• 생약학회지
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• 제24권1호
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• pp.54-57
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• 1993

The seasonal variations of five biflavones from Ginkgo biloba leaves from May to November were investigated by a reversed phase HPLC method. The total amount of biflavones was increased with time to reach its maximum in yellow autumnal leaves. Each biflavone showed a similar tendency. It increased rapidly about 3.1-fold from May to June and thereafter gradually increased about 2.5-fold. The ratio of each biflavone content to the total amount of biflavones was in the order of as follows: isoginkgetin>sciadopitysin>bilobetin>ginkgetin>amentoflavone.

• Natural Product Sciences
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• 제9권2호
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• pp.45-48
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• 2003

The content of chiisanoside in the Acanthopanax Species was determined by reversed-phase high performance liquid chromatographic method. Chiisanoside was separated from the other components in the plant extracts using Zorbax 300 SB $C_{18}$ column with gradient elution of acetonitrile. Identification of chiisanoside was carried out by comparison in the LC/MS spectrum of separated peak from extract with that of standard. By HPLC analysis in this experiment, Acanthopanax species could be classified into two groups based upon the content of chiisanoside-one with low concentration of chiisanoside, such as A. senticosus and A. koreanum, and another with high concentration of chiisanoside, such as A. senticosus f. inermis, A. Divaricatus var. albeofructus, and A. chiisanensis.

• 생약학회지
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• 제35권3호통권138호
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• pp.179-183
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• 2004

Psoralen is used in the treatment of vitiligo and angelicin(isopsoralen) is a photosensitizing agent. A reversed-phase high performance chromatographic method was developed to determine the contents of psoralen and angelicin from Psoraleae Semen and processed Psoraleae Semen. The contents of psoralen and angelicin from Psoraleae Semen showed 0.39% and 0.34% respectively. Processing Psoraleae Semen showed that increased the contents of psoralen (0.52%) and angelicin (0.50%).

• Natural Product Sciences
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• 제14권1호
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• pp.68-72
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• 2008

A simple reversed phase HPLC method was developed for extracting pharmacologically active compounds coptisine, palmatine, berberine, and epiberberine from the roots of Coptis chinensis using a binary gradient of acetonitrile : 10 mM hexanesulfonic acid-Na monohydrate with UV detection at 254 nm. The coptisine (1), palmatine (2), berberine (3), and epiberberine (4) contents of the roots of C. chinensis collected from sixteen district markets in Korea and China were $6.79\;{\sim}\;24.63\;{\mu}g/g$, $5.40\;{\sim}\;20.75\;{\mu}g/g$, $21.40\;{\sim}\;81.21\;{\mu}g/g$, and $3.45\;{\sim}\;12.04\;{\mu}g/g$, respectively.

• Journal of Pharmaceutical Investigation
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• 제39권5호
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• pp.353-357
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• 2009

As a synthetic analog of the naturally occurring hormone somatostatin, octreotide has been commercially formulated in poly(lactide-co-glycolide) (PLGA) microspheres for the treatment of acromegaly. The purpose of this study was to evaluate stability of octreotide acetate in aqueous solutions at various pH values and PLGA films. Stability-indicating reversed-phase high-performance liquid chromatographic method was developed with good precision and accuracy, and it was applied to the stability studies. In aqueous solutions at pH 2.5-9.0, the degradation of octreotide followed approximately first order kinetics and the most favorable stability was found at pH 4. In PLGA films, the formation of acylated octreotides reached approximately 55% of the released octreotides. Various acylated octreotides was structurally identified by liquid chromatography-mass spectrometric analysis.

• Ocean and Polar Research
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• 제42권1호
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• pp.15-20
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• 2020

The marine sponge Hyrtios sp. collected in the Philippines was extracted and partitioned. The resulting organic layer was purified by C₁₈ reversed-phase column chromatography and HPLC to achieve the separation of nine scalarane-type sesterterpenes, including one new compound with eight known scalarane analogs. The chemical structures of the isolated compounds 1-9 were elucidated by 1D and 2D NMR and MS data analysis. All nine compounds were evaluated for their antibacterial activities against three Gram-positive and three Gram-negative bacteria. The compound 3 exhibited potent antibacterial activities against Bacillus subtilis and Micrococcus luteus. The compounds 7 and 9 displayed considerable activities against Bacillus subtilis and the others had moderate results.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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• pp.76-76
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• 2003

Here we report an antifungal peptide isolation from G. mellonella larvae. The peptide shows a high degree of sequence homology to an insect defensin, named heliomicin, first reported in Lepidoptera. The peptide was purified by a three-step procedure consisting of acid extraction, gel permeation chromatography and reversed-phase HPLC. First the N-terminal amino acid sequence of the purified peptide was determined by automated Edman degradation. (omitted)

• Preventive Nutrition and Food Science
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• 제9권4호
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• pp.295-299
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• 2004

Alpha-tocopherol was thermally oxidized and degraded at high temperatures and the resulting products were chromatographically separated and identified by LC-MS. Alpha-tocopherol dissolved in glycerol was heated at 200^{\circ}C for 30 min. The thermal products were separated by hexane extraction and analyzed by HPLC using a reversed phase $\mu$-Bondapak $C_{18}-column$ with two kinds of elution solvents: a mixture of acetonitrile and methanol (3:2), and of acetonitrile, methanol, 2-propanol, chloroform and methylene chloride (3:2:5:0.5:0.5) in a gradient mode. The isolated thermal. products of alpha-tocopherol were more viscous than alpha-tocopherol, and dark brown in color. Major thermal degradation products of alpha-tocopherol were identified by LC-MS, and the structures of thermal products were proposed. Alpha-tocopherol and its thermal degradation products were degraded into fragments, mainly at the non-aromatic parts. The degradation products of alpha-tocopherol. were combined with oxidized product (tocopherylquinone) to make thermal. products through dimerization.

• 한국식품영양과학회지
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• 제22권5호
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• pp.581-585
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• 1993

참죽나무(Cedrela sinensis A. Juss.) 잎의 ethyl acetate분획으로부터 분리한 5종의 flavonoid성분들은 HPLC에 의한 용매계 THF-dioxane-MeOH-HOAc-5% $H_3PO_4-H_2O$(145 : 125 : 50 : 20 : 2 : 658)에서 양호한 분리능을 나타내었다. 또한 주성분인 quercitrin의 함량은 MeOH엑스 및 EtOAc 분획에서 각각 9.48%(w/w) 및 37.06%(w/w) 함유되어 있음을 알 수 있었다.

• Journal of Information Display
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• 제13권4호
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• pp.145-149
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• 2012

Liquid crystals are useful for a wide range of applications due to their exceptional properties. Doping of liquid crystals with carbon nanotubes (CNTs), even at very low concentrations, produces a detectable effect on the liquid crystal (LC) properties that can be very attractive for various functions. In this study, an attempt was made to investigate the effect of CNTs on the electrical properties of a short-pitch and high-spontaneous-polarization ferro-electric LC mixture, FLC-6304, at different temperatures. The inclusion of the CNTs significantly reduced the polarization at temperatures well within the $SmC^*$ phase, but the effect was gradually reversed as the transition temperature was approached. The insertion of the CNTs also reduced the response time and the rotational viscosity of the FLC mixture, which is highly desirable in the LCD industry.