Yingjie Chen

Lipoprotein lipase activation by red Ginseng saponins in hyperlipidemia model animals

The effect of ginseng saponins isolated from red ginseng (a steamed and dried root of Panax ginseng) has been studied in a cyclophosphamide (CPM)-induced hyperlipidemia model in fasted rabbits. In this model, chylomicrons and very low density lipoprotein (VLDL) accumulation was known to occur as a result of reduction in lipoprotein lipase (LPL) activity in the heart and heparin-releasable heart LPL. Oral administration of ginseng saponins at a dose of 0.01 g/kg for 4 weeks was found to reverse the increase in serum triglycerides (TG) and concomitant increase in cholesterol produced by CPM treatment, especially in chylomicrons and VLDL. In addition, ginseng saponins treatment led to a recovery in postheparin plasma LPL activity and heparin-releasable heart LPL activity, which were markedly reduced by CPM treatment. In rats given 15% glycerol/15% fructose solution, postheparin plasma LPL activity declined to two third of normal rats, whereas ginseng saponins reversed it to normal levels. In the present study we first demonstrated that ginseng saponins sustained LPL activity at a normal level or protected LPL activity from being decreased by several factors, resulting in the decrease of serum TG and cholesterol.

Studies on the chemical constituents from the roots of Platycodon grandiflorum

Three known monodesmosidic saponins: 3-O-β-d-glucopyranosyl-2β,3β,16α,23,24-pentahydroxyolean-12-ene-28-oic acid, 3-O-β-d-glucopyranosyl polygalacic acid, and 3-O-β-d-glucopyranosyl-(1→3)-β-d-glucopyranosyl polygalacic acid; and two known nonsaponin compounds: a mixed compound of n-tetracosanoic acid (lignoceric acid), n-hexacosanoic acid (cerotic acid), and n-octacosanoic acid, and α-monopalmitin; were isolated for the first time from the root of Platycodon grandiflorum A. DC. together with another seven known compounds: platycoside G1 (3-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-2β,3β,16α,23,24-pentahydroxyolean-12-ene-28-oic acid 28-O-β-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside), deapio-platycodin D, Polygalacin D, deapio-platycodin D3, platycoside A, α-spinasterol, and α-spinasteryl-3-O-β-d-glucopyranoside. Alkaline hydrolysis of platycoside G1 afforded a new monodesmosidic prosaponin: 3-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-2β,3β,16α,23,24-pentahydroxyolean-12-ene-28-oic acid. Their chemical structures were elucidated on the basis of their spectral data and chemical evidence.

Phenolic Glycosides from Rhizomes of Smilax glabra

A new lignan glycoside, (+)-syringaresinol 4-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (1), together with twelve known compounds, were isolated from the rhizomes of Smilax glabra. The structure was established on thebasis of chemical and spectroscopic methods.

Triterpenoid saponins from Platycodon grandiflurum

A new bisdesmosidic saponin, named deapio-platycoside E (1), together with two known triterpenoid saponins (2, 3) were isolated from the roots of Platycodon grandiflorum (Jacq.) A. D.C. Their structures were elucidated by spectroscopic and chemical methods.