Volatile ketones from the preorbital gland of reindeer (Rangifer t. tarandus L.)

The identification of 4-heptanone and 2-methyl-4-heptanone from the preorbital gland of reindeer (Rangifer t. tarandus L.) is reported. The secretion of the gland exhibit marked seasonal and sexual differences.     

Comparative study of neighboring group participation in reactions of N-bromoor N-chlorosuccinimide on methyl isoricinoleate

Reacting methyl isoricinoleate with N-bromosuccinimide in the presence of excess diols [mono-, di-, tri-, and tetraethylene glycol] gave the 1,4-epoxy derivative in 80% yield along with the respective ß-bromoethoxylates as minor products (20%). However, when the reaction was carried out with N-chlorosuccinimide, the yield of 1,4-epoxy derivative was reduced to 20%, and formation of ß-chloroethoxylates was increased to 80%.     

Effect of urea and salt on micelle formation of zwitterionic surfactants

The effect of urea on micelle formation of zwitterionic surfactants was investigated by measuring conductivity, critical micelle concentration (CMC), relative viscosity, and the spectrophotometric shift in wavelength. We examined two zwitterionic surfactants, N,N-dimethyl dodecylamine N-oxide and N,N-dimethyl tetradecylamine N-oxide (DMTAO). The CMC values of the surfactants increased with the addition of urea. Also, the relative viscosity of the surfactant solutions decreased at higher concentrations of urea and increased with increasing KCl concentration. The absorbance maxima of the surfactants decreased with increasing urea concentration.     

Molal volumes of somen-Fatty acids and their methyl and ethyl esters

The densities of some pure methyl and ethyl esters ofn-fatty acids were determined at temperatures between 10° to 80°C. The molal volumes of these esters and the long-chain fatty acids were correlated with temperature and chainlength. The reciprocals of the average methylene contribution at long-chain and the end group contribution to the molal volumes were found to be linear functions of the temperature. With the introduction of a correction term to account for mutual interaction of the end groups, three equations, one for each of the esters and the acids, were developed. These equations were used to calculate the molal values of the acids with carbon numbers up to 30 and up to 20 for the esters at temperatures ranging from 10° to 100°C. Excellent agreements were obtained between the molal volumes calculated by the equations and those obtained from the literature and experimental data.     

Sucrose esters of carboxylic acids in glandular trichomes ofSolanum berthaultii deter settling and probing by green peach aphid

Removal of type B trichome exudate fromSolanum berthaultii leaflets leads to a decrease in tarsal gumming and mortality and an increase in feeding by the green peach aphid,Myzus persicae. Type B trichome exudate of theS. berthaultii accession PI 473331 is composed of a complex of 3,3,4,6-tetra-O-acyl sucroses containing primarily short-chain branched carboxylic acids. The acyl constituents are primarily derived from 2-methylpropanoic, 2-methylbutyric, and 8-methylnonanoic acids but constituents derived fromn-decanoic and dodecanoic acids are also present. Sucrose esters inhibit settling and probing by aphids in glass feeding cages.     

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.     

Gas chromatography-fourier transform infrared spectrometry of fatty acids: New applications with a direct deposition interface

Infrared spectroscopy is a suitable spectroscopic method to differentiate geometric Z and E isomers of unsaturated compounds. A direct-deposition Fourier transform infrared spectrometer (FTIR), coupled to a gas chromatograph, was used successfully to analyze with a high sensitivity traces of C18:1 fatty acid methyl ester (FAME) isomers. It could also conclusively distinguish between isomers of conjugated diunsaturated FAME. The achievable sensitivity of this direct-deposition device makes possible accurate FAME mixture analyses that are not currently attainable with the more conventional light-pipe interface.     

Identification,Quantification, and Determination of the Absolute Configuration of the Bacterial Quorum‐Sensing Signal Autoinducer‐2 by Gas Chromatography–Mass Spectrometry

Sensing the signal : A gas chromatography–mass spectrometry (GC–MS) method for the analysis of the quorum‐sensing autoinducer‐2 is described. It allows, for the first time, the direct analysis and accurate determination of this highly water soluble signaling compound, which exists in complex equilibria. The application on the caries‐causing bacterium Streptococcus mutans is described.

     

Mammalian Exocrine Secretions. XIII: Constituents of Preorbital Secretions of Bontebok, Damaliscus dorcas dorcas, and Blesbok, D. d. phillipsi

The 42 compounds identified in the pale yellow preorbital secretions of the bontebok, Damaliscus dorcas dorcas, and the blesbok, D. d. phillipsi, include acetic acid, 2-methylbutanoic acid, (E)-2-methyl-2-butenoic acid, benzoic acid, 4-hydroxybenzoic acid, saturated and unsaturated long-chain carboxylic acids, 4-hydroxybenzaldehyde, saturated and unsaturated, unbranched, long-chain alcohols and aldehydes, 2-heptanone, pentane, heptane, pepiritone, dimethylsulfone, isopropyl tetradecanoate, isopropyl hexadecanoate, hexadecyl acetate, -lactones, cholesterol, -tocopherol, and squalene. Some qualitative and quantitative differences were found between the secretions of males and females of both subspecies.     

Synthesis of β-bromoethoxylates and β-chloroethoxylates from olefinic fatty methyl esters

Olefinic fatty methyl esters [undec-10-enoate (1), octadec-Z-9-enoate (2), methyl-12 hydroxy octadec-Z-9-enoate (3)], on reaction with an N-halosuccinimide (4–5)—i.e., N-bromosuccinimide (NBS; 4) or N-chlorosuccinimide (NCS; 5)—in the presence of diols such as mono-, di-, tri-, and tetraethylene glycols (6–9), gave the respective β-bromo- or β-chloroethoxylates (11–34).     

Reinvestigation of the polymethylene-interrupted 18:2 and 20:2 acids of Ginkgo biloba seed lipids

The fatty acid composition of Ginkgo biloba seed lipids was reinvestigated with particular emphasis on the polymethylene-interrupted octadecadienoic and eicosadienoic acids. Analysis of the picolinyl esters and 4,4-dimethyloxazoline derivatives by capillary gas-liquid chromatography on a highly polar cyanopropyl polysiloxane stationary phase coupled with mass spectrometry revealed the presence of three such acids, with the structures 5,9–18:2, 5,11–18:2, and 5,11–20:2. This indicated that in G. biloba seeds, cis-vaccenic (11–18:1) acid may be a substrate for the Δ5-desaturase characteristic of gymnosperms. The 5,11-18:2 acid was not limited to G. biloba, as it may occur in a few other species. The 5,11-20:2 acid is a common component of the seed lipids from almost all gymnosperm species analyzed so far.     

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.     

Mammalian Exocrine Secretions. XII: Constituents of Interdigital Secretions of Bontebok, Damaliscus dorcas dorcas, and Blesbok, D. d. phillipsi

In addition to the nine compounds identified in the interdigital secretion of the bontebok, Damaliscus dorcas dorcas, in a previous study, 76 compounds belonging to different compound types, were identified in the interdigital secretions of the bontebok and the blesbok, D. d. phillipsi. These compounds include alkanes, alcohols, aldehydes, ketones, fatty acids, terpenoids, -lactones, an isopropyl ester, long-chain hydroxyesters, 2-substituted pyridines, phenols, steroids, and dimethylsulfone. No qualitative differences were found between secretions from the two sexes or from animals from different habitats. Although no attempt was made to correlate territorial behavior or other behavioral phenomena with the qualitative composition of interdigital secretions from individual animals, available information seems to indicate that quantitative differences probably do not have a major semiochemical function. Only two species of bacteria, Bacillus brevis and Planococcus citreus, were found in the interdigital pouches of male and female members of the two subspecies, regardless of the habitat of the animals. B. brevis synthesized, among other unidentified constituents, (Z)-3-penten-2-ol, 2-hexanone, 2-octanone, 2-nonanone, tetradecanoic acid, pentadecanoic acid, heptadecanoic acid, octadecanoic acid, (Z)-9-hexadecenoic acid, and isopropyl hexadecanoate in vitro, while P. citreus produced, among others, the -lactones dodecan-4-olide and (Z)-6-dodecen-4-olide, which is one of the major constituents of the interdigital secretions of both subspecies. Some components of the interdigital secretions are not present in the interdigital glandular tissue, and the possibility is discused that these compounds could be produced by microbiological activity in the interdigital pouch.     

Synthesis and Characterization of Diepoxyalkenes Derived from (3Z,6Z,9Z)-Trienes: Lymantriid Sex Pheromones and Their Candidates

All stereoisomers of three diepoxyalkenes derived from (3Z,6Z,9Z)-trienes with a C₂₁, C₁₉, or C₁₈ straight chain, lymantriid sex pheromones and their candidates, were synthesized by MCPBA oxidation of optically active epoxyalkadienes. Their chromatographic behaviors were examined with GC and LC equipped with achiral and chiral columns. Detailed inspection of the mass spectra of these epoxides indicated the following diagnostic ions for determining the chemical structures: m/z 128, 167, M-87 and M-85 for (Z)-cis-3,4-cis-6,7-diepoxy-9-enes; m/z 111, M-125 and M-69 for (Z)-cis-6,7-cis-9,10-diepoxy-3-enes; and m/z M-125 and M-139 for (Z)-cis-3,4-cis-9,10-diepoxy-6-enes. Mass chromatographic analysis that monitored these fragment ions revealed the existence of a new pheromonal compound with a C₂₁ chain in an extract from virgin females of a lymantriid species, Perina nuda F. The three diepoxyalkenes were converted into the corresponding DMDS adducts, which showed characteristic ions from fragmentation between the two thiomethyl groups, reflecting the position of an original double bond.     

Sex pheromone of the scarab beetle Phyllophaga elenans and some intriguing minor components

Three amino acid-derived compounds were identified in extracts from the pheromone glands of the scarab beetle Phyllophaga elenans, i.e., L-isoleucine methyl ester (LIME), N-formyl L-isoleucine methyl ester (For-LIME), and N-acetyl L-isoleucine methyl ester (Ac-LIME). The compounds were characterized from their spectral data (MS and IR), confirmed by synthesis, and their absolute configurations were assigned by gas chromatography with a chiral phase column. The amount of LIME in calling females was ca. 2 g/gland, whereas only traces of For-LIME and Ac-LIME (0.005% of LIME) were detected in fresh extracts. Regardless of the storage temperature, the amounts of the minor constituents in the extracts increased over time. Field tests showed that traps baited with For-LIME captured more beetles than control traps. Ac-LIME per se was not attractive, and it did not increase trap catches when combined with For-LIME. Traps baited with LIME caught ca. 150 beetles/trap/day, but catches did not increase with the addition of For-LIME and/or Ac-LIME in binary or tertiary blends.     

Geometrical and optical isomerism of pheromones in two sympatricDryocoetes species (Coleoptera: Scolytidae), mediates species specificity and response level

In a field-trapping experiment, western balsam bark beetles,Dryocoetes confusus Swaine, were highly attracted to a 51 mixture of (±)-exo-and (±)-endo-brevicomin. Beetles in the sympatric speciesD. affaber (Mann.), were best attracted to a 11 blend of these semiochemicals [either (±)(±) or (±)(±)], suggesting that both geometrical isomers are pheromone components in these species. In laboratory bioassays and further field experiments, attraction ofD. confusus was greatest when the (+) enantiomers of both geometrical isomers of brevicomin were presented in a 91 ratio. Responses by maleD. confusus to attractive mixtures were reduced in the presence of (–)-exo-brevicomin. Exploitation of the complete range of variability in pheromone structure (both geometrical and optical isomerism) would allow for optimization and regulation of response levels within a species and also could maintain reproductive isolation among sympatric congeneric species primarily through production and response to species-specific blends.During the course of the research, A.D. Camacho was on educational leave from the Escuela Nacional de Ciencias Biológicas. I.P.N. Depto. de Zoología. Prol. Carpio y Plan de Ayala, Mexico 11340D.F. México.     

Mammalian exocrine secretions: X. constituents of preorbital secretion of grysbok,Raphicerus melanotis

Using electron impact and chemical ionization mass spectrometry with methane and nitric oxide as reactant gases in conjunction with mass spectral analysis of the dimethyl disulfide derivatives of unsaturated constituents, 51 compounds have been identified in addition to the compounds previously found in the preorbital secretion of the grysbokRaphicerus melanotis. The compounds identified are saturated, monounsaturated, and diunsaturated alcohols and formates, saturated and monounsaturated aldehydes, saturated carboxylic acids,- and-lactones, alkyl methyl sulfides, and-hydroxyalkyl acetates. All of these compounds have unbranched structures. The constituent previously incorrectly identified as (Z)-5-tetradecen-1-ol, was found to consist of the coeluting (Z)-7- and (Z)-8-tetradecenols.     

Mandibular gland secretions of the male beewolvesPhilanthus crabroniformis,P. barbatus,andP. pulcher (Hymenoptera: Sphecidae)

The composition of the territorial marking pheromones from mandibular glands of males of the beewolvesPhilanthus crabroniformis, P. barbatus, andP. pulcher have been determined. The structures of the components were elucidated by gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared spectroscopy. The major compound ofP. crabroniformis is isopropyl tetradecanoate, with somewhat lesser amounts of 2-tridecanone, 3-methyl-3-butenyl tetradecanoate, and 928 (Z)(E)-11-eicosen-1-ol. The major compounds ofP. barbatus are ethyl tetradecanoate and hexadecanal, which are present in approximately a 6040 ratio. These two compounds comprise over 95% of the neutral lipids. Also present in lesser amounts are ethyl dodecanoate, tetradecanal, hexadecan-1-ol, a ^x -octadecen-1-ol, and octadecan-1-ol. The major compounds ofP. pulcher are ethyl (Z)-7-hexadecenoate and geranylgeraniol acetate, which comprise nearly 90% of the neutral lipid fraction, with smaller amounts of tetradecanal, pentadecanal, and ethyl hexadecanoate; trace amounts of ^x hexadecenal, hexadecanal, and octadecanal are also present.     

Characterization of wax esters in the roe oil of amber fish,Seriola aureovittata

The wax esters of the roe oil of the amber fish,Seriola aureovittata, have been resolved by high-performance liquid chromatography (HPLC) in the silver-ion mode. Each of the fractions collected was transmethylated, and the fatty acids and alcohols were identified by gas chromatography/mass spectrometry (GC/MS) as the picolinyl esters and nicotinates, respectively. Their compositions were determined by GC. The fatty acid composition is complex, and the main components are C18:1n-9 (35.5 mol%), C22:6n-3 (20.3 mol%), and C16:1n-7 (10.7 mol%), while fatty alcohols are limited to saturated (C16:0, 60.3 mol%; C18:0, 15.3 mol%; C14:0, 5.1 mol%) and monoenoic alcohols (C18:1n-9, 6.5 mol%; C16:1n-7, 4.5 mol%) with traces (<0.1 mol%) of polyunsaturated fatty alcohols such as C20:3n-3, C20:4n-6, C20:5n-3, and C22:5n-3. Silver-ion HPLC exhibited excellent resolution in which fractions were resolved on the basis of the number and configuration of double bonds as well as the distribution pattern between the acid and alcohol moieties of the molecules with a given number of double bonds. The main wax ester fraction are those of monoenoic acid-saturated alcohol species, hexaenoic acid/saturated alcohol species, and pentaenoic acid/saturated alcohol species. Appreciable specificity was observed in the esterification of fatty acids with alcohols, and surprisingly, no saturated acid-monoenoic alcohol species were detected.     

GC-MS detected difunctional carboxylic acids released by driedCladophora at the pH of lake ontario and the st. lawrence river

A study to identify the acidic components ofCladophora glomeata active againstAedes triseriatus larvae was extended to a mixture obtained by extracting the dried powdered alga in aqueous suspension at pH 8.5. The presence of 1,9-nonanedioic, 1,10-decanedioic, 1,11-undecanedioic and 4-ketononanoic acids was determined by GC-EIMS and GC-CIMS and confirmed by analytical coinjection GC. The presence of 5-pentyldihydro-2(3H)-furanone, a minor component, was also indicated. The group of major acidic constituents is different from those obtained by extracting driedCladophora with methanol. In contrast to the C₁₀–C₁₄ monocarboxylic acids, which hadLD ₅₀ values<20 ppm againstA. triseriatus, none of the dicarboxylic acids of the series G₄–C₁₄, C₁₆, and C₂₂ were active; nor were 4-ketononanoic acid and 5-pentyldihydro-2(3H)-furanone active.