• Mass Spectrometry Letters
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• 제12권3호
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• pp.60-65
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• 2021

As a part of the Chromosome-centric Human Proteome Project (C-HPP), we have developed a few algorithms for accurate identification of missing proteins, alternative splicing variants, single amino acid variants, and characterization of function unannotated proteins. We have found missing proteins, novel and known ASVs, and SAAVs using LC-MS/MS data from human brain and olfactory epithelial tissue, where we validated their existence using synthetic peptides. According to the neXtProt database, the number of missing proteins in chromosome 11 shows a decreasing pattern. The development of genomic and transcriptomic sequencing techniques make the number of protein variants in chromosome 11 tremendously increase. We developed a web solution named as SAAvpedia for identification and function annotation of SAAVs, and the SAAV information is automatically transformed into the neXtProt web page using REST API service. For the 73 uPE1 in chromosome 11, we have studied the function annotaion of CCDC90B (NX_Q9GZT6), SMAP (NX_O00193), and C11orf52 (NX_Q96A22).

• 한국환경농학회지
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• 제30권3호
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• pp.288-294
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• 2011

최근에는 전처리가 단순하며 정량 시 방해물질의 영향을 최소화하기 위해 액체크로마토그래피를 이용하여 메틸수은을 분리한 후 유도결합플라즈마/질량분석기로 part per billion 수준까지 정량하는 방법들의 연구가 활발하다. 하지만 대부분의 액체크로마토그래피-유도결합플라즈마/질량분석기는 메틸수은 분리 시 전처리 용액의 pH를 조절하지 않으면 피크깨짐 등의 문제가 발생하여 pH를 조절하고 있다. 본 연구에서는 어류에 잔류하는 메틸수은을 신속하고 정확하게 분석하기 위하여 마이크로웨이브를 이용한 전처리 방법, HPLCICP/MS 조건, 시험법 검증의 실험을 통하여 효율적인 분석법을 확립하였다. 전처리 방법은 추출용매 1% L-cysteine HCl로 추출온도 $60^{\circ}C$에서 추출시간 120분 동안 추출하는 최적 조건을 확립하였다. 기기조건 중 HPLC에서는 시료주 입량 $50{\mu}L$, 컬럼온도는 $25^{\circ}C$에서 0.1% L-cysteine HCl + 0.1% L-cysteine 이동상으로 메틸수은을 분리 한 후, ICP-MS에서 분자량 202의 분석물질을 정량하는 조건을 확립하였다. 직선성에 대한 상관계수 값은 0.9998 이였으며, 검출한계 및 정량한계는 각각 0.15, $0.45{\mu}g/kg$ 이었다. 확립된 전처리 및 기기조건을 통하여 시료별 회수율을 구한 결과 95~99%였다. 전처리 용매와 이동상에 L-cysteine이 존재함으로써 수은에 대한 안정성, Memory effect 및 피크 끌림 등의 문제를 해결할 수 있었다. 확립된 HPLC-ICP/MS 방법에 대해 표준인증물질을 이용하여 검증한 결과, 회수율 및 상대표준편차가 각각 93~96%, 1~3%였다. 확립된 방법은 추출과정 후 별도의 전처리 과정 없이 바로 HPLC-ICP/MS를 이용하여 검출할 수 있어 메틸수은을 분석하기에 매우 적합한 것으로 판단된다.

• 대한한의학방제학회지
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• 제32권3호
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• pp.235-245
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• 2024

Objective : The study's objective is to assess the components of Dendropanax morbifera (DM) utilizing UPLC-MS/MS and assess their antioxidant properties in order to establish fundamental information for quality control of herbal formulations. Methods : The DM leaves were ground into powder and extracted with water at 80℃. The extract was subsequently concentrated and subjected to freeze-drying for subsequent analysis. The LC-MS/MS analysis was performed using a 1260 series HPLC system and a 3200 QTrap tandem mass system in positive ion mode, with detection conducted at 280 nm. The Folin-Ciocalteu method was employed to measure the phenolic content, while a colorimetric method using aluminum chloride was used to determine the flavonoid content, with gallic acid and quercetin as standards, respectively. The evaluation of antioxidant activity was conducted through the measurement of DPPH radical scavenging activity, by adding the DPPH solution to the extract and recording the absorbance at 517 nm. Results : The UPLC-MS/MS analysis identified five polyphenolic compounds in the DM extract, specifically syringin, 6-hydroxyluteolin 7-O-laminaribioside, shaftoside, rutin, and kaempferol-3-O-rutinoside. The extract was found to contain a total phenolic content of 83.106 ± 0.21 mg GAE/g and a total flavonoid content of 87.963 ± 1.014 mg QE/g. The DM extract demonstrated substantial antioxidant properties, resulting in a reduction of DPPH radicals that was evident at concentrations as low as 40 ㎍/㎖. Conclusions : The study determined important polyphenolic compounds in DM and established its considerable antioxidant efficacy. These findings provide evidence for the efficacy of DM in disease prevention related to oxidative stress and establish a foundation for ensuring quality control in herbal preparations.

• 생물환경조절학회지
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• 제17권4호
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• pp.297-305
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• 2008

치커리와 쑥갓에 있어 기내 파종 시 발아 및 무균묘 생산을 증진시키기 위한 적절한 방법을 제안하기 위해 일련의 실험들이 수행되었다. NaOCl의 적정 처리농도와 시간 검정을 통해 치커리 'Precole'과 'Chiavari' 및 쑥갓 'Okiku 3' 모두 Naocl 5%로 15분간 처리하는 것이 발아 및 유묘형성을 촉진시키고 오염발생을 억제하는 것으로 관찰되었다. 배지조성에 있어 MS와 1/2 MS처리구들의 발아반응성은 뚜렷이 차이가 나타나지 않았으며, sucrose 농도가 높아짐에 따라 발아 및 유묘형성이 지연되었다. 배양용기에 따른 반응성의 차이는 치커리 'Precole'의 경우 petri-dish에서 양호한 발아율 및 유묘형성율을 보여주었지만, 치커리 'Chiavari'와 쑥갓 'Okiku 3'에서는 용기에 큰 영향을 받지 않았다. 초음파 처리는 치커리의 발아율 및 유묘형성율을 증가시켰지만, 쑥갓 'Okiku 3'에서는 초음파 처리효과가 나타나지 않았다. 따라서 치커리와 쑥갓 모두에서 NaOCl 5%, 15분간 종자소독하고, sucrose가 무첨가된 1/2 MS 배지로 petri-dish를 이용하며, 초음파 처리는 NaOCl 5% 용매에서 120분간 하는 것이 기내 발아향상에 적당한 조건으로 선정되었다.

• Mass Spectrometry Letters
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• 제3권1호
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• pp.21-24
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• 2012

$5{\alpha}$-Dihydrotestosterone (DHT) is the primary active metabolite of testosterone, catalyzed by $5{\alpha}$-reductase ($5{\alpha}R$) in the skin, prostate, and liver. In this study, the $5{\alpha}R$ activity in rat liver S9 fraction in the presence of a NADPH-generating system was evaluated and compared by gas chromatography-mass spectrometry (GC-MS)-based in vitro assays. Testosterone and a $5{\alpha}R$ inhibitor, finasteride, were added to the S9 fractions and incubated at $37^{\circ}C$ for 1 h. Both testosterone and DHT were quantitatively measured and compared with two different GC-MS-based steroid profiling techniques. DHT was not detected by conventional GC-MS analysis in the absence of finasteride when the concentration of testosterone in the S9 fraction was less than $0.2{\mu}M$, whereas the isotope-dilution GC-MS (GC-IDMS) system was able to evaluate the $5{\alpha}R$ activity. Because the S9 fraction contains more reactive enzymes and is easier to collect from tissues compared with a microsomal solution, the combination of the S9 fraction and GC-IDMS technique may be a promising assay for evaluating the $5{\alpha}R$ activity in large-scale clinical studies.

• Environmental Engineering Research
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• 제20권2호
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• pp.133-140
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• 2015

The aim of this study was to investigate the bacteriophage removal in various clay minerals and clay-amended soils. Batch experiments in kaolinite, montmorillonite, and bentonite showed that kaolinite was far more effective at the MS2 removal than montmorillonite and bentonite. In kaolinite, the log removal increased from 0.046 to 2.18, with an increase in the adsorbent dose from 0.3 to $50g\;L^{-1}$, whereas the log removals in montmorillonite and bentonite increased from 0.007 to 0.40 and from 0.012 to 0.59, respectively. The MS2 removal in kaolinite-amended silt loam soils was examined at three different soil-to-solution (STS) ratios. Results indicated that the log removal of MS2 increased with an increase in the kaolinite content and the STS ratio. At the STS ratio of 1:10, the log removal of MS2 increased from 2.33 to 2.80 with an increase in the kaolinite content from 0% to 10% in kaolinite-amended soils. The log removals of MS2 at the STS ratios of 1:2 and 1:1 increased from 2.84 to 3.47 and from 3.46 to 4.76, respectively, with an increase in the kaolinite content from 0% to 10%. Results also indicated that the log removals of PhiX174 and $Q{\beta}$ in kaolinite-amended soils were similar to each other, but they were far lower than those of MS2 at all the kaolinite contents. The log removal of PhiX174 increased from 0.16 to 0.32, whereas the log removal of $Q{\beta}$ changed from 0.17 to 0.22 with an increase in the kaolinite content from 0% to 10%.

• Journal of Plant Biotechnology
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• 제30권1호
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• pp.109-113
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• 2003

고구마 품종 '율미'를 이용해 2,4-D 1.0 mg/L가 첨가된 MS 배지에 정단분열조직배양을 통하여 발생된 배발생 캘러스를 실험재료로 여러 가지 동결보호제를 처리하여 2-step method 에 의해 동결보존을 실시하였다. ABA 10m/L가 포함된 배지에서 전처리된 배발생 캘러스는 ABA 1.0mg/L 처리구보다 액체질소에 저장 후 생존율이 더 높게 나타났다. TTC방법과 FDA 염색법을 통해 초저온 보존 후에 생존을 확인한 결과 10mg/L의 ABA를 전처리 한 0.4M sucrose가 포함된 1.28M DMSO 처리구에서 46.8%의 가장 높은 생존율을 나타냈다. 캘러스를 1.0mg/L 2,4-D가 포함된 MS 고체배지에서 암배양한 결과 배양 4주일 후부터 1.28 M DMSO 단독처리구에서 캘러스가 생장하는 것을 육안 관찰할 수 있었으며 배양 8주일 후에는 배가 발생하였고, 0.1 mg/L 2,4-D＋0.1 mg/L kinetin 혼용구에 2주일간 계대배양한 다음 MS기본배지에서 완전한 식물체로 재생되었다.

• 분석과학
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• 제28권1호
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• pp.1-7
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• 2015

4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco specific nitrosamine found only in tobacco products. The ability to monitor biomarker concentrations is very important in understanding environmental tobacco smoke (ETS). In this study, an efficient and sensitive method for the analysis of NNK in dust was developed and validated using liquid chromatography tandem mass spectrometry. Dust was collected with filter paper soaked in methanol. The standard solution and dust sample were diluted with 100 mM ammonium acetate and extracted using dichloromethane. Our calibration curves ranged from 25 to $10^4pg/mL$. Excellent linearity was obtained with correlation coefficient values between 0.9996 and 1.0000. The limit of detection (LOD) was 5 pg/mL ($S/N{\geq}3$) and the retention time was 10 min. The limit of quantification (LOQ) was 25 pg/mL, and the acceptance criteria was the rate of 98-103% (80-120% at levels up to $3{\times}LOQ$). The coefficient of variations (CV) was 2.8%. Accuracies determined from dust samples spiked with four different levels of NNK racurves ranged that from 25 to 104 pg/mL. Excellent linearity was obtained between 92.1% and 114%. The precision of the method was acceptable (5% of CV). The recovery rates of the whole analytical procedure at low, medium, and high levels were 105.7-116.5% for NNK. The carry-over effects during LC-MS/MS analysis were not observed for NNK. This manuscript summarizes the scientific evidence on the use of markers to measure ETS.

• Applied Biological Chemistry
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• 제39권6호
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• pp.506-511
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• 1996

우리나라에서 식용으로 이용되는 진달래꽃으로부터 6성분의 폐놀산 화합물이 분리동정되었다. 이들 화합물의 구조는 IR, UV, $^{1}H$과 $^{13}C$ NMR, FAB-MS, ES-MS와 EI-MS에 의해 얻어진 분광학적인 결과에 근거하여, chlorogenic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid, caffeic acid, ferulic acid, p-coumaric acid인 것으로 밝혀졌다. Chlorogenic acid (0.2 g)는 ethyl acetate과 ethyl ether 분획에 동시에 함유되어 있었고, polyamide C-200 관 크로마토그래피법, 분취용 박층크로마토그래피법, 재결정법, Sephadex LH-20 관 크로마토그래피법을 통해서 양 구분으로부터 최종적으로 회수된 총 페놀산 함량 (0.52 g)의 38.5%를 차지하였다. 항산화성은 티오시안산철의 존재하에서 리놀레산의 에타놀 용액 중에서 측정되었다. 항산화능은 p-coumaric acid<${\alpha}-tocopherol$

• Bulletin of the Korean Chemical Society
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• 제23권8호
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• pp.1139-1143
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• 2002

Analysis of lysophosphatidic acids (LPAs) is of clinical importance as they can serve a potential marker for ovarian and other gynecological cancers and obesity. It is critically important to develop a highly sensitive and specific method for the early detection of gynecological cancers to improve the overall outcome of this disease. We have established a novel quantification method of LPAs in human plasma by negative ionization tandem mass spectrometry (MS-MS) using multiple reaction monitoring (MRM) mode without the conventional TLC step. Protein-bound lipids, LPAs in plasma were extracted with methanol : chloroform (2:1) containing LPA C14:0 as an internal standard under acidic condition. Following back extraction with chloroform and water, the centrifuged lower phase was evaporated and reconstituted in methanol. The reconstituted solution was directly injected into electrospray source of MS/MS. For MRM mode, Q1 ions selected were m/z 409, 433, 435, 437 and 457 which corresponds to molecular mass [M-H]- of C16:0, C18:2, C18:1, C18:0 and C20:4 LPA, respectively. Q2 ions selected for MRM were m/z 79, phosphoryl product. Using MS/MS with MRM mode, all the species of LPAs were completely separated from plasma matrix without severe interferences. This method allowed simultaneous detection and quantification of different species of LPAs in a plasma over a linear dynamic range of 0.01-25 ㎛olL-1 . The detection limit of the method was 0.3 pmol/mL, with a correlation coefficient of 0.9983 in most LPAs analyzed. When applied to the plasmas of normal and gynecological cancer patients, this new method differentiated two different groups by way of total LPA level.