Bak-Kwang Kim

Anti-tumor activities of decursinol angelate and decursin from Angelica gigas

Thein vivo anti-tumor activities of decursinol angelate (1) and decursin (2) isolated from the roots ofAngelica gigas were investigated. These two compounds, when administered consecutively for 9 days at 50 and 100 mg/kg i.p. in mice, caused a significant increase in the life span and a significant decrease in the tumor weight and volume of mice inoculated with Sarcoma-180 tumor cells. These results suggest that decursinol angelate (1) and decursin (2) fromA. gigas have anti-tumor activities.

Anti-diabetic activities of fucosterol from Pelvetia siliquosa.

Fucosterol isolated fromPelvetia siliquosa was tested for its anti-diabetic activityin vivo. Fucosterol, when administered orally at 30 mg/kg in streptozotocin-induced diabetic rats, was caused a significant decrease in serum glucose concentrations, and exhibited an inhibition of sorbitol accumulations in the lenses. Fucosterol, when administered orally at 300 mg/kg in epinephrine-induced diabetic rats, was also caused an inhibition of blood glucose level and glycogen degradation. These results demonstrated that fucosterol is a main anti-diabetic principle from the marine algaeP. siliquosa.

Anti-oxidant activities of the extracts from the herbs of Artemisia apiacea.

The anti-oxidant activities of the various fractions from the herbs of Artemisia apiacea were investigated. The n-hexane and n-butanol fractions were found to cause significant free radical scavenging effects on DPPH, their scavenging potencies as indicated in IC(50) values, being 230.1 and 183.7 microg/ml, respectively. The n-butanol fraction exhibited a significant decrease in serum transaminase activities elevated by hepatic damage induced by CCl(4)-intoxication in rats. All fractions tested exhibited a lipid peroxidation causing a significant decrease in MDA production in TBA-reactant assay. The n-butanol fraction was the strongest in the increase in the anti-oxidant enzymes such as hepatic cytosolic superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-px) activities in CCl(4)-intoxicated rats. These results suggest that the herbs of A. apiacea possess not only the anti-oxidant, but also the activities in CCl(4)-intoxicated rats. Especially, the n-butanol extract was found to cause significant increases in the rat liver cytosolic SOD, catalase, GSH-px activities as well as a significant decrease in the MDA production.

Synthesis and hypoglycemic effect of chrysin derivatives.

A series of 18 chrysin derivatives, prepared by alkylation and condensation, were fully characterized by NMR and other techniques and tested in vivo against the diabetes mellitus. Several modified compounds especially those with propyl, butyl, octyl and tolyl groups were found to have hypoglycemic effect on diabetec mice in spite of the fact that chrysin itself had inhibited insulin release by 40-60%. None of the test animals died at the maximum dose 500mg/kg and did not cause any significant change in general feature, water and food consumption, body weight and organ weight when we examined the acute oral toxicity of those compounds having significant hypoglycemic effect.

Prolonged Systemic Delivery of Streptokinase Using Liposome

To prolong the biological half-life of streptokinase, a thrombolytic agent, streptokinase-bearing liposome with and distearolyphosphatidyl ethanolamine-N-poly (ethylene glycol) 2000 (DSPE-PEG 2000) was prepared and evaluated. Streptokinase-bearing liposomes composed of distearolyphosphatidylcholine (DSPC), cholesterol and cholesterol-3-sulfate with DSPE-PEG 2000 was prepared by the freeze-thawing method and administered via femoral vein to rats (15000 IU/kg). The activity of streptokinase in plasma was determined by the method based on the amidolytic activity of streptokinase-plasminogen complex. Pharmacokinetic parameters on streptokinase incorporated in liposomes were compared with those of streptokinase alone. The T1/2 and AUC∞ of streptokinase incorporated in DSPC-PEG liposome increased 16.3- and 6.1-fold, respectively, compared with those of streptokinase alone. Streptokinase-bearing long-circulating liposome could increase the circulation time of streptokinase in blood and expect longer thrombolytic activity compared with streptokinase alone.

Phytochemical constituents from the fruits ofAcanthopanax sessiliflorus

Six compounds were isolated from the fruits ofAcanthopanax sessiliflorus. Their structures cwere elucidated as (-)-sesamin, scoparone, protocatechuic acid, ursolic acid, hyperin and 5-chydroxymethylfurfural by physicochemical and spectroscopic analysis. Among them, scopacrone, ursolic acid and 5-hydroxymethylfurfural were isolated for the first time fromAcanthocpanax species.

Antiinflammatory activity of hyperin from Acanthopanax chiisanensis roots.

The chloroform and the ethyl acetate fractions from the roots of Acanthopanax chiisanensis exhibited a significant inhibition of prostaglandin E2 (PGE2) production in rat peritoneal macrophages stimulated by the protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA). Hyperin was isolated as an active principle from the ethyl acetate fraction. It suppressed not only PGE2 production but also nitric oxide (NO) productionin vitro in a concentration dependent manner, their IC50, being 24.3 and 32.9 μM, respectively. Hyperin also caused a significant inhibition of increase in acetic acid-induced vascular permeability in micein vivo.

An antiviral furanoquinone from Paulownia tomentosa Steud.

A methanol extract of the stem bark of Paulownia tomentosa showed antiviral activity against poliovirus types 1 and 3. Sequential liquid–liquid extraction with n‐hexane, chloroform and water, and a silicagel column chromatography resulted in the purification of a compound. The compound was identified as methyl‐5‐hydroxy‐dinaphthol[1,2–2′,3′]furan‐7,12‐dione‐6‐carboxylate on the basis of spectroscopic data. The component caused a significant reduction of viral cytopathic effect when it was subjected to a standard antiviral assay by using HeLa cells. The EC50 of the compound against poliovirus type 1 strain Brunhilde, and type 3 strain Leon were 0.3 µg/mL and 0.6 µg/mL, respectively. Copyright

Purification and characterization of Moran 20K fromMorus alba

A new glycoprotein was purified from the aqueous methanolic extract of the root bark ofMorus alba which has been used as a component of antidiabetic remedy in Oriental Medicine. SDS-PAGE result shows that the molecular weight of the glycoprotein was approximately 20 kDa. This new glycoprotein was named as Moran 20K. The protein lowered blood glucose level in streptozotocin-induced hyperglycemic mice model and it also increased the glucose transport in cultured epididymis fat cells. The amino acid composition of the protein was analyzed, and the protein contained above 20% serine and cysteine such as insulin. The actual molecular weight of the protein was determined as 21,858 Da by MALDI-TOF mass spectroscopy.

Constituents from the non-polar fraction ofArtemisia apiacea

Five compounds of terpenoids and coumarins were isolated from the non-polar fraction ofArtemisia apiacea by open column chromatography. Their structures were elucidated as α-amyrin (1), β-amyrin (2), β-sitosterol (3), 5,6,7-trimethoxycoumarin (4) and 6-methoxy-7,8-methylenedioxycoumarin (5) by chemical and spectroscopic analysis. This is the first report of the isolation of α-amyrin, β-amyrin, 5,6,7-trimethoxycoumarin and 6-methoxy-7,8-methylene-dioxycoumarin from this plant.