Man Ki Park

Liquid chromatographic determination of less polar ginsenosides in processed ginseng.

Reversed-phase LC with an evaporative light scattering detector (ELSD) is used for the determination of less polar ginsenosides in processed ginseng. These ginsenosides include ginsenosides F4, Rg3, Rg5, Rg6, Rk1, Rk3, Rs3, Rs4, and Rs5. The method used a C18-bonded silica column with a CH3CN/H2O/CH3COOH gradient elution. (20R) and (20S) epimers and geometric isomers at the C-20 position of ginsenosides, which are not generally separated by amino columns, were now clearly separated.

Three new dammarane glycosides from heat processed ginseng.

Three new dammarane glycosides were isolated from the processed ginseng (SG; Sun Ginseng). Their structure were determined to be 3β,12β-dihydroxydammar-20(21),24-diene-3-O-β-D-glucopyranosyl(1 → 2)-β-D-glucopyranoside; 3β,12β-dihydroxydammar-20(21),24-diene-3-O-β-D- glucopyranoside and 3β,6α,12β-trihydroxydammar-20(21),24-diene-6-O-β-D-glucopyr-anoside based on spectroscopic evidences. The compounds were named as ginsenoside Rk1 Rk2, and Rk3 respectively.

High-performance liquid chromatographic analysis of ginseng saponins using evaporative light scattering detection

Abstract Ginseng saponins were analysed using HPLC with evaporative light scattering detection (ELSD). A LiChrosorb NH 2 column was used to separate ginseng saponins in white and red ginseng. The complete separation of ginsenoside Rb 1 , Rb 2 , Rc, Rd, Re, Rf, Rg 1 , Rg 2 , Rg 3 and Rh 1 was achieved within 35 min with an amino-bonded column using an acetonitrile-water-2-propanol gradient system. The ELSD drift tube temperature was set at 145°C and the nitrogen flow was set at 40 mm rotameter units. The detection limits ( S / N =3) of the ginsenosides ranged from 35 to 155 ng.

Four new acetylated ginsenosides from processed ginseng (sun ginseng).

Four new acetylated ginsenosides were isolated from the processed ginseng (SG, sun ginseng). Their structures were determined to be 3β,12β-dihydroxydammar-20(22),24-diene-3-O-β-D-glucopyranosyl(1→2)-P-D-6″-O-acetylglucopyranoside; 3β,12β-dihydroxydammar-20(21), 24-diene-3-O-β-D-glucopyranosyl(1→2)-β-D-6″-O-acetylglucopyranoside; 3β, 6α,12p-trihydro-xydammar-20(22),24-diene-6-O-β-D-6′-O-acetylglucopyranoside and 3β,6α, 12β-trihydroxydam-mar-20(21),24-diene-6-O-β-D-6′-O-acetylglucopyranoside based on spectroscopic evidences. The compounds were named ginsenoside Rs4, Rs5, Rs6 and Rs7, respectively.

Determination of betaine in Lycium chinense fruits by liquid chromatography-electrospray ionization mass spectrometry.

A rapid and sensitive high-performance liquid chromatography-electrospray mass spectrometric method has been developed for the determination of betaine in Lycium chinense fruits. Betaine was analyzed on a system consisting of a NH2 stationary phase and a mobile phase of water-acetonitrile (25:75) by isocratic elution for 40 min. Betaine was identified and quantitated by electrospray ionization mass spectrometry with selected ion monitoring of the protonated ion [Betaine+H]+ and clustered ions [nBetaines+H]+. The limit of detection for betaine by this method was ca. 0.2 ng/ml and the relative standard deviations of the assay (intra- and inter-day) were less than 8.1%.

A butyrolactone lignan dimer from Arctium lappa

Abstract A novel lignan, diarctigenin, together with the known butyrolactone derivatives, arctigenin and arctiin, has been isolated from the seeds of Arctium lappa . Its structure was elucidated as bis-5′,5′-arctigenin by spectral analyses and chemical modification.

Sesquiterpene alkaloids from Euonymus japonica

Abstract Five new sesquiterpene alkaloids, euojaponine A, C, I, L, and M, and a known compound, mayteine, were isolated from the root bark of Euonymus japonica . The structures of these compounds were elucidated by various spectroscopic methods.

Antimetastatic and antitumor effects of benzoquinonoid AC7-1 from Ardisia crispa

An antimetastatic and cytostatic substance, termed AC7‐1, was isolated from Ardisia crispa and identified as a benzoquinonoid compound, 2‐methoxy‐6‐tridecyl‐1,4‐benzoquinone. It was originally characterized as the potent PAF (platelet‐activating factor) receptor‐binding antagonist with nonspecific antiplatelet effects on platelet aggregation induced by various agonists including PAF, ADP, thrombin and collagen. The nonspecific antiaggregatory properties of AC7‐1 drew our interest given its possible relationship in integrin receptor‐binding antagonistic activity. The integrin receptor plays an important role in metastasis and thrombosis as the cell surface transmembrane protein. Based on the aforementioned facts, the antimetastatic activities of AC7‐1 were examined using various in vitro and in vivo metastasis assays. AC7‐1 strongly blocked B16‐F10 melanoma cell adhesion to extracellular matrix (ECM) and B16‐F10 melanoma cell invasion. AC7‐1 also remarkably inhibited pulmonary metastasis and tumor growth in vivo. AC7‐1 inhibited B16‐F10 melanoma cell adhesion to only specific synthetic peptides including RGDS. These findings suggest that antimetastatic activities of AC7‐1 can be caused by blocking integrin‐mediated adherence. We found AC7‐1 to be a potential candidate for the development of a new antimetastatic drug.

Antibacterial Phenylpropanoid Glycosides from Paulownia tomentosa Steud

The butanol extract ofPaulownia tomentosa stem showed antibacterial activity againstStaphylococcus aureus (SG511, 285 and 503),Streptococcus pyogenes (A308 and A77) andStreptococcus faecium MD8b etc. The most active compound of the extract was identified to be campneoside I, which had a minimal inhibitory concentration(MIC) of 150 μg/ml againstStreptococcus andStaphylococcus species. From such antibacterial activity, the methoxy group of campneoside I was postulated to be the essential element for the antibacterial activity.

Isolation of ginsenosides Rb1, Rb2, Rc, Rd, Re, Rf and Rg1 from ginseng root by high performance liquid chromatography

Ginsenosides Rb1, Rb2, Rc, Rd, Re, Rf and Rg1 were effectively isolated from ginseng root by preparative liquid chromatography (LC) on two PrepPAK-500/C18 cartridges in series and semipreparative LC on a μBondapak cabohydrate analysis column, a μBondapak C18 column or a μPorasil column. The identities of the isolated ginsenosides were confirmed by analytical high-performance liquid chromatography (HPLC) and infrared spectrophotometry. By this method large scale isolation of pure ginsenosides was efficiently accomplished.