Separation β-apocarotenals and related compounds by reversed-phase paper and thin-layer chromatography

Abstract is not available.

Combinations of plant-derived compounds against Campylobacter in vitro

Campylobacter occur in fresh retail poultry products as a result of their colonization of the gastro-intestinal tract of chickens during growth. Feed additives could be used for suppression of Campylobacter levels in the chickens prior to slaughter. To address this opportunity, feed manufacturers are targeting natural antimicrobials from plant material as new forms of consumer-accepted feed additives. However, to be practical, these natural antimicrobials must be effective at low concentrations. The current study has validated an improved laboratory method to study minimal inhibitory concentrations of plant compounds and their combinations against Campylobacter. The assay was shown to be valid for testing lipid-soluble and water-soluble plant extracts and byproducts from the food industry. The study screened 29 extracts or plant-derived compounds and their mixtures for anti-Campylobacter activity using a laboratory assay. Combinations of oregano, lactic acid, and sorghum byproduct showed effective synergy in anti-Campylobacter activity. The synergies allowed a large reduction in the concentration of the individual compounds needed to kill the bacteria with an 80% reduction in concentration being achieved for oregano essential oil. The assay gives rise to further opportunities for the testing of a greater range of combinations of plant-derived compounds and other natural antimicrobials. The method is robust, simple, and easily automated, and it could be used to adjust the cost of feed formulations by reducing costs associated with antimicrobial feed additives.

Amide-catalysed isomerisation of 5,6-dihydroisoquinolines: a novel synthesis of 1,2-dihydroisoquinolines

Knoevenagel condensation of 2-acylcyclohexanones or 2-ethoxycarbonylcyclohexanone with either cyanoacetamide or malononitrile followed by silver salt alkylation gave the 5,6,7,8-tetrahydroisoquinolines (3a–i). Chromic acid oxidation of the 5,6,7,8-tetrahydroisoquinolines (3a–i) to the corresponding tetralones (4a–i) followed by sodium borohydride reduction and p-toluenesulphonic acid-catalysed dehydration of the resulting alcohols (5a–i) gave the 5,6-dihydroisoquinolines (6a–i). Reaction of 5,6-dihydroisoquinolines (6a–g) with potassium amide in liquid ammonia gave a mixture of the 1,3-dihydroisoquinolines (7a–g) and the isoquinolines (8a–g). The C-1 unsubstituted 1,2-dihydroisoquinoline (7c) was found to be very unstable. In the case of the 5,6-dihydroisoquinolines (6h and 6i), reaction of potassium amide in liquid ammonia resulted in a mixture of 1-aminoisoquinoline (9) and the isoquinolines (8h and 8i). All the above compounds have been characterised by spectral data. A probable pathway for the formation of the 1,2-dihydroisoquinolines (7a–g) and the isoquinolines (8a–i) is suggested.

Non-target species interaction with sodium fluoroacetate (1080) meat bait for controlling feral pigs (Sus scrofa)

Fresh meat baits containing sodium fluoroacetate (1080) are widely used for controlling feral pigs in Queensland, but there is a potential poisoning risk to non-target species. This study investigated the non-target species interactions with meat bait by comparing the time until first approach, investigation, sample and consumption, and whether dying bait green would reduce interactions. A trial assessing species interactions with undyed bait was completed at Culgoa Floodplain National Park, Queensland. Meat baits were monitored for 79 consecutive days with camera traps. Of 40 baits, 100% were approached, 35% investigated (moved) and 25% sampled, and 25% consumed. Monitors approached (P < 0.05) and investigated (P < 0.05) the bait more rapidly than pigs or birds, but the median time until first sampling was not significantly different (P > 0.05), and did not consume any entire bait. A trial was conducted at Whetstone State Forest, southern Queensland, with green-dyed and undyed baits monitored for eight consecutive days with cameras. Of 60 baits, 92% were approached and also investigated by one or more non-target species. Most (85%) were sampled and 57% were consumed, with monitors having slightly more interaction with undyed baits than with green-dyed baits. Mean time until first approach and sample differed significantly between species groups (P = 0.038 and 0.007 respectively) with birds approaching sooner (P < 0.05) and monitors sampling later (P < 0.05) than other (unknown) species (P > 0.05). Undyed bait was sampled earlier (mean 2.19 days) than green-dyed bait (2.7 days) (P = 0.003). Data from the two trials demonstrate that many non-target species regularly visit and sample baits. The use of green-dyed baits may help reduce non-target uptake, but testing is required to determine the effect on attractiveness to feral pigs. Further research is recommended to quantify the benefits of potential strategies to reduce the non-target uptake of meat baits to help improve the availability of bait to feral pigs.

The elastic constants of isomorphous sodium bromate and sodium chlorate from 77 to 350 K

The elastic constants of NaBrO3 and NaClO3 are evaluated from ultrasonic velocity measurements using pulse superposition techniques. The values of C11, C12 and C44 for NaBrO3 at 298°K are 5.578, 1.705, 1.510 (x 1010 N/m2) and for NaClO3 the values are 4.897, 1.389, 1.174. The values at 77°K are respectively 6.35, 1.98 and 1.65 for NaBrO3 and 6.15, 2.16 and 1.32 for NaClO3.

Temperature-dependence of 35Cl N.Q.R. in sodium chloroacetate

N.q.r. in sodium chloroacetate has been investigated at temperatures from 77 K to room temperature (c.300 K). A single line has been observed throughout this temperature range. Torsional frequencies of the molecule have been calculated in the above temperature range from Bayer's theory. Also the temperature coefficient of the torsional frequencies has been calculated by Brown's method.

Dipole moments and structure of organophosphine and organoarsine compounds

The formal charge distributions in and the dipole moments of some organophosphines and arsines have been calculated, and the dipole moments of (p-chlorophenyl)dichlorophosphine (2.28 D) and (p-bromophenyl)dichlorophosphine (2.04 D) have been determined in benzene at 35° C. The differences between the observed and the calculated moments are explained in terms of dπ---pπ back-bonding and hyperconjugative effects in alkylhaloarsines. The mesomeric effects operating in the aromatic systems are evaluated by comparing the moments with those for the corresponding aliphatic systems. In unsaturated compounds the differences are attributed to mesomeric effects involving the expansion of arsenic valence shell.

Crystal structure of ferroelectric sodium meta vanadate, NaVO3

The crystal structure of ferroelectric sodium meta vanadate, NaVO3 has been solved using three dimensional X-ray data and refined to an R-value of 0.077 for 375 observed reflections. The crystal belongs to the monoclinic system with space group Cc and with unit cell dimensions a = 10.494 (9) Aring, b = 9.434 (7) Aring, c = 5.863 (6) Aring and β = 108° 48' in the room temperature ferroelectric phase. The unit cell dimensions in the high temperature paraelectric phase (above 380°C) are a = 10.595 (15) Aring, b = 9.671 (10) Aring, c = 5.926 (8) Aring and β = 108° 45' with space group C2/c. The crystal structure may be viewed as consisting of alternate channels of sodium polyhedra and VO4 tetrahedra.

Sodium-ammonia reduction of some cyclic vinyl bromides

Abstract is not available.

Homogeneous hydrogenations ofα, β-unsaturated compounds using pentacyanocobaltate (II) anion as catalyst system

Hydrogenation of someα, β-unsaturated carbonyl compounds using potassium pentacyanocobaltate (II), K3Co(CN)5, as a homogeneous catalyst has been investigated. Thus, hydrogenation of 1-carvone (I), mesityl oxide (4), 2-cyclohexenone (8) and benzalacetone (6) afforded the corresponding dihydrocompounds. Hydrogenation ofβ-ionone (10) afforded a mixture of theα, β-dihydrocompounds (14) and (15). In all these cases, it was observed that the reaction proceeded to completion only in the presence of added base. Hydrogenation of 5α-androst-l-en-17β-ol-3-one acetate (19) afforded the saturated compound, 5α-androst-17β-ol-3-one (20) in 60% yield. It was found that other steroid enones and dienones were not reduced by this catalyst system.

Factors influencing kinetic and equilibrium behaviour of sodium ion exchange with strong acid cation resin

This study reports an investigation of the ion exchange treatment of sodium chloride solutions in relation to use of resin technology for applications such as desalination of brackish water. In particular, a strong acid cation (SAC) resin (DOW Marathon C) was studied to determine its capacity for sodium uptake and to evaluate the fundamentals of the ion exchange process involved. Key questions to answer included: impact of resin identity; best models to simulate the kinetics and equilibrium exchange behaviour of sodium ions; difference between using linear least squares (LLS) and non-linear least squares (NLLS) methods for data interpretation; and, effect of changing the type of anion in solution which accompanied the sodium species. Kinetic studies suggested that the exchange process was best described by a pseudo first order rate expression based upon non-linear least squares analysis of the test data. Application of the Langmuir Vageler isotherm model was recommended as it allowed confirmation that experimental conditions were sufficient for maximum loading of sodium ions to occur. The Freundlich expression best fitted the equilibrium data when analysing the information by a NLLS approach. In contrast, LLS methods suggested that the Langmuir model was optimal for describing the equilibrium process. The Competitive Langmuir model which considered the stoichiometric nature of ion exchange process, estimated the maximum loading of sodium ions to be 64.7 g Na/kg resin. This latter value was comparable to sodium ion capacities for SAC resin published previously. Inherent discrepancies involved when using linearized versions of kinetic and isotherm equations were illustrated, and despite their widespread use, the value of this latter approach was questionable. The equilibrium behaviour of sodium ions form sodium fluoride solution revealed that the sodium ions were now more preferred by the resin compared to the situation with sodium chloride. The solution chemistry of hydrofluoric acid was suggested as promoting the affinity of the sodium ions to the resin.

Elastic constants of sodium chlorate from 77 K to 350 K

The elastic constantsC 11,C 12 and C 44 of sodium chlorate single crystal have been evaluated using 10 MHz ultrasonic pulse echo superposition technique. The values are C 11=4.90,C 12=1.39,C 44=1.17 (× 1010 N/m 2) at 298 K and 6.15, 2.16, 1.32 (×1010 N/m 2) at 77 K. The data agree well with the values measured earlier up to 223 K. Brief mention is also made of the low temperature bonding problems in these soft crystals.

The nonplanar peptide unit III. Quantum chemical calculations for related compounds and experimental X-ray diffraction data

The possible nonplanar distortions of the amide group in formamide, acetamide, N-methylacetamide, and N-ethylacetamide have been examined using CNDO/2 and INDO methods. The predictions from these methods are compared with the results obtained from X-ray and neutron diffraction studies on crystals of small open peptides, cyclic peptides, and amides. It is shown that the INDO results are in good agreement with observations, and that the dihedral angles N and defining the nonplanarity of the amide unit are correlated approximately by the relation N = -2, while C is small and uncorrelated with . The present study indicates that the nonplanar distortions at the nitrogen atom of the peptide unit may have to be taken into consideration, in addition to the variation in the dihedral angles (,), in working out polypeptide and protein structures.

Thermal decomposition of sodium azide

The thermal decomposition of sodium azide has been investigated in the temperature range 240–365°C. Three values for the activation energy, 37.0, 59.0 and 14 kcal mol−1 have been obtained depending on the temperature range of study. The mechanism of decomposition seems to involve excited azide ions (through internal conversion) and excitations. The activation energy of 14 kcal mol−1 appears to be associated with the promotion of electron in the presence of sodium metal.

Dielectric and Electron Spin Resonance Spectroscopic Studies of Glassy Crystalline States of Organic Compounds

Dielectric studies of the glassy crystalline states of cyclohexanol, cyclohexanone, and camphor obtained by upercooling the plastic crystalline phase demonstrate the presence of characteristic a- and p-relaxations. The parameters of the a-relaxation fit the Vogel-Tammann-Fulcher (VTF) equation. ESR spin-probe studies of the glassy crystalline phase of cyclohexanol show that there is a marked decrease in the correlation time above the glasslike transition temperature. The present studies suggest the similarity between glassy crystals having long-range orientational disorder and glasses which are known to betra nslationally disordered.