• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1833-1839
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• 2004

Recently mass spectrometry and separation methods such as liquid chromatography have become major tools in the field of proteomics. In this report, we describe in detail our efforts to develop ultra-high pressure capillary reverse-phase liquid chromatography (cRPLC) and its online coupling to a mass spectrometer by a nanoelectrospray (nanoESI) interface. The RPLC system is constructed in house to deliver LC solvents at the pressure up to 20,000 psig, which is four times higher than conventional RPLC systems. The high operation pressure allows the efficient use of packed micro-capillary columns (50, 75 and 150 ${\mu}$m i.d., up to 1.5 m long). We will discuss the effect of column diameter on the sensitivity of cRPLC/MS/MS experiments and the utility of the developed technique for proteome analysis by its application in the analysis of proteome samples having different levels of complexity.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.566-569
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• 2005

한국산 개비자나무로부터 새로운 개념의 homoharringtonine 분리 및 정제 공정을 개발하였다. 메탄올을 사용한 4회 반복 추출에 의해 biomass로부터 대부분(>99%)의 homoharringtonine을 회수 할 수 있었다. 흡착 공정에서는 활성 백토(active clay)를 사용하여 추출물에 포함되어 있는 식물유래 타르, 왁스 성분을 효과적으로 제거하였다. Silica gel low-pressure chromatography공정을 통해서 순도 52% 이상의 homoharringtonine을 얻었으며, HPLC 공정을 통해 고순도 및 고수율의 homharringtonine을 정제할 수 있었다. 정제된 homoharringtonine의 분자량 및 구조분석을 수행한 결과 표준물질(Homharringtonine)과 동일 물질임을 확인할 수 있었다.

• Natural Product Sciences
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• 제21권2호
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• pp.111-121
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• 2015

The root of Panax ginseng, is a Korea traditional medicine, which is used in both raw and processed forms due to their different pharmacological activities. As part of a continued chemical investigation of ginseng, the focus of this research is on the isolation and identification of compounds from Panax ginseng root by open column chromatography, medium pressure liquid chromatography, semi-preparative-high performance liquid chromatography, Fast atom bombardment mass spectrometric, and nuclear magnetic resonance. Dammarane-type triterpenoid saponins were isolated from Panax ginseng root by open column chromatography, medium pressure liquid chromatography, and semi-preparative-high performance liquid chromatography. Their structures were identified as protopanaxadiol ginsenosides [gypenoside-V (1), ginsenosides-Rb1 (2), -Rb2 (3), -Rb3 (4), -Rc (5), and -Rd (6)], protopanaxatriol ginsenosides [20(S)-notoginsenoside-R2 (7), notoginsenoside-Rt (8), 20(S)-O-glucoginsenoside-Rf (9), 6-O-[$\alpha$-L-rhamnopyranosyl(1$\rightarrow$2-$\beta$-D-glucopyranosyl]-20-O-$\beta$-D-glucopyranosyl-$3\beta$,$12\beta$, 20(S)-dihydroxy-dammar-25-en-24-one (10), majoroside-F6 (11), pseudoginsenoside-Rt3 (12), ginsenosides-Re (13), -Re5 (14), -Rf (15), -Rg1 (16), -Rg2 (17), and -Rh1 (18), and vinaginsenoside-R15 (19)], and oleanene ginsenosides [calenduloside-B (20) and ginsenoside-Ro (21)] through the interpretation of spectroscopic analysis. The configuration of the sugar linkages in each saponin was established on the basic of chemical and spectroscopic data. Among them, compounds 1, 8, 10, 11, 12, 19, and 20 were isolated for the first time from P. ginseng root.

• 한국식품영양학회지
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• 제23권4호
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• pp.556-561
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• 2010

Tomato fruits(Lycoperisicon esculentum) synthesize the glycoalkaloids dehydrotomatine and ${\alpha}$-tomatine, possibly as defense against bacteria, fungi and insects. We developed a new effective method to prepare and purify dehydrotomatine and ${\alpha}$-tomatine that exists in tomato fruits using alumina column chromatography and high performance liquid chromatography (HPLC). The tomato glycoalkaloids(TGA) in tomato was extracted with 2% acetic acid, and then precipitated with ammonium hydroxide(pH=10.5). The dry precipitate substance was applied on alumina column, and then fractionated with water saturated n-butylalcohol. The TGA(Fr. No. 26~36) were collected and dried under reduced pressure. The TGA was performed on a reverse phase HPLC(Inertsil ODS-2, $5\;{\mu}m$), eluted with acetonitrile/20mM $KH_2PO_4$(24:76, v/v) at 208 nm. Two peaks were detected on HPLC, and individual peak was collected by repeating HPLC. Furthermore, to confirm the identity dehydrotomatine and ${\alpha}$-tomatine, each peak isolated was hydrolyzed with 1N HCl into sugar and aglycone tomatidine. The sugars were converted to trimethylsilyl ester derivatives. The nature and molar ratios of sugars were identified by gas-liquid chromatography(GLC) and the aglycone by high-performance liquid chromatography(HPLC). The first peak (Rt=17.5 min) eluted from HPLC was identified as dehydrotomatine, and second peak(Rt=21.0 min) was as ${\alpha}$-tomatine. This technique has been used effectively to prepare and isolate dehydrotomatine and ${\alpha}$-tomatine from tomato fruits.

• Mass Spectrometry Letters
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• 제10권4호
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• pp.108-111
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• 2019

The hydrolysis of penicillin G, carbenicillin and ampicillin in pure water at room temperature was studied by high pressure liquid chromatography electrospray ionization mass spectrometry. Hydrolysis of ampicillin did not occur under these conditions; however, penicillin G and carbenicillin were completely hydrolyzed after seven days. A short interpretation of this difference is proposed. The mass spectrometric behaviour, namely ESI response and fragmentation pathway, of hydrolyzed penicillin G and hydrolyzed carbenicillin have been also discussed.

• Journal of Applied Biological Chemistry
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• 제62권1호
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• pp.31-38
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• 2019

Scutellaria baicalensis Georgi (Scutellariae Radix)는 이뇨제, 고지혈증, 항박테리아, 항알레르기, 항염증제 및 항암제와 같은 건강보조식 및 전통 생약으로도 널리 사용되어 왔다. 본 연구에서 복잡한 S. baicalensis 추출물에서 지표 물질 또는 유효화합물들을 분리하는 것은 신원 확인 및 생리활성 평가를 위한 필수적인 단계다. 8개의 성분들로 구성된 타겟 분획물을 두개의 gradient elution를 사용하여 고성능 액체 크로마토 그래피에서 분석하였다. 중압 액체크로마토그래피 및 개방형칼럼으로 분취를 시뮬레이션함으로 예비실험에서 충분히 분리가 되도록 용리 조건을 결정할 수 있었다. 최적 분취방법으로 확보된 표준유효분획물로부터 8개의 지표성분들이 포함된 것을 확인하였다. 또한, 분획물은 UPLC-QTof-MS 비교 분석으로 MS, UV, HRESIMS 결과를 확인할 수 있었다. 따라서, 스케일 업 실험법은 S. baicalensis 추출물에 성공적으로 적용될 수 있었다.

• FOCUS: LIFE SCIENCE
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• 제1호
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• pp.8.1-8.3
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• 2024

Ultra-high performance liquid chromatography (UHPLC) systems are integral to modern analytical laboratories, necessitating careful maintenance and operation protocols to ensure optimal performance. This document provides comprehensive guidelines for the proper shutdown and reactivation of UHPLC systems to prevent damage and maintain operational efficiency. • Shutdown: Remove the column and replace it with a union to avoid blockages. Flush the system with a compatible solvent mix, clean mobile phase reservoirs to prevent microbial growth, flush the pump with storage solvent, and clean the autosampler, including the needle and injection port. • Reactivation: Inspect the system for wear or damage, gradually reintroduce mobile phases starting with a weak solvent, reinstall the column securely, and perform system checks on baseline stability, pressure consistency, and detector performance. By adhering to these guidelines, laboratories can ensure the longevity and reliability of their UHPLC systems, maintaining high analytical performance and minimizing downtime. These procedures help prevent common issues such as blockages, contamination, and component wear, thereby supporting efficient and accurate analytical operations.

• Natural Product Sciences
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• 제21권1호
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• pp.30-33
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• 2015

Anthocyanins are water soluble plant pigments which are responsible for the blue, red, pink, violet colors in several plant organs such as flowers, fruits, leaves and roots. In recent years, anthocyanin-rich foods have been favored as dietary supplements and health care products due to diverse biological activities of anthocyanins including antioxidant, anti-allergic, anti-diabetic, anti-microbial, anti-cancer and preventing cardiovascular disease. High-performance countercurrent chromatography (HPCCC) coupled with reversed-phase medium pressure liquid chromatography (RP MPLC) method was applied for the rapid and efficient isolation of cyanidin 3-glucoside (C3G) and peonidin 3-glucoside (P3G) from black rice (Oryza sativa L., Poaceae). The crude black rice extract (500 mg) was subjected to HPCCC using two-phase solvent system composed of tert-butyl methyl ether/n-butanol/ acetonitrile/0.01% trifluoroacetic acid (TBME/B/A/0.01% TFA, 1 : 3 : 1 : 5, v/v, flow rate - 4.5 mL/min, reversed phase mode) to give enriched anthocyanin extract (37.4 mg), and enriched anthocyanin extract was sequentially chromatographed on RP-MPLC to yield C3G (16.5 mg) and P3G (8.7 mg). The recovery rate and purity of isolated C3G were 76.0% and 98.2%, respectively, and those of P3G were 58.3% and 96.3%, respectively. The present study indicates that HPCCC coupled with RP-MPLC method is more rapid and efficient than multi-step conventional column chromatography for the separation of anthocyanins.

• Food Science and Biotechnology
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• 제18권4호
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• pp.978-984
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• 2009

An analytical method for the simultaneous determination of 9 quinolones (QNs) in porcine, chicken, and bovine muscles was developed and validated using liquid chromatography-fluorescence detector (LC-FLD). The samples were extracted using a liquid-liquid extraction (LLE) process. Chromatographic separation was achieved on a reverse phase $C_8$ column with a gradient elution using a mobile phase of 200 mM ammonium acetate buffer (pH 4.5) and acetonitrile (ACN). The proposed method was validated according to the Food and Drug Administration (FDA) guideline for bioanalytical assay procedures. Recoveries of QNs were 83.1-111.9% with relative standard deviations (RSDs) below 15%. Linearity within a range of 30-500 ${\mu}g/kg$ was obtained with the correlation coefficient ($R^2$) of 0.9967-0.9999. The limits of detection (LOD) were 1-16 ${\mu}g/kg$. These values were lower than the maximum residues limits (MRLs) established by the European Union (EU). The present method was successfully applied to determine QNs in edible muscles.

• Applied Biological Chemistry
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• 제34권4호
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• pp.334-338
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• 1991

고상법으로 새로운 반응기구에 의한 bradykinin 및 $(D-Phe7\;-Leu^8)$ bradykinin을 합성하였다. Coupling은 N, N'-dicyclohexylcarbodiimide로 행하였으며 HBr 용액으로 cleavage한 후 조펩티드는 high pressure liquid chromatography로 정제하였다. 이들 펩티드의 순도는 paper chromatography, thin layer chromatography, paper electrophoresis, 융점측정기 및 아미노산기분석기에 의하여 분석하였다. Endopeptidase인 ${\alpha}-chymotrypsin$과 trysin, exopeptidase인 carboxypeptidase A와 leucine aminopeptidase를 사용하여 in vitro 상에서 이들 펩티드의 분해실험을 하였다. ${\alpha}-Chymotrypsine$ 및 carboxypeptidase A에 의하여 이들 펩티드는 빠르게 분해하였으나 leucine aminopeptidase는 N-말단의 2번 위치에 proline의 imino결합 때문에 분해하지 않았다.