scholarly journals Identification of the Compounds Responsible for the Sweat-Like Odor in Hop (Humulus lupulus L.) Volatile Oil

2013 ◽  
Vol 2 (5) ◽  
pp. 34 ◽  
Author(s):  
Hironari Miyazato
Keyword(s):  
Mass Spectrometry ◽  
Volatile Oil ◽  
Gas Chromatography Mass Spectrometry ◽  
Aroma Extract Dilution Analysis ◽  
Dilution Technique ◽  
Unknown Compound ◽  
Acid Methyl ◽  
Humulus Lupulus L ◽  
Combined Use ◽  
First Time

<p>The aroma of hop volatile oil contains a sweat-like odor. We studied the odorous volatile compounds responsible for the sweat-like odor in the volatile oil extracted from Hallertau Perle hop (<em>Humulus</em><em> </em><em>lupulus</em><em> </em>L.) pellets. The combined use of gas chromatography-mass spectrometry/olfactometry (GC-MS/O), aroma extract dilution analysis (AEDA) by GC-MS/O (an odor dilution technique), and heart-cut multidimensional GC-MS (heart-cut MDGC-MS) equipped with the polar (1D) and apolar (2D) capillary columns revealed seven sweat-like odor producing compounds: methyl-branched saturated and unsaturated aliphatic acids, such as 3-methylbutanoic acid (sweaty/rancid/cheese-like), 2-methylbutanoic acid (sweaty/rancid/cheese-like), 4-methyl-3-pentenoic acid (sweaty/urine-like/malodor in laundry), and (<em>E</em>)-4-methyl-3-hexenoic acid (sweaty/urine-like/malodor in laundry), as well as others, such as an unknown compound (sweaty), methyl (<em>E</em>)-4-methyl-3-hexenoate (sweaty/malodor in laundry/fruity), and <em>S</em>-methyl (<em>E</em>)-4-methyl-3-hexenethioate (sweaty/rubber). The reference substances were synthesized stereo selectively using for the identification procedures. In this study, (<em>E</em>)-4-methyl-3-hexenoic acid, methyl (<em>E</em>)-4-methyl-3-hexenoate, and <em>S</em>-methyl (<em>E</em>)-4-methyl-3-hexenethioate were identified for the first time in hop volatile oil.</p>

scholarly journals Upon the opportunity to apply ART2 Neural Network for clusterization of biodiesel fuels

2016 ◽  
Vol 3 (1) ◽  
pp. 19-25
Author(s):  
T. Petkov ◽  
Z. Mustafa ◽  
S. Sotirov ◽  
R. Milina ◽  
M. Moskovkina
Keyword(s):  
Neural Network ◽  
Mass Spectrometry ◽  
Artificial Neural Network ◽  
Gas Chromatography ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Gas Chromatography Mass Spectrometry ◽  
Acid Methyl ◽  
Chemometric Approach ◽  
Biodiesel Fuels

Abstract A chemometric approach using artificial neural network for clusterization of biodiesels was developed. It is based on artificial ART2 neural network. Gas chromatography (GC) and Gas Chromatography - mass spectrometry (GC-MS) were used for quantitative and qualitative analysis of biodiesels, produced from different feedstocks, and FAME (fatty acid methyl esters) profiles were determined. Totally 96 analytical results for 7 different classes of biofuel plants: sunflower, rapeseed, corn, soybean, palm, peanut, “unknown” were used as objects. The analysis of biodiesels showed the content of five major FAME (C16:0, C18:0, C18:1, C18:2, C18:3) and those components were used like inputs in the model. After training with 6 samples, for which the origin was known, ANN was verified and tested with ninety “unknown” samples. The present research demonstrated the successful application of neural network for recognition of biodiesels according to their feedstock which give information upon their properties and handling.

Identification by Gas Chromatography-Mass Spectrometry of 150 Compounds in Propolis

1991 ◽  
Vol 46 (1-2) ◽  
pp. 111-121 ◽  
Author(s):  
W. Greenaway ◽  
J. May ◽  
T. Scaysbrook ◽  
F. R. Whatley
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Components ◽  
Alcoholic Extract ◽  
Headspace Volatiles ◽  
Chromatography Mass Spectrometry ◽  
First Time

Abstract Propolis was analyzed by gas chromatography-mass spectrometry for both its headspace volatiles and for the less volatile components of its alcoholic extract (propolis balsam). 181 peaks were located of which 171 representing 150 compounds were identified, including 28 identified in propolis for the first time. The majority of compounds were typical of poplar bud exudate.

scholarly journals Chemical Composition and Antimicrobial Activity of the Volatile Oil from Fusarium tricinctum, the Endophytic Fungus in Paris polyphylla var. yunnanensis

2011 ◽  
Vol 6 (11) ◽  
pp. 1934578X1100601
Author(s):  
Ying Zhang ◽  
Jianglin Zhao ◽  
Jihua Wang ◽  
Tijiang Shan ◽  
Yan Mou ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Antimicrobial Activity ◽  
Endophytic Fungus ◽  
Inhibitory Concentration ◽  
Volatile Oil ◽  
Gas Chromatography Mass Spectrometry ◽  
Paris Polyphylla ◽  
The Mean ◽  
Fusarium Tricinctum

The volatile oil, obtained by hydrodistillation from Fusarium tricinctum, the endophytic fungus isolated from Paris polyphylla var. yunnanensis, was analyzed by gas chromatography-mass spectrometry (GC-MS). trans-1,2,3,3a,4,7a-Hexahydro-7a-methyl-5H-inden-5-one (73.1%), 2-methylene-4,8,8-trimethyl-4-vinyl bicyclo [5.2.0] nonane (12.0%), and 2,6-dimethyl-6-(4-methyl-3-pentenyl) bicyclo [3.1.1] hept-2-ene (4.5%) were the major compounds of the 15 identified components accounting for 95.4% of the volatile oil. The antimicrobial activity of the volatile oil was assayed against eight bacteria and two fungi. The minimum inhibitory concentration (MIC) values of the volatile oil against the test bacteria ranged from 25 to 45 μg/mL. The MIC values against the fungi Candida albicans and Magnaporthe oryzae were 100 and 225 μg/mL, respectively. The mean inhibitory concentration (IC50) values of the volatile oil against the test bacteria ranged from 17.8 to 31.6 μg/mL, and those of the volatile oil against C. albicans and M. oryzae were 84.3 and 204.3 μg/mL, respectively.

Comprehensive analysis of metabolites in Corynebacterium glutamicum by gas chromatography/mass spectrometry

2004 ◽  
Vol 385 (9) ◽  
pp. 853-861 ◽  
Author(s):  
Sergey Strelkov ◽  
Mirko von Elstermann ◽  
Dietmar Schomburg
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Corynebacterium Glutamicum ◽  
Growth Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Fast Method ◽  
Chromatography Mass Spectrometry ◽  
High Matrix ◽  
First Time ◽  
Derivatives Of

AbstractAn analytical method based on gas chromatography/mass spectrometry was developed for metabolome investigation ofCorynebacterium glutamicum. For the first time a fast method for metabolic screening that can be automated is described for this organism. More than 1000 compounds could be detected per experiment, ca. 330 of those showed a peak area significantly above background. Out of these 164 compounds were identified so far, representing derivatives of 121 different metabolites, which were quantified in one sample. In spite of the different chemical nature of metabolites and high matrix content, a measurement reproducibility in the range of 6% error was achieved. The application of this method for the analysis of the adaptation ofC. glutamicumto different growth conditions is demonstrated.

scholarly journals Analysis of amphetamines illegally produced in Serbia

2008 ◽  
Vol 73 (7) ◽  
pp. 691-701 ◽  
Author(s):  
Marina Nevescanin ◽  
Sonja Banovic-Stevic ◽  
Slobodan Petrovic ◽  
Vlatka Vajs
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Chemical Characterization ◽  
Gas Chromatography Mass Spectrometry ◽  
Active Components ◽  
Forensic Practice ◽  
The Republic ◽  
Phosphate Salts ◽  
First Time

Forensic practice in the Republic of Serbia faced the illegal production of amphetamine for the first time in 2003. This paper presents the results of the chemical characterization of 32 batches of amphetamine samples from three separate cases, for the purpose of identification of the active components and additives. Through the profiling of impurities of all samples, using gas chromatography/mass spectrometry (GC/MS), 30 compounds associated with amphetamine were identified. The results of the analysis of powder tartrate, sulfate and phosphate salts of amphetamine, as well as variously formulated tablets are presented in this study. The analyses showed that the amphetamines were synthesized by the Leuckart method in all cases. .

Nitrogen Configuration of Polybenzoxazine Carbide

2015 ◽  
Vol 34 (3) ◽  
Author(s):  
Huachuan Zhang ◽  
Wu Gu ◽  
Rongqi Zhu ◽  
Qichao Ran ◽  
Yi Gu
Keyword(s):  
Mass Spectrometry ◽  
Photoelectron Spectroscopy ◽  
Carbon Materials ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Amine Nitrogen ◽  
X Ray ◽  
Pyrolysis Gas Chromatography ◽  
First Time ◽  
Pyridinic Nitrogen

AbstractCarbon materials should have specific centers for its functionalities. In this study, the specific centers of polybenzoxazine carbides were studied for the first time. Three classical benzoxazine monomers were chose as the object. The transformation of nitrogen configuration of polybenzoxazines carbides was characterized via pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and X-ray photoelectron spectroscopy (XPS). The results showed that the tertiary amine nitrogen converted to pyridinic nitrogen and pyrrolic nitrogen incorporated in graphene residuals during the carbonization, which were the specific centers for the functionality.

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