Wen Yi Jin

Chemical constituents of the root of Dystaenia takeshimana and their anti-inflammatory activity.

In our ongoing search for bioactive compounds originating from the endemic species in Korea, we found that the hexane and EtOAc fractions of the MeOH extract from the root ofDystaenia takeshimana (Nakai) Kitagawa (Umbelliferae) showed cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) dual inhibitory activity by assessing their effects on the production of prostaglandin D2 (PGD2) and leukotriene C4 (LTC4) in mouse bone marrow-derived mast cells. By activity-guided fractionation, five coumarins, viz. psoralen (2), xanthotoxin (3), scopoletin (4), umbelliferone (5), and (+)-marmesin (6), together with β-sitosterol (1), were isolated from the hexane fraction, and two phenethyl alcohol derivatives, viz. 2-methoxy-2-(4′-hydroxyphenyl)ethanol (7) and 2-hydroxy-2-(4′-hydroxyphenyl)ethanol (8), three flavonoids, viz. apigenin (9), luteolin (10), and cynaroside (11), as well as daucosterol (12) were isolated from the EtOAc fraction using silica gel column chromatography. In addition, D-mannitol (13) was isolated from the BuOH fraction by recrystallization. Two of the coumarins, scopoletin (4) and (+)-marmesin (6), the two phenethyl alcohol derivatives (7, 8) and the three flavonoids (9–11) were isolated for the first time from this plant. Among the compounds isolated from this plant, the five coumarins as well as the three flavonoids showed COX-2/5-LOX dual inhibitory activity. These results suggest that the anti-inflammatory activity ofD. takeshimana might in part occurvia the inhibition of the generation of eicosanoids.

Antioxidant Activity of Anthraquinones and Flavonoids from Flower ofReynoutria sachalinensis

Bioassay-guided fractionation of methanol extract ofReynoutria sachalinensis flower using DPPH assay has led to the isolation of three anthraquinones and three flavonoids. Their structures were identified as emodin (1), emodin-8-O-β-D-glucopyranoside (2), physcion-8-O-β-D-glucopyranoside (3), quercetin-3-O-α-L-arabinofuranoside (4), quercetin-3-O-α-D-galactopyranoside (5), and quercetin-3-O-β-D-glucuronopyranoside (6) by comparing their physicochemical and spectral data with those published in literatures. All isolated compounds were evaluated for antioxidant activities with free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, superoxide radical scavenging and Cu2+-mediated low density lipoprotein (LDL) oxidation assay. The results demonstrated that three flavonoids,4, 5, and6 had remarkable antioxidant activities with the IC50 values of 64.3, 54.7, and 46.2 μM (DPPH scavenging), the IC50 values of 6.0, 6.7, and 4.4 μM (superoxide radical scavenging) and the IC50 values of 3.8, 3.2, and 5.4 μM against LDL oxidation, respectively.

Cytotoxic coumarins from the root of Angelica dahurica.

Ten coumarins were isolated from the root ofAngelica dahurica by repeated silica gel column chromatography. Their chemical structures were elucidated on the basic of physicochemical and spectroscopic data. Among them, oxypeucedanin hydrate acetonide (7) was isolated for the first time from this plant. Cytotoxicity of coumarins isolated were determinedin vitro against L1210, HL-60, K562, and B16F10 tumor cell lines by MTT method. Pangelin (5) and oxypeucedanin hydrate acetonide (7) showed a potent cytotoxic activity with the IC50 values of 8.6 to 14.6 μg/mL against four kinds of tumor cell lines. Other compounds showed the moderate cytotoxic activity or no activity against the tumor cell lines.

Cytotoxic and COX-2 inhibitory constituents from the aerial parts ofAralia cordata

Three diterpenes (1, 8, and9), three triterpenes (3, 4, and7), one saponin (11), four sterols (2, 5, 6, and12), and one cerebroside (10) were isolated from the EtOH extract of the aerial parts ofAralia cordata by repeated silica gel column chromatography. Their chemical structures were identified by comparing their physicochemical and spectral data with those published in literatures. All isolated compounds were evaluated for their cytotoxicity against L 1210, K562, and LLC tumor cell lines using MTT assay. Of which, 3β, 5α-dihydroxy-6β-methoxyergosta-7,22-diene (6) showed a potent cytotoxicity against all cell lines with IC50 values of 11.7, 11.9, and 15.1 μM, respectively, while compounds1, 5, and11 showed a moderate or weak cytotoxicity. These isolates were also examined for their inhibitory activity against COX-1 and COX-2. Although most compounds, except for2, 10, and12, showed a strong inhibitory activity against COX-1, they exhibited a moderate or weak inhibitory activity against COX-2.

Cytotoxic saponins from the root ofDipsacus asper wall

Cytotoxic activity of seven hederagenin saponins isolated from the root ofDipsacus asper were investigatedin vitro against L1210, HL-60, and SK-OV-3 tumor cell lines by the MTT method. 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin (2), 3-O-β-D-xylopyranosyl-(1→3)-α-L-Rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin (6) and 3-O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin (7) exhibited the potent cytotoxicity against the three tumor cell lines with IC50 values ranging from 4.7 to 8.7 μg/mL, with the exception of compound7, which exhibited weak cytotoxic activity against SK-OV-3 (IC50 22.5 μg/mL). Other compounds did not exhibit any cytotoxic activity (IC50>30 μg/mL).