Fast repair of the poly G hydroxyl radical adduct by two phenylpropanoid glycosides.

The repair activities and the reaction mechanisms of two phenylpropanoid glycosides (PPGs), isolated from a herb used in Chinese folk medicine, towards the oxidizing hydroxyl radical adduct of poly G were studied with a pulse radiolytic technique. On pulse irradiation of a nitrous oxide saturated 4 mM aqueous solution of poly G containing one of the tested compounds, the transient absorption spectrum of the hydroxyl radical adduct of poly G decays with the formation of that of the phenoxyl radical of the tested compound within several tens microseconds after the electron pulse irradiation. The results indicated that there was a repair reaction between the hydroxyl radical adduct of poly G and the compounds tested. The rate constants for the repair reactions of poly G hydroxyl radical adducts by verbasicoside and cistanoside C were determined to be 1.4 and 1.0 x 10(9) M(-1) x s(-1), respectively.

Theoretical study of fast repair of DNA damage by cistanoside C and analogs: mechanism and docking.

Experiments show that the natural substances phenylpropanoid glycosides (PPGs) extracted from pelicularis spicata are capable of repairing DNA damaged by oxygen radicals. Based on kinetic measurements and experiments on tumor cells, a theoretical study of the interaction between PPG molecules and isolated DNA bases, as well as a DNA fragment has been performed. An interaction mechanism reported early has been refined. The docking calculations performed using junction minimization of nucleic acids (JUMNA) software showed that the PPG molecules can be docked into the minor groove of DNA and form complexes with the geometry suitable for an electron transfer between guanine radical and the ligand. Such complexes can be formed without major distortions of DNA structure and are further stabilized by the interaction with the rhamnosyl side-groups.

Docking study of cistanoside C to telomeric DNA fragment.

Experiments show that the natural products phenyl propanoid glycosides (PPGs) extracted from the plant Pedicularis spicata are capable of repairing DNA damaged by oxygen radicals. Based on kinetic measurements and experiments on tumor cells, a theoretical study of the interaction between PPG molecule Cistanoside C and telomeric DNA fragment has been carried out. The docking calculations performed using JUMNA software showed that the Cistanoside C could be docked into the minor groove of telomeric DNA and form complexes with the geometry suitable for an electron transfer between guanine radical and the ligand. Such complexes can be formed without major distortions of DNA structure and are further stabilized by the interaction with the saccharide side-groups.

Eudesmanolides, aromatic derivatives, and other constituents from Carpesium cernuum.

A new eudesmanolide 13-hydroxy-4 alpha H-eudesman-5,7(11)-dien-12,8 beta-olide (1) and a new aromatic derivative 3-methyl-8-acetoxy-9,10-diisobutanoyloxy-p-cymene (6), along with ten known compounds were isolated from the roots of Carpesium cernuum L. Their structures were elucidated by spectral methods (IR, EIMS, FAB-MS, 1D and 2D NMR). Compound 2, 3 and compound 10 exhibited moderate antibacterial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus.

Rubupungenosides A and B, two novel triterpenoid saponin dimers from the aerial parts of Rubus pungens.

Two new triterpenoid saponin dimers, rubupungenosides A (1) and B (2), were isolated in their methylated forms 1a and 2a, respectively, from an ethanol extract of the aerial parts of Rubus pungens. The structures of 1a and 2a were established on the basis of spectroscopic and chemical methods.

Nor-lignan and sesquiterpenes from Cremanthodium ellisii.

A nor-lignan and two sesquiterpenes, along with six known compounds, have been isolated from the medicinal plant Cremanthodium ellisii. Their structures were determined on the basis of spectral evidence, especially 2D NMR (1H-1H COSY, HMQC, HMBC).

Aquaticol, a bis-sesquiterpene and iridoid glucosides from Veronica anagallis-aquatica.

Aquaticol, an unusual bis-sesquiterpene was isolated from the medicinal plant Veronica anagallis-aquatica, in addition to 11 known compounds, aucubin, geniposidic acid, mussaenoside, catalposide, verproside, amphicoside, catalpol, boschnaloside, shanzhiside methyl ester, sitosterol and beta-stigmast-4-en-6 beta-ol-3-one. The structure of aquaticol was determined by spectroscopic means and by X-ray crystallographic analysis.

Eremophilenolides from Ligularia fischeri.

The chemical investigation of Ligularia fischeri afforded three new eremophilenolides which were identified as 6 beta-methoxy-8 beta-hydroxy-eremophil-7(11)-en-12,8 alpha-olide, ligufischerin, and 6-oxo-8 beta-hydroxy-eremophil-7(11)-en-12,8 alpha-olide by 1D- and 2D-NMR spectra. In addition, six known eremophilenolides were also obtained.

New bisabolane sesquiterpenes from Ligularia songarica.

Phytochemical investigation of Ligularia songarica (Compositae) afforded seven new bisabolane-type sesquiterpenes. Their structures were confirmed on the basis of spectroscopic methods, especially 2D-NMR techniques, and compound 7 showed stronger antibacterial activity against Escherichia coli, Pseudomonas acruginosa and Salmonella pullorum.

Novel highly oxygenated bisabolane sesquiterpenes from Cremanthodium discoideum.

Five new highly oxygenated bisabolane sesquiterpenes (1-5) were isolated from Cremanthodium discoideum. Their structures were elucidated on the basis of spectroscopic analysis and chemical transformations. The structure and relative stereochemistry of 1 were determined by single-crystal X-ray crystallography on the acetate derivative, 1a. Compound 1 showed antibacterial activity against Bacillus acidilatici and Bacillus subtilis.

Retardation of skeletal muscle fatigue by the two phenylpropanoid glycosides: verbascoside and martynoside from Pedicularis plicata maxim.

The effects of the phenylpropanoid glycosides verbascoside and martynoside from Pedicularis plicata were investigated on muscle contractility in Bufo gastrocnemius muscle electrically stimulated in vitro. The maximum amplitude and maintained time of contraction were mechanically recorded and used as indices of muscle contractility. After 30 min pretreatment of the muscle, verbascoside at 20.0 microM resisted muscle fatigue significantly while martynoside at 80.0 microM improved muscle contractility only slightly. These two glycosides resisted muscle fatigue depending on their antioxidative activities, which is in agreement with the role of reactive oxygen species (ROS) in promoting fatigue in skeletal muscle.

Germacranolides from Carpesium lipskyi.

Two new germacranolides, carpelipine A and carpelipine B in the form of its pyrazoline derivative were isolated from the whole plants of CARPESIUM LIPSKYI, and their structures were elucidated by spectroscopic methods including 2D NMR techniques ( (1)H- (1)H COSY, (1)H- (1)H NOESY, HMQC, HMBC) and chemical transformations. In addition, two known compounds beta-sitosterol and 7,4'-dimethoxy-5-hydroxylflavanone were also obtained.

Two new aromatic monoterpene derivatives from Carpesium lipskyi.

From the whole plants of Carpesium lipskyi, two new monoterpene derivatives, 2-(2'-methoxy-p-tolyl)glyceryl 1,3-di-isobutyrate and 2-(2'-methoxy-p-tolyl)glyceryl 1-isobutyrate-3-acetate were isolated. Their structures were elucidated by spectroscopic methods including 2D-NMR techniques (HMQC, HMBC).

Iridoid and phenylpropanoid glycosides from Pedicularis artselaeri.

Six new compounds, an iridoid glucoside, 6- O-methyl-epiaucubin, three iridoids, artselaenins A, B, C, a phenylethanoid glycoside, artselaeroside A, and a phenylpropanoid glycoside, artselaeroside B, as well as fourteen known compounds, nine iridoid glycosides and five phenylpropanoid glycosides were isolated from the whole plants (including roots, stems, leaves and flowers) of Pedicularis artselaeri. Their structures were identified mainly by spectral evidence.

Syntheses and pharmacological activities of the derivatives of furanosesquiterpenes from Ligularia virgaurea.

Four benzofuranosesquiterpenes, 1-hydroxy-2-(3'-pentenyl)-3,7-dimethylbenzofuran (1), 1-hydroxy-2-(3'-pentenyl)-3,7-dimethylbenzofuran (2), cacalol (13), and 1,2-dehydrocacalohastin ( 14) were isolated from the rhizomes of Ligularia virgaurea (Compositae). A lipophilic group and an aqueous-favoring group were introduced to the compounds 1 and 13 to afford twelve new derivatives. Their structures were elucidated by spectroscopic methods. The results of the pharmacological test indicated that some of them can block Ca (++) influx by occupying binding sites of dihydropyridine.

New sesquiterpenes from two Ligularia species.

Further phytochemical investigation of the roots of Ligularia sagitta afforded two new eremophilane sesquiterpene acids, and from the roots of Ligularia nelumbifolia, two new guaiane sesquiterpenes were isolated. Their structures were elucidated by spectroscopic methods including 2D NMR techniques and chemical transformations.

Neolignan glycosides from Pedicularis longiflora.

Four new neolignan glucosides, longiflorosides A, B, C and D, in addition to one known neolignan glucoside, dehydro-diconiferyl alcohol-4-O-beta-D-glucopyranoside were obtained from whole plants of Pedicularis longiflora. The structures of these compounds were determined mainly on spectral evidence.

Two new oplopanol esters from Cremanthodium ellisii.

Two new sesquiterpenoids have been isolated from Cremanthodium ellisii Kitam. Their structures were established on the basis of spectral analysis (IR, MS, 1H-1H COSY, NOESY, 1H-13C COSY, and COLOC) and chemical evidence.

A new eremophilane sesquiterpenoid and a new iridoid from Pedicularis striata subsp. arachnoides.

A new sesquiterpenoid, eremophila-10,11-diene-7alpha,13-diol, and a new iridoid aglycone, dihydrocatalpolgenin, have been isolated and identified from Pedicularis striata Pall subsp. arachnoides (Franch) Tsoong in addition to the known iridoid glycosides, aucubin and 8-O-acetylharpagide.

Antioxidative and chelating activities of phenylpropanoid glycosides from Pedicularis striata.

AIM: To study the antioxidative and iron chelating activities of phenylpropanoid glycosides (PPG) isolated from a Chinese herb Pedicularis striata. METHODS: Antioxidative effects of PPG on lipid peroxidation induced by FeSO4-edetic acid in linoleic acid were measured by thiobarbituric acid method. Chelating activities of PPG for Fe2+ were tested by differential spectrum method. RESULTS: The reaction rates (A532.min-1) of lipid peroxidation were 0.0046 in the control, 0.0021 in verbascoside group, and 0.0008 in isoverbascoside group. The chelating activity of isoverbascoside was 2-fold stronger than that of verbascoside. Permethyl verbascoside showed neither antioxidative nor chelating activities. CONCLUSION: The inhibitory effects of PPG with phenolic hydroxy groups on lipid peroxidation are owing to their chelating properties. Under physiological condition PPG-Fe2+ chelates are sufficiently stable. Thus PPG are able to inhibit the Fe(2+)-dependent lipid peroxidation in vivo through chelating Fe2+ and exhibit their therapeutic potential by the same mechanism in vitro.