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Background: Veronica ciliata Fisch., widely distributed in western China, has been traditionally used in Tibetan Medicine as a treatment for hepatitis, cholecystitis, rheumatism, and urticaria. However, V. ciliata Fisch. has not been subjected to detailed chemical constitution analysis and the bioactive studies were restricted to its crude extracts. It is necessary to investigate the active chemical components of these extracts and identify their biological effects. Results: Four iridoid glycosides, (veronicoside, cataposide, amphicoside, and verminoside) were isolated from the ethyl acetate fraction. Among these compounds, veronicoside and verminoside were isolated for the first time from this plant. These compounds exhibited strong antioxidant activity and inhibitory activity on HepG2 cell proliferation. The antioxidant activity of verminoside was equal to Vc. Cataposide, amphicoside and verminoside had stronger anti-hepatocarcinoma activity than 5-fluorouracil. Conclusions: Four iridoid glycosides,(veronicoside, cataposide, amphicoside and verminoside) were isolated from the extract of V. ciliata Fisch. using bioassay-guided screening.Among these compounds, veronicoside and verminoside were isolated for the first time from this plant. The above results indicated that these compounds were the active chemical components responsible for the antioxidant and anti-hepatocarcinoma properties of V. ciliata Fisch. The underlying mechanism of their bioactivity is worthy of further investigation. [Figure not available: see fulltext. Caption: Bioactivity-guided isolation of antioxidant and anti-hepatocarcinoma constituents from Veronica ciliata]

Six compounds were isolated from alcoholic extracts of Meconopsis quintuplinervia Regel.. On the basis of spectroscopic methods, their structures were identified as 8,9 -dihydroxy-1,5,6,10b-tetrahydro-2H-pyrrolo [ 2,1-a ] isoquinolin-3-one (1), o-methylflavinantine (2), amurine (3), tricin (4), luteolin (5) and β-sitosterol (6). Among them, compounds 1 and 4 were isolated from the plant for the first time.

The chemical constituents of the traditional Tibetan medicine of Saussurea medusa Maxim. (Compositae) were investigated and a new flavonoid glucoside, together with 14 known compounds, was isolated. The structure of the new compound was established as 6''-O-crotonoylhomoplantaginin by using one- and two-dimensional nuclear magnetic resonance spectroscopy and mass spectrometry analyses.

An improved HPLC-DAD-ESI-MS(n) method has been developed to simultaneously quantify eight major compounds in Saussurea tridactyla Sch.-Bip. ex Hook. f. which has long been used as a traditional Tibetan medicine. This method was validated to be sensitive, precise and accurate with the LODs of 0.11-5.01 microg/ml, the overall intra-day and inter-day variations less than 2.70%, and the overall recovery over 98.0%, respectively. The correlation coefficients (r(2)) of the calibration curves were higher than 0.991. This newly established method was successfully applied to reveal the difference in the chemical profiles and contents of these analyses in S. tridactyla from different localities. In addition, by comparison UV and MS spectra with those of authentic compounds and literatures, a total of fourteen peaks were identified. It can be concluded that this method was effective to ensure the safety and efficacy consistency of S. tridactyla, and can be applied to other traditional Tibetan medicinal plants from different resources in Tibet.

A new isoquinoline alkaloid (6), along with nine known ones (1-5, 7-10), was isolated from the plateau plant Corydalis hendersonii, which is used as a traditional Tibetan medicine. The structure of the new compound was elucidated as 9-methyldecumbenine C by spectroscopic evidence.

From the aerial parts of <i>Senecio dianthus</i>, four new eremophilenolides (<b>1</b>-<b>4</b>, resp.) and one new eremophilenolide alkaloid (<b>5</b>), of the relatively uncommon eremophilenoid-type sesquiterpenoid lactones, were isolated together with three known sesquiterpenoid lactones, 10<i>β</i>-hydroxyeremophil-7(11)-en-12,8<i>α</i>-olide (<b>6</b>), 8<i>β</i>,10<i>β</i>-dihydroxyeremophil-7(11)-en-12,8<i>α</i>-olide (<b>7</b>), and 10<i>α</i>-hydroxy-1-oxoeremophila-7(11),8(9)-dien-12,8-olide (<b>8</b>). On the basis of IR, MS, and NMR data, particularly 2D-NMR analyses, the structures of the new compounds were established as: 2<i>β</i>-(angeloyloxy)-10<i>β</i>-hydroxyeremophil-7(11)-en-12,8<i>α</i>-olide (<b>1</b>), 6<i>β</i>-(angeloyloxy)-10<i>β</i>-hydroxyeremophil-7(11)-en-12,8<i>α</i>-olide (<b>2</b>), 2<i>β</i>-(angeloyloxy)-8<i>β</i>,10<i>β</i>-dihydroxyeremophil-7(11)-en-12,8<i>α</i>-olide (<b>3</b>), 2<i>β</i>-(angeloyloxy)-8<i>α</i>-hydroxyeremophila-7(11),9(10)-dien-12,8<i>β</i>-olide (<b>4</b>), and 8<i>β</i>-amino-10<i>β</i>-hydroxyeremophil-7(11)-en-12,8<i>α</i>-olide (<b>5</b>). In addition, the relative configuration of <b>1</b> was corroborated by X-ray diffraction analysis.

A new proaporphine alkaloid, 8, 9-dihydroprooxocryptochine (1), together with three known alkaloids, was isolated from the aerial parts of Meconopsishorridula Hook. f. & Thomson (Papaveraceae), a traditional Tibetan medicine. The structure of 1 was determined by spectroscopic methods.

A new proaporphine alkaloid, 8, 9<b>-</b>dihydroprooxocryptochine (1), together with three known alkaloids, was isolated from the aerial parts of <b>Meconopsis</b> <b>horridula</b> Hook. f. & Thomson (Papaveraceae), a traditional Tibetan medicine. The structure of 1 was determined by spectroscopic methods.<br>8, 9-Dihydroprooxocryptochine, a new proaporphine alkaloid from <b>Meconopsis</b> <b>horridula</b>, a tradional Tibetan medicine.<br>▪

Three new flavone C-glycosides, paraquinins A-C, were isolated from the aerial parts of Paraquilegia microphylla (Royle) Dromm. et Hutch, a Tibetan medicine distributed in the Qinghai-Tibet plateau. On the basis of 1D and 2D NMR evidence, their structures were elucidated as acacetin-6-C-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (1), acacetin-6-C-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (2), and acacetin-6-C-α-L-rhamnopyranosyl-(1 → 2)-(6'''-O-E-feruloyl)-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (3).