• 인간식물환경학회지
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• 제21권6호
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• pp.485-492
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• 2018

This study aimed to develop and validate highly sensitive determination method of a prostaglandin ($PGE_1$, OP 1206) in human plasma by LC-MS/MS using column switching. Plasma stored at $-30^{\circ}C$ and treated with methanol effectively inhibited interferences synthesized post-sampling. Samples were added with internal standard and were separated by reversed-phase HPLC with a cycle time of 30min. The method was selective for OP 1206 and the regression models, based on internal standard, were linear across the concentration range 0.5-50 pg/mL with the limit of quantification of 0.5 pg/mL (limit of quantitation, LOQ) for OP 1206. The calibration curve of OP 1206 standards spiked in five individual plasma samples was linear ($r^2=0.9999$). Accuracy and precision at the concentrations of 0.5, 1.5, 5.0 and 40 pg/mL, and at the lower LOQ of 0.5 pg/mL were excellent at 20%. OP120 < 6 was stable in plasma samples for at least 24 hours at room temperature, 24 hours frozen at $-70^{\circ}C$, 24 hours in an auto sampler at $6^{\circ}C$, and for two freeze/unfreezing cycles. The validated determination method successfully quantified the concentrations of OP 1206 in plasma samples from simulated administrating a single $5{\mu}g$ OP 1206 formulation. Thus, this novel LC-MS/MS technique for drug separation, detection and quantitation is expected to become the standard highly-sensitive detection method in bioanalysis and to be applied to many low dose pharmaceutical products.

• 분석과학
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• 제32권4호
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• pp.139-146
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• 2019

A simple and reliable analytical method based on high-performance liquid chromatography-ultraviolet detection was established for the analysis of the flowers of Chrysanthemum morifolium (CM). Luteolin-7-O-glucoside (LU7G) was chosen as a target analyte considering its content, availability, and ease of analysis. Chromatographic separation of LU7G was achieved using a Phenomenex Gemini $C_{18}$ column ($250{\times}4.6mm$, $5{\mu}m$) run with a mobile phase consisting of 0.5 % acetic acid in water and 0.5 % acetic acid in acetonitrile at a flow rate of $1.0mL\;min^{-1}$. The detection wavelength and column temperature were set at 350 nm and $40^{\circ}C$, respectively. Method validation was performed according to the AOAC guidelines and the method was specific, linear ($R^2=0.9991$ for $50-300{\mu}g\;mL^{-1}$), precise (${\leq}3.91%$RSD), and accurate (100.1-105.7 %). The limits of detection and quantification were 3.62 and $10.96{\mu}g\;mL^{-1}$, respectively. The established method was successfully applied to determine the contents of LU7G in various batches of bulk CM extracts and labscale CM extract. The developed method is a readily applicable method for the quality assessment of CM and its related products.

• Biomolecules & Therapeutics
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• 제27권2호
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• pp.193-200
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• 2019

Ceramide metabolism is known to be an essential etiology for various diseases, such as atopic dermatitis and Gaucher disease. Glucosylceramide synthase (GCS) is a key enzyme for the synthesis of glucosylceramide (GlcCer), which is a main ceramide metabolism pathway in mammalian cells. In this article, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine GCS activity using synthetic non-natural sphingolipid C8-ceramide as a substrate. The reaction products, C8-GlcCer for GCS, could be separated on a C18 column by reverse-phase high-performance liquid chromatography (HPLC). Quantification was conducted using the multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z $588.6{\rightarrow}264.4$ for C8-GlcCer at positive ionization mode. The calibration curve was established over the range of 0.625-160 ng/mL, and the correlation coefficient was larger than 0.999. This method was successfully applied to detect GCS in the human hepatocellular carcinoma cell line (HepG2 cells) and mouse peripheral blood mononuclear cells. We also evaluated the inhibition degree of a known GCS inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) on GCS enzymatic activity and proved that this method could be successfully applied to GCS inhibitor screening of preventive and therapeutic drugs for ceramide metabolism diseases, such as atopic dermatitis and Gaucher disease.

• 분석과학
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• 제32권2호
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• pp.56-64
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• 2019

Recently, a number of adulterated products, which are advertised as hair-growth enhancer have been emerged among those who suffer hair loss disease. For continuous control of illegal products, in this study, a rapid and sensitive method for simultaneous screening of 12 compounds that enhance hair-growth was established to protect public health by ultrahigh-performance liquid chromatography coupled to quadrupole-orbitrap mass spectrometry (UHPLC-Q-Orbitrap-MS). Fragmentation pathways of them were proposed based on $MS^2$ spectral data obtained using the established method. In this analysis, the LODs and LOQs ranged from 0.05 to 50 ng/mL and from 0.17 to 167 ng/mL, respectively. The square of the linear correlation coefficient ($R^2$) was determined as more than 0.995. The intra- and inter-assay accuracies were respective 88-112 % and 88-115 %. Their precision values were measured within 5 % (intra-day) and 10 % (inter-day). Mean recoveries of target compounds in adulterated products ranged from 84 to 115%. The relative standard deviation of stability was less than 12 % at $4^{\circ}C$ for 48 h. The method was employed to screen 14 dietary supplements advertised to be effective for the treatment of hair loss. Some of the products (~21 %) were proven to contain synthetic drugs that promote hair growth such as triaminodil, minoxidil, and finasteride.

• 한국환경농학회지
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• 제41권3호
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• pp.206-216
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• 2022

BACKGROUND: Dithiocarbamate fungicide propineb can be analyzed quantitatively by derivatization reaction followed by HPLC/UVD, which has high reproducibility and stability. However, the presence of high protein in soybeans and peas affects the derivatization process resulting in extremely low recoveries. Therefore, this study was conducted to improve the analytical method for analysis of propineb in soybeans and peas by applying a deproteinization process using chloroform-gel method. METHODS AND RESULTS: The deproteinization process was carried out up to 6 times for soybeans and 5 times for peas using 50 mL chloroform. After 4 times of deproteinization process followed by a derivatization reaction with methyl iodide, the recovery yields of propineb in both pulses were >90%. However, the recovery yield tended to decrease when the deproteinization process was performed more than 5 times. The method limit of quantification (LOQ) was 0.04 mg/L. The recovery conducted in triplicate at 10 times and 50 times of the LOQ ranged from 87.2 to 95.0 % with a coefficient of variation <10%. CONCLUSION(S): This study confirmed that 4 times of deproteinization process using the chloroform-gel method was effective when derivatizing and analyzing dithiocarbamate fungicides in pulses with high protein content. However, depending on the initial protein content present in the pulses, there was a difference in the recovery: the lower the protein content, the higher the recovery rate of propineb. It is expected that the method proposed in this study could be applied to remove high content of protein as analytical interference substance from agricultural samples.

• 한국미생물·생명공학회지
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• 제50권4호
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• pp.488-500
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• 2022

Most fungal infections by opportunistic yeast pathogens such as Candida spp. are the major causes of morbidity and mortality in patients with lowered immune. Previous studies have reported that some strains of Candida secret secondary metabolites play an important role in the decreasing of immunity in the infected patient. In this study, 110 Candida spp. were isolated from different clinical specimens from Baghdad hospitals. Candida isolates were identified by conventional methods, they were processed for Candida speciation on CHROMagar. The results of identification were confirmed by internal transcribed spacer (ITS) sequencing. Phylogenetic trees were analyzed with reference strains deposited in GenBank. Antifungal susceptibility testing was evaluated by the disc diffusion method and performed as recommended by the Clinical and Laboratory Standard Institute (CLSI) M44-A document. Candida isolates investigated produce secondary metabolites gliotoxin with HPLC technique and quantification. Out of 110 Candida isolates, C. albicans (66.36%) was the most frequent isolate, followed by the isolates of C. tropicalis (10.9%) and C. glabrata (6.36%) respectively. Concerning the antifungal susceptibility test, Candida isolates showed a high level of susceptibility to Miconazole (70.9%), Itraconazole (68.2%), and Nystatine (64.5%). The ability of obtained isolates of Candida spp. to produce gliotoxin on RPMI medium was investigated, only 28 isolates had the ability to secret this toxin in culture filtrates. The highest concentrations were detected in C. albicans (1.048 ㎍/ml). Gliotoxin productivity of other Candida species was significantly lower. The retention time for gliotoxin was approximately 5.08 min.

• 생약학회지
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• 제54권1호
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• pp.44-51
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• 2023

Fine dust has emerged as seriously hazardrous particles, which can cause respiratory and cardiovascular diseases. Thus, we have developed a natural complex extract consisted of Codonopsis lanceolata (Siebold & Zucc.) Trautv., Platycodon grandiflorum A. De Candolle, and Glycyrrhiza uralensis Fischer in the ratio of 3 : 5 : 2, which have a beneficial effect on respiratory system. In this study, simultaneous quantitative analysis of marker compounds, lobetyolin, platycodin D, and glycyrrhizic acid in the natural complex extract was developed and validated with high performance liquid chromatography-photodiode array detector. The marker compounds were shown in a large linearity with a correlation coefficient (R²) of 1.000. The limit of detection (LOD) of lobetyolin, platycodin D and glycyrrhizic acid were 5.40 ㎍/mL, 3.94 ㎍/mL and 5.86 ㎍/mL, respectively. The limit of quantification (LOQ) of lobetyolin, platycodin D and glycyrrhizic acid were 16.36 ㎍/mL, 11.94 ㎍/mL and 17.75 ㎍/mL, respectively. The content analysis revealed that the amounts of lobetyolin, platycodin D, and glycyrrhizic acid were 0.039±0.013 mg/g, 0.337±0.048 mg/g, and 1.171±0.003 mg/g, respectively, in the natural complex extract. Therefore, these results could be used as basic data for the standardization and quality control of the natural complex extract.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.62-62
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• 2023

Zanthoxylum piperitum ("chopi" in Korean) has been used as traditional medicinal plants with high anti-inflammatory, antioxidant, and antifungal activities. The aims of the study were to identify marker compounds and to investigate metabolites variation of chopi according to different parts and harvest times. Every month from June to September, chopi were harvested with three different parts: leaves, leaf-twig mixtures, twigs. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), two main marker compounds (quercitrin and quercetin-3-O-glucoside) were characterized in 70% ethanol extracts of chopi. Quantification of the two marker compounds were subsequently conducted by high performance liquid chromatography (HPLC), representing that contents of these compounds were higher in leaves and leaf-twig mixtures rather than twigs. For the comprehensive analysis of metabolites associated with production of marker compounds, 35 primary metabolites were identified using gas chromatography-mass spectrometry (GC-MS). Multivariate analysis results represented that plant parts were main contributors to the separation of chopi. However, significant differences were not observed between leaves and leaf-twig mixtures samples. The partial least square (PLS) predictive model revealed that monosaccharides (fructose, galactose, glucose, mannose, xylose) and branched-chain amino acids (isoleucine, valine, leucine) were important determinants for the production of marker compounds together with alanine, inositol, GABA, and theronic acid. This study could be extended to stabilize and utilize chopi as an industrial material, as well as to find good candidates with various nutritional traits.

• 한국식품영양학회지
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• 제36권6호
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• pp.436-444
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• 2023

To produce an intestinal immunomodulatory beverage containing Centella asiatica extract (CAE), three types of CAE-added beverage prototypes were prepared, and their immunomodulatory activities and marker compounds were analyzed. As a result of the cytotoxicity assessment, all the beverages did not show significant toxicity compared to the control group. Next, the immunomodulatory activities of the beverage prototype were evaluated using the inflammatory model of IL-1β-induced intestinal epithelial cell line. All the samples significantly reduced the production of IL-6, IL-8, and MCP-1 in a CAE concentration-dependent manner. In addition, CAE-added beverages inhibited NO, IL-6, and IL-12 production in LPS-induced RAW 264.7 cells. When the major triterpenoids, as marker compounds for the production of CAE-added beverages, were analyzed by HPLC-DAD, only asiaticoside was detected beyond the limit of quantification, while madecassoside, madecassic acid, and asiatic acid were not detected. The amounts of asiaticoside in CAE-added beverage prototypes were confirmed in No. 1 (19.39 ㎍/mL), 2 (19.25 ㎍/mL), and 3 (19.98 ㎍/mL). In conclusion, the results of this study suggested that CAE-added beverage prototypes induced immunomodulatory effects in the intestinal inflammatory cell line models and asiaticoside could be used as a marker compound for CAE-added beverage production.

• 한국식품위생안전성학회지
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• 제37권2호
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• pp.39-45
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• 2022

본 연구에서는 오크라를 이용하여 건강기능식품 개발 시원료의 표준화를 위하여 HPLC-PDA를 이용하여 지표성분 quercetin-3-𝑜-gentiobioside 및 isoquercitrin의 기존 보고된 분석법을 개선하고 분석법에 대한 유효성 검증을 실시하였다. 분석법의 유효성 검증은 ICH 가이드라인에 근거하여 특이성, 직선성, 정확성, 정밀성, 검출한계 및 정량한계를 통해 신뢰성 및 타당성을 검증하였다. HPLC를 이용한 분석방법에서 표준용액의 지표성분 피크 머무름 시간과 오크라 분말 시료의 지표성분 피크 머무름 시간 및 spectrum의 확인결과 모두 일치하므로 특이성을 확인하였다. Quercetin-3-𝑜-gentiobioside 및 isoquercitrin의 검량선은 1에 가까운 높은 상관계수 값(0.9999, 0.9999)으로 우수한 직선성을 확인할 수 있었으며 분석에 적합함을 알 수 있었다. 농도를 알고 있는 오크라 분말 시료에 표준물질을 저, 중, 고농도로 제조한 후 첨가하여 정밀성 및 정확성을 계산하였다. Quercetin-3-𝑜-gentiobioside 및 isoquercitrin의 정밀성은 일내, 일간 정밀성으로 확인하였으며, quercetin-3-𝑜-gentiobioside 및 isoquercitrin의 일내 정밀성은 각각 0.50-1.48%, 0.77-2.82% 수준으로 확인되었으며, 일간 정밀성은 0.07-3.37%, 0.58-1.37% 수준으로 5% 이하의 우수한 정밀성을 보였다. 정확성 측정결과 quercetin-3-𝑜-gentiobioside 및 isoquercitrin의 일내 정확성은 104.87-109.64%, 108.50-109.70%를 나타내었으며, 일간 정확성은 106.69-111.08%, 106.85-109.06% 수준으로 우수한 정확성을 나타내었다. Quercetin-3-𝑜-gentiobioside 및 isoquercitrin의 검출한계는 각각 0.24 ㎍/mL, 0.16 ㎍/mL이었고 정량한계는 0.71 ㎍/mL, 0.49 ㎍/mL로 나타내어, 낮은 농도에서도 검출이 가능함을 확인하였다. 확립된 분석법은 특이성, 직선성, 정밀성, 정확성, 검출한계 및 정량한계에 대한 분석법 검증결과가 모두 우수한 분석법임을 증명하였다. 또한 검증된 분석법을 이용하여 오크라 분말 시료 중 quercetin-3-𝑜-gentiobioside 및 isoquercitrin의 함량분석 결과, quercetin-3-𝑜-gentiobioside은 1.49±0.01 mg/dry weight g, isoquercitrin은 1.39±0.01 mg/dry weight g의 함량을 함유하고 있는 것으로 분석되었다. 본 연구는 HPLC-PDA를 이용한 오크라의 지표성분인 quercetin-3-𝑜-gentiobioside 및 isoquercitrin의 동시 분석방법이 과학적으로 신뢰성이 있는 적합한 분석방법임이 검증되었다.