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At least 775 records · Page 43Linked to original sources
PubMed2005

Effects of garcinol on free radical generation and NO production in embryonic rat cortical neurons and astrocytes.

Garcinol (camboginol) is a polyisoprenylated benzophenone derivative isolated from fruit rind of Garcinia indica. This study was to elucidate the anti-oxidative and neuroprotective properties of garcinol in rat cortical neuron cultures. First, garcinol protects DNA from Fenton reaction-induced breakage in a dose-dependent manner, with an IC(50) value of 0.32 microM. Garcinol also inhibits xanthine oxidase activity with an IC(50) value of 52 microM and exhibits competitive inhibition. To further ascertain the neuroprotective effects of garcinol in inflammatory-mediated neurotoxicity, we utilized primary neuron/astrocyte co-cultures treated with LPS or cytokine. Our data implicate that treatment with garcinol (5 microM) for 7 days promotes neuronal attachment and neurite extension. The formation of nitric oxide (NO) by LPS in rat astrocytes has been suggested to correlate with the neurodegenerative process. In identifying the effect of neuroprotection, we found that garcinol prevented NO accumulation in LPS-treated astrocytes. Garcinol significantly reduced the expression of LPS-induced inflammatory mediators, such as iNOS and COX-2. Consequently, our results suggest that the neuroprotective effects of garcinol are associated with anti-oxidation and inhibition of iNOS induction in astrocytic cells. Garcinol may exert a similar anti-inflammatory effect and may be neuroprotective against brain injury.

Animals↗
PubMed2006

Biomimetic phosphorylcholine polymer grafting from polydimethylsiloxane surface using photo-induced polymerization.

The biomimetic synthetic phospholipid polymer containing a phosphorylcholine group, 2-methacryloyloxyethyl phosphorylcholine (MPC), has improved the surface property of biomaterials. Both hydrophilic and anti-biofouling surfaces were prepared on polydimethylsiloxane (PDMS) with MPC grafted by surface-initiated photo-induced radical polymerization. Benzophenone was used as the photoinitiator. The quantity of the adsorbed initiator on PDMS was determined by UV absorption and ellipsometry. The poly(MPC)-grafted PDMS surfaces were characterized by XPS, ATR-FTIR and static water contact angle (SCA) measurements. The SCA on PDMS decreased from 115 degrees to 25 degrees after the poly(MPC) grafting. The in vitro single protein adsorption on the poly(MPC)-grafted PDMS decreased 50-75% compared to the unmodified PDMS. The surface friction of the poly(MPC)-grafted PDMS was lower than the unmodified PDMS under wet conditions. The oxygen permeability of the poly(MPC)-grafted PDMS was as high as the unmodified PDMS. The tensile property of PDMS was maintained at about 90% of the ultimate stress and strain after the poly(MPC) grafting. The surface-modified PDMS is expected to be a novel medical elastomer which possesses an excellent surface hydrophilicity, anti-biofouling property, oxygen permeability and tensile property.

Biomimetic Materials↗
PubMed2006

Synthesis of bilirubin imprinted polymer thin film for the continuous detection of bilirubin in an MIP/QCM/FIA system.

A bilirubin imprinted polymer (BIP) was coated on a thiol pretreated Au electrode on a quartz crystal microbalance (QCM) chip. The BIP thin film was synthesized using 4-vinylpyridine (4-Vpy) as the monomer, divinylbenzene (DVB) as the cross-linker, and benzophenone as the initiator. By using a photo-graft surface polymerization technique with irradiation by ultra-violet (UV) light, a thin BIP film was prepared, from which a biomimetic sensor for the detection of bilirubin was developed. The sensor was able to discriminate bilirubin in solution owing to the specific binding of the imprinted sites. The BIP/QCM chip has been repeatedly used for more than 7 months in many continuous experiments. The detection signal of bilirubin from the BIP thin film/QCM was compared with the non-BIP thin film/QCM. Biliverdin, an analogue of bilirubin, was used for comparison. The analogue comparison confirmed the binding specificity of the BIP film toward bilirubin. The selectivity can be as high as 31.2. The effect of pH on the detection of bilirubin is also discussed. With proper solvent for elution and recovery, flow injection analysis (FIA) could be applied to the system. The performance of the BIP/QCM chip was evaluated. A linear calibration of the bilirubin concentration with respect to the frequency shift was successfully obtained. The reproducibility of measurements from the same BIP/QCM chip was confirmed. In addition, repeatability of detection was also confirmed from different BIP/QCM chips. In conclusion, a combined BIP thin film/QCM/FIA method was successfully established for the detection of bilirubin concentration using a molecularly imprinted film.

Bilirubin↗
PubMed2005

Synthesis of benzoyl phenyl benzoates as effective inhibitors for phospholipase A2 and hyaluronidase enzymes.

Benzoylation of (hydroxy phenyl) phenyl methanone 2a-g to benzoyl phenyl benzoates 4a-g, a benzophenone analogue, was achieved in good yield. All the newly synthesized compounds were evaluated for their phospholipase A2 [E.C. 3.1.1.4] and hyaluronidase [E.C. 3.2.1.35] enzyme inhibitory activity in snake venom as source and their structure-activity relationship with respect to different groups is reported for the first time. The in vitro PLA2 enzyme inhibitory activity and in vivo anti-inflammatory activity studies of benzoyl phenyl benzoates are illustrated.

Animals↗
PubMed2006

Design, synthesis, and biochemical evaluation of novel cruzain inhibitors with potential application in the treatment of Chagas' disease.

A series of compounds bearing tetrahydronaphthalene, benzophenone, propiophenone, and related rigid molecular skeletons functionalized with thiosemicarbazone or unsaturated carbonyl moieties were prepared by chemical synthesis and evaluated for their ability to inhibit the enzyme cruzain. As potential treatment agents for Chagas' disease, three compounds from the group demonstrate potent inhibition of cruzain with IC(50) values of 17, 24, and 80 nM, respectively.

Carbon↗
PubMed2006

Rapid synthesis of 4-benzylidene and 4-[bis-(4-methoxyphenyl)-methylene-2-substituted phenyl-benzopyrans as potential selective estrogen receptor modulators (SERMs) using McMurry coupling reaction.

7-Methoxy-4-(4-methoxybenzylidene)-2-substituted phenyl-benzopyrans I and 4-[bis-(4-methoxyphenyl)-methylene-2-substituted phenyl-benzopyrans II carrying different alkylamino residues, designed as estrogen receptor (ER) binding ligands, were successfully synthesized through the McMurry coupling reaction of substituted benzaldehyde/substituted benzophenones and 2-hydroxyphenyl-7-methoxy-chroman-4-one in presence of lithium aluminum hydride and titanium (IV) chloride (LAH-TiCl(4)). Self-coupling of carbonyl reactants led to the formation of several side products. The prototypes were evaluated for their relative binding affinity (RBA), as well as their estrogenic and antiestrogenic activities. High order of estrogenic activity (>50% gain) observed with compounds 3, 7a, 7b, 7c, 8, and 10a and also their partial estrogen antagonistic activity (> or =15%) at the uterine level points toward successful designing of the compounds. Compounds 4, 7a, 7b, 7c, and 10a also possessed significant anticancer activity against human adenocarcinoma cell line (MCF-7 cell line) that may be related to their estrogen-dependent action.

Benzylidene Compounds↗
PubMed2006

Inhibitors of the FEZ-1 metallo-beta-lactamase.

Metallo-beta-lactamases (MBLs) catalyze the hydrolysis of beta-lactams including penicillins, cephalosporins and carbapenems. Starting from benzohydroxamic acid (1) structure-activity studies led to the identification of selective inhibitors of the FEZ-1 MBL, e.g., 2,5-substituted benzophenone hydroxamic acid 17 has a K(i) of 6.1+/-0.7microM against the FEZ-1 MBL but does not significantly inhibit the IMP-1, BcII, CphA or L1 MBLs.

Enzyme Inhibitors↗
PubMed2005

Dietary garcinol inhibits 4-nitroquinoline 1-oxide-induced tongue carcinogenesis in rats.

The effects of dietary feeding with a polyisoprenylated benzophenone, garcinol, isolated from Garcinia indica fruit rind on the development of 4-nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis were investigated in male F344 rats. At 7 weeks of age, animals were given 4-NQO at 20 ppm in the drinking water for 8 weeks to induce tongue neoplasms. They also received the diets containing 100 or 500 ppm garcinol either during (for 10 weeks) or after (for 22 weeks) the carcinogen exposure. The other rats were given tap water without 4-NQO throughout the experiment, and fed garcinol (500 ppm)-containing diet or basal diet alone. At the end of the study (week 32), incidences of tongue neoplasms and preneoplastic lesions, cell proliferation activity in the normal-like tongue epithelium estimated by 5-bromodeoxyurideine (BrdU)-labeling index and cyclin D1-positive cell ratio, and immunohistochemical expression of cyclooxygenase-2 (COX-2) in the tongue lesions were determined. Dietary garcinol significantly decreased the incidence and multiplicity of 4-NQO-induced tongue neoplasms and/or preneoplasms as compared to the control diet. Dietary administration of garcinol also significantly reduced the BrdU-labeling index and cyclin D1-positive cell ratio, suggesting reduction in cell proliferation activity in the tongue by garcinol. The COX-2 expression in the tongue lesions was also suppressed by feeding with garcinol. These results indicate that dietary administration of garcinol inhibited 4-NQO-induced tongue carcinogenesis through suppression of increased cell proliferation activity in the target tissues and/or COX-2 expression in the tongue lesions.

4-Nitroquinoline-1-oxide↗
PubMed2006

Synthesis of hexa- to tridecasaccharides related to Shigella dysenteriae type 1 for incorporation in experimental vaccines.

Hexa- to tridecasaccharides corresponding to the O-specific polysaccharide (O-SP) of the Gram-negative bacterium Shigella dysenteriae type 1 were synthesized in solution phase. The syntheses utilized tetra-, octa-, and dodecasaccharide intermediates that represent one to three contiguous tetrasaccharide repeating units of the O-SP [Synlett2003, 743]. These compounds were glycosylated with mono-, di-, and trisaccharide trichloroacetamidates, which were synthesized in this study. The excellent stereodirecting effect of 4,6-O-benzophenone ketals in glycosylation reactions of 2-azido-2-deoxy-glucopyranosyl donors was demonstrated. The free oligosaccharides were characterized by 1H and 13C NMR spectroscopy and by high-resolution mass spectrometry. The oligosaccharides described herein contain the 5-(methoxycarbonyl)pentyl aglycon for eventual attachment to immunogenic carriers using a recently published protocol [J. Org. Chem.2005, 70, 6987].

Carbohydrate Sequence↗
PubMed2004

Occurrence of UV filter compounds from sunscreens in surface waters: regional mass balance in two Swiss lakes.

Consumer care products often contain UV filters, organic compounds which absorb ultraviolet light. These compounds may enter surface waters directly (when released from the skin during swimming and bathing) or indirectly via wastewater treatment plants (when released during showering or washed from textiles). Predicted and measured UV filter concentrations were compared in a regional mass balance study for two Swiss lakes: Lake Zurich, a typical midland lake which is also an important drinking water resource, and Hüttnersee, a small bathing lake. Both lakes are extensively used for recreational activities and considerable direct input of UV filters is thus expected. This input was estimated from the number of visitors at swimming areas around the lakes and a survey of the usage of sunscreen products among these visitors. Possible additional indirect input via wastewater treatment plants was not considered in this study. The quantitatively most important UV filters, as indicated by the survey data, ethylhexyl methoxycinnamate, octocrylene, 4-methylbenzylidene camphor, butyl methoxydibenzoylmethane, and benzophenone-3, all lipophilic compounds, were selected for analysis by gas chromatography-mass spectrometry. Concentrations of individual UV filters in water from Lake Zurich were low, ranging from <2 ng l(-1) (detection limit) to 29 ng l(-1), and somewhat higher at Hüttnersee, ranging from <2 to 125 ng l(-1), with the highest concentrations found in summer, consistent with direct inputs to the lakes during this time. The concentrations were clearly lower than predicted from input estimates based on the surveys. This may be in part due to (i) an overestimation of these inputs (e.g. less than the 50% wash-off of UV filters assumed to occur during swimming), and (ii) some removal of these compounds from the lakes by degradation and/or sorption/sedimentation. UV filters were also detected in semipermeable membrane devices (SPMDs) deployed at Lake Zurich and Greifensee, another midland lake, at concentrations of 80-950 ng SPMD(-1), confirming the presence of the compounds in surface waters and indicating a certain potential for bioaccumulation. SPMD-derived water concentrations were in the range of 1-10 ng l(-1) and thus corresponded well with those determined in water directly. No UV filters were detected above blank levels in SPMDs deployed at a remote mountain lake used for background measurements.

Fresh Water↗
PubMed2004

Photodegradation of organic pollutants on the spruce needle wax surface under laboratory conditions.

The photochemistry of selected organic compounds, including common pollutants, on the paraffin (as a model matrix) and spruce wax surfaces was studied under laboratory conditions. Two model transformations were evaluated: (1) intramolecular rearrangements of valerophenone and 2-nitrobenzaldehyde, and (2) hydrogen abstraction between an excited benzophenone and the hydrocarbon paraffin/wax chains. The steric or polar influence of the solid matrix on conformational and translational motion, its optical properties, hydrogen abstraction probabilities, and consequences of the guest-molecule segregation are discussed in this work. Furthermore, the photochemical reactivity of some common anthropogenic pollutants, such as chlorinated biphenyls (4-chlorobiphenyl, 2,4-dichlorobiphenyl, and 4,4'-dichlorobiphenyl), 4-chlorophenol, and DDT, was evaluated. The surface of spruce wax is presented as probable reaction medium for photochemical transformations. Although the matrix presents certain restrictions for bimolecular reactions, common photodegradations should be generally feasible in nature. In addition, paraffin was found to be a suitable model matrix for the studies of possible photochemical transformations that can occur on natural plant surfaces.

Air Pollutants↗
PubMed2006

Effects-directed analysis of organic toxicants in wastewater effluent from Zagreb, Croatia.

The organic toxicants present in the effluent of the main sewer of the city of Zagreb, Croatia were isolated and identified through the use of effects-directed characterisation techniques. At the time of investigation, the wastewater effluent received no treatment and was comprised of a mixture of effluent from domestic and industrial sources. The organic load of the wastewater was isolated by solid phase extraction and toxicity profiles obtained using reverse-phase HPLC. All procedures were evaluated through the analysis of a series of reference compounds of widely differing polarity. Toxicity profiles for EROD activity (CYP1A induction), vitellogenin induction (estrogenic activity), cytotoxicity (membrane stability and metabolic inhibition) were obtained using a rainbow trout (Oncorhynchus mykiss) primary hepatocyte bioassay. The suite of bioassays showed biological responses after exposure to the raw extracts for all the endpoints tested. However, a combination of mixture toxicity and cytotoxicity in the complex raw extract had some masking effect on the sub-lethal responses of vitellogenin and EROD induction. Bioassay testing of the fine fractions obtained by HPLC produced a range of endpoint-specific toxicity profiles for each sample. A number of compounds were identified by the use of GC-MS and LC-MS/MS as responsible for the observed effects. The steroid estrogens 17 beta-estradiol and estriol were identified by LC-MS/MS as estrogen receptor agonists in two of the estrogenic fractions. In addition, GC-MS analysis identified different alkylphenols, benzophenone and methylparaben which also contributed to the estrogenic activity of the sample. Polycyclic aromatic hydrocarbons (PAHs), alkyl substituted PAHs, nitro-polycyclic aromatic compounds (nitro-PACs), carbazoles and alkyl substituted carbazoles and other known CYP1A inducers were identified by GC-MS analysis as responsible for some of the observed EROD activity. Some active compounds remain unidentified.

Animals↗
PubMed2006

Photoinduced phospholipid polymer grafting on Parylene film: advanced lubrication and antibiofouling properties.

Poly(p-xylylene) (Parylene C) coatings have been applied in implantable electronic devices because of their electrical insulation and moisture barrier properties. To provide lubrication and an antibiofouling surface, a biomimetic phospholipid polymer--poly(2-methacryloyloxyethyl phosphorylcholine (MPC))--was grafted from the surface using UV irradiation with benzophenone as an initiator. The poly(MPC) grafting on the Parylene C films was confirmed by attenuated total reflection-Fourier transfer inflated irradiation, X-ray photoelectron spectroscopy and ellipsometry. These analyses indicated that the Parylene C films were completely covered by the poly(MPC)-graft layer with an average thickness of 140 nm under dry condition. The atomic force microscope (AFM) images revealed that the poly(MPC)-graft chains extended under wet condition. However, they formed globular structures under dry condition. Water contact angle measurements revealed a decreased receding angle of 29.5 degrees on the poly(MPC)-grafted surface with a high hysteresis of 41.4 degrees. These results indicate that the poly(MPC)-graft chains gain mobility in a wet environment. The average kinetic friction coefficient of the poly(MPC)-grafted surface in water was 0.018, which was 90% lower than that of the original surface. The in vitro single protein adsorption reduced by over 70% due to the poly(MPC) grafting. The hydrated poly(MPC)-graft chains are considered to provide lubrication and antibiofouling properties. The surface zeta potential measurement clarified the electroneutrality of the poly(MPC)-grafted surface. We concluded that the poly(MPC) grafting from the Parylene C layer significantly improved its surface properties and, subsequently, its biological properties.

Animals↗
PubMed2005

Non-thiol farnesyltransferase inhibitors: N-(4-aminoacylamino-3-benzoylphenyl)-3-[5-(4-nitrophenyl)-2 furyl]acrylic acid amides and their antimalarial activity.

Water solubility was previously found to be essential for in vivo-antimalarial activity of a novel type of benzophenone-based farnesyltransferase inhibitors. Introduction of a alpha-amino group into the phenylacetic acid substructure provided more soluble compounds with high farnesyltransferase inhibitory activity. The in vitro-antimalarial activity was detrimentally influenced by this structural modification.

Acrylamides↗
PubMed2004

Anti-Helicobacter pylori metabolites from Rhizoctonia sp. Cy064, an endophytic fungus in Cynodon dactylon.

A new benzophenone, named rhizoctonic acid (1), together with three known compounds monomethylsulochrin (2), ergosterol (3) and 3beta,5alpha,6beta-trihydroxyergosta-7,22-diene (4) were isolated through bioassay-guided fractionations from the culture of Rhizoctonia sp. (Cy064), an endophytic fungus in the leaf of Cynodon dactylon. The structure of the new acid 1 was elucidated to be 5-hydroxy-2-(2-hydroxy-6-methoxy-4-methylbenzoyl)-3-methoxybenzoic acid by a combination of spectral analyses. Furthermore, the structure of monomethylsulochrin 2 was confirmed by 13C-NMR analysis. All four metabolites were subjected to a more detailed in vitro assessment of their antibacterial action against five clinically isolated and one reference (ATCC 43504) Helicobacter pylori strains.

Anti-Infective Agents↗