Substituted benzoic acid anions undergo decarboxylation in the medium-pressure region of an electrospray ion source yielding in most cases the correspondingly substituted phenide anions in high yield. The location of the anionic center is specified by the position of the carboxylic group. The only exceptions are compounds with substituents containing acidic hydrogen atoms, like OH and NH(2) groups. For such compounds, either an intra- or an intermolecular (mediated by the molecules of methanol or water) proton transfer from the more acidic position to the benzene ring is observed. The generated anions can be selected using the first quadrupole for studying their ion-molecule chemistry in the second quadrupole of a triple quadrupole mass spectrometer. Their reactions with CO(2), O(2), CH(3)COCH(3) and CCl(4) may serve as typical examples. The general applicability of this method for the generation of phenide anions has been confirmed on three different mass spectrometers. Experiments performed using carboxylic acids other then benzoic acid and its derivatives show that this method is not limited to phenide anions and can be used for the generation of a much wider range of carbanions in the gas phase.

Plant isoprenoids are derived from two biosynthetic pathways, the cytoplasmic mevalonate (MVA) and the plastidial methylerythritol phosphate (MEP) pathway. In this study their respective contributions toward formation of dolichols in Coluria geoides hairy root culture were estimated using in vivo labeling with 13 C-labeled glucose as a general precursor. NMR and mass spectrometry showed that both the MVA and MEP pathways were the sources of isopentenyl diphosphate incorporated into polyisoprenoid chains. The involvement of the MEP pathway was found to be substantial at the initiation stage of dolichol chain synthesis, but it was virtually nil at the terminal steps; statistically, 6 -8 isoprene units within the dolichol molecule (i.e. 40 -50% of the total) were derived from the MEP pathway. These results were further verified by incorporation of Polyisoprenoid alcohols together with sterols and quinone side chains constitute three main branches of terpene products originating from farnesyl diphosphate (FPP) 4 (1). These linear five-carbon unit polymers are divided into two groups, i.e. polyprenols and dolichols, according to the hydrogenation status of the ␣-terminal isoprene unit (dolichol structure is shown in Fig. 1). In cells, polyprenols and dolichols are always found as mixtures of prenologues, and data collected so far show polyprenols to be typical for bacteria and plants, whereas dolichols are generally attributed to animals and yeast (2). Nevertheless, it should be remembered that dolichols are the predominant form in some plant organs like roots (3). Data on the occurrence and functions of polyisoprenoids are summarized in recently published reviews (4, 5). The formation of the polyisoprenoid chain, starting from the -end of the molecule (Fig. 1), proceeds in a biphasic manner with farnesyl-diphosphate synthase responsible for the synthesis of the all-trans-FPP (three isoprene units of -t 2 structure, t stands for trans-isoprene unit), and its further elongation by cis-prenyltransferase. The latter enzyme, cloned from several prokaryotic and eukaryotic organisms (see Refs. 6, 7 and references therein), including Arabidopsis thaliana (8,9) and Hevea brasiliensis (10), utilizes isopentenyl diphosphate (IPP) for elongation of FPP up to the desired chain length, thus producing a family of polyprenyl diphosphates (n isoprene units of -t 2 -c n-3 structure, c stands for cis-isoprene unit), which are subsequently converted to polyprenols or dolichols according to the "tissue-specific requirements" by a still unknown mechanism.In plant cells two pathways are known to produce IPP utilized by numerous enzymes to finally give more than 50,000 different isoprenoid structures, the mevalonate pathway (MVA) and the mevalonate-independent methylerythritol phosphate pathway (MEP) (for reviews, see Refs. 11-13). Both pathways are compartmentalized as follows: the MVA in the cytoplasm to provide sterols, the many sesquiterpenes, and the prenyl chains of ubiquinones, and the MEP one in the plastids Tables 1 and 2

Polyisoprenoid alcohols of the plant Coluria geoides were isolated and analyzed by HPLC with UV detection to determine the nature of the polyprenol and dolichol mixture in the organs studied. In roots, a family of dolichols (Dol-15 to Dol-23, with Dol-16 dominating, where Dol-n is dolichol composed of n isoprene units) was accompanied by traces of polyprenols of similar chain lengths, whereas in hairy roots grown in vitro, identical patterns with a slightly broader chain-length range were found. Conversely, in leaves and seeds polyprenols were the dominant form, and their pattern was shifted toward longer chains (maximal content of Pren-19, where Pren-n is polyprenol composed of n isoprene units). Interestingly, the pattern of dolichols in seeds and leaves (in which Dol-17 dominated) was similar to that found in roots. Structures of the dolichols and polyprenols isolated were confirmed by the application of a new HPLC/electrospray ionization-MS method, which also offers a much higher sensitivity in detection of these compounds compared to a UV detector. The highest sensitivity was obtained when the [M + Na]+ ions of polyprenols and dolichols were recorded in the selected ion monitoring mode and a small amount of sodium acetate solution was added post-column to enhance the formation of these ions in an electrospray ion source.

In the gas-phase reactions of halonitro-and dinitrophenide anions with X (X ϭ F, Cl, Br, NO 2 ) and NO 2 groups in ortho or para position to each other with selected C-H acids: CH 3 CN, CH 3 COCH 3 , and CH 3 NO 2 , products of the S N Ar-type reaction are formed. Nitrophenide anions are generated by decarboxylation of the respective nitrobenzenecarboxylate anions in ESI ion source and the S N Ar reaction takes place either in the medium-pressure zone of the ion source or in the collision chamber of the triple quadrupole mass spectrometer. In the case of F, Cl, and NO 2 derivatives, the main ionic product is the respective [NO 2 -Ph-CHR] Ϫ anion (R ϭ CN, COCH 3 , NO 2 ). In the case of Br derivatives, the main ionic product is Br Ϫ ion because it has lower proton affinity than the [NO 2 -Ph-CHR] Ϫ anion (for R ϭ CN, COCH 3 ). For some halonitrophenide anion C-H acid pairs of reactants, the S N Ar reaction is competed by the formation of halophenolate anions. This reaction can be rationalized by the single electrontransfer mechanism or by homolytic C-H bond cleavage in the proton-bound complex, both resulting in the formation of the halonitrobenzene radical anion, which in turn undergoes -NO 2 to -ONO rearrangement followed by the NO

Purpose: While an increasing number of studies demonstrate the importance of vitamin D for athletic performance, the effects of any type of exercise on vitamin D metabolism are poorly characterized. We aimed to identify the responses of some vitamin D metabolites to ultra-marathon runs. Methods: A repeated-measures design was implemented, in which 27 amateur runners were assigned into two groups: those who received a single dose of vitamin D3 (150,000 IU) 24 h before the start of the marathon (n = 13) and those (n = 14) who received a placebo. Blood samples were collected 24 h before, immediately after, and 24 h after the run. Results: In both groups of runners, serum 25(OH)D3, 24,25(OH)2D3, and 3-epi-25(OH)D3 levels significantly increased by 83%, 63%, and 182% after the ultra-marathon, respectively. The increase was most pronounced in the vitamin D group. Body mass and fat mass significantly decreased after the run in both groups. Conclusions: Ultra-marathon induces the mobilization of vitamin D into the blood. Furthermore, the 24,25(OH)2D3 and 3-epi-25(OH)D3 increases imply that the exercise stimulates vitamin D metabolism.

Profiling of vitamin D metabolites in dried blood spots, including 24,25(OH)2D3, has been performed for the first time.

In the standard electrospray ionization mass spectra of many common, low molecular mass organic compounds dissolved in methanol, peaks corresponding to ions with formula [3M + Met](2+) (M = organic molecule, Met = bivalent metal cation) are observed, sometimes with significant abundances. The most common are ions containing Mg(2+), Ca(2+) and Fe(2+). Their presence can be easily rationalized on the basis of typical organic reaction work-up procedures. The formation of [3M + Met](2+) ions has been studied using N-FMOC-proline methyl ester as a model organic ligand and Mg(2+), Ca(2+), Sr(2+), Ba(2+), Fe(2+), Ni(2+), Mn(2+), Co(2+) and Zn(2+) chlorides or acetates as the sources of bivalent cation. It was found that all ions studied form [3M + Met](2+) complexes with N-FMOC-proline methyl ester, some of them at very low concentrations. Transition metal cations generally show higher complexation activity in comparison with alkaline earth metal cations. They are also more specific in the formation of [3M + Met](2+) complexes. In the case of alkaline earth metal cations [2M + Met](2+) and [4M + Met](2+) complex ions are also observed. It has been found that [3M + Met](2+) complex ions undergo specific fragmentation at relatively low energy, yielding fluorenylmethyl cation as a major product. [M + Na](+) ions are much more stable and their fragmentation is not as specific.

Di- and trinitrophenide anions generated by decarboxylation of the anions of 2,4-, 3,5-, and 2,6-dinitrobenzoic acids and 1,3,5-trinitrobenzoic acid in the medium-pressure region of an electrospray ion source react locally with various C-H acids delivered in the form of vapors mixed with the curtain gas, yielding anionic sigma-adducts. Positive results were obtained for aliphatic aldehydes, ketones, esters and nitriles. All three dinitrobenzoic acids bearing NO(2) groups in the meta position to each other gave the same sigma-adducts which can be rationalized by a reaction sequence including proton transfer from the C-H acid to the nitrophenide anion and subsequent formation of the sigma-adduct by the reaction of 1,3-dinitrobenzene with the carbanion within the ion-molecule complex. It was found that such a reaction is possible only for C-H acids with a gas-phase acidity lying within a narrow, strictly defined range whose location on the acidity scale depends on the acidity of the nitroarene. The sigma-adduct formed in the reaction of the 2,4-dinitrophenide anion with CH(2)Cl(2) undergoes rapid HCl elimination yielding an anion with the same composition as that produced by the Vicarious Nucleophilic Substitution of hydrogen reaction but with a different structure.