Biomedical subjects
Publications and source records attributed to Jun-Shan Yang.
Three new lignan oligosaccharide esters, rupestrin A (1), rupestrin B (2), and rupestrin C (3), were isolated from the ethanol extract of Eritrichium rupestre. Their structures were elucidated on the basis of spectroscopic and chemical evidence.
A new labdane type diterpenoid, (8alpha,13R)-epoxy-14-labden-6beta,7beta-diol-7-beta-D-(4'-acetyl) fucopyranoside, named ledebourene 1, was isolated from the flowers of Trollius ledebouri. The absolute stereostructure was elucidated on the basis of the spectroscopic analysis.
Two new xanthones, 1,5,6-trihydroxy-3-methoxy-4-(3-hydroxyl-3-methylbutyl)xanthone (1) and 1,5-dihydroxy-3-methoxy-6',6'-dimethyl-2H-pyrano(2',3':6,7)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated together with six known xanthones: 1,3,5-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':6,7)xanthone (3), dulxanthone A (4), 1,5,6-trihydroxy-3,7-dimethoxyxanthone (5), 1,7-dihydroxyxanthone (6), 1,3,5-trihydroxy-6-methoxyxanthone (7), 1,3,6,7-tetrahydroxyxanthone (8), from the stems of Garcinia cowa (Guttiferae).
Five new cyclolanostane triterpene glycosides, 12-deacetyloxy-15alpha-hydroxy-23-epi-26-deoxyactein, 12-deacetyloxy-23-epi-26-deoxyactein, 24-O-acetyldahurinol-3-O-beta-D-xylopyranoside, 12beta-hydroxycimigenol-3-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranoside, 25-anhydrocimicigenol-3-O-beta-D-(2'-O-acetyl)xylopyranoside, were isolated from the rhizome of Souliea vaginata collected in China. Their structures were elucidated by spectroscopic techniques, including 2D NMR spectra, and in the case of 5, by chemical correlation.
The ethanol extract of the flowers of Trollius ledebouri yielded four flavone C-glycosides, 2''-O-vanilloylvitexin, 2''-O-feruloylorientin, 2''-O-beta-L-galactopyranosylvitexin, and 2''-O-beta-L-galactopyranosylorientin, along with known compounds, 6''-O-acetylorientin, 2''-O-(4'''-hydroxybenzoyl)vitexin, vitexin, and orientin. Their structures were elucidated by means of UV, IR, MS and NMR spectroscopic analyses.
Three new xanthones, 2-hydroxy-1,6,7-trimethoxyxanthone (1), 1,4-dimethoxy-2,3-methylenedioxyxanthone (2), and 7-hydroxy-1,2-dimethoxyxanthone (3), together with five known compounds, 2,7-dihydroxy-1-methoxyxanthone (4), 1-methoxy-2,3-methylenedioxyxanthone (5), 7-hydroxy-1-methoxyxanthone (6), euxanthone (1,7-dihydroxyxanthone) (7), and gentitein (1,3,7-trihydroxyxanthone) (8), were isolated from the roots of Polygala caudata. Their structures were established on the basis of spectral evidence. In the antioxidation activity screening in vitro with luminol chemiluminescence methods, compounds 1 - 5 and 7 and 8 showed H2O2 scavenger activity, with a scavenging effect of 58.4 - 94.5% at 10 microg/mL, and 26.0 - 84.7% at 2 microg/mL. Compounds 4 and 8 also exhibited scavenging effects on the reactive oxygen free radicals produced by macrophage respiratory bursts, with a scavenging effect of 71.7% and 63.4% at 10 microg/mL, 41.2% and 47.8% at 2 microg/mL, respectively. In the vasodilatation assay, compounds 4 - 7 exhibited relaxing activity on the contractions evoked by KCl in Wistar rat thoracic aorta rings in a dose-dependent manner.
A new flavonoid, 7-hydroxyl-4'-O-beta--(6'-O-alpha-hydroxylpropionyl)-glucopyranosyl dihydroflavone (1), together with 12 known flavonoids, has been isolated from the EtOAc fraction of the aqueous extract of Sini Tang. The structures of the compounds have been elucidated by spectral methods. The new compound comes from Glycyrriza uralensis Fisch., as determined by HPLC-ESI-MS.
OBJECTIVE: To provide evidence for establishing an efficient method of growing Panax quinquefolium by rotation of crops. METHOD: Four-year old P. quinquefolium was cultivated in water and soil cultures. Biological assays were conducted with the aqueous extracts of P. quinquefolius, Fructus Perillae and roots of Coix lacryma-jobi. P. quinquefolium was cultivated in the soil where purple Perilla frutesens and C. lacryma-jobi were grown previously. The effects of rotation were determined. RESULT: The stems, leaves and fibrous roots of Panax quinquefolium contained allelopathic substances. When the concentration of the allelopathic substances exceeded 1g per kg soil, P. quinquefolius could not grow. On the other hand, when the concentration of allelopathic substances fell below 0.2 g per kg soil, the rate of seedling growth was decreased by 25%. When P. quinquefolius was cultivated in the soil in which purple Perilla frutesens had previously grown, or in the soil supplemented with Fructus Perillae, the rates of seedling growth and the yield were raised by 26.8% and 11.5% tively, in comparison with the controls. CONCLUSION: Rotation of Panax quinquefolium and Perilla frutesens was shown to be a good way for the cultivation of the former. During the growing process, application of Fructus Perillae to the soil could further enhance the growth and of Panax quinquefolium.
OBJECTIVE: To study the chemical constituents in roots of P. fallax and their anti-oxidation activities in vitro. METHOD: Column chromatographic techniques were employed for isolation and purification of chemical constituents of the plant. The structures were elucidated on the basis of the spectral evidence and the physical and chemical character. The isolated compounds were screened with four anti-oxidation models in vitro. RESULT: Seven xanthones, 1,7-dihydroxy-2,3-methylenedioxyxanthone (1), 1-methoxy-2,3-methylenedioxyxanthone (2), 3-hydroxy-1,2-dimethoxyxanthone (3), 1,6,7-trihydroxy-2,3-dimethoxyxanthone (4), 7-hydroxy-1-methoxy-2,3-methylenedioxyxanthone (5), 1,3-dihydroxy-2-methoxyxanthone (6) and 1,3,7-trihydroxy-2-methoxyxanthone (7), were isolated from the roots of P. fallax. And compounds 1 - 7 showed different anti-oxidation activities in the different pharmacological models. CONCLUSION: Compounds 2, 3, 5 and 7 were isolated from this plant for the first time. Xanthones from this plant showed anti-oxidation activities. The pharmacological activities of the pure compounds from this plant were also reported for the first time.
Caragaphenol A (1), a new trimeric stilbene, was isolated from the roots of Caragana stenophylla (Leguminosae) along with three known oligomeric stilbenes: (+)-alpha-viniferin (2), miyabenol C (3) and kobophenol A (4). The stereostructure of 1 was elucidated by one- and two-dimensional (1D- and 2D-)-NMR spectral studies.
A new compound, nigeglanine (1), and its new artificial derivative (1a), were isolated from the seeds of Nigella glandulifera, together with a known aporphine alkaloid, fuzitine (2). Their structures were established by spectral analysis, including two-dimensional (2D)-NMR spectroscopy. Nigeglanine (1) is the third natural product determined to contain an indazole nucleus.