Synthesis of a Particular Class of Silicon‐Tethered Dinucleophiles: Several Propargyloxydimethylsilyl Enol Ethers

The propargyloxydimethylsilyl enol ethers derived from propanone, 2‐butanone, 3,3‐dimethyl‐2‐butanone, 3‐pentanone, 4‐methyl‐2‐pentanone, 2‐heptanone, 4‐heptanone, 2,6‐dimethyl‐4‐heptanone, cyclopentanone, cyclohexanone, cycloheptanone, benzophenone, and propiophenone have been synthesized by two methods: The thermodynamic method is conducted by heating the propargyloxysilyl chloride, triethylamine, and the corresponding ketone in acetonitrile at 40–50°C for less than an hour in the presence of an equimolar amount of sodium iodide; the mixture is maintained at that temperature for an hour. The yields were in the range of 50–95%. In method two (kinetic controlled), lithium diisopropylamide (LDA) was used as a base to abstract the acidic hydrogen, and then the resulted enolate was quenched with silyl chloride, with lower yields than the previous method. NMR, IR, and elemental analysis were used to characterize the products. Some reactions of these compounds have been investigated.     

Maculatic Acids—Sex Attractant Pheromone Components of Bald‐Faced Hornets

Yellowjackets in the genera Vespula and Dolichovespula are prevalent eusocial insects of great ecological and economic significance, but the chemical signals of their sexual communication systems have defied structural elucidation. Herein, we report the identification of sex attractant pheromone components of virgin bald‐faced hornet queens (Dolichovespula maculata). We analyzed body surface extracts of queens by coupled gas chromatographic–electroantennographic detection (GC‐EAD), isolated the compounds that elicited responses from male antennae by high‐performance liquid chromatography (HPLC), and identified these components by GC mass spectrometry (MS), HPLC‐MS, and NMR spectroscopy. In laboratory olfactometer experiments, synthetic (2Z,7E)‐3,7‐dimethyldeca‐2,7‐diendioic acid (termed here maculatic acid A) and (2Z,7E)‐10‐methoxy‐3,7‐dimethyldeca‐10‐oxo‐deca‐2,7‐dienoic acid (termed here maculatic acid C) in binary combination significantly attracted bald‐faced hornet males. These are the first sex attractant pheromone components identified in yellowjackets.     

Total Synthesis,Stereochemical Assignment,and Field‐Testing of the Sex Pheromone of the Strepsipteran Xenos peckii

The sex pheromone of the endoparasitoid insect Xenos peckii (Strepsiptera: Xenidae) was recently identified as (7E,11E)‐3,5,9,11‐tetramethyl‐7,11‐tridecadienal. Herein we report the asymmetric synthesis of three candidate stereostructures for this pheromone using a synthetic strategy that relies on an sp³–sp² Suzuki–Miyaura coupling to construct the correctly configured C7‐alkene function. Comparison of ¹H NMR spectra derived from the candidate stereostructures to that of the natural sex pheromone indicated a relative configuration of (3R*,5S*,9R*). Chiral gas chromatographic (GC) analyses of these compounds supported an assignment of (3R,5S,9R) for the natural product. Furthermore, in a 16‐replicate field experiment, traps baited with the synthetic (3R,5S,9R)‐enantiomer alone or in combination with the (3S,5R,9S)‐enantiomer captured 23 and 18 X. peckii males, respectively (mean±SE: 1.4±0.33 and 1.1±0.39), whereas traps baited with the synthetic (3S,5R,9S)‐enantiomer or a solvent control yielded no captures of males. These strong field trapping data, in combination with spectroscopic and chiral GC data, unambiguously demonstrate that (3R,5S,9R,7E,11E)‐3,5,9,11‐tetramethyl‐7,11‐tridecadienal is the X. peckii sex pheromone.     

Controlled release of 2‐heptanone using starch gel and polycaprolactone matrices and polymeric films

Varroa jacobsoni is a parasitic mite that is threatening the honeybee industry in many parts of the world. 2‐Heptanone, a natural product made by honeybees at low concentrations, is effective at elevated concentrations in controlling mite populations in honeybee colonies, especially when released over a 42 day period. An extrusion process was used to encapsulate 14, 18, and 25% 2‐heptanone in a polycaprolactone (PCL) matrix. Less than 18% of the 2‐heptanone was encapsulated in the PCL matrix. The high vapor permeability of PCL to 2‐heptanone resulted in a high flux rate and limited the usefulness of PCL as an encapsulation matrix for controlled‐release devices. A starch gel containing three times its weight in 2‐heptanone was prepared from starch‐based microcellular foam (MCF). The gel had compressive, tensile, and flexural strength values in the range of 0.56 to 1.9 MPa. 2‐Heptanone quickly evaporated from non‐laminated gels. However, when the gel was laminated with different polymeric films, a wide range of flux rates was obtained. The T₅₀ for gels laminated or coated with poly(vinyl alcohol) (PVAL, 99% hydrolyzed) and ethylene‐vinyl alcohol copolymer (EVAL) was 72 and 1030 days, respectively. The most promising film was a starch/glycerol film that released 50% of the 2‐heptanone (T₅₀) in approximately 13 days. Copyright © 2007 John Wiley & Sons, Ltd.     

Bed Bug Aggregation Pheromone Finally Identified

Bed bugs have become a global epidemic and current detection tools are poorly suited for routine surveillance. Despite intense research on bed bug aggregation behavior and the aggregation pheromone, which could be used as a chemical lure, the complete composition of this pheromone has thus far proven elusive. Here, we report that the bed bug aggregation pheromone comprises five volatile components (dimethyl disulfide, dimethyl trisulfide, (E)‐2‐hexenal, (E)‐2‐octenal, 2‐hexanone), which attract bed bugs to safe shelters, and one less‐volatile component (histamine), which causes their arrestment upon contact. In infested premises, a blend of all six components is highly effective at luring bed bugs into traps. The trapping of juvenile and adult bed bugs, with or without recent blood meals, provides strong evidence that this unique pheromone bait could become an effective and inexpensive tool for bed bug detection and potentially their control.     

（—）—莰烷磺内酰胺法合成（S）和（R）切叶蚁警戒信息素

本文以樟脑衍生物(-)-莰烷磺内酰胺(2)为原料,经N-烷酰基莰烷-2,10-磺内酚胺(3)与碘代烷的不对称烷基化反应,用二锂代乙基苯基砜取代磺内酰胺助剂以及铝汞还原性脱硫反应等三步合成(S)和(R)一切叶蚁警戒信息素(1),其光学纯度高达95％e.e以上。     

2-吡咯烷甲醇法合成切叶蚁警戒信息素

甲基庚酮;昆虫信息素;不对称烷基化反应;2-吡咯烷甲醇法合成切叶蚁警戒信息素     

Monitoring sea lamprey pheromones and their degradation using rapid stream‐side extraction coupled with UPLC‐MS/MS

Pheromones guide adult sea lamprey (Petromyzon marinus) to suitable spawning streams and mates, and therefore, when quantified, can be used to assess population size and guide management. Here, we present an efficient sample preparation method where 100 mL of river water was spiked with deuterated pheromone as an internal standard and underwent rapid field‐based SPE and elution in the field. The combination of field extraction with laboratory UPLC‐MS/MS reduced the sample consumption from 1 to 0.1 L, decreased the sample process time from more than 1 h to 10 min, and increased the precision and accuracy. The sensitivity was improved more than one order of magnitude compared with the previous method. The influences of experimental conditions were assessed to optimize the separation and peak shapes. The analytical method has been validated by studies of stability, selectivity, precision, and linearity and by the determination of the limits of detection and quantification. The method was used to quantify pheromone concentration from five streams tributary to Lake Ontario and to estimate that the environmental half‐life of 3kPZS is about 26 h.     

Rate Study of Proton Catalyzed SmI2 Reduction of 2‐Heptanone and 1,2‐Epoxydecane

Rate constants directly measured from the GC‐analyzed method for SmI₂ reduction of 2‐heptanone and 1,2‐epoxydecane in the presence of various proton sources were obtained. Water exhibits much stronger catalytic effect than methanol and t‐butanol. Dependence of reaction rates on concentration of SmI₂ and temperature were studied.     

Effects of variation in modulator temperature during cryogenic modulation in comprehensive two‐dimensional gas chromatography

Many modulation systems in comprehensive 2D GC (GC×GC) are based on cryogenic methods. High trapping temperatures in these systems can result in ineffective trapping of the more volatile compounds, whilst temperatures that are too low can prevent efficient remobilisation of some compounds. To better understand the trapping and release of compounds over a wide range of volatilities, we have investigated a number of different constant temperature modulator settings, and have also examined a constant temperature differential between the cryo‐trap and the chromatographic oven. These investigations have led us to modify the temperature regulation capabilities of the longitudinally modulated cryogenic system (LMCS). In contrast to the current system, where the user sets a constant temperature for the cooling chamber, the user now sets the temperature difference between the cryo‐trap and the chromatographic oven. In this configuration, the cooling chamber temperature increases during the chromatographic run, tracking the oven temperature ramp. This produces more efficient, volatility‐dependent modulation, and increases the range of volatile compounds that can be analysed under optimal trap‐and‐release conditions within a single analytical run. This system also reduces cryogenic fluid consumption.     

Determination of natural olive fruit fly pheromone in insect samples by enzyme linked immunoassays

The olive fruit fly pheromone avidin-biotin ELISA immunoassay, based on the use of polyclonal G antibodies derived from rabbits (reported previously) and a newer assay, based on the use of polyclonal Y antibodies isolated from the eggs of laying hens (reported in this paper), were applied successfully for the analysis of natural pheromone in virgin adult female olive fruit flies. According to the results obtained, the pheromone content in the glands of adult female olive fruit flies increases from the third to the ninth day of their age. During the calling period, the female olive fruit flies seem to emit approximately 1.1microg pheromone/insect/day at least. The immunoassay, based on the Y antibodies, is slightly more sensitive (detection limit 40ng/mL) than the assay based on polyclonal anti-pheromone rabbit antiserum (detection limit 80ng/mL). As revealed by thorough cross-reactivity studies, including 14 structurally similar to the olive fruit fly pheromone molecules, the newer immunoassay is less selective than the previous one and seems to cross react with few molecules bearing the spiroketal moiety.     

On the inter‐instrument and inter‐laboratory transferability of a tandem mass spectral reference library: 1. Results of an Austrian multicenter study

The inter‐instrument and inter‐laboratory transferability of a tandem mass spectral reference library originally built on a quadrupole‐quadrupole‐time‐of‐flight instrument was examined. The library consisted of 3759 MS/MS spectra collected from 402 reference compounds applying several different collision‐energy values for fragmentation. In the course of the multicenter study, 22 test compounds were sent to three different laboratories, where 418 tandem mass spectra were acquired using four different instruments from two manufacturers. The study covered the following types of tandem mass spectrometers: quadrupole‐quadrupole‐time‐of‐flight, quadrupole‐quadrupole‐linear ion trap, quadrupole‐quadrupole‐quadrupole, and linear ion trap‐Fourier transform ion cyclotron resonance mass spectrometer. In each participating laboratory, optimized instrumental parameters were gathered solely from routinely applied workflows. No standardization procedure was applied to increase the inter‐instrument comparability of MS/MS spectra. The acquired tandem mass spectra were matched against the established reference library using a sophisticated matching algorithm, which is presented in detail in a companion paper. Correct answers, meaning that the correct compound was retrieved as top hit, were obtained in 98.1% of cases. For the remaining 1.9% of spectra, the correct compound was matched at second rank. The observed high percentage of correct assignments clearly suggests that the developed mass spectral library search approach is to a large extent platform independent. Copyright © 2009 John Wiley & Sons, Ltd.     

Identification of the sex pheromone of Phyllophaga cuyabana (Coleoptera: Melolonthidae)

Phenol 1 and p-cresol 2 were identified as sex pheromone components released by females Phyllophaga cuyabana. The compounds are produced in a ratio of 1:1, as detected by the analysis of pheromone gland extract. In field experiments, the capture of males in traps baited with the synthetic blend were significantly higher than in control traps.     

Analyses of lepidopteran sex pheromones by mass spectrometry

Lepidoptera, including about 150,000 species in the world, comprise the second largest insect group, and sex pheromones have been identified from virgin female moths of more than 600 species. The chemical structures are simple, but diverse, because species-specific pheromones play an important role in the reproductive isolation of each species. The pheromone content in each female is quite low, and gas chromatography coupled to mass spectrometry (GC-MS) is most frequently utilized to reveal the chemical structure. Almost all pheromone components are straight-chain compounds and are classified into two major groups [i.e. unsaturated C₁₀-C₁₈ fatty alcohols and their derivatives (Type I) and C₁₇-C₂₃ polyenyl hydrocarbons and their epoxides (Type II)]. In addition to the unbranched compounds, some species secrete methyl-branched compounds (e.g., 2-ketones). For the identification of these compounds, determining the positions of the double bond, the epoxy ring, and the methyl group is an important key step. Copious spectral information measured by electron-impact ionization (70 eV) has been accumulated for these compounds. This review therefore deals with their spectral characteristics, namely, diagnostic ions, to apply them to pheromone studies on new target insects.     

Synthesis and Acaricidal Activity of Some New 1,2,4‐Triazine Derivatives

A new series of 1,2,4‐triazine derivatives were designed, synthesized, and identified on the basis of IR, ¹H‐NMR, ¹³C‐NMR, and EI‐MS spectral data. The potent acaricidal activity of 1,2,4‐triazine derivatives against eggs and adult female of Tetranychus urticae (Koch) was assessed compared with pyridaben under laboratory conditions. Structure acaricidal activity relationships of the promising 1,2,4‐triazine derivatives were analyzed for eggs and adult female; the nature and position of the substituents were important in demonstration of the activities.     

Detection of α2u‐globulin and its bound putative pheromones in the preputial gland of the Indian commensal rat (Rattus rattus) using mass spectrometry

The role of pheromones and pheromone‐binding proteins in the laboratory rat has been extensively investigated. However, we have previously reported that the preputial gland of the Indian commensal rat produces a variety of pheromonal molecules and preputial glands would seem to be the predominant source for pheromonal communication. The presence of pheromone‐binding proteins has not yet been identified in the preputial gland of the Indian commensal rat; therefore, the experiments were designed to unravel the α_2u‐globulin (α2u) and its bound volatiles in the commensal rat. Total preputial glandular proteins were first fractionated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS‐PAGE) and subsequently analyzed by mass spectrometry. Further, we purified α2u and screened for the presence of bound pheromonal molecules with the aid of gas chromatography/mass spectrometry (GC/MS). A novel α2u was identified with a high score and this protein has not been previously described as present in the preputial gland of Indian commensal rats. This novel α2u was then characterized by tandem mass spectrometry (MS/MS). Peptides with m/z values of 969, 1192, 1303 and 1876 were further fragmented with the aid of MS/MS and generated de novo sequences which provided additional evidence for the presence of α2u in the preputial gland. Finally, we identified the presence of farnesol 1 and 2 bound to α2u. The present investigation confirms the presence of α2u (18.54 kDa) in the preputial gland of the Indian commensal rat and identifies farnesol 1 and 2 as probably involved in chemo‐communication by the Indian commensal rat. Copyright © 2010 John Wiley & Sons, Ltd.     

Investigation of the in vivo metabolism of harpagoside and distribution of its metabolites in rats by HPLC‐IT‐TOF‐MSn

Harpagoside, an iridoid glycoside, is the major bioactive constituent of the traditional Chinese medicine Scrophulariae Radix. High‐performance liquid chromatography with a diode array detector combined with electrospray ionization ion trap time‐of‐flight multistage mass spectrometry (HPLC‐ESI‐IT‐TOF‐MSⁿ) was used to profile and identify the metabolites of harpagoside in rats in vivo and to study the distribution of these metabolites in rats for the first time. A total of 45 metabolites were identified, 37 of which were postulated to be new compounds. The number of detected metabolites in the heart, liver, spleen, lung, kidney, stomach and small intestine was 2, 9, 6, 16, 4, 16 and 6, respectively, which indicated that the target organs of harpagoside should be spleen, lung and stomach. The main types of metabolic reactions of harpagoside in rats are hydrolysis, reduction, sulfuric acid addition, hydroxylation, methoxylation, sulfate substitution, methylation, glucose conjugation and amino acid conjugation. Furthermore, 23 metabolites were determined to have bioactivities based on the literature and ‘PharmMapper’ analysis. These findings are useful for better comprehension of the effective forms, target organs and pharmacological effects of harpagoside. Moreover, these findings provide a reference for studying the metabolism and distribution of iridoid compounds.     

Application of a solvent‐free solid injection technique coupled with GC–MS for discrimination between the secondary metabolites of wild and cultivated South Korean medicinal foods

Solvent‐free solid injection was applied to differentiate between wild and cultivated South Korean medicinal foods, including dureup (Aralia elata ), deodeok (Codonopsis lanceolata ) and doraji (Platycodon grandiflorus ). A number of compounds were identified in wild and cultivated dureup (53 and 46), deodeok (47 and 51) and doraji (43 and 38). Secondary metabolites, including butanal,2‐methyl‐, β ‐caryophyllene, neoclovene, α ‐humulene, γ ‐curcumene, β ‐bisabolene, and phytol, were identified in dureup with significantly (P < 0.05) different amounts between both types. In deodeok, squalene and other main components such as acetic acid, methyl ester, furan‐methyl‐furfural, 2‐furan‐methanol, and 5‐methyl‐furfural, were statistically different between the two types. Doraji has significantly different compounds such as furfural, 5‐methyl‐furfural, 2‐methoxy‐phenol, 2‐methoxy‐4‐(1‐propenyl)‐phenol, and 1‐(4‐hydroxy‐3‐methoxyphenyl)‐2‐propanone. Although we failed to confirm the key compounds, a new compound, namely desaspidinol, was synthesized for the first time and its retention index determined under the experimental conditions. This solventless, easy technique can be used as a simple way to discriminate between wild and cultivated types of medicinal plants via identification of volatile markers or specific fingerprints.     

Palaeophytochemical Components from the Miocene‐Fossil Wood of Pinus Griffithii

Some Miocene‐fossil wood of Pinus griffithii preserved as lignified wood in brown coal was found in an open coalmine in Xundian of Yunnan Province, China. To explore its chemical components, here we show the palaeophytochemical investigation of this Pliocene‐fossil wood of P. armandii, resulting in the isolation of 11 compounds ( 1–11 ) including one new compound named 3,3‐dimethoxy‐24‐ethyl‐cholestan ( 1 ) by liquid column chromatography. Furthermore, sixteen volatiles were detected from this fossil wood by gas chromatography‐mass spectrometry (GC‐MS). These structures of 11 compounds were elucidated by analysis of their MS, 1D and 2D‐NMR spectra, and comparison with published data.     

金属化合物催化的1,1′-联二萘酚-4,4′-二乙酸酯和二(2-乙基己醇)碳酸酯的酯交换

芳香族聚碳酸酯性能优良,其中双酚-A型聚碳酸酯是应用广泛的工程塑料,通常采用光气法或酯交换法来制备,但芳香双羟基化合物与二烷基碳酸酯的酯交换反应速度十分缓慢,需要使用催化剂,且反应温度较高,反应过程伴随着复杂的副反应。本文用金属化合物作催化剂进行1,1′-联二萘酚-4,4′-二乙酸酯和二(2-乙基己醇)碳酸酯的酯交换反应,评价了不同金