• Archives of Pharmacal Research
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• v.29 no.3
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• pp.241-248
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• 2006

Angiotensin converting enzyme (ACE) inhibitors have cardioprotective effects in different species including human. This cardioprotective effect is mainly due to the inhibition of bradykinin (BK) degradation rather than inhibition of the conversion of angiotensin I to angiotensir. II. Bradykinin, a nonapeptide, has been considered to be the potential target for various enzymes including ACE, neutral endopeptidase 24.11, carboxypeptidase M, carboxypeptidase N, proline aminopeptidase, endopeptidase 24.15, and meprin. In the present study, the coronary vascular beds of Sprague Dawley rat isolated hearts were perfused (single passage) with Krebs solution alone or with different concentrations of BK i.e. $2.75{\times}10^{-10},\;10^{-7},\;10^{-6}\;and\;10^{-5}M$ solution. Percent degradation of BK was determined by radioimmunoassay. The degradation products of BK after passing through the isolated rat-hearts were determined using RP-HPLC and mass spectroscopy. All the four doses of BK significantly decreased the perfusion pressure during their passage through the hearts. The percentage degradation of all four doses was decreased as the concentration of drug was increased, implying saturation of a fixed number of active sites involved in BK degradation. Bradykinin during a single passage through the hearts degraded to give [1-7]-BK as the major metabolite, and [1-8]-BK as a minor metabolite, detected on HPLC. Mass spectroscopy not only confirmed the presence of these two metabolites but also detected traces of [1-5]-BK and arginine. These findings showed that primarily ACE is the major cardiac enzyme involved in the degradation of bradykinin during a single passage through the coronary vascular of bed the healthy rat heart, while carboxypeptidase M may have a minor role.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.111-114
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• 2008

Adsorption isotherm with the most fundamental information related to chromatography process is obtained experimentally. The adsorption isotherm of 2-deoxyuridine (dUrd) and 2-deoxycytidine (dCyd) with ${\mu}$-Bondapak $C_{18}$, static method was adopted in RP-HPLC. The concentrations of mobile and stationary phases were measured with different initial concentrations of dUrd and dCyd, 1, 3, 5, 7, 10 mg/mL, respectively. The adsorption isotherm data were applied by Freundlich, Langmuir, Sips, and Radke-Prausnitz model equations. As a result of the regression analysis, standard error between adsorption isotherm of dUrd and Radke-Prausnitz equation was very low, and adsorption isotherm of dCyd was in an agreement with Sips equation very well.

• Journal of Life Science
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• v.25 no.7
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• pp.780-785
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• 2015

Dietary intake and bioavailability of phorotannins in abalone was investigated after feeding with the phlorotannin-rich brown seaweed Ecklonia stolonifera after 4 days starvation. Reverse-phase high-performance liquid chromatography (RP-HPLC) affords isolation and quantification of the major phlorotannins of 7-phloroeckol and eckol, which were identified by mass spectrometry and nuclear magnetic resonance. Abalone growth and feed consumption rates were similar when fed either with the E. stolonifera or the common feed seaweed Saccharina japonica for 20 days. Throughout the feeding period, 7-phloroeckolol was accumulated in the abalone flesh tissue up to an average of 0.58±0.13 mg/g dry weight after 6 days. Eckol was reached to 0.25±0.05 mg/g dry tissue after 6 days, and maintained the level until end of feeding period. By feeding S. japonica as a control, no phlorotannins were detected in the abalone tissues. Both of the abalone, fed with E. stolonifera or S. japonica, had enzymes that decomposed 7-phloroeckol and eckol in muscle tissues, with similar degradation rates of −0.05 or less and −0.05 mg/ml/hr, respectively. Phlorotannins were reduced by constitutive enzymes in abalone tissues. Therefore, value-added abalone containing bioactive phlorotannins can be produced by simply changing the feed to the phlorotannin-rich brown seaweed E. stolonifera 6 days before harvest.

• KSBB Journal
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• v.9 no.2
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• pp.165-173
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• 1994

In this paper we have described the structural characterization of recombinant bovine somatotropin produced in Escherichia coli. Recombinant bovine somatotropin consists of 191 amino acid residues with a calculated molecular weight of 21,802 Da. For fragmentation of recombinant bovine somatotropin, we have used trypsin, Staphylococcus aureus V8 pretease, CNBr, and mild acid hydrolysis method. Digestion and cleavage with these proteases and chemicals yielded peptides of various size for amino acid sequence determination. The N-terminal sequence analysis was carried out up to thirty residues. Because the design of the recombinant bovine somatotropin gene for expression was such that the coding sequence begins with an initiation codon, AUG, before Ala, the first amino acid of bovine somatotropin, we could expect the initial amino acid as N-formyl Met. But the first amino acid of this protein, expressed in E. coli cells as inclusion bodies, was Ala. And the amino acid composition of RP-HPLC purified recombinant bovine somatotropin was determined and no essencial difference was observed. The amino acid sequence of the recombinant bovine somatotropin was identical to that predicted from its recombinant gene. There was no processing or replacement of amino acid residues in recombinant bovine somatotropin expressed in E. coli. The hydropathy plot of recombinant bovine somatotropin revealed a hydrophobic region at the NH2-terminus and hydrophilic region at the COOH-terminus. The E. coli expression system is thought to be valuable for the expression of recombinant bovine somatotropin because protein was processed to remove the N-terminal Met residue by methionyl-aminopeptidase autonomously.

• KSBB Journal
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• v.10 no.3
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• pp.271-282
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• 1995

The authentic hGH converted from met-hGH by immobilized ApM was purified by successive chromatographic processes based on the differences in isoelectric points, hydrophobicities and charges. The final recovery yield was about 14.1% and the specific activity of the purified hGH was 2.75IU per mg when assayed by enzyme immunoassay. The purified hGH was verified to be authentic hGH through the analysis of amino acid composition, amino-terminal amino acid sequence, carboxy-terminal amino acid and tryptic peptide map. The purity of purified hGH was higher than that of commercial hGH when assessed by SDS-PAGE, PAGE, IEF and HSGF. In weight-gain assay and tibia test with hypophysectomized rats, the hGH produced in this study showed the same growth effect as the commercial hGH.

• Analytical Science and Technology
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• v.36 no.1
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• pp.32-43
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• 2023

This study reports for the first time about a stability indicating RP-HPLC method for qualitative and quantitative determination of acalabrutinib in bulk and dosage form and in presence its impurities 1, 2 and 3. The chromatographic separation was carried on Zorbax XDB-C18 (250×4.6 mm; 5 µ id) as stationary phase, Phosphate buffer pH 6.4 and methanol 80:20 (v/v) as mobile phase at a flow rate of 1.0 mL/min, UV detection was carried at wavelength of 238 nm and the analysis was completed with a run time of 15 min. In these conditions the retention time of acalabrutinib and its impurities 1, 2 and 3 was observed to be 3.50, 4.83, 8.40 and 9.93 min respectively. The method was validated for system suitability, range of analysis, precision, specificity, stability and robustness. Spiked recovery at 50 %, 100 % and 150 % was carried for both standard and impurities and the acceptable % recovery of 98-102 was observed for acalabrutinib and both impurities studied and the % RSD in each spiked level was found to be less than 2. Stability tests were done through exposure of the analyte solution to five different stress conditions i.e expose to 1N hydrochloric acid, 1 N sodium hydroxide, 3 % peroxide, 80 ℃ temperature and UV radiation at 254 nm. In all the degradation condition, standard drug acalabrutinib was detected along with both the impurities studied and the degradation products were successfully separated. In the formulation analysis there is no other chromatographic detection of other impurities and formulation excipients. Hence the developed method was found to be suitable for the quantification of acalabrutinib and can separate and analyse impurities 1 and 2.

• Analytical Science and Technology
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• v.20 no.5
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• pp.442-447
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• 2007

The properties of garlic (Allium sativum L.) are attributed to organosulfur compounds. In this paper, an analytical technique with a rapid and simple sample preparation procedures for determination of diallyl disulfide (DADS) in garlic was reported. The DADS was simply extracted with various solvents (methanol, benzene or tetrahydrofuran) from garlic and prepared for HPLC analysis. From the results, the methanol was select as an optimal extraction solvent. The mobile phase was composed from methanol and water, and the gradient elution mode was applied. 0.61 mg of DADS per g garlic powder can be extracted with methanol. This work offers some advantages over the currently accepted techniques and would be useful for chemical and biological studies of garlic and its products.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.174-179
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• 2002

A simple and sensitive analysis method based on reverse phase (RP) HPCL with flourescence detector was developed for simultaneous determination of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE), and their degradation products, $BADGE{\cdot}H_2O$, $BADGE{\cdot}2H_2O$, $BFDGE{\cdot}H_2O$, $BFDGE{\cdot}2H_2O$, $BADGE{\cdot}HCl{\cdot}H_2O$, $BADGE{\cdot}HCl$, $BADGE{\cdot}2HCl$, $BFDGE{\cdot}HCl{\cdot}H_2O$, $BFDGE{\cdot}HCl$ and $BFDGE{\cdot}2HCl$, which were hydrolyzed and chlorinated forms of BADGE and BFDGE, in canned foods and food simulants. These compounds were identified by GC/MSD with $MSTFA-NH_4I-DTE$ derivatization. Recovery study was performed at each 100 ng/mL levels of BPA, BPF, BADGE and BFDGE added to canned foods and food simulants. This method was resulted in recovery of $90{\sim}114%$ with relative standard deviation of $4.1{\sim}7.0%$, detection limits of $6{\sim}11$ ng/mL and quantitation limits of $12{\sim}18\;ng/mL$. Calibration curves were linear with correlatin coefficients of 0.997 for BPF, 0.996 for BPA, 0.9987 for BFDGE, and 0.9989 for BADGE.

• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.233-240
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• 1988

A simple and selective isocratic HPLC method for the analysis of tissue polyamine contents is described and applied on the study of the changes of the hepatic polyamine contents after partial hepatectomy in male rats. The hepatic polyamines are extracted with 0.4 M perchloric acid containing 2 mM disodium EDTA, and then the extract is redissolved in 100 ul of 1 M sodium carbonate and incubated with 300 ul of FNBT-dimethylsulfoxide (1: 100) mixture. The N-2'-nitro-4'-trifluoromethylphenyl drivatives of polyamines are separated through a ERC-ODS column in an isocratic mode with an acetonitrile-water (80:20) mobile phase within 20 min. per a sample, while monitoring the effluent at 242 nm. This improved method which could detect subnanogram of each polyamines is highly specific and reproducible as evidenced by the application of it on the study of the changes of polyamine contents in the regenerating rat liver after partial hepatectomy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.210-219
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• 2017

This study aimed to establish an optimal extraction process and high-performance liquid chromatography (HPLC)-photodiode array (PDA) analytical method for determination of marker compounds, dihydrokaempferol (DHK) and 3-O-methylquercetin (3-MeQ), as a part of materials standardization for the development of health functional foods from stems of Opuntia ficus-indica var. saboten (OFS). The quantitative determination method of marker compounds was optimized by HPLC analysis, and the correlation coefficient for the calibration curve showed very good linearity. The HPLC-PDA method was applied successfully to quantification of marker compounds in OFS after validation of the method in terms of linearity, accuracy, and precision. Ethanolic extracts from stems of O. ficus-indica var. saboten (OFSEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 50, 70, and 80% ethanol for 3, 4, 5, and 6 h. Among OFSEs, OFS70E at $80^{\circ}C$ showed the highest contents of DHK and 3-MeQ of $26.42{\pm}0.65$ and $3.88{\pm}0.29mg/OFS100g$, respectively. Furthermore, OFSEs were determined for their antioxidant activities by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation (LPO) inhibitory activities in rat liver homogenate. OFS70E at $70^{\circ}C$ showed the most potent antioxidant activities with $IC_{50}$ values of $1.19{\pm}0.11$ and $0.89{\pm}0.09mg/mL$ in the DPPH radical scavenging and LPO inhibitory assays, respectively. To identify active components of OFS, various chromatographic separation of OFS70E led to isolation of 11 flavonoids: dihydrokaempferol, dihydroquercetin, 3-O-methylquercetin, quercetin, isorhamnetin 3-O-glucoside, isorhamnetin 3-O-galactoside, narcissin, kaempferol 7-O-glucoside, quercetin 3-O-galactoside, isorhamnetin, and kaempferol 3-O-rutinoside. The results suggest that standardization of DHK in OFSEs using HPLC-PDA analysis would be an acceptable method for the development of health functional foods.