• Analytical Science and Technology
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• v.34 no.5
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• pp.193-201
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• 2021

We have demonstrated a sensitive analytical method of measuring oleracone D in mouse plasma using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Oleracone D and oleracone F (internal standard) in mouse plasma samples were processed using a liquid-liquid extraction method with methyl tertbutyl ether, resulting in high and reproducible extraction recovery (80.19-82.49 %). No interfering peaks around the peak elution time of oleracone D and oleracone F were observed. The standard calibration curves for oleracone D ranged from 0.5 to 100 ng/mL and were linear with r² of 0.992. The inter- and intra-day accuracy and precision and the stability fell within the acceptance criteria. The pharmacokinetics of oleracone D following intravenous and oral administration of oleracone D at doses of 5 mg/kg and 30 mg/kg, respectively, were investigated. When oleracone D was intravenously injected, it had first-order elimination kinetics with high clearance and volume of distribution values. The absolute oral bioavailability of this compound was calculated as 0.95 %, with multi-exponential kinetics. The low aqueous solubility and a high oral dose of oleracone D may explain the different elimination kinetics of oleracone D between intravenous and oral administration. Collectively, this newly developed sensitive LC-MS/MS method of oleracone D could be successfully utilized for investigating the pharmacokinetic properties of this compound and could be used in future studies for the lead optimization and biopharmaceutic investigation of oleracone D.

• Mass Spectrometry Letters
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• v.12 no.4
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• pp.200-205
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• 2021

Polynemoraline C, a pyridocoumarin alkaloid, exhibits anticholinergic, anti-inflammatory, antitumor, and antimicrobial activities. A sensitive analytical method of polynemoraline C in mouse plasma was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Polynemoraline C and ¹³C-caffeine (internal standard) in mouse plasma were extracted using a liquid-liquid extraction method coupled with ethyl acetate. This extraction method resulted in high and reproducible extraction recovery in the range of 73.49%-77.31% with no interfering peaks around the peak retention time of polynemoraline C and ¹³C-caffeine. The standard calibration curves for polynemoraline C were linear over the range of 0.5-200 ng/mL with r² > 0.985. The accuracy, precision, and the stability of the data were within acceptable limits on the FDA guideline. After intravenous and oral administration of polynemoraline C at doses of 5 and 30 mg/kg, respectively, the present method was successfully applied to the pharmacokinetic study of polynemoraline C. Polynemoraline C in mouse plasma showed a multi-exponential elimination pattern with a high volume of distribution values. This compound's absolute oral bioavailability was found to be 17.0%. Polynemoraline C's newly developed LC-MS/MS method can be used for further studies on the efficacy, toxicity, and biopharmaceutics of polynemoraline C, as well as its pharmacokinetic studies.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.270-278
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• 2018

This study was conducted to compare the anesthetic effects of 2,2,2-tribromoethanol (TBE, $Avertin^{(R)}$) in ICR mice obtained from three different sources. TBE (2.5%) was intraperitoneally injected at three doses: high-dose group (500 mg/kg), intermediate-dose group (250 mg/kg), and low-dose group (125 mg/kg). Anesthesia time, recovery time, end-tidal peak $CO_2$ ($ETCO_2$), mean arterial blood pressure, heart rate, oxygen saturation ($SpO_2$), body temperature, pH, $PCO_2$, and $PO_2$ of the arterial blood were measured. Stable anesthesia was induced by all doses of TBE and the anesthesia time was maintained exhibited dose dependency. No significant differences in anesthetic duration were found among the three different strains. However, the anesthesia time was longer in female than in male mice, and the duration of anesthesia was significantly longer in female than in male mice in the high-dose group. The recovery time was significantly longer for female than male mice in the intermediate- and high-dose groups. In the ICR strains tested, there were no significant differences in the mean arterial blood pressure, $SPO_2$, arterial blood $PCO_2$, and $PO_2$, which decreased after TBE anesthesia, or in heart rate and $ETCO_2$, which increased after TBE anesthesia. In addition, body temperature, blood biochemical markers, and histopathological changes of the liver, kidney, and lung were not significantly changed by TBE anesthesia. These results suggested that ICR mice from different sources exhibited similar overall responses to a single exposure to TBE anesthesia. In conclusion, TBE is a useful drug that can induce similar anesthetic effects in three different strains of ICR mice.

• Analytical Science and Technology
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• v.32 no.4
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• pp.147-154
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• 2019

Ampicillin and Sulbactam (2:1, w/w) are combined in formulation to provide broader antibacterial action in treatment of many infections. The development of analytical method for simultaneouly determine these two compounds was difficult because of the differences in their chemical structures and ratio in the formulation. Current published methods still have some limitations. In this study, we developed an alternative high-performance liquid chromatography (HPLC) assay method for simultaneously determination of ampicillin sodium and sulbactam sodium in powder for injection. Method validation of HPLC method was conducted to determine linearity, precision, accuracy, system suitability, robustness. The linearity of the calibration curves in the desired concentration range was good ($r^2$> 0.9994). RSDs of intra-day and inter-day precision obtained were less than 2.00 %. Accuracy was obtained with the recoveries in range of 98.42 % and 101.36 %. As a result of system suitability, RSD of both retention time and the peak area obtained were not more than 1.0 %. The values of plate number were more than 7000 and symmetric factors obtained were 0.8. As intermediate-precision and robustness of the developed assay, it could be expected to become valuable tools for revising the Korean Pharmacopoeia (KP XI).

• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.509-518
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• 2019

This study analyzed the effect of organic solvent extractives on the classification of wood species via near-infrared spectroscopy (NIR). In our previous research, five species of Korean softwood were classified into three groups (i.e., Cryptomeria japonica (cedar)/Chamaecyparis obtuse (cypress), Pinus densiflora (red pine)/Pinus koraiensis (Korean pine), and Larix kaempferi (Larch)) using an NIR-based principal component analysis method. Similar tendencies of extractive distribution were observed among the three groups in that study. Therefore, in this study, we qualitatively analyzed extractives extracted by an organic solvent and analyzed the NIR spectra in terms of the extractives' chemical structure and band assignment to determine their effect in more detail. Cedar/cypress showed a similar NIR spectra patterns by removing the extractives at 1695, 1724, and 2291 nm. D-pinitol, which was detected in cedar, contributed to that wavelength. Red pine/Korean pine showed spectra changes at 1616, 1695, 1681, 1705, 1724, 1731, 1765, 1780, and 2300 nm. Diterpenoids and fatty acid, which have a carboxylic group and an aliphatic double bond, contributed to that wavelength. Larch showed a catechin peak in gas chromatography and mass spectroscopy analysis, but it exhibited very small NIR spectra changes. The aromatic bond in larch seemed to have low sensitivity because of the 1st overtone of the O-H bond of the sawdust cellulose. The three groups sorted via NIR spectroscopy in the previous research showed quite different compositions of extractives, in accordance with the NIR band assignment. Thus, organic solvent extractives are expected to affect the classification of wood species using NIR spectroscopy.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.734-741
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• 2019

Objective: The objective of the study was to determine the relationship between plasma and salivary cortisol concentrations in beef cattle that were subjected to handling prior to sampling. Methods: Twenty-one Nguni cows of three age categories; 5 to 7 yr (n = 7), 8 to 10 yr (n = 6), and 11 to 13 yr (n = 8) were handled for five consecutive weeks. In the pen, a human avoidance test was performed and cattle responses to restraint in the chute and crush were observed. In addition, rectal temperature readings were taken and, faecal samples were collected and analysed for glucocorticoid metabolites. Through the handling and restraint process, excretory and vocalisation behaviour, as a sign of stress were observed and recorded. Thereafter, six cows were randomly selected and subjected to an adrenocorticotropic hormone (ACTH) challenge. Blood and saliva samples were extracted to determine cortisol concentrations. Results: Repeated handling affected (p<0.05) faecal glucocorticoid metabolites, rectal temperatures, avoidance distance, crush scores as well as urination and defaecation behaviour. Acclimation to handling was variable based on each respective parameter. Saliva cortisol concentrations increased and decreased significantly (p<0.001). A peak value of $136.78{\pm}15.869nmol/L$ was observed 30min after administration of ACTH, from a baseline value of $8.75{\pm}15.869nmol/L$. Plasma cortisol concentrations did not differ (p>0.05) across the time of sampling. A low and insignificant correlation (r = 0.0131, p>0.05) between plasma and saliva cortisol was therefore observed. Conclusion: We conclude that if beef cows are subjected to handling prior to sampling, a weak relationship exists between plasma and salivary cortisol levels.

• Analytical Science and Technology
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• v.32 no.2
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• pp.48-55
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• 2019

The simple and effective analytical method for the quality control of a novel scalp tonic formulation has been developed and optimized in terms of HPLC conditions and sample preparation method, meanwhile, the optimization of preparation condition was using response surface methodology (RSM) based on central composite design (CCD). Oleanolic acid was selected as marker compound because of its bioactivities for alopecia therapy. The developed analytical method and extraction condition were successfully qualified. Coefficient of determination ($r^2$) for the calibration was 0.9997 with a line passing through the origin point in the range of 0.1-100 mg/mL. The limit of detection (LOD) and the limit of quantitation (LOQ) were 17.5 ng/mL and 55.0 ng/mL, respectively. The intra-day and inter-day precision of the method were 0.5-1.4 % and 0.7-1.8 % in relative standard deviation, respectively, while those accuracy were 99.5-100.9 % and 100.0-102.2 %, respectively. The repeatability of oleanolic acid in samples ranged of 0.3-1.9 % based on peak area and 0.3-0.7 % for retention time. Recoveries from samples were 95.0-99.4 % with lower than 1.8 % in relative standard deviation. Overall, the developed analytical method will be used for quality control of this commercial scalp tonic products successfully.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.53-62
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• 2021

Gindai (Pristipomoides zonatus) is one of six snappers in a management complex called the Deep 7 of the Hawaiian Islands. Little is known about its life history and a preliminary analysis of otolith thin sections indicated the species may exhibit moderate growth with a lifespan approaching 40 years. Preliminary age estimates from the previous study were reinvestigated using the same otolith sections in an attempt to validate those ages with bomb radiocarbon (¹⁴C) dating. From the misalignment of birth years for the otolith ¹⁴C measurements with regional references - the post-peak bomb ¹⁴C decline period - it was concluded that previous ages were inflated from overcounting of the earliest growth zone structure in otolith sections. The oldest gindai was re-aged to 26 years once the age reading was adjusted for early overcounting, 13 years younger than the original estimate of 39 years for this fish. In general, the earliest otolith growth of gindai was massive and complicated by numerous subannual checks. The approach of lumping the early growth structures was supported by the alignment of ¹⁴C measurements from otolith core material (first year of growth). The result was greater consistency of calculated birthdates with the ¹⁴C decline reference, along with minor offsets that may indicate age estimation was imprecise by a few years for some individuals. The revised von Bertalanffy growth function applied to the validated age-at-length estimates revealed more rapid growth (k = 0.378 cf. 0.113) and a lifespan of approximately 30 years. The findings presented here are a case study of how the bomb ¹⁴C decline period can be used as a tool in the refinement of age reading protocols.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.334-343
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• 2021

Background: Gut microbiota mainly function in the biotransformation of primary ginsenosides into bioactive metabolites. Herein, we investigated the effects of three prebiotic fibers by targeting gut microbiota on the metabolism of ginsenoside Rb1 in vivo. Methods: Sprague Dawley rats were administered with ginsenoside Rb1 after a two-week prebiotic intervention of fructooligosaccharide, galactooligosaccharide, and fibersol-2, respectively. Pharmacokinetic analysis of ginsenoside Rb1 and its metabolites was performed, whilst the microbial composition and metabolic function of gut microbiota were examined by 16S rRNA gene amplicon and metagenomic shotgun sequencing. Results: The results showed that peak plasma concentration and area under concentration time curve of ginsenoside Rb1 and its intermediate metabolites, ginsenoside Rd, F2, and compound K (CK), in the prebiotic intervention groups were increased at various degrees compared with those in the control group. Gut microbiota dramatically responded to the prebiotic treatment at both taxonomical and functional levels. The abundance of Prevotella, which possesses potential function to hydrolyze ginsenoside Rb1 into CK, was significantly elevated in the three prebiotic groups (P < 0.05). The gut metagenomic analysis also revealed the functional gene enrichment for terpenoid/polyketide metabolism, glycolysis, gluconeogenesis, propanoate metabolism, etc. Conclusion: These findings imply that prebiotics may selectively promote the proliferation of certain bacterial stains with glycoside hydrolysis capacity, thereby, subsequently improving the biotransformation and bioavailability of primary ginsenosides in vivo.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.73-87
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• 2011

An abnormal mono-specific bloom of the cyanobacterium Microcystis aeruginosa had developed at a specific location (transitional zone, monitoring station of Hoenam) in Daecheong Reservoir from middle of July to early August, 2001. The maximum cell counts during the peak bloom reached 1,477,500 cells/mL, which was more than 6~10 times greater than those at other monitoring sites. The hypothesis of this study is that the timing and location of the algal bloom was highly correlated with the local environmental niche that was controled by physical processes such as hydrodynamic mixing and pollutant transport in the reservoir. A three-dimensional, coupled hydrodynamic and ecological model, ELCOM-CAEDYM, was applied to the period of development and subsequent decline of the bloom. The model was calibrated against observed water temperature profiles and water quality variables for different locations, and applied to reproduce the algal bloom event and justify the limiting factor that controled the Microcystis bloom at R3. The simulation results supported the hypothesis that the phosphorus loading induced from a contaminated tributary during several runoff events are closely related to the rapid growth of Microcystis during the period of bloom. Also the physical environments of the reservoir such as a strong thermal stratification and weak wind velocity conditions provided competitive advantage to Microcystis given its light adaptation capability. The results show how the ELCOM-CAEDYM captures the complex interactions between the hydrodynamic and biogeochemical processes, and the local environmental niche that is preferable for cyanobacterial species growth.