Mi-Hee Woo

Cytotoxicity and DNA Topoisomerases Inhibitory Activity of Constituents from the Sclerotium of Poria cocos

The bioactivity-guided fractionation of the methylene chloride extract of the sclerotium ofPoria cocos led to the isolation of (S)-(+)-turmerone (1), ergosterol peroxide (2), polyporenic acid C (3), dehydropachymic acid (4), pachymic acid (5), and tumulosic acid (6). Compounds4-6 exhibited moderate cytotoxicities, with IC50 values of 20.5, 29.1, and 10.4 αM, respectively, against a human colon carcinoma cell line. However,3-6 not only showed inhibitory activities as potent as etoposide used as a positive control on DNA topoisomerase II (36.1, 36.2, 43.9 and 66.7% inhibition at a concentration of 20 μM, respectively), but also inhibition of DNA topoisomerase I (55.8, 60.7, 43.5, and 83.3% inhibition at a concentration of 100 μM, respectively).

Cytotoxicity and DNA topoisomerase inhibitory activity of constituents isolated from the fruits of Evodia officinalis.

Four alkaloids (1–4), three quinolone alkaloids (5–7), and three flavanoid glucosides (8–10) were isolated from the fruits ofEvodia officinalis Dode, and their structures were determined from chemical and spectral data. Compounds,3, 8, 9 and10 were isolated from this plant for the first time. Of these compounds,1–3 and5–7 exhibited moderate cytotoxicities against cultured human colon carcinoma (HT-29), human breast carcinoma (MCF-7), and human hepatoblastoma (HepG-2). Compound8 showed strong inhibitory effects on DNA topoisomerases I and II (70 and 96% inhibition at a concentration of 20 μM, respectively).

Insulin-Mimetic Selaginellins from Selaginella tamariscina with Protein Tyrosine Phosphatase 1B (PTP1B) Inhibitory Activity

As part of an ongoing search for new antidiabetic agents from medicinal plants, three new (2, 4, and 5) and two known selaginellin derivatives (1 and 3) were isolated from a methanol extract of Selaginella tamariscina. The structures of the new compounds were determined by spectroscopic data analysis. All isolates showed strong glucose uptake stimulatory effects in 3T3-L1 adipocyte cells at a concentration of 5 μM. Furthermore, these compounds were found to possess inhibitory effects on PTP1B enzyme activity with IC50 values ranging from 4.6 ± 0.1 to 21.6 ± 1.5 μM. Compound 2 showed the greatest potency, with an IC50 value of 4.6 ± 0.1 μM, when compared with the positive control (ursolic acid, IC50 = 3.5 ± 0.1 μM). Therefore, these selaginellin derivatives may have value as new lead compounds for the development of agents against type 2 diabetes.

A new stilbene glucoside from the roots ofPolygonum multiflorum Thunb.

One new stillbene glucoside (6), along with five known compounds (1–5), were isolated from the roots ofPolygonum multiflorum Thumb., and their chemical structures established based on physicochemical and spectroscopic data. Of the compounds, compound3 showed DNA topoisomerase I and II inhibitory activities.

Lignans from the roots of Saururus chinensis.

Four new lignans, saucerneol F (1), saucerneol G (2), saucerneol H (3), and saucerneol I (4), were isolated from the EtOAc extract of the roots of Saururus chinensis, together with one known compound, saucerneol D (5). The structures of compounds 1-4 were elucidated by spectroscopic analysis. These compounds showed cytotoxic activities against HT-29, MCF-7, and HepG-2 cell lines.

Inhibition of DNA topoisomerases I and II of compounds from Reynoutria japonica.

Three anthraquinones (1, 2 and 4), three stilbenes (5, 6 and 7) and 3,5-dihydroxybenzyl alcohol (3) were isolated from Reynoutria japonica. Their structures were identified as emodin (1), emodin-8-O-β-d-glucoside (2), 3,5-dihydroxybenzyl alcohol (3), citreorosein (4), cis-resveratrol (5), trans-resveratrol (6) and trans-resveratrol-5-O-β-d-glucopyranoside (7) by comparing their physicochemical and spectral data with published data. Compound 3 was isolated for the first time from the Polygonaceae family. Among the purified compounds, 3 showed more potent inhibitory activity against topoisomerase I (IC50: 4 μM) than camptothecin, as the positive control (IC50: 18 μM). Compounds 3, 4, 5, 6 and 7 showed stronger inhibitory activities toward DNA topoisomerase II (IC50: 0.54, 14, 15, 0.77 and 3 μM, respectively) than the positive control, etoposide (IC50: 44 μM). Compounds 1 and 4 displayed weak cytotoxicities against human lung cancer (A549), ovarian cancer (SK-OV-3), human liver hepatoblastoma (HepG2) and colon adenocarcinoma (HT-29) cell lines.

Cytotoxic constituents isolated from the fruit bodies of Hypsizigus marmoreus.

The bioactivity-guided fractionation of chloroform extracts of the fruit bodies ofHypsizigus marmoreus led to our isolation of (22E, 24R)-ergosta-7,22-diene-3β,5α,6β-triol (1), ergosterol-3-O-β-D-glucopyranoside (2), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (3), hypsiziprenol A9 (4), hypsiziprenol AA8 (5), hypsiziprenol AA9 (6) and hypsiziprenol BA10 (7). Among these seven isolates, compound2 was identified for the first time from this plant. All compounds (1–7) exhibited moderate cytotoxicity towards cultured human colon carcinoma (HT-29), human breast carcinoma (MCF-7) and human hepatoblastoma (HepG-2) cell lines.

Quality assessment and discrimination of the roots of Cynanchum auriculatum and Cynanchum wilfordii by HPLC-UV analysis.

Cynanchum auriculatum and Cynanchum wilfordii are widely used as folk medicine in Eastern Asia. However, the indeterminacy in the authentic original plant material has resulted in the same appellative name being given to the two plants, and they are commonly misused. Therefore, it is necessary to establish an analytical method for discrimination as well as quality control of the two species. This study was to develop HPLC–UV methods for quality assessment of C. auriculatum and C. wilfordii and discrimination between the two species. Two HPLC methods to analyze eight marker compounds were established and validated. The first method analyzed seven marker compounds simultaneously on a reversed-phase column, while the second method analyzed a single marker compound, conduritol F, which exists only in C. wilfordii, on a Si-column. Thirty-nine batches of C. auriculatum and nineteen batches of C. wilfordii that were collected from different geographical regions of South Korea were analyzed by these methods. The constructed data matrix was subjected to principal components analysis and hierarchical cluster analysis in order to classify the samples. The established methods offer a potential strategy for authentication and differentiation of the two species.

High-performance Liquid Chromatographic Analysis for Quantitation of Marker Compounds of Artemisia capillaris Thunb.

Two stable high-performance liquid chromatography (HPLC) methods were developed that could quantitatively analyze 10 major marker compounds of Artemisia capillaris Thunb and could also distinguish among ‘Injinho’ and ‘Myeon-injin’ and ‘Haninjin’ — A. capillaris collected in autumn, A. capillaris collected in spring and A. iwayomogi, which can be misused as ‘Injinho’ in Korean herbal drug markets. The first HPLC method was a reversed-phase chromatography using a C18 column with an isocratic solvent system of phosphoric acid (0.05%) and acetonitrile at the flow rate of 1.0 mL/min, ultraviolet (UV) detection wavelength at 254 nm and column temperature at 40°C. Calibration and quantitation were made by using acetaminophen as an internal standard (I.S-A) and chlorogenic acid (1) was determined within 20 min. The second HPLC method was a reversed-phase chromatography using a C18 column with a gradient solvent system of phosphate buffer (0.015 M, pH 6) and acetonitrile at the flow rate of 1.0 mL/min, UV detection wavelength at 254 nm and column temperature at 40°C. Calibration and quantitation were made by using ethylparaben as an internal standard (I.S-B) and 3,5-di-O-caffeoylquinic acid (2), 3,4-di-O-caffeoylquinic acid (3), 4,5-di-O-caffeoylquinic acid (4), hyperoside (5), isoquercitrin (6), isorhamnetin 3-O-robinobioside (7), isorhamnetin-3-O-galactoside (8), isorhamnetin-3-O-glucoside (9) and scoparone (10) were determined within 60 min. Pattern recognition analysis of data from the 60 samples classified them clearly into three groups. These assay methods could be applied for QA/QC of A. capillaris and Artemisia iwayomogi.

Effects of Constituent Compounds of Smilax china on Nicotine-Induced Endothelial Dysfunction in Human Umbilical Vein Endothelial Cells

This study investigated the effects of compounds isolated from 70% ethanol (EtOH) extraction of Smilax china L. (SCE), a plant belonging to the family Smilacaceae on nicotine-induced endothelial dysfunction (ED) in human umbilical vein endothelial cells. We isolated 10 compounds from ethyl acetate (EtOAc) fraction of 70% EtOH extract of SCE and investigated their inhibitory effect on nicotine-induced ED in endothelial cells. Kaempferol, kaempferol 7-O-α-L-rhamnopyranoside, puerarin and ferulic acid showed strong inhibition of nicotine-induced vascular cell adhesion molecule (VCAM-1) expression while kaempferol, kaempferin, and caffeic acid attenuated intercellular adhesion molecule (ICAM-1) expression. Lepidoside, caffeic acid and methylsuccinic acid caused the highest up-regulated expression of endothelial nitric oxide synthase at the protein level with caffeic acid and ferulic acid showing strong inhibitory effects on inducible nitric oxide synthase (iNOS) expression. In addition, ferulic acid and kaempferol showed inhibition against interleukin-8 (IL-8) and interleukin-1β (IL-1β) expression while ferulic acid and caffeic acid showed comparatively higher inhibition of ED associated tumor necrosis factor-α (TNF-α) expression. These results show the potential of the aforementioned compounds to reverse the toxic effects of nicotine on the endothelium.