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PubMed2005

A novel azulenyl nitrone antioxidant protects against MPTP and 3-nitropropionic acid neurotoxicities.

Oxidative stress plays an important role in neuronal death in neurodegenerative disorders such as Parkinson's disease (PD) and Huntington's disease (HD). Animal models of PD or HD, produced by administration of the mitochondrial toxins 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or 3-nitropropionic acid (3NP), respectively, show increased free radical generation. Free radicals generated in biological systems can react with spin-trapping compounds, such as nitrones, to form stable adducts. In recent years, the utility of nitrones has moved beyond analytical applications and into the realm of neuroprotection as antioxidants in both brain ischemia and models of neurodegenerative diseases. In the present study, we administered a new nitrone antioxidant, stilbazulenyl nitrone (STAZN), with either MPTP or 3NP. STAZN attenuated MPTP-induced striatal dopamine depletion by 40% and showed a tendency to dose-dependent neuroprotection. STAZN dose-dependently protected against loss of tyrosine hydroxylase immunoreactive neurons in the substantia nigra pars compacta. STAZN reduced the striatal lesion volume caused by systemic 3NP administration from 44 +/- 9 to 20 +/- 6 mm(3). The lipid peroxidation marker, malondialdehyde(MDA), was significantly increased in the striatum, cortex, and cerebellum of rats after administration of 3NP. These increases were blocked by co-injection of STAZN. Our data provide further evidence that STAZN is a neuroprotective free radical spin trap, and suggest that the development of new antioxidants will broaden our therapeutic strategies for neurodegenerative diseases.

Animals↗
PubMed2006

Efficiency of NaOCl and laser-assisted photosensitization on the reduction of Enterococcus faecalis in vitro.

OBJECTIVE: To investigate the action of a red laser associated with a photosensitizer on the reduction of Enterococcus faecalis in dental root canal in vitro. STUDY DESIGN: Thirty prepared teeth with single canals were contaminated. The chemical group was irrigated with 0.5% NaOCl and left flooded for 30 minutes. In the laser group, a paste-based photosensitizer was maintained in the root canals for 5 minutes, and then irradiated with a laser at 685 nm using an optical fiber for an E of 1.8 J during 3 minutes. After treatment, the canal content was collected, serially diluted, and cultured to determine the number of colony-forming units. RESULTS: Photosensitizer alone or laser alone did not have any bactericidal effect. Chemical solution reduced viable bacteria in 93.25%. Laser photosensitization resulted in a reduction of 99.2%, a significantly higher bacterial reduction than NaOCl. CONCLUSION: Laser photosensitization was effective for reducing E. faecalis in root canals and could be an adjunct to endodontic treatment.

Azulenes↗
PubMed1999

An optimal redox status for the survival of axotomized ganglion cells in the developing retina.

The neuronal redox status influences the expression of genes involved in neuronal survival. We previously showed that antioxidants may reduce the number of dying ganglion cells following axotomy in chick embryos. In the present study, we show that various antioxidants, including the new spin trap azulenyl nitrone and 1,3-dimethyl-2-thiourea, protect axotomized ganglion cells, confirming that neuronal death involves an imbalance of the cellular redox status towards oxidation. However, high concentrations of antioxidants did not protect ganglion cells, suggesting that excessive reduction is detrimental for neurons. Simultaneous injections of two different antioxidants gave results only partly supporting this view. Combinations of azulenyl nitrone and N-acetyl cysteine in fact gave greater protection than either antioxidant alone, whereas N-acetyl cysteine lost its neuroprotective effects and diminished those of alpha-phenyl-N-tert-butyl nitrone when the two compounds were injected simultaneously. The results of the combined treatments suggest that azulenyl nitrone and alpha-phenyl-N-tert-butyl nitrone do not have the same chemical effects within the ganglion cells. Moreover, N-acetyl cysteine's own antioxidant properties enhance the spin trapping effects of azulenyl nitrone but potentiate the toxicity of alpha-phenyl-N-tert-butyl nitrone. Our main conclusion is that neuronal survival requires the maintenance of the redox status near an optimal set-point. "Reductive stress" may be as dangerous as oxidative stress.

Acetylcysteine↗
PubMed2003

Stabilization of sodium guaiazulene sulfonate in granules for tableting prepared using a twin-screw extruder.

Sodium guaiazulene sulfonate (GAS-Na), which has an anti-inflammatory effect, is an unstable compound, which is gradually decomposed in the solid state at room temperature. In fact, when heated (40 degrees C 6% RH), GAS-Na decomposes almost completely within 1 week. It was found that a kneaded mixture of GAS-Na and cornstarch (weight ratio; 1:250) for tableting with water is stable. So, during production, GAS-Na could be stabilized using water. Four kinds of tablet were prepared in different ways: direct tableting, tableting via screw granulation, tableting via fluidized bed granulation, and tableting via twin-screw extrusion. The stability of GAS-Na in these tablets was compared. The tablet prepared using screw granulation, during which 30% water was added to the material, was the most stable. It was, however, shown that reducing the water content to 12.5%, when screw granulation was conducted, made the GAS-Na less stable. Also, when a twin-screw extruder with kneading paddle elements in the screws was used even with lower water content of 12.5%, the stability of GAS-Na improved. In addition, when the kneading paddle elements were detached from the screws and only the feed screw elements were operated, GAS-Na lost its stability. These results show that the kneading paddle elements play a role in uniformly dispersing a small amount of water into the powder and stabilizing GAS-Na. It was found that the water presence was a very important factor with respect to the decomposition of GAS-Na, irrespective of the crystallinity. Furthermore, a twin-screw extruder with kneading paddle elements is useful for uniformly dispersing water to prepare stable formulations of GAS-Na.

Azulenes↗
PubMed2002

Novel potent antagonists of human neuropeptide Y-Y5 receptor. Part 4: tetrahydrodiazabenzazulene derivatives.

Novel tetrahydrodiazabenzazulene derivatives, designed from the lead compound 1 discovered by screening of our in-house chemical library, were prepared and found to be potent neuropeptide Y-Y5 (NPY-Y5) receptor antagonists. The structure-activity relationships are described. Compounds 7 (FR240662) and 16 (FR252384) were especially attractive owing to their high affinities for the NPY-Y5 receptors, oral absorption and permeability to brain.

Administration, Oral↗
PubMed2002

Ultrafast bidirectional dihydroazulene/vinylheptafulvene (DHA/VHF) molecular switches: photochemical ring closure of vinylheptafulvene proven by a two-pulse experiment.

The photochromic couple dihydroazulene/vinylheptafulvene (DHA/VHF) is an established system for molecular switching. The photoinduced ring opening of the thermally stable dihydroazulene proceeds in the picosecond time regime with subsequent rapid relaxation to the electronic ground state. So far it was not possible to reverse the reaction photochemically. It was always found that the back reaction proceeds thermally on a longer time scale. In the case of the cyanophenyl-DHA derivative utilized in the present study, this is accounted to s-cis/s-trans isomerization of the primarily formed s-cis VHF. Since this particular isomerization takes much longer than nanoseconds, we now successfully applied a second visible femtosecond pulse subsequent to the initial UV pulse (25 ps delay) achieving ring closure of the primarily formed s-cis VHF. The now bidirectional photoswitching was monitored by the changes in the cw spectrum. As a result, the DHA/VHF system is found to be a multifold switchable system by itself: it is both a very fast photoreversible switch and a photochemical/thermal switch with a thermal lock mode.

Azulenes↗
PubMed2005

Screening of chemical composition and antifungal and antioxidant activities of the essential oils from three Turkish artemisia species.

The compositions of essential oils isolated from the aerial parts of Artemisia absinthium, Artemisia santonicum, and Artemisia spicigera by hydrodistillation were analyzed by GC-MS, and a total of 204 components were identified. The major components of these essential oils were camphor (34.9-1.4%), 1,8-cineole (9.5-1.5%), chamazulene (17.8-nd%), nuciferol propionate (5.1-nd%), nuciferol butanoate (8.2-nd%), caryophyllene oxide (4.3-1.7%), borneol (5.1-0.6%), alpha-terpineol (4.1-1.6%), spathulenol (3.7-1.3%), cubenol (4.2-0.1%), beta-eudesmol (7.2-0.6%), and terpinen-4-ol (3.5-1.2%). The antifungal activities of these essential oils were tested against 11 plant fungi and were compared with that of a commercial antifungal reagent, benomyl. The results showed that all of the oils have potent inhibitory effects at very broad spectrum against all of the tested fungi. Pure camphor and 1,8-cineole, which are the major components of the oils, were also tested for antifungal activity against the same fungal species. Unlike essential oils, these pure compounds were able to show antifungal activity against only some of the fungal species. In addition, the antioxidant and DPPH radical scavenging activities of the essential oils, camphor, and 1,8-cineole were determined in vitro. All of the studied essential oils showed antioxidant activity, but camphor and 1,8-cineole did not.

Antioxidants↗
PubMed2005

Total synthesis of two novel subpicomolar sarco/endoplasmatic reticulum Ca2+-ATPase inhibitors designed by an analysis of the binding site of thapsigargin.

Analysis of molecular interaction fields based on the published crystal structure of thapsigargin bound to the sarco/endoplasmatic reticulum Ca(2+)-ATPase and analysis of the volume and shape of the ligand binding site and of the SERCA-thapsigargin interactions have enabled design of two new compounds inhibiting SERCA in the subpicomolar range. The two inhibitors were synthesized using (S)-carvone as starting material and found to be 3 and 10 times more potent than thapsigargin.

Azulenes↗
PubMed2006

Syntheses of (+)-alismoxide and (+)-4-epi-alismoxide.

The first total syntheses of (+)-alismoxide and (+)-4-epi-alismoxide are reported. Formal chemo-, regio-, and stereoselective addition of water to 10alpha-acetoxy-1alphaH,5betaH-guaia-3,6-diene afforded the target compounds after reduction. The absolute stereochemistry of (+)-alismoxide has been established. The low [alpha](D) +8.6 value indicates that significant amounts of alismoxide result from biosynthetic processes. Furthermore, the structure of the natural guaienediol isolated from Silphium perfoliatum has been corrected to (-)-alismoxide.

Asteraceae↗
PubMed2000

New terpenoid components from the volatile oils of the soft corals Clavularia viridis and Sarcophyton acutangulum.

A new tetracyclic terpenoid hydrocarbon, cyclosinularane (1), and (+)-alloaromadendrene (2), the enantiomer of terrestrial (-)-alloaromadendrene, have been isolated from the volatile oil of the soft corals Clavularia viridis and Sarcophyton acutangulum, respectively. Their structures have been determined on the basis of NMR spectral analysis and their chiroptical properties.

Animals↗
PubMed2003

Copacamphane, picrotoxane, and alloaromadendrane sesquiterpene glycosides and phenolic glycosides from Dendrobium moniliforme.

Seven sesquiterpene glycosides with copacamphane, picrotoxane, and alloaromadendrane sesquiterpene aglyons along with three phenolic glycosides have been isolated from the stems of Dendrobium moniliforme. Among them, dendromonilisides A-D (1-4) were characterized as new compounds, and their structures were determined on the basis of spectral and chemical methods and by X-ray diffraction analysis. The six known compounds were identified as dendrosides A, C, and F, dendromoniliside E, vanilloloside, and acanthoside B. In a preliminary biological test procedure, compounds 1, 3, and vanilloloside were found to stimulate the proliferation of B cells and inhibit the proliferation of T cells in vitro.

Azulenes↗
PubMed2005

Two new cytotoxic linderazulenes from a deep-sea gorgonian of the genus Paramuricea.

The known compound linderazulene (1) and two new linderazulenes (2, 3) were isolated from a deep-sea gorgonian Paramuricea sp. The structures of 2 and 3 were determined through spectroscopic methods. Compounds 1-3 show moderate in vitro cytotoxicity against the P388 murine leukemia cell line with IC(50)'s of 18.8, 2.7, and 15.6 microg/mL, respectively. Compound 2 showed moderate activity against the PANC-1 pancreatic cell line with an IC(50) of 18.7 microg/mL.

Animals↗
PubMed2006

Chamazulene carboxylic acid and matricin: a natural profen and its natural prodrug, identified through similarity to synthetic drug substances.

Chamazulene carboxylic acid (1) is a natural profen with anti-inflammatory activity and a degradation product of proazulenic sesquiterpene lactones, e.g., matricin. Both 1 and proazulenes occur in chamomile (Matricaria recutita), yarrow (Achillea millefolium), and a few other Asteraceae species. It was isolated in improved yields, characterized physicochemically, and found to be an inhibitor of cyclooxygenase-2, but not of cyclooxygenase-1. It had anti-inflammatory activity in several animal models with local and systemic application. When human volunteers were given matricin orally, plasma levels of 1 were found to be in the micromolar range. Matricin was converted to 1 in artificial gastric fluid, but not in artificial intestinal fluid. Matricin and the yarrow proazulenes are proposed to be anti-inflammatory through conversion to 1. Intriguingly, the biological activity of the natural compound 1 was found because of its similarity to fully synthetic drug substances. This is the reverse process of the common lead function of natural compounds in drug discovery.

Achillea↗
PubMedDate not supplied

Daphnane diterpenes from Diarthron vesiculosum: vesiculosin and isovesiculosin.

An alcoholic extract of Diarthron vesiculosum seed has yielded two novel daphnane diterpene esters, vesiculosin and isovesiculosin. Compounds 1 and 2 undergo rapid interconversion to an equilibrium mixture containing approximately 80% 1 and 20% 2 in solution at elevated temperatures. At 25 degrees or below, 1 and 2 may be isolated and stored for extended periods with minimal interconversion. Excoecariatoxin and simplexin are the major daphnane orthoesters present in D. vesiculosum, and 1 and 2 apparently are biosynthetic precursors of 3. Isolation of these compounds was monitored by bioassay against PS leukemia (in vivo), and structures were determined by 1H nmr, 13C nmr, ms, and comparison with known compounds.

Afghanistan↗