• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.2
• /
• pp.135-143
• /
• 2014

Exopeptidase active fractions from the hepatopancreas of the Argentina shortfin squid Illex argentinus, were obtained with acetone (AC 30-40%), ammonium sulfate (AS 60-70% saturation), anion exchange chromatography (AE-II, 0.2 M NaCl) and gel filtration chromatography (GF-I, 30-50 kDa) fractionation methods. A bitter peptide solution that has a bitterness equivalent to that of 2% glycylphenylalanine and prepared by tryptic hydrolysis of milk casein, was treated with the exopeptidase active fractions. The GF-I fraction was the best based on aminopeptidase activity (35.3 U/mg), percentage of recovery (30.7%) and a sensory evaluation (1.7). The amount of released amino acids increased as incubation time increased, and the bitterness of the enzyme reaction mixtures decreased. Incubation with the GF-I fraction for 24 h resulted in the hydrolysis of several peptides as revealed by the reverse-phase high performance liguid chromatography profile, with three peaks (3, 5 and 6) decreasing in area (%) and three peaks (1, 2 and 4) increasing in area (%). Therefore, the GF-I fraction appeared to be ideally suited to reduce bitterness in protein hydrolysates by catalyzing the hydrolysis of bitter peptides.

• Korean Journal of Veterinary Research
• /
• v.31 no.3
• /
• pp.319-327
• /
• 1991

Gingko biloba is one of the oldest trees on earth. It can be traced 300 million years or more into past. In recent years, this tree has become increasingly popular because of its longevity. Amount of comsumption of Gingko leaves in Korea is increased to produce drugs for blood circulating system's disorder. The workers who work at the company of product drug with Gingko leaves complain pruritus at belt position of west, however toxic substance from extracts of Gingko biloba was carried out to determine what kind of the toxic substance from extract could induce a contact dermatitis by means of histopathological study. Dried leaves of Korean G. biloba were exhaustively extracted with chloroform. The aqueous chloroform residue was extracted with hexane. After evaporation, the hexane extract was passed through a silica gel column chromatography, it was separated into 9 fractions by means of gradient solvent (benzene: acetone/ 98~93 : 2~7%). The 4th and 7th fraction were idendified as bilibol and gingkolic acid by silica gel thin layer chromatography and NMR spectrophotometer. The 4th and 7th fractions of Korean Gingko leaves have an irritant substances which can be induced ear swelling and increased thickness of stratum cornium of rabbit ear exposed with the fractions (3 time/3 day, $100{\mu}l$ of 50mg/ml ethyl alcohol). In the 4th fraction, the substance have induced the surface of ear to swell and mass of unknown cell like inflammatory cell were infiltrated within the stratum corneum, and the 7th fraction have the surface of ear to loss the hairs, and sebaceous gland and follicle of hair were infiltrated with inflammatory cells. and other fractions at all did not induced a certain contact dermatitis and also Deutschen drug of Gingko (named as Gerigeron) have induced the contact dermatitis such as dematitis of Korean Gingko extract.

• Journal of the Korean Wood Science and Technology
• /
• v.32 no.1
• /
• pp.59-66
• /
• 2004

The dried neeldes(1.5 kg) of Juniperus rigida were ground, extracted with acetone-H₂O(7:3, v/v), concentrated, and fractionated with a series of hexane, CH₂Cl₂, EtOAc and water on a separatory funnel. Each fraction was freeze dried to give dark-brown powder and EtOAc and water soluble fractions were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluent. Spectrometric analysis such as NMR and FAB or EI-MS including TLC were performed to characterize the structures of the isolated compounds. The needles of Juniperus rigida contained a large amount of (+)-catechin, quercetin-3-O-α-L-rhamnopyranoside and isoconiferin, in addition to a small amount of umbelliferone and quercetin-3-O-β-D-rutinoside. The antioxidative activities of each fraction and isolated compounds were tested by DPPH radical scavenging method, and EtOAc soluble fraction, (+)-catechin and quercetin-3-O-α-L-rhamnopyranoside were effective.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.2
• /
• pp.83-87
• /
• 2006

The leaves of Paulownia coreana Uyeki were extracted with acetone-$H_2O$ (7:3, v/v), concentrated under reduced pressure and fractionated successively with n-hexane, methylene chloride and ethyl acetate, leaving residual water soluble fraction. A portion of the resulting aqueous soluble powder was chromatographed on a Sephadex LH-20 column using aqueous methanol and ethanol-hexane as washing solvents. Three apigenin derivatives were isolated and identified as apigenin-7-O-${\beta}$-D-glucpyranoside, apigenin-7-O-${\beta}$-D-glucuronopyranoside and apigenin-7-O-[${\beta}$-D-glucuronopyranosyl($1{\rightarrow}2$)-O-${\beta}$-D-glucuronopyranoside] by spectroscopic methods including NMR and FAB-MS.

• Korean Journal of Pharmacognosy
• /
• v.16 no.4
• /
• pp.221-226
• /
• 1985

To screen biologically active components of the higher fungi of Korea, the dried carpophores of Auricularia polytricha were extracted with water. The extract was examined for acute toxicity in ICR mice. A low molecular weight toxin of this fungus was purified by acetone precipitation followed by cellulose, silica gel and LH-20 Sephadex column chromatography. Major symptoms of this toxin were eye extrusion, hair erection, trembling of head, paralysis, rapid running or moving before death and depression of respiration. The median lethal doses of the total extract were 1.25 g/kg and 4.18 g/kg by i.p. and p.o. administrations, respectively. The amounts of one mouse lethal unit (MLU) of the total extract and final fraction that killed a 20-g mouse within 30 minutes were 28.5 mg/mouse and 12 mg/mouse, respectively.

• Korean Journal Plant Pathology
• /
• v.10 no.3
• /
• pp.215-221
• /
• 1994

Polygalacturonase (PG) produced by Botrytis cinerea in the culture broth containing citrus pectin as a carbon source was partially purified and characterized. PG was produced on a range of carbon sources such as starch, glycerol, cellobiose, and Na+-PAG with total activities of 34.8, 32.0, 29.2, 27.8 units, respectively. The specific activity was highest with 2316.7 units on Na+-PGA. Proteins of culture filtrate were concentrated with polyethylene glycol and acetone and applied to a hydroxyapatite column. Among three active fractions collected from the column, the reaction containing the highest PG activity was resolved by a Q-sepharose column. The active fraction from the Q-sepharose column was further purified by HPLC Mono Q column. The partially purified enzyme was analyzed by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Among a few protein bands revealed, the amount of the protein of which molecular weight estimated to be 43 kDa coincided with the PG activity. The partially purified PG had optimal temperatures between 35~55$^{\circ}C$ and pH between 4.5~5.5.

• Journal of the Korean Wood Science and Technology
• /
• v.35 no.5
• /
• pp.93-99
• /
• 2007

Paulownia coreana inner bark was collected, extracted in 70% acetone, concentrated under reduced pressure and sequentially fractionated using n-hexane, $CH_2Cl_2$, EtOAc and $H_2O$, then freeze dried to give brown powders. A portion of the EtOAc soluble powder was chromatographed on a Sephadex LH-20 column using a serious of aqueous methanol and ethanol-hexane mixture as eluting solvents. Two phenolic acid, $\rho$-courmaric acid and caffeic acid, two isomeric phenylethanoid glycosides, verbascoside and iso-verbascoside, and one epimeric phenylpropanoid glycoside, cistanoside F, were isolated and their structures were elucidated by spectroscopic analysis such as NMR and MS.

• YAKHAK HOEJI
• /
• v.36 no.3
• /
• pp.205-211
• /
• 1992

A simple dignostic method using Fast Atom Bombardment mass spectrometry was applied to the characterization of green tea flavonols from the eluates of Sepahadex LH-20 column chromatography. From the ethyl acetate extracts, crude mixture of flavonol fraction(Fr.$1{\sim}4$) were separated by the stepwise gradient elution with 30, 45, and 60% aqueous acetone. Procyanidine B analogues were found to be typical constituents of Fr. 1. Main components of Fr. 2 were catechins and gallo-catechins. Fr. 3 contained mainly ester type compounds, catechin-gallates, gallocatechin-gallates with their analogues. Fr. 4 was contaminated with some phthalate esters.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.2
• /
• pp.171-176
• /
• 2009

The chemical constituents of Acer komarovii Pojark. which belongs to Aceraceae has never been reported. The bark of A. komarovii was extracted with 70% aqueous acetone, and the concentrated extract was successively partitioned with n-hexane, dichloromethane, ethyl acetate and $H_2O$. From the ethyl acetate soluble fraction, four compounds were isolated by the repeated Sephadex LH-20 and RP C-18 column chromatography. From the results of spectroscopic methods including FAB-MS, 1D and 2D NMR, the structures of the compounds were determined as quercetin (1), guaijaverin (2), hirsutrin (3) and hyperin (4). These compounds (1-4) have not been reported in this tree yet.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.2
• /
• pp.164-170
• /
• 2009

The bark of Acer barbinerve was extracted with 70% aqueous acetone and the organic extracts were concentrated to small volume using rotary evaporator and then fractionated successively with n-hexane, dichloromethane, ethyl acetate and water. The chromatographic separation of ethyl acetate soluble fraction led to the isolation of five phenolic compounds. By means of spectroscopic method, the structures of these compounds were identified to methyl gallate (1), methyl gallate-4-O-${\beta}$-D-glucose (2), (+)-catechin (3), (-)-epicatechin (4) and (-)-epicatechin-3-O-gallate (5). These compounds (1-5) have not been reported in this plant yet.