Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• ) of the FA glycerides to the corresponding FA methyl esters (FAMEs) [11][13]. The derivatization involved methanol–boron trifluoride (20% BF3), hexane (GC grade) and anhydrous sodium sulfate, all purchased from Merck & Co., Inc., Rahway, NJ, USA. Sodium chloride (reagent grade) used for the separation

• of FAMEs was purchased from Reactivul (Bucharest, Romania). The identification of the FAME components of the hazelnut oil involved FAME37 standard mixture, as well as C8–C20 linear alkane standard mixture for the determination of the specific retention index (RI) of compounds (both purchased from

• Sigma-Aldrich, St. Louis, MO, USA). Finally, 2-propanol (ACS reagent, Reag. Ph. Eur.) used for FTIR cleaning was obtained from Merck & Co., Inc., Rahway, NJ, USA. Gas chromatography–mass spectrometry (GC–MS) The FA profile of the hazelnut oil was determined by GC–MS, after derivatization to FAMEs

Acyl-group specificity of AHL synthases involved in quorum-sensing in Roseobacter group bacteria

• Lisa Ziesche,
• Jan Rinkel,
• Jeroen S. Dickschat and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 1309–1316, doi:10.3762/bjoc.14.112

• concomitantly transfers any bound or free fatty acid into its methyl ester (FAME) [33]. The extracts were analyzed by GC/MS (Figure 1). Short and long FAMEs were detected, ranging from methyl octanoate to methyl icosanoate (Table 2). The three Phaeobacter strains produced identical fatty acids. We identified

• FAMEs with a C8:0, C12:0, C12:1, C16:0, C16:1, C17:0, C18:2, C18:0, C18:1, and C19:1 chain, the three last ones being the most abundant. D. shibae DFL-12 showed a similar fatty acid production, but no FAMEs with C8 or C12 chains were detected. Instead, 3-OH-C10:0-HSL, C14:0, and C20:0 FAMEs occurred in

• bond in C12:1-FAME at C-5. Similarly, 9-C16:1 (m/z 145, 185, 217) and 11-C18:1-FAMEs (m/z 145, 213, 245) were assigned. The three Phaeobacter strains showed also a small peak with identical mass spectrum compared to 11-C18:1-FAME eluting slightly earlier than the major compound, indicating minor

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• such or as mixtures are widely used to convert natural triglycerides into FAMEs or FAEEs (fatty acid methyl or ethyl esters) with methanol or ethanol, respectively [10]. The most commonly used system is CaO, which is obtained by calcination of readily available and cheap resources including waste

• (Scheme 2) [15][16]. The reaction allows obtaining FAMEs and fatty acid glycerol carbonate monoesters (FAGCs), without the concurrent formation of glycerol, a frequently formed highly undesirable byproduct. Enzyme catalysts: A major driving force for the choice of enzymes is their high efficiency, which

• conversion of rapeseed oils into FAMEs products [45]. A series of Brønsted acidic imidazolium ILs has been investigated for the catalytic synthesis of sec-butanol by transesterification of sec-butyl acetate with methanol (Scheme 5) [46]. The reaction is of interest for the preparation of less toxic

The EIMS fragmentation mechanisms of the sesquiterpenes corvol ethers A and B, epi-cubebol and isodauc-8-en-11-ol

• Patrick Rabe and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 1380–1394, doi:10.3762/bjoc.12.132

• , Ryhage and Stenhagen presented detailed studies on the EI mass spectra of deuterated and methyl-branched fatty acid methyl esters that revealed their fragmentation mechanisms [7][8]. Based on this work, we have recently identified various volatile fatty acid methyl esters (FAMEs) in headspace extracts of

• , contain several methyl groups, and possibly one or more olefinic double bonds, an alcohol or ether function. Their much higher structural complexity compared to, e.g., FAMEs and monoterpenes renders a prediction of the fragmentation behaviour of unknown compounds in mass spectrometry and consequently the

Thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) and complexation with β-cyclodextrin

• Daniel I. Hădărugă,
• Mustafa Ünlüsayin,
• Alexandra T. Gruia,
• Cristina Birău (Mitroi),
• Gerlinde Rusu and
• Nicoleta G. Hădărugă

Beilstein J. Org. Chem. 2016, 12, 179–191, doi:10.3762/bjoc.12.20

• concentration of these FA methyl esters (FAMEs) can indicate the stability and/or the degradation level of the ASO in a simple and relevant way. MUFAs were the most concentrated in the raw ASO (Table 1). The highest relative concentration of 35.6% was found for oleic acid methyl ester. On the other hand, PUFAs

• had a total concentration of 25.4% and the main FAMEs were linoleic acid methyl ester (11.2%), EPA methyl ester (6.1%) and DHA methyl ester (4.1%). Myristic, palmitic and stearic acid methyl esters were the most important saturated fatty acids (SFAs) (3.5%, 10.7% and 2.7%, respectively). Some of the

• FAMEs could not be clearly identified, even when their MS spectra indicated the class of these compounds. All of them had a relative concentration lower than 0.05%. These results are in good agreement with those obtained by Bencze Rørå and collaborators [23]. They determined a DHA concentration of 4.5

Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

• Jeroen S. Dickschat,
• Hilke Bruns and
• Ramona Riclea

Beilstein J. Org. Chem. 2011, 7, 1697–1712, doi:10.3762/bjoc.7.200

• (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