• Natural Product Sciences
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• 제16권2호
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• pp.116-122
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• 2010

A high-performance liquid chromatography (HPLC) with diode array detector (DAD) and electrospray ionization mass spectrometry (ESI-MS) was established for the simultaneous determination of five representative metabolites of the iridoid and phenolic classes from Rehmannia glutinosa. The optimal chromatographic conditions were obtained on an ODS column (5 mm, $4.6{\times}250\;mm$) with the column temperature at $25^{\circ}C$. The mobile phase was composed of water and acetonitrile using a gradient elution with the flow rate 0.3 mL/min. Detection wavelength was set at 205 nm. All calibration curves showed good linear regression ($r^2$ > 0.997) within test ranges. Limits of detection (LOD) and quantitation (LOQ) values were lower than 0.123 and $0.373\;{\mu}g/mL$, respectively. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.09 - 0.76% and 0.16 - 1.41%, respectively, and the overall recoveries of 99.03 - 102.67% for all of the compounds analyzed. In addition, effectiveness of diverse extraction methods was compared to each other for the development of standard analytic method. The verified method was successfully applied to the quantitative determination of five representative metabolites in twenty-one commercial Rehmannia glutinosa samples from different markets in Korea and China. The analytical results showed that the contents of the five analytes vary significantly with sources.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2287-2293
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• 2009

Gas Chromatography-Mass Spectrometry (GC-MS) fingerprint analysis, Principle Components Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were introduced for quality assessment of Curcuma longa L. (C. longa). The GC-MS fingerprint method was developed and validated by analyzing 33 batches of samples of C. longa from different geographic locations. 18 chromatographic peaks were selected as characteristic peaks and their relative peak areas (RPA) were calculated for quantitative expression. Two principal components (PCs) were extracted by PCA. C. longa collected from Guizhou and Fujian were separated from other samples by PC1, capturing 71.83% of variance. While, PC2 contributed for their further separation, capturing 11.13% of variance. HCA confirmed the result of PCA analysis. Therefore, GC-MS fingerprint study with chemometric techniques provides a very flexible and reliable method for quality assessment of C. longa.

• 산업공학
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• 제10권3호
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• pp.75-93
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• 1997

Unlike individual applications, it is extremely hard to obtain user requirements for group systems, since there exists very complicated dynamics in group. This may result in spreading a great amount of products with a broad range of contents. Thus, this study presents a comparative analysis of groupware products. As a result, these products have been categorized into three areas which include cooperation/document management systems, collaborative writing systems, and decision-making/meeting systems. While the systems reviewed here focus on the cooperation/document management systems, the other two areas will be dealt in details in part Ⅱ. The first area ends up with two large categories such as proprietary groupware products and intranet groupware products. However, it has been observed that there is a natural convergence between these two categories. Consequently, the comparative analysis has been performed in terms of functions provided on the two categories and a combined category. Each group of the functions has been divided into three parts which consist of basic functions, quasi-basic functions, and others. Such a decision has been made based on the frequency rate of the functions provided in the products. With a more strict rule, the basic functions comprise electronic mail, sanction, bulletin board, document management, scheduling, security, Web browser, and Internet connectivity. This study also provides a framework for integrated functional model of groupware systems. The basic functions are merged into the model. However, the model is so flexible that it can partially include the quasi-functions in addition to the basic functions. In the future, it is expected that a large number of products will stem from the modification of the functional model.

• Natural Product Sciences
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• 제14권3호
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• pp.171-176
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• 2008

Column chromatographic separation of 70% EtOH extract of the roots of Korean cultivated-wild ginseng led to the isolation of ten ginsenosides (1 - 10). The isolated compounds were identified as ginsenoside $Rg_1$ (1), ginsenoside Re (2), ginsenoside Rc (3), ginsenoside $Rb_1$ (4), ginsenoside $Rb_2$ (5), ginsenoside Rd (6), ginsenoside $Rg_3$ (7), ginsenoside $F_2$ (8), ginsenoside $Rb_3$ (9), and ginsenoside $Rd_2$ (10) by physicochemical and spectroscopic methods. The compounds (1 - 10) were for the first time isolated from the roots of Korean cultivated-wild ginseng.

• Archives of Pharmacal Research
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• 제18권5호
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• pp.361-363
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• 1995

Two furofuran lignans, sesamolin and sesangolin were isolated from the seeds of Sesamum indicum and S.angolense, respectively. Detailed analysis of the $^1H-and^{13}C-NMR$ spectra of these lignans was carried out by the application of two-dimensional $^1H-^1/H\; COSY\; and^1/H^{13}C$ multiple-bond, multiple-quantum spectroscopic correlation techniques.

• Archives of Pharmacal Research
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• 제19권5호
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• pp.406-410
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• 1996

The flowers of Chrysanthemum boreale afforded handelin, a unique guaianolide dimer and a mixture of n-hydrocarbons and n-hydrocarbon alcohols in addition to b-sitosterol and b-sitosterol glucoside. Detailed analysis of the $^{1}H$- and $^{13}C$-NMR spectra of handelin was carried out by the application of two-dimensional $^{1}H-^{1}H$-COSY and $^{1}H$- $^{13}C$ multiple-bond, multiple-quantum spectroscopic correlation techniques. Handelin was inactive in the in vitro anti-tumor activity.

• 생약학회지
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• 제21권2호
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• pp.148-152
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• 1990

Seven flavonol glycosides from the EtOAc fraction of Ginkgo biloba leaves were identified by high performance liquid chromatography. Separation by reversed phase chromatography on $Lichrosorb^{\circledR}$ RP-18 column was achieved by isocratic elution. The content of the major acylated flavonol glycoside, kaempferol 3-0-[$6'-O-{p}-coumaroyl-{\beta}-_D-glucosyl(1{\rightarrow}2)-{\alpha}-_L-rhamnoside$] was about 8.0% and 0.55% for EtOAc fraction and MeOH extract, respectively.

• 한국작물학회지
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• 제49권spc1호
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• pp.17-22
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• 2004

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1457-1460
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• 2017

Seven flavonoids were isolated from Spatholobus suberectus via repetitive column chromatography and high-performance liquid chromatography. The chemical structures of these compounds were identified by spectroscopic analysis and comparison with values reported in the literature. Among the flavonoids tested, 7-hydroxy-6-methoxyflavanone (1) and formononetin (4) exhibited strong inhibitory activity against Streptococcus mutans SrtA, with $IC_{50}$ values of 46.1 and $41.8{\mu}M$, respectively, but did not affect cell viability. The onset and magnitude of inhibition of saliva-induced aggregation in S. mutans treated with compounds 1 and 4 were comparable to the behavior of a srtA-deletion mutant without treatment.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.709-715
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• 1999

A series of antifungal compounds were obtained from the methanol extract of the mycelium from marine actinomycetes M428 which was identified as a Stereptomyces species by fatty acid composition and biochemical characteristics. These compounds were purified by combined chromatographic techniques and the structures were characterized with spectroscopic methods including 1D and 2D NMR, and mass spectrometry as sn-l lysophosphatidyl inositols. The side chains were established by chemical degradation followed by GC analysis to be 14-methyl pentadecanoic acid (iso-palmitic acid, i-C16:0, compound A) and 13-methyl tetradecanoic acid (iso-pentadecanoic acid, i-C15:0, compound B). These compounds displayed highly selective antifungal activity against C. albicans with MIC values of $5{\;}\mu\textrm{g}/ml$ (compound A) and $2.5{\;}\mu\textrm{g}/ml$ (compound B), while it had almost negligible antibiotic activity against E. coli and P aerogenosa with MIC value higher than $50{\;}\mu\textrm{g}/ml$ and no cytotoxic activities against human myeloma leukemia K562 ($IC_{50}>100{\;}\mu\textrm{g}/ml$).