Short chain nitrocompounds as a treatment of layer hen manure and litter; effects on in vitro survivability of Salmonella, generic E. coli and nitrogen metabolism.

The current study was conducted to assess the bactericidal effectiveness of several nitrocompounds against pathogens in layer hen manure and litter. Evidence from an initial study indicated that treatment of layer hen manure with 12 mM nitroethane decreased populations of generic E. coli and total coliforms by 0.7 and 2.2 log10 colony forming units (CFU) g-1, respectively, after 24 h aerobic incubation at ambient temperature when compared to untreated populations. Salmonella concentrations were unaffected by nitroethane in this study. In a follow-up experiment, treatment of 6-month-old layer hen litter (mixed with 0.4 mL water g-1) with 44 mM 2-nitroethanol, 2-nitropropanol or ethyl nitroacetate decreased an inoculated Salmonella typhimurium strain from its initial concentration (3 log10 CFU g-1) by 0.7 to 1.7 log10 CFU g-1 after 6 h incubation at 37°C in covered containers. After 24 h incubation, populations of the inoculated S. Typhmiurium in litter treated with 44 mM 2-nitroethanol, 2-nitropropanol, ethyl nitroacetate or nitroethane were decreased more than 3.2 log10 CFU g-1 compared to populations in untreated control litter. Treatment of litter with 44 mM 2-nitroethanol, 2-nitropropanol, ethyl nitroacetate decreased rates of ammonia accumulation more than 70% compared to untreated controls (0.167 µmol mL-1 h-1) and loses of uric acid (< 1 µmol mL-1) were observed only in litter treated with 44 mM 2-nitropropanol, indicating that some of these nitrocompounds may help prevent loss of nitrogen in treated litter. Results warrant further research to determine if these nitrocompounds can be developed into an environmentally sustainable and safe strategy to eliminate pathogens from poultry litter, while preserving its nitrogen content as a nutritionally valuable crude protein source for ruminants.

Organocatalytic asymmetric synthesis of 1,1-diarylethanes by transfer hydrogenation.

A new organocatalytic transfer hydrogenation strategy for the asymmetric synthesis of 1,1-diarylethanes is described. Under mild conditions, a range of 1,1-diarylethanes substituted with an o-hydroxyphenyl or indole unit could be obtained with excellent efficiency and enantioselectivity. We also extended the protocol to an unprecedented asymmetric hydroarylation of 1,1-diarylalkenes with indoles for the synthesis of a range of highly enantioenriched 1,1,1-triarylethanes bearing acyclic all-carbon quaternary stereocenters. These diaryl- and triarylethanes exhibit impressive cytotoxicity against a number of human cancer cell lines. Preliminary mechanistic studies combined with DFT calculations provided important insight into the reaction mechanism.

Bulky N(,N)-(di)alkylethane-1,2-diamineplatinum(II) compounds as precursors for generating unsymmetrically substituted platinum(IV) complexes.

Investigations of the influence of bulky groups in the equatorial ligand sphere of platinum(IV) compounds on the complexes' stability and reaction pattern were performed. Four dihydroxidoplatinum(IV) complexes were reacted with anhydrides, cinnamoyl chloride, and n-propyl isocyanate and yielded the symmetric dicarboxylated products or, if steric hindrance was observed, unsymmetrically substituted monocarboxylated analogues. With the aim of raising the steric demand, the following ligands were chosen: N-cyclohexylethane-1,2-diamine, N,N-dimethylethane-1,2-diamine, N,N-diethylethane-1,2-diamine, and N,N-diisopropylethane-1,2-diamine. All of the novel complexes were characterized by electrospray ionization mass spectrometry (ESI-MS), one- and two-dimensional NMR spectroscopy, elemental analysis, and reversed-phase HPLC; complexes B3, C3, C6, and D4 were also analyzed by X-ray diffraction. Additionally, the cytotoxicities of 10 compounds toward the cisplatin-sensitive cell line CH1 and the intrinsically cisplatin-resistant cell lines A549 and SW480 were investigated, and IC50 values down to the nanomolar range were found. To aid in the interpretation of structure-activity relationships, log k(w) values as a measure for the lipophilicity were determined for all of the new complexes, and the rates of reduction of C1, C3, and C4 relative to satraplatin were determined by means of NMR spectroscopy and ESI-MS.

Real-time sensing and discrimination of single chemicals using the channel of phi29 DNA packaging nanomotor.

A highly sensitive and reliable method to sense and identify a single chemical at extremely low concentrations and high contamination is important for environmental surveillance, homeland security, athlete drug monitoring, toxin/drug screening, and earlier disease diagnosis. This article reports a method for precise detection of single chemicals. The hub of the bacteriophage phi29 DNA packaging motor is a connector consisting of 12 protein subunits encircled into a 3.6 nm channel as a path for dsDNA to enter during packaging and to exit during infection. The connector has previously been inserted into a lipid bilayer to serve as a membrane-embedded channel. Herein we report the modification of the phi29 channel to develop a class of sensors to detect single chemicals. The lysine-234 of each protein subunit was mutated to cysteine, generating 12-SH ring lining the channel wall. Chemicals passing through this robust channel and interactions with the SH group generated extremely reliable, precise, and sensitive current signatures as revealed by single channel conductance assays. Ethane (57 Da), thymine (167 Da), and benzene (105 Da) with reactive thioester moieties were clearly discriminated upon interaction with the available set of cysteine residues. The covalent attachment of each analyte induced discrete stepwise blockage in current signature with a corresponding decrease in conductance due to the physical blocking of the channel. Transient binding of the chemicals also produced characteristic fingerprints that were deduced from the unique blockage amplitude and pattern of the signals. This study shows that the phi29 connector can be used to sense chemicals with reactive thioesters or maleimide using single channel conduction assays based on their distinct fingerprints. The results demonstrated that this channel system could be further developed into very sensitive sensing devices.

Physical and physicochemical factors effecting transport of chlorohydrocarbon gases from lung alveolar air to blood as measured by the causation of narcosis.

This systematic investigation examines gas transport in the lung for two sets of chlorohydrocarbons (CHCs): the chloromethanes (C1) and chloroethanes (C2). The C1 series includes chloromethane, methylene chloride, chloroform, and carbon tetrachloride, and the C2 series includes chloroethane, 1,2-dichloroethane, 1, 1, 2-trichloroethane, and 1, 1, 2, 2-tetrachloroethane. Most CHC gases cause narcosis. The comprehensive narcosis work of Lehmann and colleagues on CHCs was used as a basis for the narcosis endpoint in the present examination. The sites for narcosis are located in the brain (midline cortex and posterior parietal area), the spine, and at many peripheral nerve sites. Central nervous system (CNS) exposure executes a multisite, neural transmission set of inhibitions that promotes rapid loss of consciousness, sensory feeling, and current and stored memory while providing temporary amnesia. Absorption into the system requires dissolution into many lipid membranes and binding to lipoproteins. Lipophilicity is a CHC property shared with many anesthetics according to the Meyer-Overton Rule. Many structurally different lipid chemicals produce the narcosis response when the lipid concentration exceeds -67 mM. This suggests narcotic or anesthetic dissolution into CNS membranes until the lipid organization is disrupted or perturbed. This perturbation includes loading of Na(+)- and K(+)-channel transmembrane lipoprotein complexes and disrupting their respective channel functional organizations. The channel functions become attenuated or abrogated until the CHC exposure ceases and CHC loading reverses. This investigation demonstrates how the CHC physical and chemical properties influence the absorption of these CHCs via the lung and the alveolar system on route to the blood. Narcosis in test animals was used here as an objective biological endpoint to study the effects of the physical factors Bp, Vp, Kd (oil: gas) partition, Henry's constant (HK), and water solubility (S%) on gas transport. Narcosis is immediate after gas exposure and requires no chemical activation only absorption into the blood and circulation to CNS narcotic sites. The three physical factors Bp, K(d) (oil: air), and S% vary directly with unitary narcosis (UN) whereas Vp and HK vary inversely with UN in linear log-log relationships for the C2 series but not for the C1 series. Physicochemical properties of C1 series gases indicate why they depart from what is usually assumed to be an Ideal Gas. An essential discriminating process in the distal lung is the limiting alveolar film layer (AFL) and the membrane layer of the alveolar acini. The AFL step influences gas uptake by physically limiting the absorption process. Interaction with and dissolution into aqueous solvent of the AFL is required for transport and narcotic activity. Narcotics or anesthetics must engage the aqueous AFL with sufficient strength to allow transport and absorption for downstream CNS binding. CHCs that do not engage well with the AFL are not narcotic. Lipophilicity and amphipathicity are also essential solvency properties driving narcotics' transport through the alveolar layer, delivery to the blood fats and lipoproteins, and into critical CNS lipids, lipoproteins, and receptor sites that actuate narcosis. AFL disruption is thought to be strongly related to a number of serious pulmonary diseases such acute respiratory distress syndrome, infant respiratory distress syndrome, emphysema, chronic obstructive pulmonary disease, asthma, chronic bronchitis, pneumonia, pulmonary infections, and idiopathic pulmonary fibrosis. The physical factors (Bp, Vp, Kd [oil: gas] partition, Henry's constant, and water solubility [S%]) combine to affect a specific transport through the AFL if lung C > C(0) (threshold concentration for narcosis). The degree of blood CHC absorption depends on dose, lipophilicity, and lung residence time. AFL passage can be manipulated by physical factors of increased pressure (kPa) or increased gas exposure (moles). Molecular lipophilicity facilitates narcosis but lipophilicity alone does not explain narcosis. Vapor pressure is also required for narcosis. Narcotic activity apparently requires stereospecific processing in the AFL and/or down-stream inhibition at stereospecific lipoproteins at CNS inhibitory sites. It is proposed that CHCs likely cannot proceed through the AFL without perturbation or disruption of the integrity of the AFL at the alveoli. CHC physicochemical properties are not expected to allow their transport through the AFL as physiological CO(2) and O(2) naturally do in respiration. This work considers CHC inspiration and systemic absorption into the blood with special emphasis on the CHC potential perturbation effects on the lipid, protein liquid layer supra to the alveolar membrane (AFL). A heuristic gas transport model for the CHCs is presented as guidance for this examination. The gas transport model can be used to study absorption for other gas delivery endpoints of environmental concern such as carcinogens.

Design and synthesis of novel 5-phenyl-N-piperidine ethanone containing 4,5-dihydropyrazole derivatives as potential antitumor agents.

A series of novel 5-phenyl-N-piperidine ethanone-4,5-dihydropyrazole derivatives as potential telomerase inhibitors were synthesized. The bioassays demonstrated that compounds 4d, 4f, 7a and 7b occupied high antiproliferative activities against SGC-7901, MGC-803 and Bcap-37 cell lines. By a modified TRAP assay, some titled compounds were tested against telomerase, and compound 7b showed the most potent inhibitory activity with IC(50) value at 2.00 ± 0.40 µM. The active compound 4d was also docked into the telomerase TERT active site to determine the probable binding model. The results indicated that conserved residues Lys189, Asp254 and Gln308 were important for ligand binding via hydrogen bond interactions.

Comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin® and the Hawaiian marine algae, Chaetoceros, for potential broad-spectrum control of anaerobically grown lactic acid bacteria.

The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen, and may also contain foodborne or opportunistic human pathogens as well as bacteria capable of causing mastitis in cows. Thus there is a need to develop broad-spectrum therapies that are effective while not leading to unacceptably long antibiotic withdrawal times. The effects of the CH(4)-inhibitors nitroethane (2 mg/mL), 2-nitro-1-propanol (2 mg/mL), lauric acid (5 mg/mL), the commercial product Lauricidin® (5 mg/mL), and a finely ground product of the Hawaiian marine algae, Chaetoceros (10 mg/mL), were compared in pure cultures of Streptococcus agalactia, Enterococcus faecium, Streptococcus bovis, and in a mixed lactic acid rumen bacterial culture. Lauricidin® and lauric acid exhibited the most bactericidal acidity against all bacteria. These results suggest potential animal health benefits from supplementing cattle diets with lauric acid or Lauricidin® to improve the health of the rumen and help prevent shedding of human pathogens.

Effect of nitroethane and nitroethanol on the production of indole and 3-methylindole (skatole) from bacteria in swine feces by gas chromatography.

Indole and 3-methylindole (skatole) are odor pollutants in livestock waste, and skatole is a major component of boar taint. Skatole causes pulmonary edema and emphysema in ruminants and causes damage to lung Clara cells in animals and humans. A gas chromatographic method that originally used a nitrogen-phosphorus detector to increase sensitivity was modified resulting in an improved flame ionization detection response for indole and skatole of 236% and 207%, respectively. The improved method eliminates the large amount of indole decomposition in the injector. A 10 micro g mL(-1) spike of indole and skatole in water and swine fecal slurries resulted in recovery of 78.5% and 96% in water and 76.1% and 85.8% in fecal slurries, respectively. The effect of the addition of nitroethane and nitroethanol at 21.8 mM in swine fecal slurries was studied on the microbial production of indole and skatole. Nitroethane and nitroethanol decreased the production of skatole in swine fecal slurries at 24 h. The nitroethane effect on l-tryptophan-supplemented fecal slurries after 6 and 24 h incubation resulted in a decrease of 69.0% (P = 0.02) and 23.5% skatole production, respectively, and a decrease of 14.9% indole at 6 h, but an increase in indole production of 81.1% at 24 h.

Enantioselectivity in zebrafish embryo toxicity of the insecticide acetofenate.

Enantioselectivity in separation and toxicology of chiral xenobiotics have become one of the frontier topics interfacing chemistry and toxicology. In this study, enantiomers of insecticide acetofenate (AF) were separated on selected chiral columns by HPLC, and enantioselectivity in developmental toxicity was evaluated using the zebrafish embryo-larval assays. The AF enantiomers were baseline separated on Chiralcel OD, Chiralpak AD, and Sumichiral OA-2500I columns under optimized conditions. Pure enantiomers were obtained on Chiralcel OD. Optical rotatory dispersion (ORD) and circular dichroism (CD) detectors were used to determine the elution order and CD spectra of the enantiomers. The absolute configuration of enantiomers was identified as S-(+)-AF and R-(-)-AF by the octant rule from force-field calculations and CD spectra. The individual enantiomers were used in 4-day zebrafish embryo-larval bioassays, and a series of developmental end points were measured and compared. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to investigate the expressions of estrogen receptor alpha (ERalpha) in zebrafish embryo exposed to varying enantiomers. While the enantiomers showed no difference in acute toxicity, significant enantioselectivity was observed in developmental toxicities such as yolk sac edema and pericardial edema. The data of qRT-PCR showed that there was about 3.2-fold induction in the mRNA levels of ERalpha between fish exposed to (+)-AF and (-)-AF. The results suggest that enantioselectivity may occur at the developmental level even in the absence of selective acute toxicity and should be considered when evaluating ecotoxicological effects of chiral contaminants.

Antioxidants from rape (Brassica campestris vir. Japonica Hara) oil cake.

A simple but novel compound, S-1-methoxy-1-(3,5-dimethoxy-4-hydroxyphenyl)ethane, was isolated as a moderately antioxidative compound from rape (Brassica campestris L. subsp. napus) oil cake together with 5 known compounds. Three of these compounds, indolacetonitrile, 4-hydroxyindolacetonitrile, and 4-hydroxyphenylacetonitrile, showed strong antioxidative activity evaluated by the ferric thiocyanate method.

The first product of phospholipid N-methylation, phosphatidylmonomethylethanolamine, is a lipid mediator for progesterone action at the amphibian oocyte plasma membrane.

Progesterone has been shown to act at plasma membrane receptors on the amphibian oocyte to trigger a cascade of changes in membrane phospholipids and to initiate the G(2)/M transition of the first meiotic division. The earliest event (0-1 min) is the transient N-methylation of phosphatidylethanolamine (PE) to form phosphatidylmonomethylethanolamine (PME), demonstrated using [(3)H]glycerol to prelabel oocyte plasma membrane PE. [(3)H]Glycerol-labeled PME rises 10-fold within the 1-2 min after exposure to progesterone and accounts for conversion of about 50% of the [3H]Glycerol-labeled PE. [(3)H]PME levels slowly decline over the following 10-30 min. [(3)H] or [(14)C] labeled fatty acid experiments showed that newly formed PME is enriched in linoleic or palmitic, but not in arachidonic acid, indicating that specific PE pools undergo progesterone-induced N-methylation. Two plasma membrane changes: activation of serine protease, and Ca(2+) release from the oocyte surface coincide with PME formation; both are prevented by pretreatment of oocytes with the N-methylation inhibitor, 2-methylaminoethane. Media containing PME micelles release both protease and Ca(2+) from intact oocytes within the first 1-2 min. The immediate downstream metabolites of PME, PDE and PC, do not induce serine protease activity or Ca(2+) release. We conclude that progesterone initially activates N-methyltransferase in the oocyte plasma membrane, and that the first product, PME, is responsible for activation of serine protease in the plasma membrane and the release of Ca(2+) from the oocyte surface.

1,1,2,2-Tetrachloroethane-induced early decrease of dolichol levels in rat liver microsomes and Golgi apparatus.

Dolichols are long-chain polyprenols containing 14-22 isoprene units, present in mammalian tissues as free dolichol (Free-Dol), fatty acyl dolichyl esters (Dol-FA), and dolichyl phosphate (Dol-P). The hepatic level of Dol-P seems to be a rate-limiting factor for glycosylation processes. Previous studies from our laboratory demonstrated the susceptibility of the dolichol molecule to undergo radical attacks. Since the toxicity of 1,1,2,2-tetrachloroethane (TTCE)is dependent on the free-radical production during hepatic biotrasformation, it was of interest to determine whether this haloalkane might affect glycosylation mechanisms by changing dolichol levels and distribution in rat liver microsomes and Golgi apparatus (GA). Male Sprague-Dawley rats received a single dose of TTCE (574 mg/kg body weight) and were then sacrificed at different times (5, 15, 30, or 60 min). In the TTCE-treated rats both serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and hepatic triglycerides (TG) were significantly higher than control, while microsomal glucose 6-phosphatase (G6Pase) activity was decreased. In total microsomes Dol-P levels considered rate-limiting for the biosynthesis of the N-glycosylated proteins were significantly lower than in the control group 15 min after TTCE treatment. In normal rat liver, F1 secretory fraction of CA is 60-fold enriched in total dolichol content with respect to microsomes. In this compartment the total dolichol content, essential for the increase in membrane fluidity and permeability required for glycoprotein maturation and secretion, decreased significantly 5 min after TTCE treatment. Our results suggest that TTCE may affect dolichol functions in rat liver.

Tetrachloroethane, pentachloroethane, and hexachloroethane: genetic and biochemical studies.

Tetrachloroethane (TTCE), pentachloroethane (PCE), and hexachloroethane (HCE) were tested in diploid strain (D7) of the yeast Saccharomyces cerevisiae in suspension test with and without mammalian metabolic activation (S9). TTCE, PCE, and HCE gave positive results on cells harvested from logarithmic growth phase; only PCE induced a significant increase (P less than or equal to .01) of mitotic gene conversion and point reverse mutation on cells from stationary growth phase with metabolic activation (S9). The in vivo effects on cytochrome P450 content (cyt. P450), pentoxyresorufin O-dealkylase (P450-like, class IIB, PROD), and ethoxy-resorufin O-deethylase (P448-like, class IA, EROD) activities were examined in hepatic microsomes from mice 24 h after acute intoxication. All the halogenated hydrocarbons displayed a marked toxic effect as shown by the significant decrease in cyt. P450 levels (maximum of 76% decrease, with TTCE 753.2 mg/kg) and EROD (maximum of 69% decrease, with PCE 925.4 mg/kg), and to a lesser extent in PROD (maximum of 52.4% decrease, with HCE 3150 mg/kg). Although a general decrease of P450 functions was observed, the toxic effects of TTCE and PCE seem to be preferentially related to P448 forms.

Antiestrogens. Synthesis and evaluation of mammary tumor inhibiting activity of 1,1,2,2-tetraalkyl-1,2 -diphenylethanes.

Among the newly synthesized 1,1,2,2-tetraalkyl-1,2-diphenylethanes, 1,1,2,2-tetramethyl-1,2-bis(4'-hydroxyphenyl)ethane (23) and 1,1,2,2-tetramethyl-1,2-bis(3'-hydroxyphenyl)ethane (26) were the most active compounds regarding estradiol receptor affinity, exhibiting Ka values of 0.73 X 10(8) and 0.67 X 10(8) M-1, respectively. In vivo, 23 and 26 showed only very small uterotrophic activity in the mouse. They strongly inhibited (73%) the estrone-stimulated mouse uterine growth. Tested on the 9,10-dimethyl-1,2-benzanthracene induced hormone-dependent mammary adenocarcinoma of the Sprague-Dawley rat, compounds 23 and 26 exhibited a dose-dependent inhibition of the tumor growth, having a strong effect at a dose of 20 (mg/kg)/day (compound 23).

Sensitive enzyme-linked immunosorbent assay for detection of antibodies against typhus rickettsiae, Rickettsia prowazekii and Rickettsia typhi.

An enzyme-linked immunosorbent assay (ELISA) has been developed for the titration of rickettsial antibodies in human and animal sera. Two preparations of soluble typhus-group antigens were obtained from Rickettsia typhi and Rickettsia prowazekii by ether extraction: a standard antigen from infected yolk sacs (YS antigen) and one free of yolk sac contaminants from Renografin-purified rickettsiae (PR antigen). Rabbit, mouse, and guinea pig sera were obtained by immunization with viable purified R. typhi or R. prowazekii. Human sera were obtained from individuals who had recovered from laboratory infections with either typhus rickettsia months or years previously. Goat-derived anti-immunoglobulins were conjugated to alkaline phosphatase with glutaraldehyde. Although the PR and YS antigens gave equivalent antibody titers in the complement fixation test, the PR antigen was clearly superior in the ELISA. With this antigen, the titration curves of all antisera were linear over a wider range of serum concentrations and the titers were higher than with the YS antigen. With YS and PR antigens, ELISA titers were higher than those obtained by complement fixation by one and two orders of magnitude, respectively. In human sera, immunoglobulin G and immunoglobulin M antibodies were demonstrated by their respective anti-immunoglobulins and by differential susceptibility to ethanethiol. ELISA titers showed some type specificity, whereas none was observed in complement fixation tests. The ELISA is highly sensitive, reproducible, and easily adaptable to the various requirements of clinical and research laboratories.

Inhibition of methanogenesis in marine sediments by acetylene and ethylene: validity of the acetylene reduction assay for anaerobic microcosms.

Methanogenesis was irreversibly inhibited in sediments by concentrations of acetylene employed in nitrogen fixation assays (1 to 20%, vol/vol). Ethylene, but not ethane, also stopped methane production, and the inhibition was reversed by gassing with hydrogen.