Volatiles mediating plant-herbivore-natural enemy interactions: Electroantennogram responses of soybean looper,Pseudoplusia includens,and a parasitoid,Microplitis demolitor,to green leaf volatiles

Electroantennograms were recorded from an herbivore,Pseudoplusia includens (Walker) (Lepidoptera: Noctuidae), and a parasitoid,Microplitis demolitor (Wilkinson) (Hymenoptera: Braconidae), exposed to 5-through 12-carbon aliphatic compounds of several chemical classes. The response of the herbivore was higher for the 6- and/or 7-carbon hydrocarbons, alcohols, aldehydes, esters, and ketones. The response of the parasitoid was higher for the 7- and 8-carbon hydrocarbons, aldehydes, and ketones. Responses of the herbivore and the parasitoid to alcohols were similar. Both the herbivore and the parasitoid were most sensitive to aldehydes and ketones, and least sensitive to alcohols and hydrocarbons. Responses of the parasitoid to hydrocarbons, aldehydes, and ketones were numerically higher than those of the herbivore. The adaptive significance of differential olfactory sensitivity between the herbivore and the natural enemy is discussed in relation to tri-trophic interactions among plants, herbivores, and natural enemies.     

Analysis of peach bark volatiles and their electroantennogram activity with lesser peachtree borer,Synanthedon pictipes (Grote and Robinson)

Bark volatiles from two peach cultivars (Bisco and Redskin) were obtained by vacuum steam distillation and fractionated by preparative gas chromatography. The fractions were then assayed with the electroantenno- gram (EAG) method on antennae of female lesser peachtree borer [Synanthedon pictipes (Grote and Robinson)]. With both cultivars, two fractions elicited the largest responses. Analysis of this material by GC-MS revealed a complex mixture made up of aromatic alcohols, esters, ketones, and acids, as well as phenols, aliphatic aldehydes, and aliphatic acids. EAG responses to pure samples of all identified components were recorded, and many of these compounds were found to be quite active. Among the most stimulatory were guaiacol, methyl benzoate, and l-phenyl-1,2-propanedione. Also tested were six-carbon aliphatic aldehydes and alcohols which are components of the foliar tissue of most plants. Of these, 1-hexanol showed moderate activity, while the aldehydes and unsaturated alcohols were only weakly active.Lepidoptera: Sesiidae.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Avian Exocrine Secretions. I. Chemical Characterization of the Volatile Fraction of the Uropygial Secretion of the Green Woodhoopoe, Phoeniculus purpureus

Using gas chromatography-mass spectrometry in conjunction with auxiliary techniques such as solid phase microextraction and determination of double bond positions by means of dimethyl disulfide derivatization, 45 constituents of the uropygial secretion of the green woodhoopoe, Phoeniculus purpureus, have been identified. The majority of these constituents are long-chain branched and unbranched alkanes, and (Z)-alkenes such as (Z)-9-tricosene, and a number of unidentified wax esters. The more volatile fraction of the secretion contained short-chain fatty acids, aldehydes, aliphatic and heterocyclic aromatic amines, ketones, and dimethyl sulfides. This group of volatile compounds is responsible for the obnoxious odor of the secretion and also for its defensive action against predators.     

Chemistry of male mandibular gland secretions ofPhilanthus basilaris cresson andPhilanthus bicinctus (Mickel) (Hymenoptera: Sphecidae)

Detailed chemical characterizations are provided for the species-specific mixtures of marking pheromones utilized by the male beewolvesPhilanthus basilaris andP. bicinctus. Successful analysis of these complex mixtures of 2-ketones, fatty acids, ethyl esters, and aldehydes was facilitated by the treatment of the crude extracts with 1,1-dimethylhydrazine and direct analysis of the resulting hydrazones, methyl esters, and starting ethyl esters by GC-MS.     

Volatile compounds from interdigital gland of male white-tailed deer (Odocoileus virginianus)

Interdigital secretions were collected from eight male white-tailed deer of various ages. Analysis of volatiles was performed by gas chromatography-mass spectrometry with a modified headspace technique. Forty-six volatile compounds were found including alkanes, arenes, aldehydes, ketones, aliphatic acids, esters, pyrroles, furans, and sulfur compounds. Eleven occurred in higher concentrations (P0.10) in dominant (3.5-year-old) than in subordinate (1.5-year-old) animals. Dominant males typically have higher serum testosterone levels, and fatty acids and esters fluctuate with sebum production, which is under hormonal control. Therefore, these compounds may reflect testosterone levels and act as chemical signals indicating the presence of a dominant male. Interdigital volatiles also may act as generalized scent trail markers.     

Attraction ofOryzaephilus surinamensis (L.) andOryzaephilus mercator (Fauvel) (Coleoptera: Cucujidae) to some common volatiles of food

Responses by adultOryzaephilus surinamensis (L.) andOryzaephilus mercator (Fauvel) to various food volatiles were assessed by means of a two-choice, pitfall olfactometer. The individual experimental stimuli, all potential products of lipid oxidation, had a range of attractive doses of 1000-fold over the test dose ranges of 0.001–100 gmg, or 0.01–1000 gmg. Of 13 aliphatic C₃-C₁₄ aldehydes and benzaldehyde tested forOryzaephilus spp., 10 C₃-C₁₀ aliphatic aldehydes and benzaldehyde showed some attractiveness for both species. ForO. mercator, nonanal had the lowest lower threshold for positive response at 0.01 g. The addition of small amounts of nonanal or of a 111 mixture of hexanal, octanal, and nonanal to small amounts of cucujolide aggregation pheromones enhanced response by mixed-sexO. mercator to the pheromones. Eleven aliphatic C₂-C₉ free fatty acids showed some attractiveness for bothOryzaephilus spp. Isovaleric acid and valeric acid had the lowest lower thresholds for positive response at 0.1 g forO. mercator andO. surinamensis, respectively. Four olefinic oat volatiles were found to possess various degrees of attractiveness for bothOryzaephilus spp. The data suggest that food volatiles in this study might be used byOryzaephilus spp. as host-finding kairomones in nature.Research supported by the Natural Sciences and Engineering Research Council of Canada, Strategic Grant G0958 and Operating Grants A3881 and A3785.     

Identification and Variation of Volatile Compounds in Sternal Gland Secretions of Male Koalas (Phascolarctos cinereus)

The content of the sternal gland secretion from four male koalas (Phascolarctos cinereus) was analyzed using gas chromatography–mass spectrometry. Volatile fatty acids, aldehydes, ketones, mono- and sesquiterpenes were identified, together with various volatile nitriles and oximes, some of which had not previously been described from any mammalian skin gland. Benzyl cyanide and phenylacetaldehyde oxime were identified as major components of the secretions, together with smaller amounts of the novel 3-methylthiopropanal oxime. The relative abundance of the identified compounds was highly variable between individuals and the scent composition was found to be partly determined by the scent of surrounding conspecifics. Principal component analysis revealed a high similarity between related individuals.     

Mammalian Exocrine Secretions. XVIII: Chemical Characterization of Interdigital Secretion of Red Hartebeest, Alcelaphus buselaphus caama

Gas chromatography, coupled gas chromatography-mass spectrometry (electron impact mode and chemical ionization with methane as reactant gas), gas chromatography-infrared spectroscopy, and derivatization techniques were used to identity 53 compounds in the interdigital secretion of the red hartebeest, Alcelaphus buselaphus caama. These compounds included alkanes, isoalkanes, alcohols, ketones, carboxylic acids, oxiranes, furanoid linalool oxides, and a large number of branched and unbranched saturated and unsaturated aldehydes. The secretion probably plays a role in demarcation of territories by dominant bulls.     

Lipoxygenase-derived aldehydes inhibit fungi pathogenic on soybean

Several unsaturated aldehydes are produced from polyunsaturated fatty acids via the lipoxygenase pathway when soybean (Glycine max) plants are wounded mechanically or by pathogens. The effects of four of these aldehydes were examined on the growth of isolated fungal cultures ofColletotrichum truncatum, Rhizoctonia solani, andSclerotium rolfsii. (E)-2-Hexenal, (E)-2-nonenal, and (Z)-3-nonenal inhibited the growth ofR. solani andS. rolfsii at 35 mol added per liter or greater when applied as volatiles, although higher levels were required for inhibition ofC. truncatum. (E)-4-Hydroxy-2-nonenal was the most inhibitory compound when applied directly in the growth medium, but it had the least effect as a volatile.Mention of firms or products does not imply endorsement by the U.S. Department of Agriculture over other firms or products not mentioned.     

Odor composition of preferred (buffalo and ox) and nonpreferred (waterbuck) hosts of some Savanna tsetse flies

A previous study on the feeding responses of tsetse flies, Glossina morsitans morsitans, implicated the existence of allomonal barriers, both volatile and nonvolatile, on the nonpreferred host, waterbuck, Kobus defassa. In the present study, electroantennogram-active compounds in odors from waterbuck were compared with those of two preferred hosts of tsetse flies, buffalo, Syncerus caffer, and ox, Bos indicus. Odors from the three bovids were trapped on activated charcoal and/or reverse-phase (octadecyl bonded) silica and analyzed with a gas chromatography-linked electroantennographic detector (GC-EAD) and, where possible, identified by using gas chromatography-linked mass spectrometry (GC-MS) and chromatographic comparisons with authentic samples. The GC-EAD profiles (with G. m. morsitans antennae) of the odors of the two preferred hosts were comparable, comprising medium-chain, saturated or unsaturated aldehydes and phenols, with buffalo emitting a few more EAG-active aldehydes. Waterbuck odor gave a richer profile, consisting of fewer aldehydes but more phenolic components and a series of 2-ketones (C₈–C₁₃) and -octalactone. This bovid also emits moderate amounts of C₅–C₉ straight-chain fatty acids, some of which were detected in buffalo and ox only in trace amounts. However, these did not elicit significant GC-EAD responses. Waterbuck profiles from the antennae of G. pallidipes showed broad similarity to those from G. m. morsitans, although the composition of aldehydes and ketones was somewhat different, indicating species-specific difference in the detection of host odors. Certain waterbuck-specific EAG-active components, particularly the 2-ketones and lactone, constitute a candidate allomonal blend in waterbuck odor.     

Analysis of gular and paracloacal gland secretions of the american alligator (Alligator mississippiensis) by thin-layer chromatography Gland,sex, and individual differences in lipid components

Secretions from the gular and the paracloacal glands of adult male and female American alligators (Alligator mississippiensis) were extracted with chloroform, weighed, and analyzed by thin-layer chromatography. In both sexes, more lipoidal secretions were recovered from the paracloacal glands than from the gular glands. Females produce more lipoidal secretions in both sets of glands than do males. The thin-layer chromatograms of extracts from both glands exhibit bands consistent with aliphatic alcohols, sterols, free fatty acids, and steryl esters. Triglycerides, hydrocarbons, phosphatidylethanolamine, and lysophosphatidylcholine also are indicated in some chromatograms. Gland, sex, and individual differences are suggested in the thinlayer profiles.     

Synthesis and surface properties of N-dodecyl-N,N-bis[3-(aldonamido)propyl]amine-N-oxides

A new group of saccharide surfactants, N-dodecyl-N,N-bis[3-(aldonamido)propyl]amine-N-oxides (derivatives of d-gluconic, d-glucoheptonic, and lactobionic acids), were synthesized with high yields by one-step oxidation reaction of an appropriate N-dodecyl-N,N-bis[3-(aldonamido)-propyl]amine with an excess of 30 wt% of an aqueous solution of hydrogen peroxide. Their structures and purity were confirmed by means of elemental analysis, electrospray ionization mass spectrometry, and ¹H and ¹³C nuclear magnetic resonance spectroscopy. In comparison to an appropriate N-dodecyl-N,N-bis[3-(aldonamido)propyl]amine, the investigated N-oxides are more soluble in water with similar critical micelle concentration values and show higher surface effectiveness. They are low-foamable but in mixtures with sodium dodecyl sulfate form high-volume and stable foams in a wide range of mixture compositions.     

Decarboxylative Oxygenation via Photoredox Catalysis

The direct conversion of aliphatic carboxylic acids to their dehomologated carbonyl analogues has been accomplished through photocatalytic decarboxylative oxygenation. This transformation is applicable to an array of carboxylic acid motifs, producing ketones, aldehydes, and amides in excellent yields. Preliminary results demonstrate that this methodology is further amenable to aldehyde substrates via in situ oxidation to the corresponding acid and subsequent decarboxylative oxygenation. We have exploited this strategy for the sequential oxidative dehomologation of linear aliphatic chains.     

Palladium‐Catalyzed Oxidative sp2 C?H Bond Acylation with Aldehydes

An efficient method was developed for the direct acylation of arene sp² C H bonds with aldehydes using palladium acetate as catalyst and peroxide as oxidant. The solvent‐free oxidative acylation reaction assisted by a pyridine directing group provides an easy access to aromatic, aliphatic, and optical active ketones.     

Perineal scent gland of wild and domestic guinea pigs

Wild and domestic male guinea pigs (Cavia aperea andCavia porcellus) prefer the perineal secretion from males of the same species to that of males of the other species. Gas chromatographic-mass spectroscopic analyses of the volatile components of the secretions show complex mixtures comprised primarily of fatty acids, alcohols, and ketones. Inter-species differences in the composition of the volatiles are evident. The possible role of bacteria in odor production is discussed.Camille and Henry Dreyfus Teacher-Scholar, 1978–1983.     

Wet 2,4,6-trichloro[1,3,5]triazine (TCT) an efficient catalyst for synthesis of -bis(substituted-benzylidene) cycloalkanones under solvent-free conditions

An array of aromatic aldehydes undergo crossed aldol condensation with ketones in the presence of catalytic amounts of wet-TCT under solvent-free conditions to afford the corresponding α,α^′-bis(substituted-benzylidene) cycloalkanones in excellent yields. Contrary to the existing methods, which use classical Lewis acids a new catalyst (TCT) is employed. This method is also general with respect to all types of aromatic aldehydes and is an eco friendly procedure.     

Synthesis of Ethyl 5 Z ,9 Z ,12 Z -octadecatrienoate (ethyl pinolenate) and Methyl 12 Z ,15 Z -octadecadienoate

Pinolenic acid (5Z,9Z,12Z-octadecatrienoic acid, 1a), one of the most abundant trienoic fatty acids in nature, is very difficult to obtain in quantity in a pure state from the highly complex mixture of unsaturated tall oil fatty acids. For this reason its chemistry has been little studied when compared to linolenic or linoleic acids. A simple synthesis of esters of 1a and of 12Z,15Z-octadecadienoic acid 3 using the one pot double Wittig procedure is described here. The products of double Wittig reactions were purified by argentation chromatography, and their structural purity was established by ¹H-, ¹³C-NMR and 2D-NMR spectroscopies.

Electroantennogram responses of the mediterranean fruit fly,Ceratitis capitata,to a spectrum of plant volatiles

Electroantennograms (EAGs) were recorded from unmated, laboratory-reared, male and femaleCeratitis capitata (medfly) in response to a range of C₁ and C₂ to C₁₂ carbon chain-length aliphatic alcohols, aldehydes, acetates, and acids, and lactones, some of which are known volatiles from leaves and fruits. A large degree of EAG response uniformity between the sexes was observed, with only eight of the 70 compounds tested eliciting significantly larger amplitude EAG responses from female than male antennae. In general, for the five functional-group series tested, aldehydes and alcohols elicited greater responses than acetates, lactones, and acids. The unsaturated alcohols, aldehydes, acetates, and acids elicited equal or larger amplitude EAG responses than their comparable saturated compounds. For four of the functional-group series tested, the EAG response amplitude was significantly greater for a particular carbon chain length, with responsiveness to primary alcohols and aldehydes peaking at C₆, acids peaking at C_5–6, and acetates peaking at both C₅ and C₈. The EAG responses to both the 2- and 3-position monoenic alcohols peaked at C₆ and C₈, while the secondary alcohols peaked at C₇. The greatest EAG responses of all compounds tested were elicited by monoenic C₆ alcohols and aldehydes that are constituents of the general green-leaf odor that emanates from most plants. The potential adaptive benefit of selective sensitivity to green-leaf volatiles is discussed in regard to foraging behavior of medflies.     

Second‐Generation N,O‐[2.2]Paracyclophane Ketimine Ligands for the Alkenylzinc Addition to Aliphatic and Aromatic Aldehydes: Scope and Limitations

Second generation N,O‐[2.2]paracyclophane ketimine ligands were investigated for their ability to catalyze the 1,2‐addition of alkenylzinc reagents to aliphatic and aromatic aldehydes with special focus on functionalized substrates. For aliphatic aldehydes, which have always been challenging in this field, remarkably high enantiomeric excesses could be determined (50–95 % ee). However, alkenylzinc reagents bearing heteroatoms proved to be demanding substrates for this system.     

Defensive and pheromonal secretion of the tergal gland of Aleochara curtula

The defensive secretion from the tergal gland of the staphylinid beetle,Aleochara curtula, acting as a supplementary mating stimulant, was investigated by gas-liquid chromatography, mass spectrometry, and IR spectroscopy. The reservoir contains a complex mixture of hydrocarbons, aliphatic aldehydes, and substituted 1,4-benzoquinones.n-Undecane, 1-undecene, and (Z)-4-tridecene were identified as the major hydrocarbon components. The main aldehydes aren-dodecanal and (Z)-5-tetradecenal, and the chief quinones are toluquinone and 2-methoxy-3-methyl-1,4-benzoquinone, the latter being established structurally by comparison of the mass spectra of the three synthesized isomers. Quantitative GLC analyses revealed no sex specificity of the relative concentrations of the compounds.Coleoptera: Staphylinidae (Aleocharinae)