Showing papers by "Byung Sun Min published in 2006"

Anti-inflammatory activity of flavonoids from Populus davidiana.

Abstract: Anin vitro bioassay-guide revealed that the methanol (MeOH) extract of the stem bark ofPopulus davidiana showed considerable inhibitory activity against cyclooxygenase (COX-1, COX-2). Continuous phytochemical study of the MeOH extract of this plant led to the isolation of ten flavonoids; sakuranetin (1), rhamnocitrin (2), 7-O-methylaromadendrin (3), naringenin (4), eriodictyol (5), aromadendrin (6), kaempferol (7), neosakuranin (8), sakuranin (9) and sakurenetin-5,4′-di-β-D-glucopyranoside (10). Their structures were identified on the basis of their physicochemical and spectroscopic analyses. The isolated compounds,1–10, were tested for their inhibitory activities against COX-1 and COX-2. Compound7 was found to have potent inhibitory effect on COX-1 and a moderate effect on COX-2, meanwhile, compounds1–6 showed moderate inhibition against COX-1 only. Moreover, compounds5–8 exhibited suppressive effects on xanthine oxidase (XO). These results may explain, in part, the traditional uses ofP. davidiana in ethnomedicine.

Isolation of flavonoids, a biscoumarin and an amide from the flower buds of Daphne genkwa and the evaluation of their anti-complement activity

Abstract: As part of an ongoing study aimed at identifying the anti-complement active compound from the flower buds of Daphne genkwa, ten flavonoids, one biscoumarin and one amide were isolated. Their structures were identified from spectroscopic and physicochemical data as genkwanin 5-O-beta-d-primveroside (1), apigenin 7-O-beta-d-glucuronide (2), genkwanin 5-O-beta-d-glucopyranoside (3), apigenin 5-O-beta-d-glucopyranoside (4), genkwanin (5), apigenin (6), luteolin 7-methyl ether (7), luteolin (8), daphnoretin (9), velutin (10), 7-methoxyacacetin (11) and aurantiamide acetate (12). Among them, compounds 9, 10 and 12 were isolated from this plant for the first time. The anti-complement activity of these compounds was tested against the classical pathway of the complement system. Among the compounds, daphnoretin (9) exhibited significant anti-complement activity with an IC(50) value of 11.4 microm, whereas the other compounds were not active in the assay.

Anti-complementary activity of ursane-type triterpenoids from Weigela subsessilis.

Abstract: A new ursane-type triterpenoid, weigelic acid (1), and seven known compounds, ursolic acid (2), ilekudinol A (3), corosolic acid (4), ilekudinol B (5), esculentic acid (6), pomolic acid (7), and asiatic acid (8) were isolated from the leaf and stem of Weigela subsessilis. The structure of the new triterpenoid was established as 1beta,2alpha,3alpha,23-tetrahydroxyurs-12-en-28-oic acid on the basis of spectroscopic analyses. In addition, the isolated compounds were evaluated for their anti-complement activity against the classical pathway of the complement system. Of these, compounds 1-2 and 4-8 exhibited anti-complement activity with IC50 values of 152, 90, 130, 51, 56, 4, and 163 microM, respectively, whereas 3 was inactive. This shows that a carboxylic group of ursane-type triterpenoids seems to play an important role in inhibiting the hemolytic activity of human serum against erythrocytes.

Anticomplement activity of cycloartane glycosides from the rhizome of Cimicifuga foetida.

Abstract: A tetranor-cycloartane glycoside and two 9,19-cycloartane glycosides were isolated from the EtOAc-soluble fraction of the rhizome of Cimicifuga foetida. The structures of the compounds were determined to be cimilactone A (1), 25-O-acetylcimigenol 3-O-beta-D-xylopyranoside (2) and cimigenol 3-O-alpha-L-arabinopyranoside (3), respectively, using spectroscopic analysis. The three compounds were examined for their anticomplement activity against the classical pathway of the complement system. Compound 1 showed significant anticomplement activity with an IC50 value of 28.6 mu m, whereas compounds 2 and 3 were inactive. Copyright (c) 2006 John Wiley & Sons, Ltd.

DNA Topoisomerases I and II Inhibition and Cytotoxicity of Constituents from the Roots of Rubia cordifolia

Abstract: College of Pharmacy, Yeungnam University, Gyeongsan 712-749, Korea College of Pharmacy, Catholic University of Daegu, Gyeongsan 712-702, Korea. E-mail: woomh@cu.ac.kr College of Natural Science, Yeungnam University, Gyeongsan 712-749, Korea College of Pharmacy, Chungbuk National University, Cheongju 361-763, Korea College of Life Science, Catholic University of Daegu, Gyeongsan 712-702, Korea Received April 8, 2006

Protein Tyrosine Phosphatase 1B Inhibitory Activity of Triterpenes Isolated from Astilbe koreana.

Abstract: Bioassay-guided fractionation of a MeOH extract of the rhizomes of Astilbe koreana (Saxifragaceae), using an in vitro protein tyrosine phosphatase 1B (PTP1B) inhibitory assay, resulted in the isolation of a new triterpene, 3alpha,24-dihydroxyolean-12-en-27-oic acid (4), along with four triterpenes, 3-oxoolean-12-en-27-oic acid (1), 3beta-hydroxyolean-12-en-27-oic acid (beta-peltoboykinolic acid; 2), 3beta-hydroxyurs-12-en-27-oic acid (3), and 3beta,6beta-dihydroxyolean-12-en-27-oic acid (astilbic acid; 5). Compounds 1-5 inhibited PTP1B with IC50 values of 6.8+/-0.5, 5.2+/-0.5, 4.9+/-0.4, 11.7+/-0.9, and 12.8+/-1.1 microM, respectively. Our results indicate that 3-hydroxyl group and a carboxyl group in this type of triterpenes may be required for the activity, while addition of one more hydroxyl group at C-6 or C-24 may be responsible for a loss of activity. Thus, compounds 2 and 3 which possess only one hydroxyl group at C-3 and a carboxyl group at C-27 could be potential PTP1B inhibitors.

Two Novel Furan Derivatives from Phellinus linteus with anti‐Complement Activity.

Abstract: Two novel stereoisomers of furan derivatives, phellinusfurans A (1) and B (2), were isolated from the fruiting body of Phellinus linteus. Their structures were elucidated by spectroscopic analysis. Compounds 1 and 2 exhibited significant anti-complement activity with IC50 values of 33.6 and 33.7 microM, respectively, in inhibiting the hemolytic activity of human serum against erythrocytes.

Chemical Constituents from the Leaf and Twig of Acer okamotoanum Nakai and their Cytotoxicity

Abstract: As a result of cytotoxic compounds against cancer cell lines from natural sources, senven compounds were isolated from the leaf and twig of Acer okamotoanum Nakai. The compounds (1-7) were identified as ethyl gallate (1), methyl gallate (2), gallic acid (3), trans (4), acertannin (5), nikoenoside (6), and fraxin (7) by physicochemical and spectroscopic data (including mp, UV, IR, MS, , DEPT, and HMBC) in comparison with those of published papers. All the compounds were tested for their cytotoxic activity against L1210, HL-60, K562, and B16F10 cancer cell lines in vitro by MTT assay method. Compounds 1-3 and 5 showed cytotoxic activity against all tested cell lines with values ranged from 12.5 to . Of the compounds, methyl gallate (2) exhibited the most potent cytotoxic activity against L1210, HL-60, K562, and B16F10 tumor cells with values of 12.5, 48.3, 22.8, and , respectively. Other compounds did not show any cytotoxic activity against four cancer cell lines.

Coumarins and a Polyacetylene from the Roots of Angelica purpuraefolia

Abstract: Four coumarins (1-4) and one polyacetylene (5) were isolated from the roots of Anglica purpuraefolia Chung (Umbelliferae) through repeated column chromatography. Four coumarins, isoscopoletin (1), oxypeucedanin hydrate (2), arnottinin (3) and isokhellactone (4), and a polyacetylene, (+)-9(Z), 17-octadecadience-12,14-diyne-1,11,16-triol (5), were identified by spectroscopic analysis including two dimensional NMR and mass. These compounds were examined for their anti-complement activity against the classical pathway of the complement system. However, compounds 1-5 were inactive in this assay system.

Revision of Structures of Flavanoids from Scutellaria indica and Their Protein Tyrosine Phosphatase 1B Inhibitory Activity

Abstract: The structures of flavonoids, 2(S)-5,7-dihydroxy-8,2'-dimethoxyflavanone (1), wogonin (2), 2(S)-5,7,2'-trihydroxy-8-methoxyflavanone (3), and 2(S)-5,2',5'-trihydroxy-7,8-dimethoxyflavanone (4), isolated from Scutellaria indica were revised on the basis of 2D NMR spectroscopy, including to gCOSY, gHSQC, and gHMBC. Compounds 1-4 were tested in vitro protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. Compounds 2 and 4 exhibited weak PTP1B inhibitory activity with IC∧50 values of 208 and 337 μM, respectively.

Cerebrosides and Triterpenoids from the Roots of Synurus deltoides

Abstract: A mixture of cerebrosides (1) and four triterpenoids (2 - 5) have been isolated from the hexane- and EtOAc-soluble fractions of the roots of Synurus deltoides (Ait.) Nakai (Compositae). Triterpenoid structures were determined as lupeol (2), (3), (4), and ursolic acid (5). Synurus cerebrosides (1) were characterized as a common long chain base (2S,3S,4R,8E)-2-amino-8-octadecene-1,3,4-triol and fatty acyl chains; palmitic acid, (2R)-2-hydroxybehenic acid, (2R)-2-hydroxytricosanoic acid, (2R)-2-hydroxylignoceric acid, (2R)-2-hydroxypentacosanoic acid, and (2R)-2-hydroxyhexacosanoic acid. The synurus cerebrosides (1) were the first isolation from a natural source.