13434-12-3Relevant academic research and scientific papers
Cuticular chemistry of the queensland fruit fly bactrocera tryoni (froggatt)
Castro-Vargas, Cynthia,Mendez, Vivian,Oakeshott, John G.,Pandey, Gunjan,Park, Soo J.,Taylor, Phillip W.
, (2020)
The cuticular layer of the insect exoskeleton contains diverse compounds that serve important biological functions, including the maintenance of homeostasis by protecting against water loss, protection from injury, pathogens and insecticides, and communication. Bactrocera tryoni (Froggatt) is the most destructive pest of fruit production in Australia, yet there are no published accounts of this species’ cuticular chemistry. We here provide a comprehensive description of B. tryoni cuticular chemistry. We used gas chromatography-mass spectrometry to identify and characterize compounds in hexane extracts of B. tryoni adults reared from larvae in naturally infested fruits. The compounds found included spiroacetals, aliphatic amides, saturated/unsaturated and methyl branched C12 to C20 chain esters and C29 to C33 normal and methyl-branched alkanes. The spiroacetals and esters were found to be specific to mature females, while the amides were found in both sexes. Normal and methyl-branched alkanes were qualitatively the same in all age and sex groups but some of the alkanes differed in amounts (as estimated from internal standard-normalized peak areas) between mature males and females, as well as between mature and immature flies. This study provides essential foundations for studies investigating the functions of cuticular chemistry in this economically important species.
Attraction and electrophysiological response to identified rectal gland volatiles in bactrocera frauenfeldi (schiner)
Alvarez, Vivian Mendez,Holgate, Danielle,Jamie, Ian,Jamie, Joanne,Jean Park, Soo,Noushini, Saeedeh,Perez, Jeanneth,Taylor, Phillip
, (2020)
Bactrocera frauenfeldi (Schiner) (Diptera: Tephritidae) is a polyphagous fruit fly pest species that is endemic to Papua New Guinea and has become established in several Pacific Islands and Australia. Despite its economic importance for many crops and the key role of chemical-mediated sexual communication in the reproductive biology of tephritid fruit flies, as well as the potential application of pheromones as attractants, there have been no studies investigating the identity or activity of rectal gland secretions or emission profiles of this species. The present study (1) identifies the chemical profile of volatile compounds produced in rectal glands and released by B. frauenfeldi, (2) investigates which of the volatile compounds elicit an electroantennographic or electropalpographic response, and (3) investigates the potential function of glandular emissions as mate-attracting sex pheromones. Rectal gland extracts and headspace collections from sexually mature males and females of B. frauenfeldi were analysed by gas chromatography-mass spectrometry. Male rectal glands contained (E,E)-2-ethyl-8-methyl-1,7-dioxaspiro [5.5]undecane as a major component and (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane as a moderate component. Minor components included palmitoleic acid, palmitic acid, and ethyl oleate. In contrast, female rectal glands contained (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane and ethyl laurate as major components, ethyl myristate and ethyl palmitoleate as moderate components, and 18 minor compounds including amides, esters, and spiroacetals. Although fewer compounds were detected from the headspace collections of both males and females than from the gland extractions, most of the abundant chemicals in the rectal gland extracts were also detected in the headspace collections. Gas chromatography coupled electroantennographic detection found responses to (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane from the antennae of both male and female B. frauenfeldi. Responses to (E,E)-2-ethyl-8-methyl-1,7-dioxaspiro[5.5]undecane were elicited from the antennae of females but not males. The two spiroacetals also elicited electropalpographic responses from both male and female B. frauenfeldi. Ethyl caprate and methyl laurate, found in female rectal glands, elicited responses in female antennae and palps, respectively. Y-maze bioassays showed that females were attracted to the volatiles from male rectal glands but males were not. Neither males nor females were attracted to the volatiles from female rectal glands. Our findings suggest (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane and (E,E)-2-ethyl-8-methyl-1,7-dioxaspiro[5.5]undecane as components of a sex-attracting pheromone in B. frauenfeldi.
Electrophysiological responses of bactrocera kraussi (Hardy) (tephritidae) to rectal gland secretions and headspace volatiles emitted by conspecific males and females
Holgate, Danielle,Jamie, Ian M.,Jamie, Joanne F.,Mendez, Vivian,Noushini, Sally,Park, Soo Jean,Perez, Jeanneth,Taylor, Phillip W.
, (2021/08/27)
Pheromones are biologically important in fruit fly mating systems, and also have potential applications as attractants or mating disrupters for pest management. Bactrocera kraussi (Hardy) (Diptera: Tephritidae) is a polyphagous pest fruit fly for which the chemical profile of rectal glands is available for males but not for females. There have been no studies of the volatile emissions of either sex or of electrophysiological responses to these compounds. The present study (i) establishes the chemical profiles of rectal gland contents and volatiles emitted by both sexes of B. kraussi by gas chromatography–mass spectrometry (GC–MS) and (ii) evaluates the detection of the identified compounds by gas chromatography–electroantennogram detection (GC–EAD) and –electropalpogram detection (GC–EPD). Sixteen compounds are identified in the rectal glands of male B. kraussi and 29 compounds are identified in the rectal glands of females. Of these compounds, 5 were detected in the headspace of males and 13 were detected in the headspace of females. GC–EPD assays recorded strong signals in both sexes against (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane, 2-ethyl-7-mehtyl-1,6-dioxaspiro[4.5]decane isomer 2, (E,Z)/(Z,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane, and (Z,Z)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane. Male antennae responded to (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane, 2-methyl-6-pentyl-3,4-dihydro-2H-pyran, 6-hexyl-2-methyl-3,4-dihydro-2H-pyran, 6-oxononan-1-ol, ethyl dodecanoate, ethyl tetradecanoate and ethyl (Z)-hexadec-9-enoate, whereas female antennae responded to (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane and 2-methyl-6-pentyl-3,4-dihydro-2H-pyran only. These compounds are candidates as pheromones mediating sexual interactions in B. kraussi.
Oxidation of amines over alumina based catalysts
Rakottyay, Karol,Kaszonyi, Alexander,Vají?ek, Stanislav
experimental part, p. 33 - 41 (2010/08/22)
Amines were oxidized by molecular oxygen in the vapor phase at atmospheric pressure over alumina and silicotungstic acid/alumina catalysts. The study is focused on the influence of structure of amine and catalyst properties on the composition of the main reaction products and byproducts. Coating of γ-Al2O3 with silicotungstic acid or its semisalt can significantly enhance its catalytic activity in amine oxidation. The adsorption of amine on weak acidic sites of catalyst is essential for its oxidation to main reaction products. Cycloalkylamines are oxidized mainly to cyclic oximes (selectivity up to 64%) and Schiff bases of appropriate cycloalkanone and cycloalkylamine (selectivity up to 38%). Mainly nitriles (selectivity up to 55%) and appropriate Schiff bases (selectivity up to 54%) were observed in the oxidation products of primary alkylamines. Their molar ratio depends on the catalyst acidity and reaction conditions. 1,6-Hexanediamine is oxidized mainly to caprolactam (yield 48%) and other cyclic lactames and Schiff bases as well as to dinitrile (yield 13%).
Stereoselective synthesis of 2-aminocyclobutanols via photocyclization of α-amido alkylaryl ketones: Mechanistic implications for the Norrish/Yang reaction
Griesbeck, Axel G.,Heckroth, Heike
, p. 396 - 403 (2007/10/03)
A series of chiral N-acylated α-amino p-methylbutyrophenone derivatives 1a-1h was synthesized from α-amino acids via a three-step procedure. These substrates were photolyzed in benzene and gave Norrish II and Norrish I cleavage products as well as the N-acylated 2-aminocyclobutanols that derive from γ-hydrogen abstraction and 1,4-triplet biradical combination (Yang cyclization). The products were formed with characteristic Yang/cleavage ratios. The quantum yields for the photodecomposition of the N-acetyl-protected substrates 1b,e,f were moderate (12-26%); the diastereoselectivities of the cyclobutanol formation were remarkably high for all substrates. High diastereospecificity was observed for the isoleucine derivatives (2S,3S)-1g and allo-(2S,3R)-1g; the Yang reaction dominated the photochemistry of allo-1g, whereas 1g gave preferentially Norrish II cleavage. The role of hydrogen bonding as one of the stereo-directing effects was demonstrated by comparison of the cyclization efficiency of the valine derivative 1e with 1h,i,j. Also, aromatic β-keto esters gave the Yang cyclization products in low yields. The diastereoselectivity of the cyclobutanol formation was rationalized by a three-step mechanism where every step is connected with one distinct stereochemical induction mechanism: (a) diastereoselective hydrogen abstraction, (b) conformational equilibration of the 1,4-tetramethylene biradicals (as calculated by semiempiric methods) controlled by hydrogen bonding, and (c) diastereoselective biradical combination (versus cleavage) influenced by spin-orbit coupling controlled intersystem crossing geometries.
DIBAL-H-H2NR and DIBAL-H-HNR1R2·HCl complexes for efficient conversion of lactones and esters to amides
Huang, Pei-Qiang,Zheng, Xiao,Deng, Xian-Ming
, p. 9039 - 9041 (2007/10/03)
The reaction of a lactone or an ester with organoaluminum species generated from DIBAL-H-H2NR or DIBAL-H-HNR1R2·HCl complexes provided efficient methods for preparation of amides. Conditions were defined for the preparation of both secondary and tertiary amides, including Weinreb amides in excellent yields.
Nucleophilic Attack vs General Base Assisted Hydrolysis in the Reactions of Acetic Anhydride with Primary and Secondary Amines. pH-Yield Studies in the Recognition and Assessement of the Nucleophilic and General Base Reactions
King, James F.,Guo, Zhen Rong,Klassen, Darryl F.
, p. 1095 - 1101 (2007/10/02)
The reaction of a set of primary and secondary amines with acetic anhydride in water at 25 deg C gave variable yields of the N-substituted acetamide in seven of the eight amines studied.The yield of the amide as a function of pH revealed the incursion in the most cases of a general base assisted hydrolysis of the acetic anhydride by the amine.From the pKa's of the amines and kw and kOH for acetic anhydride (the specific rates for the reaction of the anhydride with water and hydroxide, respectively), both kDN (for the formation of acetamides) and kGB (for the general base assisted hydrolysis) may be readily evaluated by fitting the pH-yield-data to pH-yield or pH-product ratio profiles.The reactions of ethyl chloroformate with aniline and benzylamine in water also showed the presence of the general base assisted reaction.It is concluded that (a) pH-yield data provide a new way of showing the existence of general base assisted hydrolysis in the presence of a direct nucleophilic displacement reaction, (b) the general base promoted reaction is sufficiently prevalent that it would be prudent to check specifically for its presence in any investigation of mechanisms of acyl transfer in water, and (c) until the extent of general base promoted hydrolysis can be predicted adequately, the possibility of such a reaction makes it difficult to predict yields of the products of the direct attack, and hence just how suitable a medium water may be for a particular preparative acyl transfer reaction.
