• YAKHAK HOEJI
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• v.43 no.5
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• pp.559-565
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• 1999

The two gericudranin E derivatives, GER-I & II, were synthesized and evaluated their antitumour activities for the elucidation of structure-activity relationship. 2,4,6-Trihydroxyacetophenone was converted to target molecules GER-I and GER-B in 5 steps via sequential protection, aldol condensation, Michael type-cyclization, regioselective C-benzylation. The cellular growth inhibition of compounds GER-I and GER-II were investigated against P388, L1210, K562, HCT-15, SK-HepG-1, MCF-7 as cancer cell lines and mouse splenocytes as a normal cell by MTT assay.

• Archives of Pharmacal Research
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• v.29 no.11
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• pp.952-956
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• 2006

A phytochemical investigation of stems from Salvadora persica resulted in the first isolation of four benzylamides from a natural source. The isolated compounds were identified as butanediamide, $N^{1},\;N^{4}$-bis(phenylmethyl)-2(S)-hydroxy-butanediamide (1), N-benzyl-2-phenylacetamide (2), N-benzylbenzamide (3) and benzylurea (4). The structure elucidation was accomplished using spectroscopic methods, especially 2D NMR and HREIMS. Compound 2 revealed a significant inhibitory effect on human collagen-induced platelet aggregation, and a moderate antibacterial activity against Escherichia coli.

• KSBB Journal
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• v.16 no.2
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• pp.99-106
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• 2001

Proteomics research includes identification and quantitation of single protein and/or protein complex, profiling of protein expression changes in response to biological perturbations, characterization of protein functions and interactions, and elucidation the linkage between proteins and diseases. In this review paper, recent developments in the basic technologies involved in the proteomics research such as 2-dimensional PAGE and mass spectrometry are discussed. Also, the application areas of proteomics technology such as protein expression mapping and cell map proteomics are introduced with the focus on new drug development.

• Bulletin of the Korean Chemical Society
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• v.16 no.10
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• pp.968-971
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• 1995

The heme assignment of the 1H NMR spectrum of cytochrome c3 of Desulfovibrio vulgaris Hildenborough within the X-ray structure were fully cross established according to their redox potential. The major reduction of the heme turned out to take place in the order of hemes Ⅳ,Ⅰ,Ⅱ and Ⅲ(the heme numbers indicating the order of bonding to the primary sequence). This assignment can provide the physicochemical basis for the elucidation of electron transfer of this protein.

• The Plant Pathology Journal
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• v.21 no.1
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• pp.47-54
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• 2005

Identification of host genes involved in disease progresses and/or defense responses is one of the most critical steps leading to the elucidation of disease resistance mechanisms in plants. Soybean mosaic virus (SMV) is one of the most prevalent pathogen of soybean (Glycine max). Although the soybeans are placed one of many important crops, relatively little is known about defense mechanism. In order to obtain host genes involved in SMV disease progress and host defense especially for virus resistance, two different cloning strategies (DD RT-PCR and Subtractive hybridization) were employed to identify pathogenesis- and defenserelated genes (PRs and DRs) from susceptible (Geumjeong 1) and resistant (Geumjeong 2) cultivars against SMV strain G7H. Using these approaches, we obtained 570 genes that expressed differentially during SMV infection processes. Based upon sequence analyses, differentially expressed host genes were classified into five groups, i.e. metabolism, genetic information processing, environmental information processing, cellular processes and unclassified group. A total of 11 differentially expressed genes including protein kinase, transcription factor, other potential signaling components and resistant-like gene involved in host defense response were selected to further characterize and determine expression profiles of each selected gene. Functional characterization of these genes will likely facilitate the elucidation of defense signal transduction and biological function in SMV-infected soybean plants.

• Mass Spectrometry Letters
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• v.7 no.3
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• pp.69-73
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• 2016

High-resolution quadrupole-Orbitrap mass spectrometry (HRMS), with high-resolution (> 10,000 at full-width at half-maximum) and accurate mass (< 5 ppm deviation) capabilities, plays an important role in the structural elucidation of drug metabolites in the pharmaceutical industry. ML106, a derivative of imidazobenzimidazole, decreased melanin content and tyrosinase activity in a dose-dependent manner. Here, we investigated the phase 1 metabolic pathway of ML106 using HRMS in human liver microsomes (HLMs) and recombinant cDNA-expressed cytochrome P450 (CYP). After the incubation of ML106 with pooled HLMs and recombinant cDNA-expressed CYP in the presence of NADPH, five phase 1 metabolites, including three mono-hydroxylated metabolites (M1-3) and two di-hydroxylated metabolites (M4 and M5), were investigated. The metabolite structures were postulated by the elucidation of protonated mass spectra using HRMS. The CYP isoforms related to the hydroxylation of ML106 were studied after incubation with recombinant cDNA-expressed CYP. Here, we identified the phase 1 metabolic pathway of ML106 induced by CYP in HLMs.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.246-253
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• 2021

Background: Ginseng is one of the most valuable herbal supplements. It is challenging to perform quality control of ginseng products due to the diversity of bioactive saponins in their composition. Acid or alkaline hydrolysis is often used for the structural elucidation of these saponins and sugars in their side chains. Complete transformation of the original ginsenosides into their aglycones during the hydrolysis is one of the ways to determine a total saponin group content. The main hurdle of this approach is the formation of various by-products that was reported by many authors. Methods: Separate HPLC assessment of the total protopanaxadiol, protopanaxatriol and ocotillol ginsenoside contents is a viable alternative to the determination of characteristic biomarkers of these saponin groups, such as ginsenoside Rf and pseudoginsenoside F₁₁, which are commonly used for authentication of P. ginseng Meyer and P. quinquefolius L. samples respectively. Moreover, total ginsenoside content is an ideal aggregated parameter for standardization and quality control of ginseng-based medicines, because it can be directly applied for saponin dosage calculation. Results: Different hydrolysis conditions were tested to develop accurate quantification method for the elucidation of total ginsenoside contents in herbal products. Linearity, limits of quantification, limits of detection, accuracy and precision were evaluated for the developed HPLC-MS method. Conclusion: Alkaline hydrolysis results in fewer by-products than sugar elimination in acidic conditions. An equimolar response, as a key parameter for quantification, was established for several major ginsenosides. The developed approach has shown acceptable results in the analysis of several different herbal products.

• Analytical Science and Technology
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• v.21 no.2
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• pp.65-83
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• 2008

It is noted that illegal hazardous foods containing unauthorized drugs or synthetic drung analogues are increasing. Especially, reported are unknown compounds that have the modified chemical structures of the anti-impotence drugs such as sildenafil, vardenafil, and tatalafil. In addition, it is very reserved, since illegal synthetic compounds having similar chemical structures modified from anti-impotence drug to avoid the government inspection are not proved their safety at all. This review in ulation to food safety, lists the illegal compounds added to foods and describes about the analytical methods to chanacterize 16 anti-impotence drug analogues such as homosildenafil, hongdenafil, pseudovardenafil, aminotadalafil, hydroxyhomosildenafil, hydroxyhongdenafil, dimethylsildenafil, xanthoanthrafil, hydroxyvardenafil, norneosildenafil, demethylhongdenafil, piperidinohongdenafil, carbodenafil, thiosildenafil, dimethylthiosildenafil, and acetylvardenafil.

• Natural Product Sciences
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• v.6 no.4
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• pp.189-192
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• 2000

A new isoflavone, $(+)-4'-O-methyl-8-C-{\beta}-D-glucopyranosylgenistein$, was isolated from the aerial parts of Spartidium saharae together with the known isoflavone, $(+)-8-C-{\beta}-D-glucopyranosylgenistein$ as well as dipiperidine alkaloids, (+)-ammodendrine and (+)-N-acetyl hystrine. Details of their structure elucidation are based on chemical and spectroscopic methods. N-formyl ammodendrine was detected by GC-MS. The potential chemotaxonomic value of the alkaloid content is explored. Cytotoxic activity has been determined for both alcoholic extract and isolated compounds.

• Natural Product Sciences
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• v.13 no.3
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• pp.229-233
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• 2007

Chemical investigation of the crude extract of the Egyptian marine tunicate Eudistoma laysani led to the isolation of a new nucleoside; 3-deazainosine and four known ones; inosine, 2'-deoxyuridine, adenosine and 2'-deoxyadenosine. Structural elucidation of the isolated compounds was based on intensive studies of their spectral data including 1D ($^{1}H$ and $^{13}C$) and 2D ($^{1}H-^{1}H$ COSY, HMQC, HMBC) NMR together with mass spectra. The antioxidant effects of the isolated compounds were determined using DPPH, where they exhibited significant activities.