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PubMed2000

[Nutritional importance of phenolic compounds in the diet].

Phenols are one of the major groups of nonessential dietary components appearing in vegetable foods. They are a wide chemical compounds group that are considered as secondary plant metabolites, with different activity and chemical structure, including more than 8,000 different compounds. Phenols, has traditionally been considered as antinutritive compounds due to the adverse effect of one of their main components, tannins, on protein digestibility. However, actually there is an increased interest in these compounds because they have been associated with the inhibition of atherosclerosis and cancer. The bioactivity of phenolics may be related to their antioxidant behaviour, which is attributed to their ability to chelate metals, inhibit lipoxygenase and scavenge free radicals. This review make a global view on the main phenolic compound groups, their organoleptic effects in vegetable foods, their physiological effects in humans, their metabolism, bioavailability as well as their content in the diet.

Animals↗
PubMed2002

[Quinic acid esters from herba of Siphonostegia chinensis].

OBJECTIVE: To study the bioactive constituents, quinic acid esters, from Siphonostegia chinensis. METHOD: The compounds were extracted with solvents, isolated by various column chromatography and identified by spectroscopic methods. RESULT: Three quinic acid esters were isolated and identified as 3,4-di-O-caffeoylquinic acid(I), macranthoin F(II), and methyl ester of 3, 4,5-tri-O-caffeoylquinic acid (III). CONCLUSION: All compounds were isolated from Siphonostegia for the first time.

Chlorogenic Acid↗
PubMed2004

[Two new flavonoids from the flower of Castanea mollissima Blume].

AIM: To study the bioactive constituents from the flower of Castanea mollissima Blume. METHODS: Compounds were isolated and purified by column chromatography on silica gel and polyamide. Structures were determined by various spectroscopic data,including UV, IR, 1H and 13CNMR, EIMS and FABMS, 1H-13C-COSY and HMBC. RESULTS: Two compounds were isolated from the ethyl acetate fraction of 95% ethanol extract and the structures were elucidated as kaempferol-3-O-[6"-(E)-p-coumaroyl]-alpha-D-mannopyranoside (1) and kaempferol-3-O-[6", 4"-di-(E)-p-coumaroyl]-alpha-D-mannopyranoside (2). CONCLUSION: Compounds 1 and 2 are new compounds, named castanoside A and B respectirely.

Fagaceae↗
PubMed2004

[A new lignan glycoside from the flower of Castanea mollissima Blume].

AIM: To study the bioactive constituents of the flower of Castanea mollissima Blume. METHODS: Compounds were isolated and purified by column chromatography of silica gel and TLC. Structures were determined by various spectroscopic data, including IR, 1HNMR and 13CNMR, EIMS, FABMS and HMBC as well as comparison of the data with those reported in literatures. RESULTS: Five compounds were isolated and elucidated as myricetin (I), quercetin (II), gallic acid (III), 4-quinolinone-2-caboxylic acid (IV), (+) -isolariciresinol-9'-O-alpha-L-rhamnoside (V). CONCLUSION: These compounds were separated from the flower for the first time and compound V is a new compounds, named chestnutlignansoide.

Fagaceae↗
PubMed2004

Detection of polycyclic aromatic hydrocarbon exposure from automobile exhaust fumes using urinary 1-hydroxypyrene level as an index.

UNLABELLED: Polycyclic aromatic hydrocarbons (PAHs) are hydrocarbon compounds which originate from incomplete combustion. In humans, PAHs are bioactivated to reactive metabolites which can bind covalently to DNA and subsequently initiate mutation and carcinogenesis. The measurement of PAHs exposure may be used as an index to classify a cancer risk group. The purpose of the present study was to measure the level of urinary 1-hydroxypyrene, a metabolite of PAHs, in subjects exposed to automobile exhaust fumes compared to non-exposed subjects. A urine sample was collected from each individual subject after the end of a working day and quantitated for 1-hydroxypyrene and creatinine by HPLC and spectrophotometric method, respectively. The results showed that average urinary 1-hydroxypyrene level in exposed subjects was significantly higher than non-exposed subjects (mean +/- SD of 0.0035 +/- 0.0032 and 0.0011 +/- 0.0010 micromol/l, respectively; P = 0.000). Average urinary creatinine level in exposed subjects was also significantly higher than non-exposed subjects (mean +/- SD of 0.01 +/- 0.005 and 0.008 +/- 0.006 mol/l, respectively; P = 0.040). The ratio of urinary 1-hydroxypyrene/mol creatinine level, of the exposed subjects was significantly higher than that of the non-exposed subjects (mean +/- SD of 0.37 +/- 0.28 and 0.19 +/- 0.22 micromol/mol creatinine, respectively; P = 0.002). CONCLUSION: Automobile exhaust fume exposed subjects have a higher risk to be exposed to PAHs than the non-exposed subjects. Urinary 1-hydroxypyrene level can be used as an index for an exposure of PAHs which have originated from automobile exhaust fumes and other sources as well.

Adult↗
PubMed2006

Shellfish poisons.

In our ongoing search for bioactive metabolites from marine organisms, novel shellfish poisons have been isolated. Pinnatoxins, which are amphoteric polyether compounds, were purified from the Okinawan bivalve Pinna muricata. Pinnatoxins show acute toxicity against mice and activate Ca2+ channels. Two novel alkaloids, pinnamine and pinnaic acid, were also obtained from P. muricata. Pinnaic acid inhibits cytosolic phospholipase (cPLA2). Pteriatoxins, which are pinnatoxin analogs, were isolated from the Okinawan bivalve Pteria penguin. A nanomole-order structure determination of pteriatoxins was achieved by the detailed analysis of 2D-NMR and ESI-TOF MS/MS. This review covers the isolation, structure determination, bioactivity, synthesis, and biogenesis of these shellfish poisons and related compounds.

Animals↗
PubMed2004

Suppression of HIV-1 viral replication and cellular pathogenesis by a novel p38/JNK kinase inhibitor.

OBJECTIVE: To analyze a novel compound, which inhibits serine-threonine protein kinase p38, for its possible bioactivity against HIV-1 infection. METHODS: Proteins involved in cellular signal transduction pathways represent a novel class of host therapeutic targets for infectious diseases. In this regard the serine/threonine kinase p38 MAPK, a member of the mitogen-activated protein (MAP) kinase superfamily of signal transduction molecules may play an important role in HIV-1 infection. We analyzed the ability of this compound (RWJ67657) to inhibit HIV replication in primary T cells and monocytes. Cellular expression of phospho-p38MAPK was studied by Western blot analysis. Blockade of HIV infection induced apoptosis was measured by Annexin V staining. RESULTS: p38 inhibitor RWJ67657 was effective in inhibiting HIV-1 replication in both T-cell and monocyte cell lines, irrespective of the coreceptor used by the virus for entry into the cell. Importantly, both reverse transcriptase and protease resistant escape mutant viruses were effectively suppressed by RWJ67657. In addition, the tested compounds block HIV-induced T-cell apoptosis, a critical means of T-cell depletion linked to AIDS progression. CONCLUSION: Several steps in the HIV-1 virus life cycle appear to depend on cellular activation, including activation of the p38 pathway. Without activation virus replication is thought to be blocked due to incomplete reverse transcription and a lack of proviral DNA integration. The data collectively illustrate that inhibition of the p38 pathway can affect HIV-1 replication. Interruption of HIV infection by p38 inhibitors underscores the value of exploring antiviral drugs that target host cellular proteins.

Analysis of Variance↗
PubMed2002

Characterization of urinary volatiles in Swiss male mice (Mus musculus): bioassay of identified compounds.

The present study was carried out to investigate the chemical nature of the urine of male mice and to assess its bioactivity. Urine of mature male mice was extracted with dichloromethane (1 : 1 ratio v/v) and analysed by gas-chromatography linked mass-spectrometry (GC-MS). Ten different compounds such as alkanes, alcohols, etc. were detected in the urine. Among the ten, five compounds are specific to males namely, 3-cyclohexene-1-methanol (I), 3-amino-s-triazole (II), 4-ethyl phenol (III), 3-ethyl-2,7-dimethyl octane (IV) and 1-iodoundecane (V). The compound, 4-ethylphenol, has been previously reported in several strains of male mice. Furthermore, the compounds (II) and (IV) are closely similar to 2-sec-butylthiazole and dehydro-exo-brevicomin compounds which have already been reported in male mice. Bioassay revealed that compounds (II), (III) and (IV) were responsible for attracting females and in inducing aggression towards males, as compared to the other compounds i.e. (I) and (V). The results indicate that these three volatiles (II, III and IV) of male mice appear to act as attractant of the opposite sex.

Animals↗
PubMed1992

Decreased glucuronidation and increased bioactivation of acetaminophen in Gilbert's syndrome.

Gilbert's syndrome occurs in 5%-7% of the human population and is caused by an inherited deficiency in the glucuronidation of endogenous bilirubin, resulting in its accumulation and jaundice. The authors of the present study have previously shown that rats with a similar deficiency in bilirubin glucuronidation (Gunn rats) had reduced glucuronidation and enhanced susceptibility to the toxicity of the widely used analgesic, acetaminophen. Acetaminophen is eliminated primarily by glucuronidation, which prevents its cytochrome P-450-catalysed bioactivation to a hepatotoxic reactive intermediate. The purpose of this study was to determine whether people with Gilbert's syndrome had reduced glucuronidation and enhanced bioactivation of acetaminophen. Therefore, the biotransformation of acetaminophen, 20 mg/kg IV, was investigated in six subjects with Gilbert's syndrome (total bilirubin, 41 +/- 6 mumol/L; mean +/- SE) and six normal controls (total bilirubin, 11 +/- 2 mumol/L; P less than 0.01). Formation of the acetaminophen glucuronide conjugate measured by high-performance liquid chromatography was quantified by the ratio of the area under the plasma concentration-time curve (AUC) from 0 to 2 hours for the acetaminophen glucuronide divided by the AUC for acetaminophen. Acetaminophen bioactivation was quantified by the molar percentage of acetaminophen excreted in the urine during 24 hours as glutathione-derived conjugates (cysteine and mercapturic acid). Acetaminophen glucuronide formation in subjects with Gilbert's syndrome was 31% lower than that in normal controls (0.27 +/- 0.05 vs. 0.39 +/- 0.03; P less than 0.05), and bioactivation was 1.7-fold higher (3.5% +/- 0.4% vs. 2.1% +/- 0.3%; P less than 0.05). One control subject with normal bilirubin glucuronidation had substantially decreased acetaminophen glucuronide formation (0.20) and enhanced bioactivation (4.8%). Among all subjects, glucuronidation correlated inversely with bioactivation (r = -0.84; P less than 0.001), indicating that a decrease in a major pathway of elimination can shunt more drug through the toxifying route. Thus, a deficiency in bilirubin UDP-glucuronosyltransferase, evidenced by jaundice, can be paralleled by a deficiency in glucuronidation of other compounds. In these cases, jaundice can be a phenotypic determinant of enhanced acetaminophen bioactivation. On the other hand, some people with normal bilirubin glucuronidation may have a deficiency in the glucuronidation of acetaminophen; these people are not easily recognized.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetaminophen↗
PubMed1993

3-Methylcholanthrene-inducible liver cytochrome(s) P450 in female Sprague-Dawley rats: possible link between P450 turnover and formation of DNA adducts and I-compounds.

The hepatic cytochrome P450s are mixed-function oxidases which metabolize a wide variety of xenobiotics and endobiotics, and also bioactivate carcinogens such as 3-methyl-cholanthrene (MC) to reactive metabolites capable of forming DNA adducts. To investigate possible relationships between cytochrome P450 induction and covalent DNA modifications (adducts and I-compounds), female Sprague-Dawley rats were i.p. treated with MC (25 mg/kg) in corn oil (CO), once daily for 4 days. Controls received CO only. Animals were euthanized at 1, 8, 15, 28 and 45 days after the last MC treatment, and liver microsomal cytochrome P450, ethoxycoumarin O-deethylase (ECD) and ethoxyresorufin O-deethylase (EROD) activities were determined. Liver DNA adducts and I-compounds were analyzed by 32P-postlabeling. A significant induction of the levels of P450, ECD and EROD activities was noted in MC-treated rats, and elevated enzyme levels persisted for about 6 weeks after cessation of MC administration. Linear decay of total P450, ECD and EROD activities as a function of time was observed. MC induced 11 DNA adducts in liver, which were resolved by thin-layer chromatography (TLC) and persisted at high levels throughout the study. On the other hand, MC elicited a significant depletion of both non-polar and polar I-compounds (age-dependent DNA modifications detectable by 32P-postlabeling in rodent tissues without known exposure to carcinogens). Level of most I-compounds returned to normal at 45 days, and this paralleled the return of P450-related activities to normal. These results suggest a possible link between P450 turnover, DNA adduct formation, and I-compound depletion.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1983

Poly-L-methionine sulfoxide: a biologically inert analogue of dimethyl sulfoxide with solubilizing potency.

Poly-L-methionine sulfoxide is a water-soluble polymer containing the sulfoxide moiety. The preparation and radiolabeling of this polymer is described and its bioeffects are compared with those of dimethyl sulfoxide. Poly-L-methionine sulfoxide is similar to dimethyl sulfoxide in that it is a potent solubilizer of lipophilic compounds in water. Although the partition coefficient of poly-L-methionine sulfoxide in 1-octanol-water is only 20 times lower than that of dimethyl sulfoxide, it was found not to penetrate into intracellular spaces. In contrast to dimethyl sulfoxide, poly-L-methionine sulfoxide and L-methionine sulfoxide were found to be ineffective in inducing differentiation in murine erythroleukemia cells and inhibiting differentiation of avian neural crest cells, suggesting that compounds effective in these processes must have the ability to penetrate into cells or membrane proteins. Overall lack of bioactivity of poly-L-methionine sulfoxide, combined with low toxicity (2 g/kg, iv, in the mouse with no effect), makes this compound a suitable inert solubilizer and carrier for lipophilic drugs.

Animals↗
PubMed2006

Theoretical prediction of relative and absolute pKa values of aminopyridines.

This work presents a study aimed at the theoretical prediction of pK(a) values of aminopyridines, as a factor responsible for the activity of these compounds as blockers of the voltage-dependent K(+) channels. To cover a large range of pK(a) values, a total of seven substituted pyridines is considered as a calibration set: pyridine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-chloropyridine, 3-chloropyridine, and 4-methylpirydine. Using ab initio G1, G2 and G3 extrapolation methods, and the CPCM variant of the Polarizable Continuum Model for solvation, we calculate gas phase and solvation free energies. pK(a) values are obtained from these data using a thermodynamic cycle for describing protonation in aqueous and gas phases. The results show that the relatively inexpensive G1 level of theory is the most accurate at predicting pK(a) values in aminopyridines. The highest standard deviation with respect to the experimental data is 0.69 pK(a) units for absolute values calculations. The difference increases slightly to 0.74 pK(a) units when the pK(a) is computed relative to the pyridine molecule. Considering only compounds at least as basic as pyridine (the values of interest for bioactive aminopyridines) the error falls to 0.10 and 0.12 pK(a) units for the absolute and relative computations, respectively. The technique can be used to predict the effect of electronegative substituents in the pK(a) of 4-AP, the most active aminopyridine considered in this work. Thus, 2-chloro and 3-chloro-4-aminopyridine are taken into account. The results show a decrease of the pK(a), suggesting that these compounds are less active than 4-AP at blocking the K(+) channel.

Aminopyridines↗
PubMed1998

5-Lipoxygenase and cyclooxygenase-1 inhibitory active compounds from Atractylodes lancea.

Lipophilic extracts of Atractylodes lancea rhizomes exhibited potent inhibitory activities in 5-lipoxygenase [IC50 (5-LOX) = 2.9 micrograms/mL (n-hexane extract)] and cyclooxygenase-1 [IC50 (COX-1) = 30.5 micrograms/mL (n-hexane extract)] enzymatic assays. Bioactivity-guided fractionation of the n-hexane extract led to the isolation of a new compound atractylochromene (1), a potent inhibitor in both test systems [IC50 (5-LOX) = 0.6 microM, IC50 (COX-1) = 3.3 microM]. Also obtained was 2-[(2E)-3,7-dimethyl-2,6-octadienyl]-6-methyl-2,5-cyclohexadiene-1 ,4-dione (2), which showed a selective inhibitory activity against 5-LOX [IC50 (5-LOX) 0.2 microM, IC50 (COX-1) 64.3 microM]. The sesquiterpene atractylon (3) and the coumarin osthol (4) turned out to be moderate but selective 5-lipoxygenase inhibitors. Atractylenolides I (5), II (6), and III (7) showed no significant inhibitory effects for either enzyme. Structures were established by spectral data interpretation.

Animals↗
PubMed2002

Bioactive saponins from Dioscorea futschauensis.

A new anti-neoplastic spirostanol saponin, (25S)-spirost-5-en-3 beta, 27-diol-3O-[alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranoside and three known compounds viz. prosapogenin A of dioscin, dioscin and gracilin were isolated from Dioscorea futschauensis by bioactivity-guided fractionation. Their structures were elucidated mainly by means of spectroscopic analysis. Their bioactivity against Pyricularia oryzae and cytotoxic activity on ts-FT210 cell line was evaluated.

Animals↗
PubMed1990

In vitro observations of iron-doped bioactive glasses.

Several in vitro tests are necessary to evaluate the biological compatibility of materials used to manufacture implants for humans or animals. These tests will indicate whether these materials can be tolerated when implanted in vivo. Since ceramic materials are suitable for coating layers, it was decided to study their performance by adding certain oxides as doping agents. This paper describes their influence in vivo in some preliminary tests and in vitro for iron trioxide only. This work attempts to ascertain the range of doping to maintain the bioactivity characteristics and in particular the influence of iron trioxide as a doping agent in the bioactive glass. To do so the adhesion of baby hamster kidney cells to bioactive glasses doped with different concentrations (2 and 4 wt%) of this compound was quantified. The base glass without iron oxide was used as a control as 0 wt% doping. In a second phase, a coating of fibronectin, a glycoprotein that plays an important role in cell binding and spreading on substrates, was quantified on the same surfaces. It was shown that the cell avidity for the surfaces of the materials increases with increased doping of iron oxide. The values are significantly higher than those observed for the base glass. Fibronectin adsorption quantification showed a similar trend, with values of adsorption similar for the doped samples and higher than that of the non-doped glass. It was demonstrated that iron trioxide induces an increase in cell adhesion capability with bioactive glass surfaces and the capability of adhesion of the fibronectin to act as a substrate on the same surfaces.

Adsorption↗
PubMed2002

New bioactive peroxides from marine sponges of the family plakiniidae.

In our continuing program to identify compounds with antifungal properties, the ethanol extracts of two sponges of the family Plakinidae were found to inhibit the growth of the fungal pathogens Candida albicans and Aspergillus fumigatus. From these organisms three new compounds and five known compounds have been identified. A new 1,2-dioxane ring peroxide acid, 1, has been isolated from the sponge Plakortis halichondrioides along with five known compounds. Two new 1,2-dioxolane peroxide acids, 3 and 4, have been isolated from the sponge Plakinastrella onkodes. The structures were established by interpretation of spectral data. The three new compounds exhibit moderate activity against the fungal pathogen C. albicans with MICs of 5, 1.6, and 1.6 microg/mL respectively, for 1, 3, and 4. Compound 1 also showed in vitro inhibition of the fungal pathogen A. fumigatus with an IC(90) value of 5.6 microg/mL.

Animals↗
PubMed2002

Bioactive constituents of Cedrelopsis microfoliata.

The stem bark of Cedrelopsis microfoliata has yielded the new compounds microfolian (1), microfolione (2), and microfolicoumarin (6) along with the known compounds agrandol (3), cedrecoumarin A (4), obliquin (5), and sesquichamaenol (7). Compounds 2-4 were found to show agonistic activity on both alpha- and beta-estrogenic receptors, and compounds 1, 3, and 4 were shown to inhibit the chemiluminescence of reactive oxygen metabolites and showed superoxide scavenging activity.

Benzene Derivatives↗
PubMed2004

Bioactive diels-alder type adducts from the stem bark of Morus macroura.

Five new compounds, named guangsangons A (1), B (5), C (6), D (7), and E (8), along with four known compounds, albafuran C (2), kuwanon X (3), kuwanon P (4), and kuwanon Y (9) were isolated from Morus macroura Miq.. Their structures were determined by means of spectroscopic analyses and chemical methods. These compounds were regarded biogenetically as Diels-Al-der type adducts, and 1H-NMR variable temperature experience suggested that they all existed as an equilibrium mixture of conformational isomers in solution. Compounds 1-3 and 5-9 showed good anti-oxidation activity, with the inhibitory rate of malondialdehyde being from 90.1% to 102.7% at a concentration of 10(-4) mol/L and from 70.9% to 88.1% at a concentration of 10(-5) mol/L. Compounds 1, 5, and 7 showed anti-inflammation activity, with the inhibitory rates of release of lysosome enzyme from polymorphonuclear leukocytes of rats being 19.0% (P > 0.05), 57.3% (P < 0.001) and 24.3% (P < 0.05) at concentrations of 10(-5) mol/L, respectively.

Animals↗