• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.94.2-94.2
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• 2007

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• Natural Product Sciences
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• v.4 no.3
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• pp.153-157
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• 1998

The aqueous ethanolic leaf extract of Ailanthus altissima was found to contain the new natural product, $luteolin\;7-O-{\beta}-(6"-galloylglucopyranoside)$, 13, along with fourteen known phenolic metabolites (1-12, 14 and 15). Structures of all compounds (1-15) were established by conventional methods of analysis and confirmed by FAB-MS, $^1H-\;and\;^{13}C-NMR$ spectral analysis.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.49-49
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• 2018

본 연구는 관상가치가 높아 조경 및 관상소재로 개발이 가능한 큰개관중의 전엽체 증식 및 포자체 형성에 적합한 배양조건을 구명하고자 수행되었다. 실험재료는 무가온 온실에서 채집한 포자를 기내에서 발아시켜 전엽체를 획득한 후 8주 간격으로 계대배양하여 실험에 사용하였다. 배지종류에 따른 전엽체의 기내 증식 및 형태형성의 영향을 알아보고자 배양된 전엽체 300mg을 메스로 다진 다음 농도를 1/4, 1/2, 1, 2배로 조절한 MS와 Knop배지에 8주간 배양하였다. 그 결과, 1MS배지에서 전엽체의 생체중이 5.5g으로 가장 많이 증가하였다. 1MS를 제외한 타 처리구는 생체중의 증가수준이 1.1-3.0g에 머물러 1MS배지보다 저조한 수준을 보였다. 현미경을 이용한 전엽체의 관찰결과, 1MS배지는 엽육의 색이 녹색으로 생육이 양호하였다. 전엽체의 증식이 가장 저조하였던, 2MS와 1/4MS는 생육의 저조뿐만 아니라 노화현상도 관찰되었다. 포자체 형성을 위한 최적의 토양조건을 알아보고자, 원예상토, 피트모스, 펄라이트 및 마사토의 비율을 5종류로 달리하여 배양토를 혼합하였다. 혼합된 토양은 사각분($7.5{\times}7.5{\times}7.5cm$)에 충진하여 기내배양된 전엽체 1g을 증류수와 함께 10초간 분쇄한 다음 토양표면에 분주 후 10주간 재배하였다. 그 결과, 원예상토가 높은 비율로 첨가된 혼합조건에서 포자체의 형성이 우수하였다. 그중 원예상토와 마사토를 2:1(v:v)로 혼합한 토양, 원예상토와 펄라이트를 2:1(v:v)로 혼합한 토양에서 포트 당 각 357.0, 339.8개의 포자체가 형성되었다. 또한 형성된 포자체의 생육을 조사한 결과 원예상토와 마사토를 2:1(v:v)로 혼합한 토양에서 생체중, 엽수, 엽장, 엽폭, 근수, 근장 및 SPAD value 등의 생육수치가 우수하였다. 따라서 큰개관중의 전엽체 증식에 적합한 배지는 1MS로 판단되었으며, 포자체 대량생산을 위해서는 원예상토와 마사토를 2:1(v:v)로 혼합한 토양이 적합하다고 판단된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.404-410
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• 2021

Although, mouse bioassay for the monitoring of azaspiracids (AZAs) toxins in shellfish has been used previously, the reported method has low sensitivity and it is time-consuming. Recently, there is an interest in the quantitative analysis of AZAs using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The purpose of this study is to verify the simultaneous analysis of AZAs in shellfish and tunicate in Korea using LC-MS/MS. To validate the method, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, and repeatability were determined. All standard compounds were analyzed within 7 min. The correlation coefficients (R²) of the standard solution was higher than 0.9995 (within the range of 0.8-10.0 ㎍/L). The LODs and LOQs of AZAs in shellfish were 0.08-0.16 ㎍/kg and 0.23-0.50 ㎍/kg, respectively. The accuracy and precision of the method for determining AZAs in shellfish were 87.1-93.0% and 1.23-4.91%, respectively. Consequently, the verified LC-MS/MS method is suitable to analyze AZAs in shellfish and tunicates in Korea.

• Mass Spectrometry Letters
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• v.13 no.3
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• pp.58-83
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• 2022

We developed analytical methods using high performance chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of 80 unapproved compounds in dietary supplements. The target compounds for analysis were unapproved ingredients (e.g., pharmaceuticals) that have potential adverse effects on consumers owing to accidental misuse, overuse, and interaction with other medication in dietary supplement. Two analytical methods were tested to identify the optimal validation results according to AOAC guideline. As a result, limit of quantification (LOQ) was 0.14-0.5 ㎍ mL^-1; linearity (r²) was ≥ 0.99; accuracy (expressed as recovery) was 78.9-114%; precision (relative standard deviation) was ≤ 4.28% in the HPLC method. In the LC-MS/MS method, LOQ was 0.01-2 ng mL^-1, linearity (r²) was ≥0.98, accuracy was 71.7-119%; precision was ≤ 12.5%. The developed methods were applied to 51 dietary supplements collected from 2019 to 2021 through MFDS alert system. Based on our previous monitoring study, major compounds were icariin, sibutramine, yohimbine, sildenafil, tadalafil, sennosides (A, B), cascarosides (A, B, C, D), and phenolphthalein. In this study, we re-analyzed samples of detected compounds, and evaluated the statistical difference using Bland-Altman analysis to compare two analytical approaches between HPLC and LC-MS/MS. These results showed a good agreement between two methods that can be used to monitor the unapproved ingredients in dietary supplements. The developed two methods are complementarily suitable for monitoring the adulteration of 80 unapproved compounds in dietary supplements.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.270-275
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• 2000

In order to investigate the proper processing of food wastes with miraculous soil-microorganisms (MS) for final use of swine feeds, calory, amino acid and fatty acid in food wastes were determined in relation with fermentation process with MS microorganism complex. Aflatoxin test was also performed to check safety of the fermented food wastes. Calory of food wastes was determined in average $7.60\;Kcal{\cdot}g^{-1}\;D.W.$ In finally processed food wastes, total content of amino acid was $93.0\;mg{\cdot}g^{-1}]\;D.W$, showing 18.5% of increase by the anaerobic fermentation. Essential and non-essential amino acids were measured at respectively 34.43 and $58.56\;mg{\cdot}g^{-1}\;D.W.$ Leucine, phenylalanine, isoleucine and threonine of essential amino acids and proline and glutamic acid of non-essential amino acids were highly composed as compared to others. The composition of fatty acid in food wastes was also increased by anaerobic fermentation for 3 weeks. Palmitic acid, oleic acid and palmitoleic acid were more important in quantity. Present results indicate that food wastes properly processed with MS have enough calory and are safe from aflatoxin, and that anaerobic fermentation with MS microorganism in an efficient process for hydrolyzing protein and lipids in food wastes.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.193-198
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• 2017

Scutellaria baicalensis, Eleutherococcus senticosus, and Angelica sinensis have been used as raw materials for health functional foods. This study was conducted to develop a novel method to analyze levels of baicalin (Scutellaria baicalensis), eleutheroside E (Eleutherococcus senticosus), and ligustilide (Angelica sinensis) simultaneously in health functional foods. The methanol extracted samples were analyzed and quantified via liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the positive ion mode and the negative ion mode using multiple reaction monitoring. Standard calibration curves confirmed linearity with the correlation coefficient ($r^2$) of > 0.99 at $100-2000{\mu}g/mL$ concentration range. The limits of detection (LODs) and limits of quantitation (LOQs) were in the range of $13.0{\sim}35.2{\mu}g/L$ and $39.3{\sim}106.7{\mu}g/L$, respectively. The recovery results ranged between 91.4~109.9% at 3 different concentration levels with relative standard deviations (RSDs) less than 5%. The proposed analytical method was characterized with high accuracy and acceptable precision. The new method would be an effective tool to analyze baicalin, eleutheroside E, and ligustilide simultaneously in raw materials of health functional foods.

• Analytical Science and Technology
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• v.26 no.2
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• pp.154-163
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• 2013

The maximum residue limits of pyrimisulfan is set as 0.05 mg/kg in rice in 2011, so very reliable and sensitive analytical method for pyrimisulfan residues is required for ensuring the food safety of pyrimisulfan residues in agricultural products. In this study, a rapid and sensitive analytical method was developed and validated using liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS) for the determination of herbicide pyrimisulfan residues in agricultural products. Average recoveries of pyrimisulfan ranged from 88.7 to 99.3% at the spiked level of 0.005 mg/kg and from 90.1 to 94.2% at the spiked level of 0.05 mg/kg, while the relative standard deviation was less than 10%. Linear range of pyrimisulfan was between 0.01~1.0 ${\mu}g/mL$ with the correlation coefficient ($r^2$) 0.999 and limit of quantification was 0.005 mg/kg. The results of method validation were satisfied Codex guideline. The results revealed that the developed and validated analytical method is possible for pyrimisulfan determination in agricultural product samples and will be used as an official analytical method.

• Polymer(Korea)
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• v.36 no.3
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• pp.380-392
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• 2012

Four kinds of N,O-hydroxypropyl chitosans (HPCTOs) with degree of substitution(DS) and molar substitution (MS) ranging from 2.47 to 2.52 and 4.9 to 7.8, respectively were synthesized, and their molecular chracteristics and thermotropic and lyotropic liquid crystalline properties were investigated. MS was exceedingly larger than DS, showing that in the later stages of reaction, propylene oxide was preferentially added to the side chains rather than the main chain. All the derivatives formed thermotropic cholesteric phases. The glass and clearing temperatures were decreased with increasing MS. The optical pitches (${\lambda}_m$'s) of the thermotropic cholesteric phases increased with temperature. However, the ${\lambda}_m$'s of the derivatives at the same temperature increased with increasing MS. Solutions of HPCTOs in water, methanol, ethanol, acetic acid, and formic acid containing more than 30 wt% polymer also formed cholesteic phases whose ${\lambda}_m$'s decreased exponentially with increasing polymer concentration. The concentration dependence of ${\lambda}_m$ of HPCTO solutions, however, highly depended on the nature of the solvent and MS. The thermotropic and lyotropic mesophase properties of HPCTOs were significantly different from those reported for hydroxypropyl celluloses. The results indicate that the secondary amino group in the C-2 position plays an important role on the formation, stabilization, and temperature and concentration dependencies of ${\lambda}_m$ of the cholesteric mesophase.

• Food Science and Preservation
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• v.22 no.4
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• pp.559-566
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• 2015

The aim of this study was to develop an analytical method for determination of T-2 toxin and HT-2 toxin level in cereals and to survey their levels using LC-MS/MS. The T-2 and HT-2 toxins were simultaneously analyzed by electrospray ionization with a positive ion mode and multiple reaction monitoring (MRM) after filteration and immuno-affinity column clean-up. A matrix-matched standard calibration used for quantification and recoveries of T-2 and HT-3 toxins were in the range of $100.6{\pm}7.2%$ and $96.8{\pm}9.4%$, respectively. Limits of detection and quantification of T-2 and HT-2 toxins were estimated to be 0.5 and $1.5{\mu}g/kg$, respectively. Each repeatability (RSRr) of T-2 and HT-2 toxins was determined to be 0.9~6.0%, and 4.9~6.1%, respectively. Total 115 samples cereals were collected from 9 types of cereals for analysis. The positive percentages of T-2 and HT-2 toxins obtained from collected samples were found to be 72% and 80%, respectively. The contamination level of T-2 toxin and HT-2 toxin in cereals were $37.1{\mu}g/kg$, and $5.4{\mu}g/kg$, respectively. Therefore, this study suggests that the developed method could be an useful analytical method to determine the T-2 and HT-2 toxin level in cereals and the present data could be used as a reference to estimate the risk assessment.