• Animal cells and systems
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• v.10 no.3
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• pp.163-167
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• 2006

Reverse-Phase High-performance Liquid Chromatography (RP-HPLC) based technique is one of the most sensitive techniques to detect the antibiotics present in honey. In the southern part of Tamilnadu, India, majority of the farmlands are occupied by plantations such as coconut, banana and rubber. A variety of antimicrobial compounds and antibiotics, which have been reported in pollen, nectar and other floral parts of the plant, gets accumulated in honey through honeybees (Apis mellifera). We have collected the nectar samples from banana (Musa paridasiaca) and rubber (Ficus elastica) flowers and the honey from honey hives of banana and rubber cultivated areas. The extracted nectar and honey samples are subjected to RP-HPLC analysis with authentic antibiotic standards. Nectar and honey samples showed 4-17, 11-29 ${\mu}g/kg$ of streptomycin, 2-29, 3-44 ${\mu}g/kg$ of ampicillin and 17-34, 26-48 ${\mu}g/kg$ of kanamycin respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.37-41
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• 2001

HPLC separation of ionic samples tends to be more complicated and difficult to understand than that of non-ionic compounds. On the other hand, band spacing is much more easily manipulated for ionic than for neutral samples. Ion-suppression RP-HPLC method was used with organic modifier and aqueous buffer solution. In this work, five mononucleotides of cytidine-5-monophosphate (5-CMP) disodium salt, uridine-5-monophosphate disodium salt (5-UMP), guanosine-5-monophosphate disodium salt (5-GMP), inosine-5-monophosphate disodium salt (5-IMP), and adenosine-5-monophosphate disodium salt (5-AMP) were examined. Acetic acid and sodium phosphate were used as buffers, and methanol as an organic modifier. A new relationship between the retention factor and the buffer concentration at a fixed modifier content (5% of methanol) could be expressed by following: K = (k(sub)-1 + k(sub)0 (k(sub)B/k(sub)S)/(1 + (k(sub)B/k(sub)S) C(sub)B(sup)a), where C(sub)B was the concentration of buffer. Using this relationship, the calculated values closely matched the experimental data. The derived relationship showed that as the buffer concentration increased, the retention factor approached a certain value, and this was buffer dependent.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.87-95
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• 2020

In this study, we separated and purified lipase inhibitory peptide from fermented milk by Lactobacillus plantarum Q180 with the aim of developing a new functional anti-lipase activity yogurt product. L. plantarum 180 was inoculated into 10% reconstituted skimmed milk and incubated at 37℃ until the pH of the culture reached pH 4.4. The lipase activity was measured using porcine pancreatic lipase. The lipase inhibitory peptides were gradually isolated by ultrafiltration, reversed phase column chromatography (RPC), reversed phase high-performance liquid chromatography (RP-HPLC), and gel permeation high-performance liquid chromatography (GP-HPLC) from the fermented milk by L. plantarum Q180. An ODS-AQ column was used for the RPC, a Vydac C18 column for the RP-HPLC, and a Superdex Peptide HR column for the GP-HPLC. The peptide was composed of Asp, Thr, Ile, Ser, Ala, and Gln, and the anti-lipase activity (IC₅₀) was 2,817 ㎍/mL.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.205-205
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• 1994

동물, 곤충, 해조류 등으로 부터 얻어진 독소는 해로운 것으로 알려져 있지만 의학적으로 유용한 화합물을 내포하고 있다. 본 연구는 이러한 점에 착안하여 독사, 또는 곤충의 독 30여종을 대상으로 위암 세포인 SNU-1에 대해서 MTT assay에 의한 세포 독성 시험을 실시하였다. 이 중 세포 독성 활성이 가장 놓은 코브라 계통인 Ophiphagus hannah의 독으로 부터 세포 독성 물질의 정제를 시도하였다. HPLC-GPC와 HPLC-lEX 또는 RP-HPLC를 이용하여 정제하였고 각 분획들을 암세포주에 대해서 시험하였다. TSK-2000SW로 부터 2개의 분획을 얻어 분획 I에서 $IC_{50}$/ 의 값이 0.5 - 3 $\mu\textrm{g}$/ml의 범위 내에서 확인되었다. 분자량이 작은 분획 II에서는 세포독성이 작게 나타났지만 농축하여 성분 분석을 시도하였다. 분획 I을 RP-HPLC를 이용하여 TFA와 acetonitrile의 linear gradient에 의해 더욱 분리를 하였고, phopholipase $A_2$ 활성의 가능성도 측정하였다. 분획 II는 Mono S 칼람을 이용하여 ammonium acetate농도에 따른 pH gradient에 의한 분리를 시도하여 순도를 SDS-PAGE에 의해서 확인하였다. 각각의 크로마토그리피로 부터 얻은 분획에 대해서 세포 독성을 실시중에 있으며 성질도 동정중에 있다.

• Analytical Science and Technology
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• v.8 no.4
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• pp.859-864
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• 1995

Mono- and oligosaccharides are derivatized with p-aminobenzoic ethyl ester (ABEE), strongly absorbs UV light at 254 nm, in the presence of sodium cyanoborohydride. C18-bonded silica column is used for the separation of sugar-ABEE derivatives in an isocratic mode. RP-HPLC conditions are optimized by using ternary mixture as mobile phase and $45^{\circ}C$ as a column temperature. Sugar-ABEE derivatives are separated well within a short run time (ca. 25 min) by reverse-phase partition chromatographic mode. The ($1{\rightarrow}6$) linkage type of dihexose-ABEE derivatives has shorter retention time than ($1{\rightarrow}4$)-linkage type. After acid hydrolysis of glycoproteins with 2M trifluoroacetic acid, monosaccharide composition and contents are determined. This procedure is very useful for the simultaneous analysis of neutral and amino sugars in a single chromatographic step using RP-HPLC without reacetylation of deacetylated amino sugars, which are produced by acid hydrolysis.

• KSBB Journal
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• v.18 no.5
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• pp.408-411
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• 2003

By reversed-phase high-performance liquid chromatography, the extraction and separation of glabridin by from licoricce root was performed in this work. The column efficiencies and resolutions of glabridin were investigated with mobile phase composition on the reversed-phase chromatographic system. The glabridin collected from licorice root was identified by LC/MS. The mobile phase used to extract glabridin were composed of ethanol, methanol, acetone, and ethyl acetate. For one-hour ultrasonic extraction with solvent of ethyl acetate, the favorable content of glabridin was obtained as 1.26g/kg. The glabridin was well separated in the mobile phase composition of 50/50 vol. % (acetonitrile/water).

• Analytical Science and Technology
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• v.15 no.3
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• pp.190-195
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• 2002

We analysed mutation of ${\beta}_2$-adrenergic receptor gene that controls bronchial asthma by denaturing high performance liquid chromatography (DHPLC) according to ion-pair reversed-phase high performance liquid chromatography (IP-RP-HPLC). We extracted genomic DNA from 50 asthma patients, amplified DNA using PCR, and analysed PCR product by DHPLC. As a result, we obtained that mutation frequency was 15 (30%) among 50 cases. Consequently DHPLC mutation detection was confirmed that the result of direct sequencing was coincide exactly.

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1433-1436
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• 2003

A new method for the simultaneous determination of heavy metal ions in cigarette material by microwave digestion and reversed-phase high-performance liquid chromatography (RP-HPLC) has been developed. The cigarette material was digested by microwave digestion. Lead, cadmium, mercury, nickel and tin ions in the digested samples were pre-column derivatized with tetra-(2-chlorophenyl)-porphyrin ($T_2$-CPP) to form color chelates, which were then enriched by solid phase extraction with a $C_{18}$ cartridge. The chelates were separated on a Waters Xterra$^{TM}RP_{18}$ column by gradient elution with methanol (containing 0.05 mol/L pyrrolidine-aceticacid buffer salt, pH = 10.0) and acetone (containin0.05 mol/L pyrrolidine-acetic acid buffer salt, pH = 10.0)as mobile phase at a flow rate of 0.5mL/min and analyzed with a photodiode array detector from 350-600 nm. The detection limits of lead, cadmium, mercury, nickel and tin were 4,3,3,8 and 5 ng/L, respectively, in the original samples. This method was afforded good results.

• Toxicological Research
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• v.35 no.2
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• pp.161-165
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• 2019

Cysteamine has been used in cosmetics as an antioxidant, a hair straightening agent, and a hair waving agent. However, recent studies indicate that cysteamine can act as an allergen to hairdressers. The objective of this study was to develop and validate a simple and effective reversed-phase high-performance liquid chromatography (RP-HPLC) method for the measurement of cysteamine and its dimer, cystamine. Sodium 1-heptanesulfonate (NaHpSO) was used as an ion-pairing agent to improve chromatographic performance. Separation was performed on a Gemini C18 column ($250mm{\times}4.6mm$, $5{\mu}m$ particle size) using a mobile phase composed of 85:15 (v/v) 4 mM NaHpSO in 0.1% phosphoric acid:acetonitrile. UV absorbance was monitored at 215 nm. The RP-HPLC method developed in this study was validated for specificity, linearity, limit of detection, limit of quantitation, precision, accuracy, and recovery. Cysteamine and cystamine were chromatographically resolved from other reducing agents such as thioglycolic acid and cysteine. Extraction using water and chloroform resulted in the recovery for cysteamine and cystamine ranging from 100.2-102.7% and 90.6-98.7%, respectively. This validated RP-HPLC method would be useful for quality control and monitoring of cysteamine and cystamine in cosmetics.

• Toxicological Research
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• v.13 no.3
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• pp.209-213
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• 1997

Residue and recoveries of clindamycin were investigated by reversed-phase high performance liquid chromatography (RP-HPLC) which was infected for the control of streptcoccal infection in Anguilla japonica and Paralichthys olivaceusis. Detection limit was 0.1 ppm. Recoveries of clindamycin in muscles of flounder and eel were 80.4 and 78.8%, respectively. The clindamycin in eel and flounder was detected up to 13 and 15 days after dosing, respectively.