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207 records · Page 12Linked to original sources
PubMed2003

Production of an allelopathic polyacetylene in hairy root cultures of goldenrod (Solidago altissima L.).

Hairy roots of goldenrod (Solidago altissima L.) were induced by infecting axenic plants with Agrobacterium rhizogenes strain A4. Growth and allelopathic polyacetylene (cis-dehydromatricaria ester, cis-DME) production of two independent hairy root clones were examined in several culture media and light regimes. cis-DME contents in hairy roots were at the same level as those in normal roots. cis-DME production in root cultures was several-fold lower than that of native plants and greatly repressed by light.

Alkynes↗
PubMedDate not supplied

Lignans, phenylpropanoids and polyacetylenes from Chaerophyllum aureum L. (Apiaceae).

Sub-aerial parts of Chaerophyllum aureum L. yielded two polyacetylenes, falcarinol (1), falcarindiol (2), three lignans, namely nemerosin (3), deoxypodorhizone (4), deoxypodo-phyllotoxin (5), two phenylpropanoids, 1'-hydroxymyristicin (6) and its angeloyl ester (7). Compounds 6 and 7 were isolated for the first time from plant material and their structures were elucidated by means of extensive 1- and 2-dimensional NMR spectroscopy and high resolution mass spectrometry. In bioautographic tests on TLC plates the dichloromethane extract showed a significant antimicrobial activity. Falcarindiol was identified as the main active principle whereas the phenylpropanoids and lignans showed no activity.

Acetylene↗
PubMed2004

Induction of apoptosis by dideoxypetrosynol A, a polyacetylene from the sponge Petrosia sp., in human skin melanoma cells.

Dideoxypetrosynol A, a polyacetylene from the sponge Petrosia sp., is known to exhibit significant selective cytotoxicity against several human tumor cell lines. In the present study, we investigated the possible mechanisms by which dideoxypetrosynol A exerts its anti-proliferative action in cultured human SK-MEL-2 skin melanoma cells. Exposure of SK-MEL-2 cells to dideoxypetrosynol A resulted in growth inhibition and induction of apoptosis in a dose-dependent manner as measured by MTT assay, fluorescent microscopy and flow cytometry analysis. The increase in apoptosis was associated with a dose-dependent up-regulation in proapoptotic Bax expression and down-regulation of anti-apoptotic Bcl-2. Apoptosis-inducing concentrations of dideoxypetrosynol A induced caspase-3 and caspase-9 activation accompanied by proteolytic degradation of poly(ADP-ribose)-polymerase and selective down-regulation of cIAP-1. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of dideoxypetrosynol A.

Alkynes↗
PubMed2006

Suppression of U937 human monocytic leukemia cell growth by dideoxypetrosynol A, a polyacetylene from the sponge Petrosia sp., via induction of Cdk inhibitor p16 and down-regulation of pRB phosphorylation.

Dideoxypetrosynol A, a polyacetylene from the marine sponge Petrosia sp., is known to exhibit significant selective cytotoxic activity against a small panel of human tumor cell lines, the mechanisms of which however, are poorly understood. The aim of the present study was to further elucidate the possible mechanisms by which dideoxypetrosynol A exerts its anti-proliferative action in cultured human monocytic leukemia U937 cells. We observed that the proliferation-inhibitory effect of dideoxypetrosynol A was due to the induction of G1 arrest in the cell cycle, the effects of which were associated with up-regulation of cyclin D1 and down-regulation of cyclin E, in a concentration-dependent manner without any change in cyclin-dependent-kinases (Cdks) expression. Dideoxypetrosynol A markedly induced the levels of Cdk inhibitor p16/INK4a expression. Furthermore, down-regulation of phosphorylation of retinoblastoma protein (pRB) by this compound was associated with enhanced binding of pRB and transcription factor E2F-1. Overall, our results demonstrate a combined mechanism involving the inhibition of pRB phosphorylation and induction of p16 as targets for dideoxypetrosynol A, may explain some of its anti-cancer effects.

Acetylene↗
PubMed2006

[Determination of two polyacetylenes in Herba Lobeliae Chinensis by HPLC analysis].

OBJECTIVE: To develop an HPLC method for determination of two polyacetylenes, lobetyolin and lobetyolinin, in Herba Lobeliae Chinensis. METHOD: C18 column was used with the mobile phase consisted of acetonitrile and water. Linear gradient elution from 10% to 40% acetonitrile in 25 min was applied, at the flow rate of 1.0 mL x min(-1), the detection wavelength was at 267 nm. RESULT: Lower contents of lobetyolin and lobtyolinin were found in collected samples of Herba Lobeliae Chinensis. The highest amounts of lobetyolin and lobetyolinin were found to be 0.461 and 0.436 mg x g(-1) in a sample procured from Hong Kong. However, there were no lobetyolin and lobetyolinin in some of the samples. CONCLUSION: A simple and effective HPLC method to analyze the two polyacetylenes in Herba Lobeliae Chinensis was established. It could be applied for the quality control of this herb.

Chromatography, High Pressure Liquid↗
PubMed2007

Inhibition of cyclooxygenase-2 and telomerase activities in human leukemia cells by dideoxypetrosynol A, a polyacetylene from the marine sponge Petrosia sp.

Dideoxypetrosynol A, a polyacetylene from the marine sponge Petrosia sp., is known to exhibit significant selective cytotoxic activity against several human cancer cell lines. In the present study, we investigated further possible mechanisms by which dideoxypetrosynol A exerts its anti-proliferative action in cultured human leukemia U937 cells. Exposure of U937 cells to dideoxypetrosynol A resulted in growth inhibition and induction of apoptosis as measured by hemocytometer counts, fluorescent microscopy, agarose gel electrophoresis and flow cytometry analysis. The increase in apoptosis was associated with a dose-dependent up-regulation in pro-apoptotic Bax expression and activation of caspase-3 and caspase-9. Dideoxypetrosynol A decreased the levels of cyclooxygenase (COX)-2 mRNA and protein expression without significant changes in the levels of COX-1, which was correlated with a decrease in prostaglandin E2 (PGE2) synthesis. Furthermore, dideoxypetrosynol A treatment markedly inhibited the activity of telomerase, and the expression of human telomerase reverse transcriptase (hTERT), a main determinant of the telomerase enzymatic activity, was progressively down-regulated by dideoxypetrosynol A treatment in a dose-dependent fashion. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of dideoxypetrosynol A.

Animals↗