaluation studies revealed that compounds 1 and 2 both exert neuroprotective activity against 6-hydroxydopamine (6-OHDA)-mediated neurotoxicity by blocking the generation of hydrogen peroxide in neuroblastoma SH-SY5Y cells.