Mass spectra of diterpene resin acid methyl esters

1971 ◽  
Vol 48 (9) ◽  
pp. 455-461 ◽  
Author(s):  
Teh-Liang Chang ◽  
Thomas E. Mead ◽  
Duane F. Zinkel
Keyword(s):  
Mass Spectra ◽  
Methyl Esters ◽  
Resin Acid ◽  
Acid Methyl

Mass spectra of acetylenic fatty acid methyl esters and derivatives

Lipids ◽  
1976 ◽  
Vol 11 (8) ◽  
pp. 599-603 ◽  
Author(s):  
R. Kleiman ◽  
M. B. Bohannon ◽  
F. D. Gunstone ◽  
J. A. Barve
Keyword(s):  
Fatty Acid ◽  
Mass Spectra ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Acid Methyl ◽  
Acetylenic Fatty Acid

scholarly journals Novel fatty acid methyl esters from the actinomyceteMicromonospora aurantiaca

2011 ◽  
Vol 7 ◽  
pp. 1697-1712 ◽  
Author(s):  
Jeroen S Dickschat ◽  
Hilke Bruns ◽  
Ramona Riclea
Keyword(s):  
Fatty Acid ◽  
Mass Spectra ◽  
Fatty Acid Methyl Esters ◽  
Fatty Acid Synthase ◽  
Methyl Esters ◽  
Sodium Propionate ◽  
Feeding Experiments ◽  
Acid Methyl ◽  
Adenosyl Methionine ◽  
Branched Compound

The volatiles released byMicromonospora aurantiacawere collected by means of a closed-loop stripping apparatus (CLSA) and analysed by GC–MS. The headspace extracts contained more than 90 compounds from different classes. Fatty acid methyl esters (FAMEs) comprised the major compound class including saturated unbranched, monomethyl and dimethyl branched FAMEs in diverse structural variants: Unbranched, α-branched, γ-branched, (ω−1)-branched, (ω−2)-branched, α- and (ω−1)-branched, γ- and (ω−1)-branched, γ- and (ω−2)-branched, and γ- and (ω−3)-branched FAMEs. FAMEs of the last three types have not been described from natural sources before. The structures for all FAMEs have been suggested based on their mass spectra and on a retention index increment system and verified by the synthesis of key reference compounds. In addition, the structures of two FAMEs, methyl 4,8-dimethyldodecanoate and the ethyl-branched compound methyl 8-ethyl-4-methyldodecanoate were deduced from their mass spectra. Feeding experiments with isotopically labelled [2H10]leucine, [2H10]isoleucine, [2H8]valine, [2H5]sodium propionate, and [methyl-2H3]methionine demonstrated that the responsible fatty acid synthase (FAS) can use different branched and unbranched starter units and is able to incorporate methylmalonyl-CoA elongation units for internal methyl branches in various chain positions, while the methyl ester function is derived fromS-adenosyl methionine (SAM).

scholarly journals N-Acylated amino acid methyl esters from marine Roseobacter group bacteria

2018 ◽  
Vol 14 ◽  
pp. 2964-2973 ◽  
Author(s):  
Hilke Bruns ◽  
Lisa Ziesche ◽  
Nargis Khakin Taniwal ◽  
Laura Wolter ◽  
Thorsten Brinkhoff ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mass Spectra ◽  
Antibiotic Production ◽  
Methyl Esters ◽  
Structural Similarity ◽  
Structural Motif ◽  
Acid Methyl ◽  
Signalling Compounds ◽  
Fragmentation Patterns ◽  
Amino Acid Methyl Esters

Bacteria of the Roseobacter group (Rhodobacteraceae) are important members of many marine ecosystems. Similar to other Gram-negative bacteria many roseobacters produce N-acylhomoserine lactones (AHLs) for communication by quorum sensing systems. AHLs regulate different traits like cell differentiation or antibiotic production. Related N-acylalanine methyl esters (NAMEs) have been reported as well, but so far only from Roseovarius tolerans EL-164. While screening various roseobacters isolated from macroalgae we encountered four strains, Roseovarius sp. D12_1.68, Loktanella sp. F13, F14 and D3 that produced new derivatives and analogs of NAMEs, namely N-acyl-2-aminobutyric acid methyl esters (NABME), N-acylglycine methyl esters (NAGME), N-acylvaline methyl esters (NAVME), as well as for the first time a methyl-branched NAME, N-(13-methyltetradecanoyl)alanine methyl ester. These compounds were detected by GC–MS analysis, and structural proposals were derived from the mass spectra and by derivatization. Verification of compound structures was performed by synthesis. NABMEs, NAVMEs and NAGMEs are produced in low amounts only, making mass spectrometry the method of choice for their detection. The analysis of both EI and ESI mass spectra revealed fragmentation patterns helpful for the detection of similar compounds derived from other amino acids. Some of these compounds showed antimicrobial activity. The structural similarity of N-acylated amino acid methyl esters and similar lipophilicity to AHLs might indicate a yet unknown function as signalling compounds in the ecology of these bacteria, although their singular occurrence is in strong contrast to the common occurrence of AHLs. Obviously the structural motif is not restricted to Roseovarius spp. and occurs also in other genera.

scholarly journals Discriminating cereal and pseudocereal species using a binary system of GC/MS data: A pattern recognition approach

2018 ◽  
Vol 83 (3) ◽  
pp. 317-329 ◽  
Author(s):  
Kristian Pastor ◽  
Lato Pezo ◽  
Djura Vujic ◽  
Djordje Jovanovic ◽  
Marijana Acanski
Keyword(s):  
Pattern Recognition ◽  
Binary System ◽  
Mass Spectra ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Principal Component ◽  
Acid Methyl ◽  
Good Pattern ◽  
Pattern Recognition Approach ◽  
Species Pattern

Various cultivars of different cereal and pseudocereal species (9 wheat, 8 barley, 1 rye, 3 oat, 2 triticale, 3 spelt, 12 corn, 3 amaranth and 9 buckwheat cultivar samples) were milled into flour, extracted using n-hexane, derivatized with trimethylsulfonium hydroxide solution, and subjected to GC? ?MS analysis. Fatty acid methyl esters and non-saponifiable compounds (phytosterols, ?-tocopherol and squalene) were identified by comparing mass spectra with the Wiley MS library. A binary system was applied in further data processing: the presence or the absence of a particular lipid component in each sample was coded with either (1) or (0). Major lipid components that were present in all analyzed flour samples were removed from further data analysis, leaving only those that represent a good pattern to differentiate the flour samples according to corresponding cereal/pseudocereal species. Pattern recognition tools (cluster analysis and principal component analysis) were applied to visualize groupings and separations among the samples. The presented approach enables the rapid differentiation of flour samples made from various cereal/pseudocereal species according to their botanical origin and gluten content, thereby, successfully avoiding exact quantitative determinations.

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