Intraspecific Variation of the Composition of Linear Alkanes in Social Wasp Mischocyttarus consimilis

Sociobiology ◽  
2017 ◽  
Vol 64 (4) ◽  
pp. 466
Author(s):  
Ana Cristina Ferreira ◽  
Erika Fernandes Neves ◽  
Thiago Dos Santos Montagna ◽  
Angélica Mendonça ◽  
Claudia Andrea Lima Cardoso ◽  
...  

An important attribute of the evolution and maintenance of sociality in insects is their ability to distinguish members of their own colonies by means of chemical signals during their interactions. Of this type of signals, the cuticular hydrocarbons, responsible among other functions, for intraspecific recognition stand out. Linear alkanes are indicated as the class of compounds that would be most involved in water retention in the body of insects, however, some studies have investigated their role as mediators of interactions. Thus it is possible that there is significant intraspecific variation of its composition, so the objective of this study was to test the hypothesis that linear alkanes vary significantly among populations, castes and sexes, as well as between newly emerged females of different ages of the Mischocyttarus consimilis Zikán 1949 wasp. The samples were analyzed by gas chromatography with flame ionization detector and gas chromatography coupled to mass spectrometry. The results show that there is a significant variation between the chemical cuticular profiles of samples from different populations, as well as between castes, sex and newly emergent workers of different ages. Therefore, it is possible to infer that this class of compounds may vary according to genetic differences between populations, but also by different environmental conditions. The differences between castes, sex and ages suggest that these compounds may also be involved in mediating interactions between nestmates.

2018 ◽  
Vol 40 ◽  
pp. 1
Author(s):  
Ingrid De Carvalho Guimarães ◽  
Claudia Andrea Lima Cardoso ◽  
Elina Bastos Caramão ◽  
Jaderson Kleveston Schneider ◽  
William Fernando Antonialli Junior

Communication in spiders can occur by several mechanisms, such as chemical cues and the cuticular hydrocarbons (CHCs) play an important role in intraspecific recognition. Several techniques have been used to evaluate CHCs in spiders, such as Gas Chromatography with Flame Ionization Detection, Gas Chromatography coupled with Mass Spectrometric detection and recently Fourier Transformed Infrared Photoacoustic Spectroscopy. In this study, rapid-scanning two-dimensional gas chromatography with quadrupole mass spectrometry (GC×GC/qMS) was employed to assess the CHCs of L. geometricus females and juveniles of different ages. The results demonstrate that there is variation in CHCs of different body parts of females, with abdomen presenting greater number of compounds, as well as between adults and juveniles. Branched alkanes represented the majority of compounds in all samples, followed by linear alkanes, and alkenes were only present in adult’s abdomen and cephalothorax. The compounds 10-methyloctacosaneand 14-methyloctacosane; and 10-methyltriacontane and 14-methyltriacontane showed the same retention time in the 1D and were separated in the 2D. According to the results, rapid-scanning GC×GC/qMS can be considered a reliable technique to assess CHCs since it was possible to identify the spider’s cuticular compounds, and detect and separate two cases of chromatographic coelution.


Sociobiology ◽  
2017 ◽  
Vol 64 (3) ◽  
pp. 327
Author(s):  
Jane Herondi dos Santos Brito ◽  
William Fernando Antonialli-Junior ◽  
Thiago Dos Santos Montagna ◽  
Angélica Mendonça ◽  
Denise Sguarizi-Antonio ◽  
...  

Female wasps such as Polistes versicolor can form aggregates to face weather conditions that are not suitable to sustain their colonies. The interactions between individuals in these aggregates, just as in other associations, are probably facilitated by chemical signals. Of these compounds some of the most efficient during social interactions of insects are those called contact pheromones or superficial pheromones. This special type of pheromones, known as cuticular hydrocarbons, can be found in insects cuticle. They facilitate the differentiation of caste, species and nestmates, and may be important indicators of dominance as well as fertility. Some studies indicate that linear alkanes are important cuticular compounds for intraspecific recognition and discrimination. The aim of this study was to evaluate the relationship between reproductive physiologic condition and the linear alkanes present in the cuticle of females of P. versicolor in aggregates employing Gas Chromatography with Flame Ionization Detector (GC-FID). Females from distinct aggregates were differentiated by the chemical composition of their cuticle. In each aggregate, there was difference in cuticular chemical composition between females with different ovarian development degrees, allowing the distinction between inseminated and non-inseminated females.


2017 ◽  
Vol 68 (4) ◽  
pp. 666-670 ◽  
Author(s):  
Mirela Mihon ◽  
Catalin Stelian Tuta ◽  
Alina Catrinel Ion ◽  
Dana Niculae ◽  
Vasile Lavric

The aim of this work was the development and validation of a fast analytical method to determine the residual solvents content in radiopharmaceuticals such as: 18F-Fluorodeoxyglucose (18F-FDG), 18F-Fluoroestradiol (18F-FES), 18F-Fluorothymidine (18F-FLT),18F-Fluoromisonidazole (18F-FMISO). Radiopharmaceuticals are radioactive preparations for medical purposes used in nuclear medicine as tracers in diagnostic imaging and treatment of certain diseases. Positron Emission Tomography (PET) is a medical imaging technique that consists in introducing into the body of a small amount of a biologically active chemical compound labelled with a short lived positron-emitting radioisotope (18F, 11C, 68Ga). Residual solvents are critical impurities in radiopharmaceuticals that can affect labelling, stability and physicochemical properties of drugs. Therefore, the determination of these solvents is essential for quality control of radiopharmaceuticals. Validation of the control method for residual solvents by gas chromatography is referred by the European Pharmacopoeia using a special injection technique (head space). The parameters of the method, which comply with International Conference on Harmonization guidelines, are: accuracy, precision, linearity, limit of detection, limit of quantification and robustness. The proposed method (direct gas chromatography injection) proved to be linear, precise, accurate and robust. Good linearity was achieved for all the solvents and correlation coefficients (R2) for each residual solvent were found more than 0.99.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4608
Author(s):  
Eduardo Valarezo ◽  
Génesis Gaona-Granda ◽  
Vladimir Morocho ◽  
Luis Cartuche ◽  
James Calva ◽  
...  

Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), β-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 μg/mL, a scavenging capacity SC50 of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC50 of 146 ± 20 µg/mL.


2020 ◽  
Vol 15 (12) ◽  
pp. 1934578X2098123
Author(s):  
Peng-fei Yang ◽  
Hui Lu ◽  
Qiong-bo Wang ◽  
Zhi-wei Zhao ◽  
Qiang Liu ◽  
...  

Detailed chemical constituents of essential oil from the Pterocephalus hookeri leaves and its antimicrobial activities were investigated in this study. The essential oil, obtained by hydrodistillation, was characterized by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analyses. Among the 90 identified compounds, hexadecanoic acid (21.27%), phytol (8.03%), furfural (7.08%), oleic acid (5.25%), and phytone (4.56%) were the major components. In the antimicrobial assay, the essential oil showed strong inhibitory activities against Escherichia coli, Candida albicans, and Staphylococcus aureus with minimum inhibitory concentration values of 31.3, 62.5, and 125 µg/mL, respectively. To our knowledge, this is the first report concerning chemical composition and antimicrobial activities of the essential oil from Pterocephalus hookeri.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1066
Author(s):  
Fahima Abdellatif ◽  
Muhammad Akram ◽  
Samir Begaa ◽  
Mohammed Messaoudi ◽  
Adel Benarfa ◽  
...  

This study describes the minerals elements, chemical composition, antioxidant and antimicrobial activities of Algerian Melissa officinalis plant. The essential oil (EO) was extracted by hydrodistillation (HD) using a Clevenger-type apparatus of dry leaves of M. officinalis and was analyzed by two techniques, gas chromatography coupled with flame ionization (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Eighteen minerals comprising both macro- and microelements (As, Br, K, La, Na, Sb, Sm, Ba, Ca, Ce, Co, Cr, Cs, Fe, Rb, Sc, Th, and Zn) were determined using neutron activation analysis technique for the first time from Algerian Melissa officinalis plant. Seventy-eight compounds were identified in the essential oil, representing 94.090% of the total oil and the yields were 0.470%. The major component was geranial (45.060%). Other predominant components were neral (31.720%) and citronellal (6.420%). The essential oil presented high antimicrobial activity against microorganisms, mainly five human pathogenic bacteria, one yeast, Candida albicans, and two phytopathogenic fungi. The results can be used as a source of information for the pharmaceutical industry and medical research.


1998 ◽  
Vol 275 (3) ◽  
pp. R677-R682 ◽  
Author(s):  
Susan R. Kayar ◽  
Terry L. Miller ◽  
Meyer J. Wolin ◽  
Eugenia O. Aukhert ◽  
Milton J. Axley ◽  
...  

We present a method for reducing the risk of decompression sickness (DCS) in rats exposed to high pressures of H2. Suspensions of the human colonic microbe Methanobrevibacter smithii were introduced via a colonic cannula into the large intestines of the rats. While the rats breathed H2in a hyperbaric chamber, the microbe metabolized some of the H2diffusing into the intestine, converting H2and CO2to methane and water. Rate of release of methane from the rats, which was monitored by gas chromatography, varied with chamber H2pressure. This rate was higher during decompression than during compression, suggesting that during decompression the microbe was metabolizing H2stored in the rats’ tissues. Rats treated with M. smithii had a 25% (5 of 20) incidence of DCS, which was significantly lower ( P < 0.01) than the 56% (28 of 50) incidence of untreated controls, brought on by a standardized compression and decompression sequence. Thus using a microbe in the intestine to remove an estimated 5% of the body burden of H2reduced DCS risk by more than one-half. This method of biochemical decompression may potentially facilitate human diving.


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