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.     

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.     

Suppression of the α → β-nickel hydroxide transformation in concentrated alkali: Role of dissolved cations

The presence of dissolved cations such as Al and Zn in alkaline electrolyte (6 M KOH) suppresses the -nickel hydroxide transformation. The uptake of Al (10 mol%) and Zn (30 mol%) exhibited by the active material likely stabilizes the -phase. Dissolved Al is deleterious to the performance of the nickel hydroxide electrode, whereas, dissolved Zn enhances the specific discharge capacity of nickel hydroxide by approximately 25% showing that the mode of metal uptake is different in the two cases.     

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.     

Effects of allelochemicals on plant respiration and oxygen isotope fractionation by the alternative oxidase

The goal of this investigation was to determine the effects of allelochemicals on plant respiration that thereby may be responsible for their role in growth inhibition. We have tested the effects of juglone, quercetin, cinnamic acid, and-pinene on respiration rates, and electron partitioning through the cytochrome and alternative respiratory pathways, by measuring on-line oxygen consumption and oxygen isotope fractionation in soybean cotyledon tissue. Cinnamic acid and-pinene decreased the oxygen consumption rate and increased the relative partitioning of electron transport to the alternative pathway. Possible biochemical mechanisms of these effects are discussed.     

Oxygenated monoterpenes produced by yeasts,isolated fromIps typographus (Coleoptera: Scolytidae) and grown in phloem medium

When yeasts associated withIps typographus beetles were grown in an aqueous phloem medium for two days, the main oxygenated monoterpenes produced were -terpineol and borneol. Terpinene-4-ol, myrtenol, andtrans-pinocarveol were also found but in lesser amounts. Of the six strains used in this study,Hansenula capsulata andCandida nitratophila produced the largest amounts of oxygenated monoterpenes. Addition of -pinene to the phloem medium generally reduced the amounts of oxygenated monoterpenes, probably because this substance is toxic to all tested yeast species. OurCandida diddensii strain seemed to be particularly sensitive to -pinene. None of the yeast strains producedcis-verbenol,trans-verbenol, or verbenone from the medium or from added -pinene.This study was made within the project Odour Signals for Control of Pest Insects.     

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.     

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.     

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.     

Multichemical defense of plant bugHotea gambiae (westwood) (Heteroptera: Scutelleridae)

Chemical defense in larvae of the plant bugHotea gambiae has been investigated. Results of analyses (GC, GC-MS) on the secretions from the three dorsally situated larval abdominal defense (scent) glands are reported. The secretion from the first abdominal gland consists of a mixture of C₁₀ and C₁₅ isoprenoids: (C₁₀) -pinene, -pinene, limonene, -phellandrene; (C₁₅) -caryophyllene, caryophyllene oxide, -humulene, and (the major component) humulene epoxide II. The secretions from the second and third abdominal glands are similar mixtures consisting of (E)-2-decenal, (E)-4-oxohex-2-enal, andn-tridecane together with lesser amounts of (E)-2-hexenal,n-dodecane, and other materials. Isoprenoid defense is now known from four species of plant bugs (Heteroptera) associated with Malvaceae.     

The protective effect of antioxidants to a phototoxin-sensitive insect herbivore,Manduca sexta

Photo-activated plant secondary compounds have been shown to be toxic to many organisms including insects. Insect defenses include behavioral mechanisms such as light avoidance, as well as specific biochemical defenses such as antioxidants and antioxidant enzymes. These antioxidant defenses eliminate or quench the deleterious singlet oxygen and free radicals formed by these phototoxins. In this paper we examined the role of dietary antioxidants in protecting the phototoxin-sensitive insect herbivoreManduca sexta. Elevated dietary levels of the lipid-soluble antioxidants-carotene and vitamin E resulted in a concentration-dependent reduction in the mortality associated with treatment ofM. sexta larvae with the phototoxic thiophene-terthienyl. Elevated levels of dietary ascorbic acid had no effect, whereas reduced levels greatly increased the toxicity of-terthienyl. Tissue levels of antioxidants were shown to increase substantially in larvae fed antioxidant-supplemented diets. The results suggest that the ability to absorb and utilize plant-derived antioxidants could be an important defense against photo-activated plant secondary compounds and may have allowed some insects to exploit phototoxic plants.     

Acetone conversion to isobutene in high selectivity using zeolite β catalyst

The catalytic activity of the proton forms of zeolite and ZSM-5 are compared for the conversion of acetone. Zeolite demonstrates markedly enhanced selectivity to isobutene and selectivities of >80% can be achieved for conversions up to 65%. In contrast high selectivities to isobutene with ZSM-5 can be attained only at very low conversions (5%).     

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).     

Response of the clerid predatorThanasimus dubius (F.) to bark beetle pheromones and tree volatiles in a wind tunnel

Tree volatiles and pheromones produced by southern bark beetles were bioassayed for response by the clerid predatorThanasimus dubius (F.). Upwind flights in a laboratory olfactometer, modified from Visser (1976), were used to determine the attractiveness of compounds. Differences in response to a solvent control and pheromone treatment were tested for statistical significance using the Wilcoxon signed ranks test. Both sexes ofT. dubius responded to frontalin, ipsdienol, and -pinene in a dose-dependent manner with different but overlapping concentration ranges. Strong differences between the sexes were observed in response totrans-verbenol, verbenone, andl--pinene. Neither sex responded to ipsenol orendo-brevicomin.Miss. Agric. and For. Exp. Sta. Publication No. 5251.     

Chiral specificity in responses by the bark beetleDendroctonus valens to host kairomones

The attraction of the red turpentine beetle,Dendroctonus valens, to the resin volatiles of its host,Pinus ponderosa, is elicited by three chiral monoterpenes. In field assays response was greatest to (S)-(–)--pinene; 92% (S)-(–)--pinene found inP ponderosa resin was not attractive. However, 75% (R)-(+)--pinene, which occurs inPinus lambertiana, a sympatric host ofD. valens, was attractive. (S)-(–)--Pinene interrupted response to (R)-(+)--pinene. (S)-(+)-3-Carene from both hosts was attractive at the (R)-(+)--pinene level. Three sympatric coniferous nonhosts each have the same attractive monoterpenes but produce less resin. These studies demonstrate the importance of chirality of host compounds in the host finding behavior of this bark beetle.     

β-Phellandrene: kairomone for pine engraver,Ips pini (Say) (Coleoptera: Scolytidae)

The responses ofIps pini (Scolytidae) to multiple-funnel traps baited with the pheromone, ipsdienol, and various monoterpenes were determined in stands of lodgepole pine in southern and central British Columbia.Ips pini was attracted to both ipsdienol and -phellandrene, demonstrating that -phellandrene is a kairomone for this species.Lasconotus complex (Colydiidae) and aCorticeus sp. (Tenebrionidae) were attracted to both ipsdienol and -phellandrene. TheCorticeus sp. exhibited a synergistic response to the combination of ipsdienol and -phellandrene; the responses of the other two species to the combination were additive. The predators,Thanasimus undatulus, Enoclerus sphegeus, andE. lecontei (Cleridae), were attracted to ipsdienol-baited traps, whileMonochamus clamator (Cerambycidae) andDendroctonus ponderosae (Scolytidae) were attracted to -phellandrene. Attraction of all eight species increased with increasing release rates of ipsdienol and/or -phellandrene.     

Phase Compositions of Coatings Applied to Titanium Targets by Means of Shaped‐Charge Jets

Coatings containing titanium carbides of the cubic and hexagonal modifications were applied to titanium targets by a shapedcharge explosion. In the experiments, a conical liner with a cone angle of 30° made from a mixture of fine powders of boron and ammonium nitrate were used. A quantitative Xray phase analysis of various segments of the coating was performed. The values of the unit cell parameters indicate the formation of complex phases. In some regions of the target, the microhardness reaches 3800 kg/mm².     

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% (–)].     

Investigation of sex pheromone components of female asian corn borer,Ostrinia furnacalis (Hübner) (Lepidoptera: Pyralidae) in Taiwan

(E)-12-Tetradecenyl acetate (E12–14OAc), (Z)-12-tetradecenyl acetate (Z12–143nOAc), and tetradecanyl acetate (14OAc) were extracted and identified as major chemical components from female tips of the Asian corn borer,Ostrinia furnacalis (Hübner) (Lepidoptera: Pyralidae) in Taiwan, with a combined wash ratio of 483715 and an individual female ratio of 453916. The average amount ofE12-,Z12–14OAc and 14OAc in each female gland was 6.6±4.6, 5.8±3.5, and 2.4±1.7 ng/female, respectively. The mixture of these three synthetic chemicals not only gave strong activities in male antennae but also could catch significantly more males than virgin females in field-trapping tests. The field test also showed no significant difference in trapping ability among the three-component Taiwan formulations, the two-component Taiwan formulation (Z12–14OAc andZ1214OAc, 5347), and the Japan formulation (Z12–14 OAc andE 12–14OAc, 3:2).     

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.