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PubMed2005

Polyacetylenic compounds, ACAT inhibitors from the roots of Panax ginseng.

Acyl-CoA: cholesterol acyltransferase (ACAT), which plays a role in the absorption, storage, and production of cholesterol, has been explored as a potential target for pharmacological intervention of hyperlipidemia and atherosclerotic disease. In our search for ACAT inhibitors from natural sources, the petroleum ether extract of Panax ginseng showed moderate inhibition of ACAT enzyme from rat liver microsomes. Bioactivity-guided fractionations led to the isolation of one new polyacetylenic compound, (9R,10S)-epoxy-16-heptadecene-4, 6-diyne-3-one (1), in addition to the previously reported polyacetylenic compounds 2 and 3. Their chemical structures were elucidated on the basis of spectroscopic evidence (UV, IR, NMR, and MS). The compounds 1, 2, and 3 showed significant ACAT inhibition with IC(50) values of 35, 47, and 21 microM, respectively.

Acetylene↗

PubMed2002

Polyacetylenes from a marine sponge Petrosia sp. inhibit DNA replication at the level of initiation.

In the course of our search for bioactive metabolites from the marine sponges collected from Korean water, we found that the polyacetylenes of marine sponge, genus Petrosia, deliver significant selective cytotoxicity against several human tumor cell lines. The effects of polyacetylene on DNA replication were examined using simian virus 40 DNA replication system in vitro. We found that polyacetylenes inhibited DNA replication, and predominantly inhibited the initiation stage of DNA replication. Polyacetylenes inhibited the DNA cleavage by topoisomerase I, and also significantly reduced polymerase alpha-primase activity. The ssDNA binding activity of replication protein A was little affected by polyacetylenes. We suggest that polyacetylenes might inhibit proteins required to establish replication forks during the initiation reaction, and their cytotoxicities might be related to the inhibitory effect they have on this fundamental cellular process.

Acetylene↗

PubMed2006

Does the donor-acceptor concept work for designing synthetic metals? III. Theoretical investigation of copolymers between quinoid acceptors and aromatic donors.

Homopolymers of quinoxaline (QX), benzothiadiazole (BT), benzobisthiadiazole (BBT), thienopyrazine (TP), thienothiadiazole (TT), and thienopyrazinothiadiazole (TTP) and copolymers of these acceptors with thiophene (TH) and pyrrole (PY) were investigated with density functional theory. Theoretical band-gap predictions reproduce experimental data well. For all but six copolymers, band-gap reductions with respect to either homopolymer are obtained. Four of the acceptors, BBT, TP, TT, and TTP, give rise to copolymers with band gaps that are smaller than that of polyacetylene. BBT and TTP copolymers with PY in 1:2 stoichiometry are predicted to be synthetic metals. Band-gap reductions result from upshifts of HOMO energies and much smaller upshifts of LUMO values. The smallest band gaps are predicted with TTP, since changes in LUMO energies upon copolymerization are particularly small. The consequence of the small interactions between LUMO levels of donor and acceptor are vanishingly small conduction bandwidths.

Metals↗

PubMed2004

Macromolecular helicity induction in a cationic polyacetylene assisted by an anionic polyisocyanide with helicity memory in water: replication of macromolecular helicity.

We report the first example of the replication of macromolecular helicity. An optically active helical and anionic polyelectrolyte, the sodium salt of poly(4-carboxyphenyl isocyanide), was found to serve as the template for further helicity induction in a different polyelectrolyte with opposite charges in water, resulting in interpolymer helical assemblies with controlled helicity. The effects of the pH and salt concentration on the helicity induction were investigated.

Acetylene↗

PubMedDate not supplied

Antitumor agents, 115. Seselidiol, a new cytotoxic polyacetylene from Seseli mairei.

Seselidiol [1], a new polyacetylene, has been isolated from the roots of Seseli mairei. On the basis of chemical and spectroscopic evidence, its structure has been established as heptadeca-1,8(Z)-diene-4,6-diyne-3,10-diol. Seselidiol and its acetate have been demonstrated to show moderate cytotoxicity against KB, P-388, and L-1210 tumor cells.

Acetylene↗

PubMed2003

Brominated polyacetylenes from the Philippines sponge Diplastrella sp.

Five novel brominated polyacetylenic diols, diplynes A-E (2-6), and three sulfated analogues, diplyne A 1-sulfate (7), diplyne C 1-sulfate (8), and 2-deoxydiplyne D sulfate (9), were isolated from the Philippines sponge Diplastrella sp. by employing bioassay-guided fractionation using the HIV-1 integrase inhibition assay. The novel metabolites were characterized by interpretation of spectroscopic data.

Acetylene↗

PubMed1997

Polyacetylene analogs, isolated from hairy roots of Panax ginseng, inhibit Acyl-CoA : cholesterol acyltransferase.

In the course of our screening program for acyl-CoA : cholesterol acyltransferase (ACAT) inhibitors from Korean herbal medicines, ACAT inhibitors were isolated from the hairy roots of Panax ginseng (Araliaceae) and identified as panaxynol, panaxydol, panaxydiol, and panaxytriol. These active compounds inhibit rat liver ACAT with IC50 values of 94, 80, 45 and 79 microM, respectively.

Acetylene↗

PubMed2004

Polyacetylenic compounds and butanol fraction from Bidens pilosa can modulate the differentiation of helper T cells and prevent autoimmune diabetes in non-obese diabetic mice.

Compelling evidence suggests that infiltrating CD4+ type I helper T (Th1) cells in the pancreatic islets play a pivotal role in the progression of diabetes in non-obese diabetic (NOD) mice. We demonstrate in the present report that a butanol fraction of B. pilosa suppressed the development of diabetes, helped maintain levels of blood sugar and insulin in NOD mice in a dose-dependent manner and elevated the serum IgE levels regulated by Th2 cytokines in NOD mice. Moreover, the butanol fraction inhibited the differentiation of naive helper T (Th0) cells into Th1 cells but enhanced their transition into type II helper T (Th2) cells using an in vitro T cell differentiation assay. Two polyacetylenic compounds, 2-beta-D-glucopyranosyloxy-1-hydroxy-5(E)-tridecene-7,9,11-triyne and 3-beta-D-glucopyranosyloxy-1-hydroxy-6(E)-tetradecene-8,10,12-triyne, identified from the butanol fraction also prevented the onset of diabetes like the butanol fraction. The latter compound showed a stronger activity for T cell differentiation than the former. In summary, the butanol fraction of B. pilosa and its polyacetylenes can prevent diabetes plausibly via suppressing the differentiation of Th0 cells into Th1 cells and promoting that of Th0 cells into Th2 cells.

Acetylene↗

PubMed2000

Polyacetylenes from angelica gigas and their inhibitory activity on nitric oxide synthesis in activated macrophages.

In activated macrophages the inducible form of nitric oxide synthase (i-NOS) generates high amounts of the toxic mediator, nitric oxide (NO) which contributes to the circulatory failure associated with septic shock. Two polyacetylenes were isolated from the medicinal plant Angelica gigas and their structures were elucidated as octadeca-1,9-dien-4,6-diyn-3,8,18-triol (1) and 18-acetoxy-octadeca-1,9-dien-4,6-diyn-3,8-diol (2) by spectroscopic method. These polyacetylenes and their peracetate, 3, 8, 18-triacetoxy-octadeca-1, 9-dien-4, 6-diyn (3) inhibited the production of NO in LPS-activated RAW 264.7 cells by suppressing the i-NOS enzyme expression. These new inhibitors of i-NOS expression may have potential in the treatment of endotoxemia and inflammation accompanied by the overproduction of NO.

Acetylene↗

PubMed2001

Synthesis of polyacetylenic acids isolated from Heisteria acuminata.

Four linear polyacetylenic compounds were synthesized. Pentadeca-6,8,10-triynoic acid 1 and octadeca-8,10,12-triynoic acid 2 were synthesized by using acetylene coupling reactions. The syntheses of (Z)-hexadec-11-en-7,9-diynoic acid 3 and (Z)-octadec-12-en-7,9-diynoic acid 4 by using vinylic telluride coupling reactions were accomplished.

Acetylene↗

PubMed2004

Polyacetylenes function as anti-angiogenic agents.

PURPOSE: To investigate the antiangiogenic effects of plant extracts and polyacetylenes isolated from Bidens pilosa Linn., which is a popular nutraceutical herbal tea and folk medicine in anti-inflammatory, antitumor, and other medications worldwide. METHODS: Anti-cell proliferation, anti-tube formation, and cell migration assays were used for the valuation of bioactivities of target plant extracts and phytocompounds against angiogenesis. Bioactivity-guided fractionation, HPLC, and various spectral analyses were used to identify active fraction and phytocompounds for anti-angiogenesis. RESULTS: We show that an ethyl acetate (EA) fraction of B. pilosa exhibited significant anti-cell proliferation and anti-tube formation activities against human umbilical vein endothelium cells (HUVEC). Bioassay-guided fractionation led to isolation of one new and one known polyacetylenes, 1,2-dihydroxytrideca-5,7,9,11-tetrayne (1) and 1,3-dihydroxy-6(E)- tetradecene-8,10,12-triyne (2), respectively, from the EA fraction. Compounds 1 and 2 manifested highly specific and significant activities against HUVEC proliferation with IC50 values of 2.5 and 0.375 microg/ml, respectively, however, compound 1 had a more potent effect on preventing tube formation of HUVEC than compound 2 at a dose of 2.5 microg/ml. Western blot analysis showed that both compounds upregulated p27(Kip) or p21(Cip1), cyclin-dependent kinase inhibitors, in HUVEC. CONCLUSIONS: This is the first report to demonstrate that polyacetylenes possess significant anti-angiogenic activities and the ability to regulate the expression of cell cycle mediators, for example, p27(Kip1), p21(Cip1), or cyclin E.

Acetylene↗

PubMed2005

Polyacetylenes from the Apiaceae vegetables carrot, celery, fennel, parsley, and parsnip and their cytotoxic activities.

A dichloromethane extract of root celery yielded falcarinol, falcarindiol, panaxydiol, and the new polyacetylene 8-O-methylfalcarindiol. The structure of the new compound was established by one- and two-dimensional (1D and 2D) NMR, mass spectrometry, and optical rotation data. Nonpolar extracts of roots and bulbs of carrots, celery, fennel, parsley, and parsnip were investigated for their content of polyacetylenes by high-performance liquid chromatography with diode array detection (HPLC-DAD). All five species contained polyacetylenes, although carrots and fennel only in minor amounts. Additionally, the cytotoxicity of the four polyacetylenes against five different cell lines was evaluated by the annexin V-PI assay. Falcarinol proved to be the most active compound with a pronounced toxicity against acute lymphoblastic leukemia cell line CEM-C7H2, with an IC(50) of 3.5 micromol/L. The possible chemopreventive impact of the presented findings is discussed briefly.

Acetylene↗

PubMed2001

Polyacetylene carboxylic acids from Mitrephora celebica.

A new polyacetylene carboxylic acid, 13(E),17-octadecadiene-9,11-diynoic acid (13,14-dihydrooropheic acid, 1), and the known 17-octadecene-9,11,13-triynoic acid (oropheic acid, 2) were isolated from the stem bark of Mitrephora celebica through bioassay-guided fractionation. Both compounds demonstrated significant activity against methicillin-resistant Staphylococcus aureus and Mycobacterium smegmatis.

Acetylene↗

PubMed1994

Anti-inflammatory active polyacetylenes from Bidens campylotheca.

The n-hexane extract of Bidens campylotheca Schultz Bip. ssp campylotheca (Compositae) showed significant in vitro inhibition of cyclooxygenase (CO) and 5-lipoxygenase (5-LO). Five polyacetylenes, heptadeca-2E,8E,10E,16-tetraene-4,6-diyne (1), heptadeca-2E,8Z,10E,16-tetraene-4,6-diyne (2), heptadeca-2E,8E,16-triene-4,6-diyne-10-ol (3), safynol (5) and, as a new compound, safynol-2-O-isobutyrate (4) could be isolated and their structures elucidated mainly by UV, MS, NMR, and COSY-NMR. The isolated compounds exhibited a significant inhibitory effect on cyclooxygenase and 5-lipoxygenase.

Acetylene↗

PubMed2004

New Polyacetylenes, DGAT inhibitors from the roots of Panax ginseng.

The petroleum ether extract of Panax ginseng showed a significant inhibition of the diacylglycerol acyltransferase (DGAT) enzyme from rat liver microsomes. Bioactivity-guided fractionation led to the isolation of two new polyacetylenic compounds, (9 R,10 S)-epoxyheptadecan-4,6-diyn-3-one ( 1) and 1-methoxy-(9 R,10 S)-epoxyheptadecan-4,6-diyn-3-one ( 2). Their chemical structures were elucidated on the basis of spectroscopic evidence and asymmetric synthesis. IC50 values of 9 microg/mL ( 1) and 32 microg/mL ( 2) were obtained.

Acetylene↗

PubMed1998

Hepatoprotective and nitric oxide production inhibitory activities of coumarin and polyacetylene constituents from the roots of Angelica furcijuga.

The methanolic extract from the roots of Angelica furcijuga KITAGAWA was found to exhibit protective effects on liver injury induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS). From the methanolic extract, seventeen coumarins, two phenylpropanoids, and two polyacetylenes were isolated and examined their in vitro and in vivo hepatoprotective effects and inhibitory activity of NO production in macrophages. A acylated khellactone, isoepoxypteryxin, showed protective activity against D-GalN-induced cytotoxicity in primary cultured rat hepatocytes. On the other hand, six acylated khellactones (hyuganins A, B, C, and D, anomalin, isopteryxin) and two polyacetylenes [(-)-falcarinol and falcarindiol] strongly inhibited NO production induced by LPS in cultured mouse peritoneal macrophages, and also other acylated khellactones (isoepoxypteryxin, pteryxin, and suksdorfin) and a coumarin glycosides (praeroside II) were found to show the activity. By comparison of the inhibitory activities for acylated khellactones with those for other coumarins, acyl groups were found to be essential to exerting potent activity.

Acetylene↗

PubMed2001

Cytotoxic polyacetylenic alcohols from the marine sponge Petrosia species.

New polyacetylenic alcohols (1-5) have been isolated as cytotoxic principles from the marine sponge Petrosia sp. The compounds were particularly cytotoxic against a human melanoma cell line (SK-MEL-2). The gross structures were established on the basis of NMR and MS data, and the absolute configuration was determined by the modified Mosher's method.

Acetylene↗

PubMed2002

Polyacetylene glycosides from Gymnaster koraiensis.

Two polyacetylene glycosides, gymnasterkoreasides A and B, were isolated from the roots of Gymnaster koraiensis. Their structures were elucidated to be (3R)-8-decene-4,6-diyne-1,3-diol 1-O-beta-D-glucopyraside and (3R)-8-decene-4,6-diyne-1,3-diol 1-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyraside on the basis of spectroscopic analysis including COSY, HMQC, and HMBC experiments, as well as chemical methods, which confirmed the determination of a chiral center by the modified Mosher's method.

Acetylene↗