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Rehmannia glutinosa is a medicinal herb that is tolerant to the non-selective herbicide paraquat. Acteoside, a phenolic compound present in the plant, has been shown to inhibit paraquat. To understand regulation of the phenylpropanoid pathway that produces the acteoside moiety, we isolated a phenylalanine ammonia-lyase (PAL) cDNA clone (RgPAL1) and used it(More)
It has been recognized that ginsenoside Rg3 is not naturally produced in ginseng although this ginsenoside can accumulate in red ginseng as the result of a thermal process. In order to determine whether or not Rg3 is synthesized in ginseng, hairy roots were treated with methyl jasmonate (MJ). From HPLC analysis, no peak for Rg3 was observed in the controls.(More)
In our ongoing project directed toward the discovery of novel treatments for diabetic complications from herbal medicines, sixteen compounds including three caffeoylquinic acids and four flavonoids were isolated from an EtOAc-soluble extract of the stems and leaves of Erigeron annuus. All the isolates were evaluated in vitro for inhibitory activity on the(More)
Seven phenolic compounds, caffeic acid (1), 4-hydroxybenzoic acid (2), 4-methoxybenzoic acid (3), protocatechuic acid (4), eugenol O-beta-D: -glucopyranoside (5), 3,6-di-O-feruloylsucrose (6), and 3,5-di-O-caffeoylquinic acid methyl ester (7), were isolated from an EtOAc-soluble partition of the flowers of Erigeron annuus. The structures of 1-7 were(More)
In order to produce centellosides from whole plant cultures of Centella asiatica (L.) Urban, we evaluated the synergistic effects of thidiazuron (TDZ) and methyl jasmonate (MJ) on whole plant growth and centelloside production. After 4 weeks of treatment with 0.025 mg/L of TDZ coupled with 0.1 mM MJ, the production of madecassoside and asiaticoside from(More)
All members of R. glutinosa show the unique characteristic of intrinsic tolerance to paraquat (PQ). Antioxidant enzymes have been proposed to be the primary mechanism of PQ resistance in several plant species. Therefore, the antioxidant enzyme systems of R. glutinosa were evaluated by comparatively analyzing cellular antioxidant enzyme levels, and their(More)
Hyperglycemia-induced oxidative stress has been suggested as a mechanism underlying diabetic complications. Oxidative stress triggers cell death in various cell types, including glomerular mesangial cells which play important roles in diabetic nephropathy. In the present study, we investigated the potential cytoprotective effect of erigeroflavanone, a novel(More)
A novel 2,3-dioxygenated flavanone, erigeroflavanone ( 1), as well as eight known flavonoids and two known gamma-pyranone derivatives, were isolated from an ethyl acetate-soluble extract of the flowers of Erigeron annuus. The structure of compound 1 was elucidated by interpretation of spectroscopic data. All of the isolates were subjected to in vitro(More)
The control of bolting time in onion is an important approach for bulb and seed production, as onion plants which bolt do not produce marketable bulbs and seed yields are dependent on floral induction. However, genetic and molecular studies about bolting time in onion plants have not been examined yet to date. In order to understand the regulation of(More)
Two bioactive flavonol glucosides, hyperoside and quercitrin, were successfully isolated in one step from the phytochemically unknown medicinal plant Osteomeles schwerinae by high-speed counter-current chromatography using a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (0.5:5.5:1.5:4.5 v/v). From 160 mg of crude extract, 2.1 mg(More)