Erratum to: Localization of Fatty Acyl and Double Bond Positions in Phosphatidylcholines Using a Dual Stage CID Fragmentation Coupled with Ion Mobility Mass Spectrometry.

A high content molecular fragmentation for the analysis of phosphatidylcholines (PC) was achieved utilizing a two-stage [trap (first generation fragmentation) and transfer (second generation fragmentation)] collision-induced dissociation (CID) in combination with travelling-wave ion mobility spectrometry (TWIMS). The novel aspects of this work reside in the fact that a TWIMS arrangement was used to obtain a high level structural information including location of fatty acyl substituents and double bonds for PCs in plasma, and the presence of alkali metal adduct ions such as [M + Li](+) was not required to obtain double bond positions. Elemental compositions for fragment ions were confirmed by accurate mass measurements. A very specific first generation fragment ion m/z 577 (M-phosphoryl choline) from the PC [16:0/18:1 (9Z)] was produced, which by further CID generated acylium ions containing either the fatty acyl 16:0 (C(15)H(31)CO(+), m/z 239) or 18:1 (9Z) (C(17)H(33)CO(+), m/z 265) substituent. Subsequent water loss from these acylium ions was key in producing hydrocarbon fragment ions mainly from the α-proximal position of the carbonyl group such as the hydrocarbon ion m/z 67 (+H(2)C-HC = CH-CH = CH(2)). Formation of these ions was of important significance for determining double bonds in the fatty acyl chains. In addition to this, and with the aid of (13)C labeled lyso-phosphatidylcholine (LPC) 18:1 (9Z) in the ω-position (methyl) TAP fragmentation produced the ion at m/z 57. And was proven to be derived from the α-proximal (carboxylate) or distant ω-position (methyl) in the LPC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13361-011-0172-2) contains supplementary material, which is available to authorized users

Identification of a component of the trail pheromone of the ant Pheidole pallidula (Hymenoptera: Formicidae)

The poison gland of minor workers of P.pallidula.Nyl. contains 3-ethyl-2,5-dimethylpyrazine which induces trail-following in other workers, but does not account for the full trail-following effect of one worker's poison gland. No pyrazines were detected in major workers and their glands do not contain the pheromone.CI:0.85FLWNAinfo:eu-repo/semantics/publishe

Gas-phase infrared spectroscopy for determination of double-bond configuration of some polyunsaturated pheromones and related compounds

Gas-phase Fourier transform infrared spectroscopy allows the determination of the geometric configuration of disubstituted carbon-carbon double bonds present in linear polyunsaturated compounds on the basis of the characteristic absorptions observed in the 3036-3011 and 982-947 cm(-1) regions. Although the 3036-3011 cm(-1) band, attributable to a =CH stretch vibration, is conventionally considered to be unreliable for cis/trans determinations, data obtained from a large number of mono- and polyunsaturated acetates show that many useful deductions can be based on this absorption, Double bonds of the RCH=CHR' type separated by at least two methylene groups, present in polyunsaturated compounds, give rise to an absorption at 3013-3011 cm(-1) if the double bonds are not proximal to a functional group or a terminal methyl group, Cis dienes whose double bonds are separated by only a single methylene group show the cis =CH stretch band at 3017 cm(-1). For methylene-interrupted polyenes, this band shows a gradual hypsochromic shift as the unsaturation increases, Furthermore, a band at 1391 cm(-1) was recognized to represent the deformation vibration of the CH2 groups located between the double bonds, The intensity of this band is proportional to the number of skipped methylene groups. I None of the isolated or methylene-interrupted dienes bearing only trans double bonds showed any significant absorptions above 3000 cm(-1). However, spectra of trans-trans conjugated compounds show a =CH stretch band at 3016-3012 cm(-1) as a well-defined shoulder on the high-frequency side of the CH2 asymmetric stretch band, in addition to the wag absorption observed at 984-982 cm(-1), which is highly characteristic for trans-trans conjugated compounds, The spectra of cis-trans or trans-cis conjugated compounds are virtually identical and show a characteristic ''fingerprint'' consisting of two bands of similar intensity at 978-976 and 949-946 cm(-1), in addition to the =C-H stretch band observed at 3021-3017 cm(-1), interestingly, not only are the spectra of conjugated cis-cis compounds devoid of any significant absorption in the 982-947 cm(-1) region, but also the =CH stretch band is broad and appears as a poorly defined shoulder on the high-frequency edge of the CH2 asymmetric stretch band

Aldehydic contact poisons and alarm pheromone of the ant Crematogaster scutellaris (Hymenoptera: Myrmicinae) - Enzyme-Mediated Production from acetate precursors

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The War Housing Program and Its Future

SCOPUS: cp.kinfo:eu-repo/semantics/publishe