SEARCH · Search PubMed

Results for “Propane”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources

PubMed2005

Mechanism studies of the conversion of 13C-labeled n-butane on zeolite H-ZSM-5 by using 13C magic angle spinning NMR spectroscopy and GC-MS analysis.

By using 13C MAS NMR spectroscopy (MAS = magic angle spinning), the conversion of selectively 13C-labeled n-butane on zeolite H-ZSM-5 at 430-470 K has been demonstrated to proceed through two pathways: 1) scrambling of the selective 13C-label in the n-butane molecule, and 2) oligomerization-cracking and conjunct polymerization. The latter processes (2) produce isobutane and propane simultaneously with alkyl-substituted cyclopentenyl cations and condensed aromatic compounds. In situ 13C MAS NMR and complementary ex situ GC-MS data provided evidence for a monomolecular mechanism of the 13C-label scrambling, whereas both isobutane and propane are formed through intermolecular pathways. According to 13C MAS NMR kinetic measurements, both pathways proceed with nearly the same activation energies (E(a) = 75 kJ mol(-1) for the scrambling and 71 kJ mol(-1) for isobutane and propane formation). This can be rationalized by considering the intermolecular hydride transfer between a primarily initiated carbenium ion and n-butane as being the rate-determining stage of the n-butane conversion on zeolite H-ZSM-5.

Journal Article↗

PubMed2007

Separation of olefin/paraffin mixtures using zwitterionic silver complexes as transport carriers.

Zwitterionic silver nitrate salts of 1-(1-methyl-3-imidazolio)propane-3-sulfonate, 1-(1-methyl-1-pyrrolidinio)propane-3-sulfonate, and 1-(4-methyl-4-morpholio)propane-3-sulfonate have been prepared and tested as carriers for facilitated olefin transport membranes in the separation of ethylene/ethane, propylene/propane, and C4 mixtures. The interactions of olefins with silver ions bound to sulfonate groups were investigated by FTIR spectroscopy as well as the correlation between the binding affinity of olefins and facilitated transport.

Journal Article↗

PubMed1997

Kinetic characterization of recombinant human glutathione transferase T1-1, a polymorphic detoxication enzyme.

Recombinant human theta class glutathione transferase T1-1 has been heterologously expressed in Escherichia coli and a simple purification method involving immobilized ferric ion affinity chromatography and Orange A dye chromatography is described. The catalytic properties of the enzyme differ significantly from those of other glutathione transferases, also within the theta class, with respect to both substrate selectivity and kinetic parameters. In addition to 1,2-epoxy-3-(4-nitrophenoxy)propane, the substrate used previously to monitor the enzyme, human glutathione transferase T1-1 has activity with the naturally occurring phenethylisothiocyanate and also displays glutathione peroxidase activity with cumene hydroperoxide. Further, the enzyme is active with 4-nitrobenzyl chloride and 4-nitrophenethyl bromide, but shows no detectable activity with the more chemically reactive 1-chloro-2,4-dinitrobenzene. The Michaelis constant for glutathione, K(m)GSH, with 1,2-epoxy-3-(4-nitrophenoxy)propane as second substrate, is high at low pH values but decreases at higher pH values. This is mirrored in kcat/K(m)GSH which increases with an apparent pKa value of 9.0, reflecting the ionization of the thiol group of glutathione in solution. The same results are obtained with 4-nitrophenethyl bromide as electrophilic substrate, although the K(m)GSH value (0.72 mM at pH 7.5), as well as the pKa (8.1) derived from the pH dependence of kcat/K(m)GSH, are lower with this substrate. In contrast, kcat and kcat/K(m)electrophile display either a maximum or a plateau at pH 7.0-7.5, and an apparent pKa value of 5.7 was determined for the pH dependence of kcat with both 4-nitrophenethyl bromide and 1,2-epoxy-3-(4-nitrophenoxy)propane as electrophilic substrates. This pKa value reflects an ionization of enzyme-bound GSH, most probably involving the sulfhydryl group, whose pKa value thus is lowered by the enzyme. Three differences in the cDNA as compared to the sequence previously published were found. One of these differences causes a change in the deduced amino acid sequence and involves the nucleotide triplet encoding amino acid 126, which was determined as GAG (Glu), instead of the published GGG (Gly).

Chromatography, Affinity↗

PubMed1995

Differing effects of various cryoprotectants on intercellular junctions of epithelial (MDCK) cells.

The effects of 30 min exposure to 10% v/v cryoprotectant (glycerol, dimethyl sulfoxide, or propane-1,2-diol) on intercellular junctions were investigated in monolayers of epithelial (MDCK) cells. The cells were grown on microporous membrane filters and transepithelial resistance was monitored as an index of junction integrity. At 22 degrees C, Me2SO had the least effect of the three cryoprotectants, causing a gradual fall in transepithelial resistance of only 17% in 30 min. This compares with falls of 50% in 15 min and 37% over 30 min, respectively, with glycerol and propane-1,2-diol. At 0 degrees C, however, propane-1,2-diol had no effect on transepithelial resistance, whereas the effect of Me2SO was now similar to that of glycerol, viz. a sustained reduction in resistance of approximately 30% throughout the 30-min exposure. The results could not be explained solely in terms of osmotic effects and suggested that the cryoprotectants were directly affecting components of the junctional complex or associated elements of the cytoskeleton. During removal of the cryoprotectants by two-step dilution, changes in transepithelial resistance showed little consistency between the different cryoprotectants. This suggested that the pattern of change was dictated more by the state of the junctions immediately before removal of the cryoprotectants, with each cryoprotectant having affected the junctions to different extents and perhaps by different mechanisms, than by the removal of cryoprotectant itself. Thus, intercellular junctions in epithelial sheets were affected by even modest concentrations of cryoprotectant, but the effect was influenced by the type of cryoprotectant and by temperature of exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1998

Comparison of glycerol, other polyols, trehalose, and raffinose to provide a defined cryoprotectant medium for mouse sperm cryopreservation.

Most procedures for mouse sperm cryopreservation have utilized raffinose to provide hypertonicity for cell desiccation prior to freezing and glycerol to block intracellular ice formation. Trehalose has been shown in other cell systems to provide positive protection to the plasma membrane and so was examined as a replacement for raffinose. Comparison of 3 and 6% glycerol and 7.5 and 20% sugar showed that 6% glycerol and 7.5% sugar gave maximal protection consistently and so were adopted as standard. Comparison of raffinose and trehalose at this concentration showed trehalose to give significantly better recovery of intact cells: 48 +/- 6% for trehalose, 36 +/- 9% for raffinose (+/- SE, n = 5; arc sine transformed data; P < 0.01). Less hydrophilic polyols should prove more permeant to the membrane than glycerol, enter the cell rapidly, and so possibly inhibit lethal intracellular ice formation effectively. We hypothesized that one of these polyols plus glycerol would be a more effective cryoprotectant than glycerol alone. The polyols tested as supplements to 6% glycerol were propane-1,2-diol, propane-1,3-diol, 1,1,1-tris-(hydroxymethyl)ethane (THME), and 2-ethyl-2-(hydroxymethyl)-propane-1,3-diol (EHMP). With 6% glycerol and 7.5% raffinose or trehalose, the two diols and THME gave less cryoprotection than with glycerol alone, and EHMP reduced postthaw membrane integrity to nil, thus invalidating the hypothesis. Comparison of bicarbonate-containing medium MJB to bicarbonate-free medium NTP, both with 6% glycerol/7.5% trehalose, showed no difference in recovery of membrane-intact cells. For ease of pH maintenance, NTP was chosen for studies of addition prefreeze and removal postthaw of 6% glycerol/7.5% trehalose cryoprotectant with in vitro fertilization as endpoint. Three protocols for cryoprotectant handling were tested: serial addition/dilution; dialysis addition and removal; and dialysis addition and direct insemination without cryoprotectant removal. The last proved significantly superior (P < 0.01), giving 62% fertilized eggs, normalized to controls, compared to 21% for dialysis addition and removal and 32% for serial addition and dilution. The glycerol/trehalose combination thus provides a defined cryoprotectant which, when used with addition by dialysis prefreeze and direct insemination postthaw, yields a satisfactory yield of fertilized eggs in an in vitro fertilization system.

Animals↗

PubMed1997

Prediction of Solubility of Nonpolar Gases in Micellar Solutions of Ionic Surfactants

The solubilities of methane, carbon dioxide, ethane, and propane have been determined experimentally at 1 atm partial pressure and 25°C in aqueous solutions of sodium dodecyl sulfate and cetyltrimethylammonium bromide. For this purpose a specially developed apparatus is used, which is relatively simple compared to those reported in the literature hitherto. Above the CMC, the solubility of each gas increases linearly with surfactant concentration indicating micellar solubilization. The degree of solubilization is greatest for propane and decreases in the order propane > ethane > carbon dioxide > methane. Both the length of the alkyl chain and the properties of the head-group region (i.e., the micelle-water interfacial tension) are observed to determine the intramicellar solubility. A method for estimating the solubilities is also proposed based on the rationale that the micellar phase may be represented by a droplet of a "model solvent" into which the solubilizate molecule dissolves as it would in a bulk solvent. The mixture of the solute species and the model solvent is assumed to behave as a regular solution. Accordingly, a characteristic solubility parameter is estimated for the model solvent from the interaction potential between two adjacent surfactant molecules in a micelle. The solubility computed using the regular solution approximation is further corrected for the Laplace pressure that acts across the curved micelle-water interface and generally reduces the intramicellar solubility. It is concluded that for small nonpolar solutes, micellar solubilities may be reasonably well predicted by assuming that the model solvent has a solubilizing capacity (i.e., solubility parameter) close to that of a bulk equivalent alkane. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗

PubMed1988

Functional and biochemical features of alcohol dehydrogenase in four species of the obscura group of Drosophila.

The biochemical features of ADH of four Drosophila species of the obscura group have been studied. The relationship between ethanol tolerance and ADH activity has been investigated. Propan-2-ol and acetone concentrations have been determined in propan-2-ol treated flies and ADH activity has been followed during 96 h of propan-2-ol treatment. Data on the ADH system confirm constructed phylogenies based on electrophoretic variation and chromosome homologies.

Alcohol Dehydrogenase↗

PubMed1994

Effect of n-3 fatty acid-rich fish oil supplementation on the oxidation of low density lipoproteins.

This study was aimed at determining the effect of fish oil supplementation on copper-catalyzed oxidation of low density lipoproteins (LDL) from nine hypertriglyceridemic human subjects. A rapid headspace gas chromatographic method was used to measure the volatile oxidation products from LDL. Propanal and hexanal were the major volatile products formed in the oxidation of n-3 and n-6 polyunsaturated fatty acids (PUFA), respectively. Fish oil supplementation resulted in a significant increase in propanal formation from 3.7 to 13.4 nmol/mL LDL (P < 0.01); it also resulted in small decreases in pentanal formation from 14.7 to 11.4 nmol/mL LDL and in hexanal formation from 138 to 108 nmol/mL LDL (P < 0.05). The changes in peroxidation products paralleled the changes in LDL composition, which showed a significant increase in n-3 PUFA from 3.2 to 14.6% (P < 0.01) and a decrease in n-6 PUFA from 43.7 to 35.0% (P < 0.05). Propanal formation was highly and significantly correlated with n-3 PUFA content (r = 0.950, P < 0.001). Since total volatiles remained unchanged, this indicated that the two groups of LDL samples did not differ in overall oxidative susceptibility. Although fish oil intake did not alter the oxidative susceptibility of LDL, the chemically modified LDL particles generated a distinct pattern of volatile oxidation products that reflected changes in their fatty acid composition.

Chromatography, Gas↗

PubMed1990

Testicular endocrine effects of alkane methanesulphonates related to the Leydig cell cytotoxic compound, EDS.

A series of compounds structurally similar to the specific Leydig-cell-cytotoxic substance ethane-1,2-dimethanesulphonate (EDS) were examined for Leydig cell toxicity in the rat. Within 48 h of a single injection of butane-2,3-dimethanesulphonate (BDS), propan-1,3-dimethanesulphonate (P-1,3-DS) or propan-1-chloro-2,3-DS (PCDS) there was a reduction in serum and testicular testosterone levels. The serum luteinizing hormone (LH) concentration was reduced following BDS or P-1,3-DS, and Leydig-cell LH receptors (measured by 125I-labelled hCG binding) were reduced by less than 15%, from which it is concluded that these compounds are not selectively toxic to Leydig cells. However, PCDS reduced human chorionic gonadotropin (hCG) binding by greater than 70% and could be considered to be a potential toxin. The effects of hydroxy-ethanemethane-sulphonate (HEMS), 1,5,2,4-dioxadithiepane-2,2,4,4-tetraoxide (cyclic SOSO), PCDS, propan-2,3-DS, alpha-chlorohydrin and cyclohexane-1,2-dimethane-sulphonate were compared with the effects of EDS 7 days after injection. Systemic toxicity, indicated by a loss of body weight, was associated with cyclic SOSO, PCDS and EDS, although only EDS and PCDS reduced both testicular hCG binding and serum and testis testosterone levels consistent with Leydig-cell toxicity. Further studies indicated that the potency of PCDS in reducing testicular hCG binding and serum and intratesticular testosterone levels was similar to that of EDS. However, unlike EDS, PCDS was systemically toxic and also reduced LH, which could at least in part account for changes in testosterone secretion. The experiments confirm the unique cytotoxicity of EDS. Loss of specific Leydig-cell cytotoxicity and an increase in systemic toxicity occurred when the EDS molecule was altered, even if the distance between the alkylating centres was maintained. The mechanism of action of EDS remains elusive.

Animals↗

PubMed1994

Synthesis of dibenzoylmethanes as intermediates for flavone synthesis by a modified Baker-Venkataraman rearrangement.

1-Polyoxyphenyl-3-(2,6-dioxyphenyl)propane-1,3-diones have been synthesized as intermediates for flavone synthesis by condensation of 2-(2,6-dioxybenzoyloxy)polyoxyacetophenone in the presence of phase transfer catalyst. The average yields of 1-polyoxyphenyl-3-phenylpropane-1,3- diones, 1-polyoxyphenyl-3-(2-benzyloxyphenyl)propane-1,3-diones and 1-polyoxy-3-(2,6-dibenzyloxyphenyl)propane-1,3-diones were 79%, 74% and 71%, respectively. The bulkiness of the benzyloxy groups or methoxy groups exerted steric hindrance and reduced the yield. Nevertheless, the yields were higher than the previously reported ones.

Benzoates↗

PubMed2003

Isopropanol and acetone induces vinyl chloride degradation in Rhodococcus rhodochrous.

In situ bioremediation of vinyl chloride (VC)-contaminated waste sites requires a microorganism capable of degrading VC. While propane will induce an oxygenase to accomplish this goal, its use as a primary substrate in bioremediation is complicated by its flammability and low water solubility. This study demonstrates that two degradation products of propane, isoproponal and acetone, can induce the enzymes in Rhodococcus rhodochrous that degrade VC. Additionally, a reasonable number of cells for bioremediation can be grown on conventional solid bacteriological media (nutrient agar, tryptic soy agar, plate count agar) in an average microbiological laboratory and then induced to produce the necessary enzymes by incubation of a resting cell suspension with isopropanol or acetone. Since acetone is more volatile than isopropanol and has other undesirable characteristics, isopropanol is the inducer of choice. It offers a non-toxic, water-soluble, relatively inexpensive alternative to propane for in situ bioremediation of waste sites contaminated with VC.

2-Propanol↗

PubMed1982

Investigation of human erythrocyte ghost membranes with intramolecular excimer probes.

Human erythrocyte ghost membranes have been investigated using two intramolecular excimer probes, di(1-pyrenyl)propane and di(1-pyrenylmethyl) ether. Values for the viscosity of the direct probe environment in the ghost membranes range from 76 cP at 37 degrees C to 570 cP at 5 degrees C, as reported for di(1-pyrenyl(propane, with liquid paraffin as the reference solvent. For the activation energy of the excimer formation process, determined here mainly by the viscosity of the medium, a value of 37 kJ/mol is obtained. The other probe molecule reports a higher local viscosity, 133 cP at 37 degrees C, as well as a higher activation energy of excimer formation, 54 kJ/mol. Neither thermotropic phase transitions nor temperature hysteresis effects are observed within the temperature range (0 to 40 degrees C) studied. From the vibrational structure of the fluorescence spectrum of di(1-pyrenylmethyl) ether, a polarity of the probe environment close to that of hexanol (epsilon - 13.3) results for the erythrocyte ghost membranes. The polarity measured in egg phosphatidylcholine membranes and in multibilayers of dimyristoylphosphatidylcholine is slightly larger, comparable to that of butanol (epsilon = 17.5), whereas a polarity comparable to that of methanol (epsilon = 32.7) is observed for aqueous micellar solutions of sodium dodecyl sulphate. Further, from the wavelength shifts in the absorption spectrum of di(1-pyrenyl)propane and di(1-pyrenylmethyl) ether, the polarizability of the probe surroundings can be determined, leading to a surprisingly high value for the apparent refractive index. This is attributed to a high local density of the direct environment of the probe, for which a location between the membrane/water interface and the unpolar bilayer mid-plane is deduced.

Erythrocyte Membrane↗

PubMed1993

Site-specific trapping of reactive species in low-density lipoprotein oxidation: biological implications.

Abundant data suggest that the oxidative modification of low-density lipoprotein is mediated by lipid-derived free radicals and aldehydes derived from them. In this report we have addressed the site-specific aspects of low-density lipoprotein modification. To this end, both water-soluble and lipid-soluble spin traps (i.e., diamagnetic organic molecules containing nitroso or nitrone functional groups) were used. Radical adducts were detected by electron spin resonance-spin trapping technique. Biochemical indices of low-density lipoprotein modification were thiobarbituric acid reactive substances formation, electrophoretic mobility and macrophage-mediated uptake of oxidized low-density lipoprotein. Results from this study have shown that the lipophilic spin trap, alpha-phenyl-tert-butyl-N-nitrone, traps a primary low-density lipoprotein lipid-derived radical, while also inhibiting the total oxidative modification in a dose-dependent manner. The more hydrophilic analog, i.e., alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone, appeared to trap the secondary alkyl radicals and did not exert any inhibitory effect on oxidative modification of low-density lipoprotein. The lipophilic nitroso spin trap, 2-methyl-2-nitroso propane, which traps a lipid-derived radical, inhibited the low-density lipoprotein modification as did the water-soluble nitroso analog, 2-hydroxymethyl-2-nitroso propane. However, the water-soluble nitroso analog did not trap the lipid radical. The inhibitory effect of 2-hydroxymethyl-2-nitroso propane was tentatively attributed to trapping of aldehydes. It is conceivable that spin traps can inhibit the oxidative modification of low-density lipoprotein by trapping of the lipid radicals as well as trapping aldehydes formed from lipid peroxidation.

Animals↗

PubMed1979

Absorption, distribution and metabolism of propyl anthranilate.

Analysis of the gut contents of rats killed at intervals after dosage with propyl anthranilate or anthranilic acid suggested that both acid and ester were absorbed rapidly; the chief site of absorption was the stomach. Not more than a trace of the ester was hydrolysed in the stomach but of the dosed ester detected in the small intestine (less than 7%) a considerable proportion, increasing with time after dosing was present as anthranilic acid. Measurement of the level of radioactivity in the blood after administration of 14C-labelled propan-1-ol, propyl anthranilate or anthranilic acid showed that the alcohol was absorbed more rapidly than either the ester or acid. Unchanged propyl anthranilate was readily detected in the blood of rats dosed with the ester and some unhydrolysed ester was excreted in the urine. The level of radioactivity of the organs of rats 2 h and 4 h after administration of the 14C-labelled compounds was measured. Velocity constants for the excretion of 14CO2 by rats dosed with 14C-labelled propyl anthranilate were significantly lower than those found for rats dosed with [14C]propan-1-ol indicating a limiting step in the metabolism of the propyl moiety of the ester which did not occur in the metabolism of propan-1-ol. The urinary metabolites of anthranilic acid excreted by rabbits and rats dosed with the acid were qualitatively the same as those excreted by these species after dosing with propyl anthanilate; some quantitative differences were however, observed.

Animals↗

PubMed1983

Ferrous ion-stimulated alkane expiration in rats treated with carbon tetrachloride.

Rats which were treated intraperitoneally (i.p.) with FeCl2 X 4H2O expired ethane which increased with increasing doses of iron. The same amount of ethane was expired by animals exposed to 20% or 100% oxygen. The mobilization by FeCl2 of stored ethane from the body was excluded. Propane expiration was also stimulated by FeCl2 treatment, whereas n-pentane expiration could not be detected. Rats which were treated i.p. with 500 mg CCl4/kg expired ethane, propane, and n-pentane, the amounts being higher in the presence of 20% than in the presence of 100% oxygen. The treatment of rats with FeCl2 30 min after giving CCl4 resulted in a 2-5-fold increase in ethane, propane and n-pentane expiration, the total amounts depending on the oxygen concentration in the respired air (higher under 20% and lower under 100% oxygen). This increase was due to a minor extent to FeCl2-initiated alkane formation. Therefore, we suggest that in vivo Fe2+, besides its ability to initiate lipid peroxidation, influences the CCl4-induced lipid peroxidation process. The possible relevance for CCl4 toxicity is discussed.

Alkanes↗

PubMed2005

Efficient solubilization buffers for two-dimensional gel electrophoresis of acidic and basic proteins extracted from wheat seeds.

Plant tissues are made up of a broad range of proteins with a variety of properties. After extraction, solubilization of a diverse range of plant proteins for efficient proteomic analysis using two-dimensional electrophoresis is a challenging process. We tested the efficiency of 12 solubilization buffers in dissolving acidic and basic proteins extracted from mature seeds of wheat. The buffer containing two chaotropes (urea and thiourea), two detergents (3-[(3-cholamidopropyl) dimethyl-ammonio]-1-propane-sulfonate and N-decyl-N,N-dimethyl-3-ammonio-1-propane-sulfonate), two reducing agents (dithiothreitol and tris (2-carboxyethyl) phosphine hydrochloride) and two types of carrier ampholytes (BioLyte pH 4-6 and pH 3-10) solubilized the most acidic proteins in the pH range between 4 and 7. The buffer made up of urea, thiourea, 3-[(3-cholamidopropyl) dimethyl-ammonio]-1-propane-sulfonate, DeStreak reagent (Amersham Biosciences, Uppsala, Sweden) and immobilized pH gradient buffer, pH 6-11 (Amersham Biosciences) solubilized the most basic proteins in the pH range between 6 and 11. These two buffers produced two-dimensional gels with high resolution, superior quality and maximum number of detectable protein (1425 acidic protein and 897 basic protein) spots.

Ampholyte Mixtures↗

PubMed2005

Inhibitory effects of 2-substituted-1-naphthol derivatives on cyclooxygenase I and II.

Naphthol derivatives, 2-(3'-hydroxypropyl)-naphthalen-1-ol (2), 2-(3'-hydroxy-2'-methylpropyl)-naphthalen-1-ol (3) and 2-(3'-hydroxy-2',2'-dimethylpropyl)-naphthalen-1-ol (7) were synthesized and already reported by our group. Therefore in this paper we described further synthesis of their ether derivatives, 3-(1-methoxy-naphthalen-2-yl)-propan-1-ol (4), 3-(1-methoxy-naphthalen-2-yl)-2methyl-propan-1-ol (5), 3-(1-methoxy-naphthalen-2-yl)-2,2-dimethyl-propan-1-ol (8), 2-(3-methoxy-propyl)-naphthalen-1-ol (10) and 2-(3-methoxy-2,2-dimethyl-propyl)-naphthalen-1-ol (13). Compounds 4, 5 and 8 were prepared by methylation of compounds 2, 3 and 7, respectively while compounds 10 and 13 were prepared in good yield from naphthols 2 and 7, respectively. When tested for inhibitory activity, five compounds (2, 3, 7, 10 and 13) showed preferential inhibition of COX-2 over COX-1, while compounds 4, 5 and 8 lacked inhibitory effect on either the COX-1 or COX-2 isozyme. The structure-activity relationships of these naphthols analyzed by docking experiments, indicated that the presence of hydroxyl group at C-1 position on the naphthalene nucleus enhanced the anti-inflammatory activity towards COX-2 via hydrogen bonding to the COX-2 Val 523 side chain. When this hydroxyl group was replaced by methoxy group, there was no inhibition. C-2' Dimethyl substituents on the propyl chain also increased the inhibitory activity. All active compounds have the C-1 hydroxyl group aligned so as to form hydrogen bond with Val 523. The results provide a model for the binding of the naphthol derivatives to COX-2 and facilitate the design of more potent or selective analogs prior to synthesis.

Animals↗

PubMed2005

Synthesis and antioxidant, anti-inflammatory and gastroprotector activities of anethole and related compounds.

Some derivatives of trans-anethole [1-methoxy-4-(1-propenyl)-benzene] (1) were synthesized, by introducing hydroxyl groups in the double bond of the propenyl moiety. Two types of reactions were performed: (i) oxymercuration/demercuration that formed two products, the mono-hydroxyl derivative, 1-hydroxy-1-(4-methoxyphenyl)-propane (2) and in lesser extent the dihydroxyl derivative, 1,2-dihydroxy-1-(4-methoxyphenyl)-propane (3) and (ii) epoxidation with m-chloroperbenzoic acid that also led to the formation of two products, the dihydroxyl derivative (3) and the correspondent m-chloro-benzoic acid mono-ester, 1-hydroxy-1(4-methoxyphenyl)-2-m-chlorobenzoyl-propane (4). The structures of these compounds were confirmed mainly by mass, IR, 1H and 13C NMR spectral data. The activity of anethole and hydroxylated derivatives was evaluated using antioxidant, anti-inflammatory and gastroprotector tests. Compounds (2) and (3) were more active antioxidant agents than (1) and (4). In the anti-inflammatory assay, anethole showed lower activity than hydroxylated derivatives. Anethole and in lesser extent its derivatives 2 and 4 showed significant gastroprotector activity. All tested compounds do not alter significantly the total number of white blood cells.

Allylbenzene Derivatives↗