• YAKHAK HOEJI
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• v.54 no.3
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• pp.157-163
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• 2010

A high-performance liquid chromatography (HPLC) with DAD detector and electrospray ionization mass spectrometry (ESI-MS) was established for the simultaneous determination of coniferin (1), loganic acid (2), demethylsecologanol (3), sweroside (4) and loganin (5) from caulis Lonicera joponica. The optimal chromatographic conditions were obtained on an ODS column ($5{\mu}m$, $4.6{\times}150mm$) with the column temperature $35^{\circ}C$. The mobile phase was composed of (A) water with 0.1% formic acid and (B) methanol with 0.1% formic acid using a gradient elution, the flow rate was 0.3 ml/min. Detection wavelength was set at 254 nm. All calibration curves showed good linear regression ($r^2$>0.998) within test ranges. The developed method provided satisfactory precision and accuracy with overall intra-day and interday variations of 0.16~3.28% and 0.14~1.99%, respectively, and the overall recoveries of 99.39~105.89% for the five compounds analyzed. The verified method was successfully applied to quantitative determination of the two types (phenolic compounds and iridoids) of bioactive compounds in 24 commercial caulis L. japonica samples from different markets in Korea and China. The analytical results demonstrated that the contents of the five analytes vary significantly with sources.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.446-451
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• 2008

A high-performance liquid chromatography (HPLC) with diode array detector (DAD) and electrospray ionization mass spectrometry (ESI-MS) was established for the simultaneous determination of chlorogenic acid (1), sweroside (2), luteolin-7-O-glucoside (3), (E)-aldosecologanin (4) and 3,5-dicaffeoylquinic acid (5) from Lonicera joponica flower buds. The optimal chromatographic conditions were obtained on an ODS column (5 ${\mu}m$, 4.6${\times}$150 mm) with the column temperature $25^{\circ}C$. The mobile phase was composed of (A) water with 0.1% formic acid and (B) acetonitrile with 0.1% formic acid using a gradient elution, the flow rate was 0.3 ml/min. Detection wavelength was set at 250 nm. All calibration curves showed good linear regression ($r^2$>0.994) within test ranges. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.05${\sim}$1.95% and 0.15${\sim}$2.26%, respectively, and the overall recoveries of 97.71${\sim}$103.65% for the five compounds analyzed. The verified method was successfully applied to quantitative determination of the three types (phenolic compounds, iridoids and flavonoids) of bioactive compounds in 21 commercial L. japonica flower buds samples from different markets in Korea and China. The analytical results demonstrated that the contents of the five analytes vary significantly with sources.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1639-1648
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• 2017

Curcumin is a natural polyphenolic compound, widely acclaimed for its antioxidant, anti-inflammatory, antibacterial, and anticancerous properties. However, its use has been limited due to its low-aqueous solubility and poor bioavailability, rapid clearance, and low cellular uptake. In order to assess the effect of glycosylation on the pharmacological properties of curcumin, one-pot multienzyme (OPME) chemoenzymatic glycosylation reactions with UDP-${\alpha}-{\text\tiny{D}}$-glucose or UDP-${\alpha}-{\text\tiny{D}}$-2-deoxyglucose as donor substrate were employed. The result indicated significant conversion of curcumin to its glycosylated derivatives: curcumin 4'-O-${\beta}$-glucoside, curcumin 4',4"-di-O-${\beta}$-glucoside, curcumin 4'-O-${\beta}$-2-deoxyglucoside, and curcumin 4',4"-di-O-${\beta}$-2-deoxyglucoside. The products were characterized by ultra-fast performance liquid chromatography, high-resolution quadruple-time-of-flight electrospray ionization-mass spectrometry, and NMR analyses. All the products showed improved water solubility and comparable antibacterial activities. Additionally, the curcumin 4'-O-${\beta}$-glucoside and curcumin 4'-O-${\beta}$-2-deoxyglucoside showed enhanced anticancer activities compared with the parent aglycone and diglycoside derivatives. This result indicates that glycosylation can be an effective approach for enhancing the pharmaceutical properties of different natural products, such as curcumin.

• Natural Product Sciences
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• v.16 no.2
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• pp.116-122
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• 2010

A high-performance liquid chromatography (HPLC) with diode array detector (DAD) and electrospray ionization mass spectrometry (ESI-MS) was established for the simultaneous determination of five representative metabolites of the iridoid and phenolic classes from Rehmannia glutinosa. The optimal chromatographic conditions were obtained on an ODS column (5 mm, $4.6{\times}250\;mm$) with the column temperature at $25^{\circ}C$. The mobile phase was composed of water and acetonitrile using a gradient elution with the flow rate 0.3 mL/min. Detection wavelength was set at 205 nm. All calibration curves showed good linear regression ($r^2$ > 0.997) within test ranges. Limits of detection (LOD) and quantitation (LOQ) values were lower than 0.123 and $0.373\;{\mu}g/mL$, respectively. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.09 - 0.76% and 0.16 - 1.41%, respectively, and the overall recoveries of 99.03 - 102.67% for all of the compounds analyzed. In addition, effectiveness of diverse extraction methods was compared to each other for the development of standard analytic method. The verified method was successfully applied to the quantitative determination of five representative metabolites in twenty-one commercial Rehmannia glutinosa samples from different markets in Korea and China. The analytical results showed that the contents of the five analytes vary significantly with sources.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.27-37
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• 2019

Background: The structural conversions in ginsenosides induced by steaming or heating or acidic condition could improve red ginseng bioactivities significantly. In this paper, the chemical transformations of red American ginseng from fresh Panax quinquefolium L. under steaming were investigated, and the possible mechanisms were discussed. Methods: A method with reversed-phase high-performance liquid chromatography coupled with linear ion trap mass spectrometry ($HPLC-MS^n$)-equipped electrospray ionization ion source was developed for structural analysis and quantitation of ginsenosides in dried and red American ginseng. Results: In total, 59 ginsenosides of protopanaxadiol, protopanaxatriol, oleanane, and ocotillol types were identified in American ginseng before and after steaming process by matching the molecular weight and/or comparing $MS^n$ fragmentation with that of standards and/or known published compounds, and some of them were determined to be disappeared or newly generated under different steaming time and temperature. The specific fragments of each aglycone-type ginsenosides were determined as well as aglycone hydrated and dehydrated ones. The mechanisms were deduced as hydrolysis, hydration, dehydration, and isomerization of neutral and acidic ginsenosides. Furthermore, the relative peak areas of detected compounds were calculated based on peak areas ratio. Conclusion: The multicomponent assessment of American ginseng was conducted by $HPLC-MS^n$. The result is expected to provide possibility for holistic evaluation of the processing procedures of red American ginseng and a scientific basis for the usage of American ginseng in prescription.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.675-682
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• 2011

This study was conducted to monitor the concentrations of 24 anti-impotence drugs and their analogues in various foods and dietary supplements, with the aim of ensuring the safety of the foods and supplements. The measurements were done in 226 samples using high performance liquid chromatography/photodiode array detector (HPLC/PDA) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Five male sexual function enhancing products have been detected as follows: acethylvardenafil (21,476 mg/kg; 15 mg/capsule from one sample), sildenafil (52,778 mg/kg, 29 mg/capsule in one sample; 71,535 mg/kg, 48 mg/capsule in one sample), and tadalafil (9,772-55,545 mg/kg, 6-33 mg/capsule in four samples). A sustainable monitoring of anti-impotence drugs and their analogues in various foods and dietary supplement is recommended.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.558-563
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• 2011

In the course of our investigation for chemical constituents in the ethyl acetate layer of Korean black raspberry wine, five compounds were isolated and purified by silica gel column chromatography and high-performance liquid chromatography. The isolated compounds were identified as ethyl succinate (1), vanillic acid (2), ethyl 3,4-dihydroxybenzoate (3), furan-2-ol (4), and 4-(4-hydroxyphenyl)butan-2(S)-ol (5) based on the spectroscopic data of electrospray ionization tandem mass spectrometry and nuclear magnetic resonance. The presence of 2 in Korean black raspberry has previously reported. However, 1 and 3-5 in Korean black raspberry and its wine were isolated for the first time.

• Analytical Science and Technology
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• v.20 no.4
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• pp.331-338
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• 2007

Licorice, Glycyrrhizae Radix is widely used as a herbal medicines and a dietary supplements in East Asia. We employed high performance liquid chromatography electrospray ionization tandem mass spectrometry to determine liquiritin and glycyrrhizin in the Glycyrrhizae Radix. Liquiritin and glycyrrhizin in Glycyrrhizae Radix were ionized by positive ion pneumatically assisted electrospray and detected by HPLC-MS/MS in the multiple-reaction monitoring (MRM) mode using precursor ${\rightarrow}$ product ion combinations at m/z $436.2{\rightarrow}257.0$ and $823.4{\rightarrow}453.4$, respectively. The assay had a calibration range from 10 to 3,000 ng/mL. The limits of detection (LOD) of the liquiritin and glycyrrhizin were 0.4 ng/mL and 0.01 ng/mL, respectively. The reproducibility and repeatability (relative standard deviation) at different analyte concentrations varied from 103 to 113 % and 0.95 to 1.8 %, respectively. According to the above results, HPLC-MS/MS method permits assignment of tentative structures such as liquiritin and glycyrrhizin in the Glycyrrhizae Radix.

• Analytical Science and Technology
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• v.32 no.2
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• pp.35-47
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• 2019

In this study, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to detect 26 antidiabetic compounds in adulterated dietary supplements using a simple, selective method. The work presented herein may help prevent incidents related to food adulteration and restrict the illegal food market. The best separation was obtained on a Shiseido Capcell Pak(R) C18 MG-II ($2.0mm{\times}100mm$, $3{\mu}m$), which improved the peak shape and MS detection sensitivity of the target compounds. A gradient elution system composed of 0.1 % (v/v) formic acid in distilled water and methanol at a flow rate of 0.3 mL/min for 18 min was utilized. A triple quadrupole mass spectrometer with an electrospray ionization source operated in the positive or negative mode was employed as the detector. The developed method was validated as follows: specificity was confirmed in the multiple reaction monitoring mode using the precursor and product ion pairs. For solid samples, LOD ranged from 0.16 to 20.00 ng/mL and LOQ ranged from 0.50 to 60.00 ng/mL, and for liquid samples, LOD ranged from 0.16 to 20.00 ng/mL and LOQ ranged from 0.50 to 60.00 ng/mL. Satisfactory linearity was obtained from calibration curves, with $R^2$ > 0.99. Both intra and inter-day precision were less than 13.19 %. Accuracies ranged from 80.69 to 118.81 % (intra/inter-day), with a stability of less than 14.88 %. Mean recovery was found to be 80.6-119.0 % and less than 13.4 % RSD. Using the validated method, glibenclamide and pioglitazone were simultaneously determined in one capsule at concentrations of 1.52 and 0.53 mg (per capsule), respectively.

• Journal of Life Science
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• v.29 no.1
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• pp.90-96
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• 2019

The objective of this study was to evaluate the potential of Diospyros malabarica stem extract, a natural materials, in oral health material. With this aim in mind, thin layer chromatography (TLC), TLC-bioautography, high-performance liquid chromatography (HPLC), electrospray ionization-mass spectrometry (ESI-MS), scanning electron microscopy (SEM), and real-time qPCR were performed. The antibacterial activity of D. malabarica stem extract against Streptococcus mutans KCTC3065 was confirmed in an n-hexane fraction with low polarity. The molecular weight of the antibacterial compound was estimated to be 188 by ESI-MS analysis. The inhibitory effects of the extract on biofilm formation and gene expression related to biofilm formation of S. mutans were determined by SEM and real-time PCR analysis. The extract inhibited the formation of S. mutans biofilms at D. malabarica stem extract concentrations of 1 mg/ml, as shown by SEM. The real-time PCR analysis showed that the expression of the gtfC gene, which is associated with biofilm formation, was significantly decreased in a dose-dependent manner. Based on the above results, it can be concluded that D. malabarica stem extracts, a natural materials, can be used in oral health products to suppress the formation of biofilms by inhibiting tooth adhesion of S. mutans, a causative agent of dental caries.