Mechanisms of Iron Activation on Fe-Containing Zeolites and the Charge of α-Oxygen

According to previous Mössbauer data [1] -sites formation at the activation of Fe-containing zeolites is accompanied by irreversible self-reduction of the iron, proceeding without participation of an external reducing agent. Reduced Fe²⁺ ions are inert to O₂ but are reversibly oxidized to Fe³⁺ by N₂O, generating the -oxygen species, O, which provide selective oxidation of hydrocarbons.In this work, the mechanism of -sites formation was studied via quantitative measurement of the dioxygen amount desorbed into the gas phase at the step of self-reduction. A prominent role of the zeolite matrix chemical composition has been revealed. For example, with zeolites of Al–Si composition (FeZSM-5 and Fe-), heating to 900 °C in a closed vacuum space leads to irreversible evolution of O₂, which is accompanied by the immediate formation of -sites. Similar heating of B–Si and Ti–Si zeolites also leads to dioxygen evolution; however, this evolution is reversible and is not accompanied by formation of -sites. Activation of these zeolites occurs only in the presence of water vapor. Stoichiometric measurements showed that in terms of charge one regular O^2- ion, removed at the activation, is equivalent to two -oxygen atoms. So, -oxygen is identified as an ion-radical species O ^-., whose unique oxidation properties still distinguish it from the generally observed O^-. radicals.The mechanism of -sites formation is proposed, in which the process of strong chemical stabilization of reduced Fe²⁺ atoms in the zeolite structure is a key step, making impossible the reoxidation of the iron with O₂.     

Dose and enantiospecific responses of white pine cone beetles,Conophthorus coniperda,to alpha-Pinene in an eastern white pine seed orchard

The white pine cone beetle, Conophthorus coniperda, exhibited dose and enantiospecific responses to -pinene in stands of mature eastern white pine, Pinus strobus, in a seed orchard near Murphy, North Carolina, USA. (–)--Pinene significantly increased catches of cone beetles to traps baited with (± )-trans-pityol. (+)--Pinene did not increase catches of beetles to pityol-baited traps and interrupted the response of beetles to traps baited with (±)-trans-pityol and (–)--pinene. Maximal attraction of cone beetles to pityol-baited traps was obtained with lures releasing (–)--pinene at a rate of 103 mg/day at 23^°C. Lures releasing (–)--pinene at rates lower or higher than 103 mg/day resulted in reduced catches to traps baited with (±)-trans-pityol. The sex ratio in all catches was heavily male biased. Attraction of the clerid predator, Thanasimus dubius, to traps baited with (±)-trans-pityol increased significantly with the presence of -pinene, irrespective of enantiomeric composition. Maximal attraction of T. dubius to pityol-baited traps occurred with devices releasing (–)--pinene at the highest rate tested, 579 mg/d at 23^°C, a sub optimal rate for cone beetles.     

Response of the European elm bark beetle,Scolytus multistriatus (Coleoptera: Scolytidae), to isomers and components of its pheromone

Laboratory bioassays (two methods) and field tests demonstrated synergistic action of the three components [(–)-4-methyl-3-heptanol (I); (–)-2,4-dimethyl-5-ethyl-6,8-dioxabicylo[3.2.1]octane (-multistriatin) (II); and (–)--cubebene (III)] of the pheromone bouquet ofScolytus multistriatus. Individually and in pairs the components were slightly attractive; I+II was clearly the most active doublet. Indirect evidence indicates that only one of the four enantiomers of I is active. Of the , , and isomers of II, only the is active. With the addition of compound I, slightly attractive extract from mated females became nearly as active as extract from virgin females.     

Isolation and identification of male medfly attractive components inLitchi chinensis stems andFicus spp. stem exudates

Short-range attraction/feeding stimulation of male Mediterranean fruit flies [Ceratitis capitata (Wiedemann), (Diptera: Tephritidae)] to a stem extract of a host plant,Litchi chinensis Sonn. (Sapindaceae), and to milky exudates from stems of nonhost plants,Ficus retusa L. andF. benjamina L. (Moraceae), were attributed to the presence of the sesquiterpene -copaene. The presence of -copaene in the milky exudate from stems ofF. benghalensis L. is also suggested as eliciting similar behavioral responses in male medflies. The presence of minor quantities of -ylangene in the plants and its contributory effects to the behavioral response of male medflies is discussed. Short-range attraction/feeding stimulation of male medflies to equal amounts of -ylangene-free -copaene samples (94.5%+), prepared from -copaene-enriched angelica seed oil and copaiba oil, respectively, showed no difference in intensity of response. -Ylangene elicited a slightly less intense response for male medflies than -copaene.Names of products in this paper are included for the benefit of the reader and do not imply endorsement or preferential treatment by USDA.     

Synergistic Effect of Ethanol to α-Pinene in Primary Attraction of the Larger Pine Shoot Beetle, Tomicus piniperda

-Pinene and ethanol were released in the approximate proportions 1:0.1, 1:0.9 and 1:9 (at 21°C). Ethanol, released in the range of 3–279 mg/day, generally synergized the attraction of T. piniperda to -pinene (30 mg/day at 21°C), although attraction to the mixtures varied within and between years. The low release rate of ethanol together with -pinene attracted a significantly higher number of beetles than -pinene alone in 1995, April of 1996, and in 1997. Lures with the medium release rate of ethanol were the most attractive only in March of 1996. The high dose of ethanol significantly synergized attraction to -pinene in 1995 and 1997. The variable attraction of T. pinipeda to ethanol and -pinene at various release rates and proportions may be due to the temperature dependent nature of beetle antennal sensitivity. At ambient temperatures of 10–13°C. T. piniperda was most attracted to the lures with -pinene and high release rates of ethanol, at 14–17°C it was most attracted to those with medium release rates of ethanol, and at 18°C and higher it was most attraacted to those with low release rates of ethanol.     

Oxidation of α- and β-pinene catalyzed by MnIII (Salen) Cl·H2O

The cationic complex Mn^III (Salen) is a very effective catalyst for the oxidation of both- and-pinene. The higher selectivity towards epoxide formation supports the rebound oxygen mechanism. A turnover of 40 was obtained for both compounds after 16 h of reaction with a molar ratio 10.011 (feedstock: catalyst: iodosobenzene) and conversions between 50 and 60% were observed. A very high selectivity (55%) was determined for epoxide formation from -pinene. The good selectivity observed for myrtanal isomers (6.5 and 23.2%) from-pinene is related to the prior formation of the 1,2-epoxides.     

Chemistry and Defensive Efficacy of Secretion of Burrowing Bug (Sehirus cinctus cinctus)

Adult Sehirus cinctus cinctus emit a volatile secretion from their metathoracic scent glands when tactually stimulated. We identified the volatile components by gas chromatography, high-performance liquid chromatography, and mass spectrometry. The secretion of both sexes contained (1R)-(+)--pinene, (1S)-(–)--pinene, -myrcene, (R)-(+)-limonene, and -terpinolene. Two additional compounds were found in only female secretions: (E)-2-hexenyl acetate and (E)-2-octenal. We also tested the defensive capability of this insect by offering it to various predators. Anoles, starlings, and a killdeer rejected S. c. cinctus after an initial sampling. These findings suggest that the secretion plays a defensive role.     

Monoterpene oviposition stimulants ofDioryctria amatella in volatiles from fusiform rust galls and second-year loblolly pine cones

Volatiles collected on Poropak Q from fusiform rust galls (Cronartium quercuum F. sp.fusiforme) of loblolly pine for 3 hr were better ovi-position stimulants forDioryctria amatella (Hulst) females than extracts of 8-hr collections. GLC analysis of these extracts showed no major differences in relative monoterpene composition, although 8-hr collections contained an unidentified compound not detected in the 3-hr collections. Comparison of volatiles from second-year loblolly pine cones with those from fusiform galls showed that both containeddl--pinene, (–)--pinene, myrcene, and (+)-limonene. Camphene was found in galls only, and relatively large quantities of -phellandrene were identified only from cones. The five major monoterpenes found in the two host substrates were tested in an oviposition bioassay. Eighteen trials using different combinations of these terpenes showed that the combination of -pinene, myrcene, and limonene was as attractive toD. amatella females as all other terpene combinations, including turpentine.Lepidoptera: Pyralidae.     

Effect of ethanol and α-pinene on response of ambrosia beetle,Trypodendron lineatum,to lineatin-baited funnel and drainpipe traps

The response ofT. lineatum to ethanol and -pinene, when used with the pheromone lineatin, was tested for two trap types. Funnel traps, which are passive barrier traps, caught significantly more beetles than drainpipe traps, which require an active response by the beetle to enter the trap. However, the response ofT. lineatum to the semiochemical treatments did not significantly differ for the two trap types. Treatments that included -pinene with the pheromone, either with or without ethanol, caught significantly moreT. lineatin than those with the pheromone alone. When ethanol and or -pinene were added to the pheromone significantly more female beetles were trapped than with pheromone alone. Male-female ratios were significantly lower for both types of traps when ethanol was included in the bait than for lineatin alone or with -pinene. A higher percentage of male beetles entered the drainpipe traps than was captured with funnel traps.     

Additional male mediterranean fruitfly (Ceratitis capitata wied.) Attractants from Angelica seed oil (Angelica archangelica L.)

Two sesquiterpene hydrocarbons, -copaene and -ylangene, were isolated from bioactive fractions of angelica seed oil and were shown by field bioassays to be attractive to the male Mediterranean fruit fly. Their relative attractiveness, compared with the(+)-and (–)--copaene enantiomers, are: (+)--copaene>angelica -copaene>angelica -ylangene>(–)--copaene. The enantiomer ratios for the two compounds are: -copaene, 61.4% (+), 38.6% (–); -ylangene, 91.9% (+), 8.1% (–).trans--Bergamotene was also isolated from the same fractions, but in sufficient quantity for bioassay [enantiomer ratio: 95.7% (+), 4.3% (–)].     

Synthesis and properties of aromatic polyesters and brominated polyesters derived from α,α′-bis(4-hydroxyphenyl)-1,4(or 1,3)-diisopropylbenzene

The interfacial polycondensation technique was used for the preparation of polyarylates and brominated polyarylates. Polyarylates and brominated polyarylates were prepared by mixing a solution of diacid chloride such as terephthaloyl chloride, isophthaloyl chloride, or their mixture in dichloromethane with an aqueous alkaline solution of ,-bis(4-hydroxyphenyl)-1,4(or 1,3)-diisopropylbenzene or ,-bis(4-hydroxy-3,5-dibromophenyl)-1,4(or 1,3)-diisopropylbenzene using triethylbenzylammonium chloride as the phase transfer agent. Moderate to high molecular weight polyarylates with _inh up to 1.27 dL/g were obtained, and most of them could be cast into tough and flexible films depending on the polymer composition. In general, polymers containing more 1,3-isomer or isophthaloyl chloride moieties gave transparent and flexible films and had lower glass transition temperatures and higher solubility. Although these polymers have two isopropylidene linkages in their repeating units, they still exhibit moderately high thermal stability and show no obvious weight loss before 400 °C. The introduction of bromine on the polymer backbone caused a decrease of inherent viscosity, crystallinity, and thermal stability of the polyarylates, while causing an increase in glass transition temperature and a great enhancement of fire retardancy.     

Phase transitions and dimensional and morphological changes in an “Aluminum Hydroxide-Alumina” system under a shock-wave action

A method is proposed to study the sequence of phase transitions in powdered materials under a shock-wave action. It is shown that the aluminum hydroxide-alumina system has the following sequence of phase transformations under a shock-wave action: bayerite boehmite -Al₂O₃ -Al₂O₃. It is found that there are no transitional high-temperature modifications of alumina. A method is developed for obtaining a submicron alumina powder, which allows obtaining materials with a controlled phase composition, including a thermodynamically stable -modification of Al₂O₃. The specific features of the morphological structure and the phase and structural characteristics of powders after a shock-wave action are considered.Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 1, pp. 110–119, January–February, 2005.     

Limonene inhibits attraction to α-pinene in the pine weevilsHylobius abietis andH. pinastri

The field responses ofHylobius abietis (L.) andH. pinastri (Gyllenhal) (Coleoptera: Curculionidae) to various combinations of two host monoterpenes and ethanol were studied using baited pitfall traps. Both species were attracted to -pinene, and when ethanol was added the attraction increased by 5–16 times. Limonene completely inhibited the attraction to -pinene, even when the release rate of limonene was only about 1/50 that of -pinene. The catches in traps with -pinene and limonene as well as with limonene alone were similar in size to catches in empty control traps, i.e., no true repellent effect was demonstrated. When limonene was added to the combination of -pinene and ethanol on old clear-cuttings, the catch ofH. pinastri was completely inhibited while that ofH. abietis was reduced by two thirds. On fresh clear-cuttings the inhibitory effect of limonene on the attraction to the -pinene-ethanol combination was small or absent. Some aspects of host interactions are discussed as are practical implications regarding the choice of seedling material for planting and prospects of finding deterrents for protecting seedlings from pine weevil damage.     

Stereospecific antennal response by red turpentine beetle,Dendroctonus valens to chiral monoterpenes from ponderosa pine resin

The antennal response ofDendroctonus valens to host monoterpenes from the resin of ponderosa pine was studied using the electroantennogram (EAG) technique. Male and female beetles were given a single dose of each of 11 different monoterpenes. Response amplitude to the different compounds did not vary between sexes and was generally well correlated with results from field attraction studies. Response to (S)-(–)--pinene was greatest. The relative amplitude of the responses to the (R)-(+) and (S)-(–) enantiomers of a-pinene, however, were reversed from their relative attractiveness in the field. A dose-response study was conducted for the (R)-(+) and (S) -(–) enantiomers of a-pinene, plus a reciprocal differential saturation test with successive doses of first one enantiomer of-pinene and then the other. Comparison of EAG traces suggests different receptors for the two stereoisomers of-pinene. Differential saturation curves suggest that while one set of receptors may respond to both enantiomers, some receptors respond only to the (S)-(–) enantiomer.     

Allelopathic Effects of Volatile Monoterpenoids Produced by <Emphasis Type="Italic">Salvia leucophylla</Emphasis>: Inhibition of Cell Proliferation and DNA Synthesis in the Root Apical Meristem of <Emphasis Type="Italic">Brassica campestris</Emphasis> Seedlings

Salvia leucophylla, a shrub observed in coastal south California, produces several volatile monoterpenoids (camphor, 1,8-cineole, -pinene, -pinene, and camphene) that potentially act as allelochemicals. The effects of these were examined using Brassica campestris as the test plant. Camphor, 1,8-cineole, and -pinene inhibited germination of B. campestris seeds at high concentrations, whereas -pinene and camphene did not. Root growth was inhibited by all five monoterpenoids in a dose-dependent manner, but hypocotyl growth was largely unaffected. The monoterpenoids did not alter the sizes of matured cells in either hypocotyls or roots, indicating that cell expansion is relatively insensitive to these compounds. They did not decrease the mitotic index in the shoot apical region, but specifically lowered mitotic index in the root apical meristem. Moreover, morphological and biochemical analyses on the incorporation of 5-bromo-2-deoxyuridine into DNA demonstrated that the monoterpenoids inhibit both cell-nuclear and organelle DNA synthesis in the root apical meristem. These results suggest that the monoterpenoids produced by S. leucophylla could interfere with the growth of other plants in its vicinity through inhibition of cell proliferation in the root apical meristem.     

Alleviation of α-tomatine-induced toxicity to the parasitoid,Hyposoter exiguae,by phytosterols in the diet of the host,Heliothis zea

The solitary, endoparasitic ichneumonid,Hyposoter exiguae (Viereck) is a parasitoid of the tomato fruitworm,Heliothis zea (Boddie). However, the parasitoid is deleteriously affected by the tomato glycoalkaloid, -tomatine, ingested from hosts (H. zea) fed on artificial diets or semipurified extracts of tomato plants that contained -tomatine. -Tomatine causes prolonged larval development; disruption or prevention of pupal eclosion; deformation of antennal, abdominal, and genital structures; and reduction in adult weight and longevity of the parasitoid. These toxic effects are exacerbated when the dietary dose of -tomatine is increased from 12 mol to 20 mol/g dry wt of diet. However, the toxicity of -tomatine is attenuated in parasitoids reared from hosts fed on artificial diets that contain equimolar or supramolar amounts of 3-OH-sterols admixed with -tomatine. Further, the toxicity of extracts from the foliage of different cultivars of tomatoes toH. exiguae is contingent upon the composite levels of -tomatine and total phytosterol (free and esterified). Cultivars with a low total sterol-tomatine ratio are more toxic toH. exiguae. The possible mode of action of -tomatine toxicity toH. exiguae by disruption of sterol metabolism is discussed.     

Heterogeneous asymmetric reactions. 23. Enantioselective hydrogenation of ethyl pyruvate over cinchonine- and α-isocinchonine-modified platinum catalysts

The enantioselective hydrogenation of ethyl pyruvate to (S)-ethyl lactate over cinchonine- and -isocinchonine-modified Pt/Al₂O₃ catalysts was studied as a function of modifier concentration and reaction temperature. The maximum enantioselectivities obtained under the applied mild conditions were 89% ee using cinchonine (0.014 mmoldm^–3, 1 bar H₂, 23°C, 6% AcOH in toluene), and 76% ee in the case of -isocinchonine (0.14 mmoldm^–3, 1 bar H₂, –10°C, 6% AcOH in toluene). Since -isocinchonine of rigid structure exists only in anti-open conformation these data provide additional experimental evidence to support the former suggestion concerning the dominating role of anti-open conformation in these cinchona-modified enantioselective hydrogenations.     

Isolation and identification of cotton synomones mediating searching behavior by parasitoidCampoletis sonorensis

In laboratory bioassays, the parasitoidCampoletis sonorensis was attracted to the following sesquiterpenes isolated from cotton essential oil: -humulene, -bisabolene, -caryophyllene oxide, spathulenol, -bisabolol, and a new, naturally occurring bisabolene-related alcohol, (2-p-tolyl-6-methylhept-5-en-2-ol) which we name gossonorol. This is the first report of spathulenol in cotton. -Caryophyllene, a major component of cotton, was not attractive to the parasitoids. The response of the parasitoids to these compounds and the possibility of augmenting parasitoid activity in the field by manipulating plant secondary metabolites is discussed.Synomone: A chemical produced or acquired by an organism that benefits both the emitting and receiving organisms (Nordlund and Lewis, 1976).     

Apple Fruit Infested with Codling Moth are More Attractive to Neonate Codling Moth Larvae and Possess Increased Amounts of (E,E)-α-Farnesene

Apple fruit artificially infested with codling moth larvae attracted significantly more neonate larvae of the codling moth, Cydia pomonella than uninfested fruit. A greater number of larvae responded to odor in an olfactometer from codling moth-infested cold-stored Red Delicious thinning apples than uninfested apples. Immature Granny Smith, Red Delicious, or Golden Delicious apples that were infested on the tree for five days by codling moth larvae were more attractive to neonate codling moth larvae than similar but uninfested fruit of the same varieties. Apples infested on the tree and sampled five days later also contained significantly greater amounts of the larval attractant (E,E)--farnesene, compared to uninfested apples. Other types of injury to apple fruit did not produce results similar to that from codling moth infestation, either in increased attractiveness to codling moth larvae or in increased quantities of (E,E)--farnesene. These results are consistent with the reported attractiveness of (E,E)--farnesene to neonate codling moth larvae.     

Effects of Four Monoterpenes on Germination, Primary Root Growth, and Mitochondrial Respiration of Maize

The effects of four monoterpenes—camphor, eucaliptol, limonene, and -pinene—on the oxidative metabolism of mitochondria isolated from maize root (Zea mays), on maize seed germination, and on primary root growth were investigated. The effects of individual monoterpenes on respiration were variable. -Pinene concentrations of 0.05–1.0 mM stimulated respiration with a mixture of substrates composed of NADH, L-malate, succinate, and L-glutamate, and in the absence of exogenously added ADP (basal respiration). However, at concentrations higher than 1.0 mM, -pinene inhibited respiration both in the absence (basal respiration) and presence of ADP (coupled respiration). Limonene at 0.1 mM or above stimulated basal respiration and inhibited in parallel the coupled respiration. Similar effects were promoted by eucaliptol, but at a higher concentration range (1.0 mM or above). Camphor was less active. At 10 mM concentration, it caused stimulation of basal respiration but did not affect coupled respiration. In the concentration range 0.1–10.0 mM, limonene was inactive on seed germination and primary root growth. Camphor and eucaliptol did not inhibit germination but reduced fresh and/or dry weight of roots at 5.0 mM and above. -Pinene inhibited both seed germination and fresh weight of primary roots at 10.0 mM concentration. The results indicate that intact seeds and primary roots are less sensitive than isolated mitochondria. The relatively more lipophilic monoterpenes -pinene and limonene had less activity than the more water-soluble oxygenated monoterpenes camphor and eucaliptol in inhibiting seed germination and/or primary root growth, despite the fact that they had a higher activity on the oxidative metabolism of isolated mitochondria. The findings suggest that the solubility of monoterpenes may be the major factor implicated in these differences.