Structure Elucidation

Besides a known coumarin derivative, scopoletin, the iridoids gardenoside,andgardiol were isolated for the first time from a Xeromphis species, namely Xeromphis nilotica. Their structures were established on the basis of their spectroscopic data.

Three brominated bisabolene-type sesquiterpene derivatives, aldingenin B, C and D, together with cholesterol and palmitic acid, have been isolated from the red alga Laurencia aldingensis (Ceramiales, Rodophyta) and their structures elucidated by spectroscopic methods including NMR analysis.

Boswellia resin is a major anti-inflammatory agent in herbal medical tradition, as well as a common food supplement. Its anti-inflammatory activity has been attributed to boswellic acid and its derivatives. Here, we re-examined the antiinflammatory effect of the resin, using inhibitor of nuclear factor-B␣ (IB␣) degradation in tumor necrosis factor (TNF) ␣-stimulated HeLa cells for a bioassay-guided fractionation. We thus isolated two novel nuclear factor-B (NF-B) inhibitors from the resin, their structures elucidated as incensole acetate (IA) and its nonacetylated form, incensole (IN). IA inhibited TAK/TAB-mediated IB kinase (IKK) activation loop phosphorylation, resulting in the inhibition of cytokine and This work was supported by a EC 5th framework consortium grant number QLK3-CT-2000-00-463 (Anti-Inflammatory Natural Products consortium), and by the Miriam and Sheldon Adelson program in Neural Repair and Rehabilitation for support (to R.M.).

The structure of six synthetic n-3 polyunsaturated fatty acids bearing three to six double bonds has been confirmed by high resolution NMR. Complete assignment of 13 C spectra of isomers of h-linolenic acid, EPA and DHA was established by the use of the new SAPHIR-HSQC method developed at the NMR center and compared with the results obtained from spin lattice relaxation time measurements. Sequential Attribution of Proton-carbon pairs from High Resolution (SAPHIR) HSQC, HSQC-TOCSY experiments allow both the precise measurement of olefinic coupling constants and the location of each double bond inside the chain. We have also drawn attention to the effect of an E-double bond in comparison with a Z-olefinic bond to the chemical shifts of neighboring carbon atoms. A set of shift parameters, obtained from our NMR data, allowed the visualization of electric and steric effects of E-olefinic bond in D 11 and 3 positions of the carbon chain of polyunsaturated fatty acids.

Polyurethane resins are a class of thermosetting polymers largely used in high performance surface coatings and paints. Fast depletion of petroleum stock and increase in their cost puts limit to their use in future for production of petroleum-based resins. Consequently the need for utilization of renewable resources as substitute to petrochemicals is pressing. We have attempted to synthesize polyurethane (PU) from linseed oil epoxy and have developed from it an anticorrosive coating. Trans hydroxylation of linseed oil epoxy was carried out in situ after a reported method. It was further reacted with toluylene diisocyanate to synthesize polyurethane. Physico-chemical characterization of the synthesized resin was carried out as per standard methods. Structural elucidation was carried out using IR, NMR spectral data. Physico-mechanical and weather resistance performance of the coated samples were also studied .It was found that the synthesized resin showed good performance in various corrosion tests. These studies show that the material holds promise for use as an effective anticorrosive coating compound.

In the quest for increased control and tuneability of organic patterns at metal surfaces, more and more systems emerge that rely upon coordination of metal adatoms by organic ligands using endgroups such as carbonitriles, amines, and carboxylic acids. Such systems promise great flexibility in the size and geometry of the surface pattern through choice of the ligand shape, the number and arrangement of ligating endgroups, and the nature of the metal centers. Planar (trigonal or square) arrangements of ligands around metal centers occur most commonly as a result of attractive interactions of the ligands with the substrate. In contrast, in the solution phase planar, and in particular trigonal planar, arrangements are quite rare and generally require ligands whose nature (for example bidentate, pincer shape) forces planarity.

In the original manuscript the references to alternating collision energy were missed out in error. The application of simultaneous acquisition of precursor and production ions in one analytical run was first described by Bateman et al. in 2002 for the analysis of glycopeptides. 19 This process of using alternating collision cell energies was employed for metabolite identification by Johnson and Plumb 20 in their study on the analysis of acetaminophen metabolism by UPLC/MS. Further work using this technique was also described by Wrona et al. for the 'all in one analysis' of in vitro drug metabolites in drug discovery. 21 REFERENCES 19. Bateman RH, Carruthers R, Hoyes JB, Jones C, Langridge JI, Millar A, Vissars JPC.

Structure elucidation for natural product compounds is assisted by making similarity comparisons between the uncharacterized experimental 13C NMR spectrum with relevant databases of estimated spectra. Databases of estimated spectra are deduced from a small set of assigned structures using HOSE codes. Using spectra estimated from structures circumvents problems of inconsistent, incomplete, missing or irrelevant data. It also enables rapid generation of reasonably sized databases that are unavailable from commercial sources. We validate the similarity method theoretically by analyzing what can be best expected from a match of an estimated set of peaks to the experimental spectrum. We also show by example that the method is successful when used in the laboratory.

Gomerolactones A–D along with the known majusculone, obtusol, and elatol were isolated from Laurencia majuscula, and their structures were determined spectroscopically. With the aid of Pirkle's reagent at low temperature, NMR spectroscopy was used to determine the absolute configuration at the ring closure carbon atom of a α-alkylidene-γ-lactone and an α-alkylidene-δ-lactone unit embedded in the chamigrene network of compounds 1 and 2, respectively. The absolute stereochemistry of compounds 3 and 4 was determined by X-ray analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

The 1 H and 13 C NMR spectra of the new calix[4]arene-based tetraketone were completely assigned by oneand two-dimensional homo-and heteronuclear experiments (1 H-1 H COSY, 1 H-13 C HMQC, and HMBC) at 400 and 100 MHz, respectively, at 25 • C standard pulse sequence. 1 H and 13 C spectra were measured at room temperature for 25,26,27,28-tetramethylcalix[4]arene tetraketone (1). 13 C{ 1 H}, DEPT and NMR techniques were used to distinguish the methyl, methylene and methine carbon resonance signals of calix[4]arene 1. Correlation of 1D (1 H, 13 C{ 1 H}, DEPT) and 2D (HMQC and HMBC) NMR data was used to completely assign various overlapping and broad signals of calix[4]arene 1. Heteronuclear multibond correlation (HMBC) studies were used to completely assign various carbon resonances. Our results show that the conformation of calix[4]arene 1 in the solution is very similar to the cone conformation reported in the literature.

Natural or synthetic cyclic peptides often possess pronounced bioactivity. Their mass spectrometric characterization is difficult due to the predominant occurrence of non-proteinogenic monomers and the complex fragmentation patterns observed. Even though several software tools for cyclic peptide tandem mass spectra annotation have been published, these tools are still unable to annotate a majority of the signals observed in experimentally obtained mass spectra. They are thus not suitable for extensive mass spectrometric characterization of these compounds. This lack of advanced and userfriendly software tools has motivated us to extend the fragmentation module of a freely available open-source software, mMass (http://www.mmass.org), to allow for cyclic peptide tandem mass spectra annotation and interpretation. The resulting software has been tested on several cyanobacterial and other naturally occurring peptides. It has been found to be superior to other currently available tools concerning both usability and annotation extensiveness. Thus it is highly useful for accelerating the structure confirmation and elucidation of cyclic as well as linear peptides and depsipeptides.

Two impurities found in both stressed and aged solid-state formulations of olanzapine have been identified as (Z)-1,3-dihydro-4-(4-methyl-1-piperazinyl)-2-(2-oxopropylidene)-2H-1,5-benzodiazepin-2-one (1) and (Z)-1-[1,2-dihydro-4-(4-methyl-1piperazinyl)-2-thioxo-3H-1,5-benzodiazepin-3-ylidene]propan-2-one (2). The structures indicate that the two impurities are degradation products resulting from oxidation of the thiophene ring of olanzapine. The impurities were isolated by preparative HPLC from a thermally stressed formulation, and characterized by UV, IR, MS, and NMR. A synthetic preparation of compounds 1 and 2 by reaction of olanzapine with the singlet oxygen mimic 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) is presented. The structure of 2 was also determined by single-crystal X-ray diffraction analysis. A degradation pathway for the formation of 1 and 2 is proposed. ß a ''Long-Range Correlations'', that is, carbon-proton correlations through two-and three-bond coupling. In each cell is a list of the protons which are within two or three bonds of the carbon in that row. b Chemical shift taken from one-bond heteronuclear correlation experiment. c Resonance not observed.

In the present study, toremifene urinary excretion studies were evaluated in order to examine main metabolic reactions and to select target metabolites in doping control analysis. Urine samples from three female subjects were collected every 3 h for at least 15 days after the oral administration of a single dose of Fareston® (60 mg). The elemental compositions of the compounds detected were determined by liquid chromatography-mass spectrometry using a time-of-flight system with accurate mass measurement. More detailed structure elucidation was obtained by monitoring the presence or absence of structure-specific ions, using product ion scan and neutral loss acquisition modes, whereas the metabolites urinary profiles were evaluated in selected reaction monitoring acquisition mode. The results showed that the main routes of phase-I modifications involved carboxylation of the chlorinated side chain, N-demethylation and hydroxylation in different positions. Fifteen metabolites were found in all subjects studied, most of them were detected for more than 10 days in the free, glucuronide and sulphate fractions, with a maximum of excretion generally after 9–22 and 34–47 h from drug administration. These metabolites can be divided in two groups: metabolites with the characteristic chlorine isotope pattern and metabolites without the characteristic chlorine isotope pattern. The most abundant and long-term compounds were the carboxylated metabolites followed by the hydroxylated metabolites. Their product ions originating after collision-induced dissociation were observed to occur prevalently in the dimethylaminoethoxy and in the chlorinated side chains. These structure-specific ions were used to design screening and confirmation procedures to positively identify toremifene administration in doping control analysis. Figure Suggested main metabolic routes of toremifene, as postulated by excretion studies followed by both LC-MS/MS assays with different acquisition modes and LC-QTOF

Three flavanones, pinostrobin (1), pinocembrin (2) and alpinetin (3) and two chalcones, cardamonin (4) and boesenbergin A (5) were isolated from the hexane and chloroform extracts of rhizomes of Boesenbergia rotunda (L.). The structures of all ...

ABsm~.-Bioassay-guided analysis ofan EtOH extract ofMminga oleifera leaves showing hypotensive activity led to the isolation of two nitrile glycosides, niazirin 111 and niazirinin 121, and three mustard oil glycosides, 4-1(4'-O-acetyla-~-rhamnosylo~)~n~l}isothiocyanate 147, niaziminin A, and niaziminin B. Glycoside 2 is a new compound. Niaziminins A and B have previously been obtained from the leafextract as a mixture, while compound 4 is new from this source. Structural determination was accomplished by means ofspectroscopic methods including appropriate 2D nmr experiments and chemical reactions. This is the h t report of the isolation of nitriles, an isothiocyanate, and thiocarbamates from the same plant species. Isothiocyanate 4 and the thiocarbamate glycosides niaziminin A and B showed hypotensive activity while nitrile glycosides 1 and 2 were found to be inactive in this regard.

The technical feasibility and performance of photocatalytic degradation of anti-inflammatory drug acetaminophen (ACTP) and b-blocker atenolol (ATL) have been studied in a well-defined system of a pilot-plant scale Compound Parabolic Collectors (CPCs) under natural illumination. Heterogeneous photocatalysis with titanium dioxide (TiO 2 ) and homogeneous photocatalysis by photo-Fenton were investigated with two different matrices: distilled water and synthetic municipal wastewater treatment plant effluent (S.E.). The initial concentrations of the pharmaceuticals studied were 10 mg L À1 , whereas the concentrations of the catalysts employed were 200 mg L À1 of TiO 2 and 5 mg L À1 of iron. Total disappearance of the parent compounds and discreet mineralization were attained in all experiments. Furthermore, kinetic parameters, release of heteroatoms and formation of carboxylic acids are discussed. The main intermediate products of photocatalytic degradation of atelonol has been structurally elucidated by tandem mass spectrometry (MS 2 ) experiments performed at quadrupole-time of flight (QqToF) mass analyzer coupled to ultra-performance liquid chromatograph (UPLC). Six transformation products were characterized, formed by consecutive attacks of hydroxyl ( OH) radical in concomitance with the disappearance of the primary compound. The proposed TiO 2 and photo-Fenton degradation route of ATL is reported for the first time.

The 13C-NMR chemical shifts of dicyanocobyrinic acid heptamethyl ester (l), an important corrinoid model compound, are correlated with those of some derivatives. Isotope effects on the I3C chemical shifts (over two to four bonds) are observed for the I@-deuterio and the 10,13-dideuterio analogues 4 and 5 of 1. The effect of the deuterium at C-13 in 5 upon the two 12-methyl groups is stereospecific. Together with spin-lattice relaxation times, these informations allow the complete interpretation of the I3C-NMR spectrum of 1 (apart from the ester methyl resonances of sidechains a to f, which all absorb within a range of 0.3 ppm). The 'H-NMR spectrum of 1 is partly assigned via selective 13C{1H)-double resonance.

The synthesis and characterisation of a range of cobalt pivalate cage complexes are reported. The cages include: a dinuclear Co II complex; an oxo-centred Co III triangle; tetranuclear Co II heterocubanes and butterflies; tetranuclear heterovalent cobalt butterflies and hexanuclear edge-sharing bitetrahedra; heterovalent penta-, hexa-and hepta-nuclear cages based on {M 4 O 4 } heterocubane cores; and a tetradecanuclear cage based on heterocubanes sharing edges and vertices. Spectroscopic studies suggest that some of these cores are retained in solution, but that only in the Co III triangle is the structure including ligands retained. A scheme is proposed to account for the many structures observed, which may be applicable to other polymetallic cage complexes.

Chiral salen metal complexes are of great importance as catalysts for enantioselective transformations. A special field, where Jacobsen's Co(III) catalysts are employed, 1 is their application for hydrolytic kinetic resolution (HKR), using water as a nucleophile for the ring opening of epoxides. Although it seems that association of epoxide with the salen complex is not responsible for enantioselection, 2-4 a remaining crucial question is how selectivity is achieved: In a widely accepted proposal derived from kinetic measurements, the nucleophile consists of a s not observed s second catalyst species, which in turn would need to be able to differentiate between the two diastereomeric epoxide complexes. 2 Herein, we report an in situ solution NMR study of chiral salen Co(III) complexes combined with state-of-the-art density functional calculations of NMR shielding tensors for diamagnetic as well as paramagnetic systems. 5 This sheds light on coordination as well as electronic and conformational properties of these compounds, which are essential for an understanding of the mechanism of this reaction.

The developments during 2002-2005 in the methods used for saponin analyses in plant material are presented. There were number of papers published on isolation and identification of new saponins by chromatographic techniques. Some new developments can be found in separation techniques or solid and mobiles phases used. Separation of individual saponins is still complicated and time consuming. This is due to the fact that in most of the plant species saponins occur as a multi-component mixture of compounds of very similar polarities. Thus, to isolate single compound for structure elucidation or biological activity testing, a combination of different chromatographic techniques has to be used, e.g. first separation of the mixture to simpler sub-fractions on reversed phase C18 has to be followed by further purification on normal phase Silica gel column. Especially difficult is determination of saponins in plant material as these compounds do not posses chromophores and their profiles cannot be registered in UV. Most HPLC methods apply not only specific registration at 200-210 nm, but these methods are not applicable for determination of many saponins in plant material at levels lower than 200-300 mg/kg. Some new or improved techniques for quantification of saponins in plant material were published in reviewed period. These include further progress in the application of evaporative light scattering detection (ELSD) for saponin profiling and quantification, which is also not only specific but also more sensitive in comparison to 200-210 nm detection. Some progress in development of new applications for liquid chromatography-electrospray mass spectrometry (LC/ESI/MS) for saponin determination has also been done. This method gives highest sensitivity and on line identification of separated saponins and should be recommended for specialized analyses of extracts and pharmaceutical formulas like the validation of a new assay. From non-chromatographic techniques for saponin determination, a sensitive and compound specific ELISA tests for some saponins were developed.

Deflazacort (DFZ) is an oxazoline derivative of prednisolone with anti-inflammatory and immunosuppressive activity. The aim of this study was to investigate and to identify the main degradation product of DFZ, and to evaluate the anti-inflammatory effect of both DFZ and its major degradation product (namely DDP1). DFZ was subjected to alkaline and acid degradation. In 0.1 N NaOH, DFZ was immediately degraded and 99.0% of product DDP1 was detected by high performance liquid chromatography (HPLC). The HPLC method was ideal to separate the primary and other minor degradation products and was carried out using C 18 column, mobile phase consisting of water: acetonitrile: (60:40, v/v) with flow rate of 1.0 mL/min and detection at 244 nm. DDP1 was isolated and identified as 21-hydroxy deflazacort (21-OH-DFZ) by NMR, IR and LCMS. The in vivo pharmacological assays showed that both DFZ as 21-OH-DFZ are active in in vivo and in vitro inflammatory models, but 21-OH-DFZ is more potent than DFZ.

We investigated the effects of two natural dietary retinoid X receptor (RXR) ligands, phytanic acid (PA) and docosahexaenoic acid (DHA), on proliferation and on the metabolism of retinol (vitamin A) in both cultured normal human prostate epithelial cells (PrECs) and PC-3 prostate carcinoma cells. PA and DHA inhibited the proliferation of the parental PC-3 cells and PC-3 cells engineered to overexpress human lecithin:retinol acyltransferase (LRAT) in both the absence and presence of retinol. A synthetic RXR-specific ligand also inhibited PC-3 cell proliferation, whereas all-trans retinoic acid (ATRA) did not. PA and DHA treatment increased the levels of retinyl esters (REs) in both PrECs and PC-3 cells and generated novel REs that eluted on reverse-phase HPLC at 54.0 and 50.5 min, respectively. Mass spectrometric analyses demonstrated that these novel REs were retinyl phytanate (54.0 min) and retinyl docosahexaenoate (50.5 min). Neither PA nor DHA increased LRAT mRNA levels in these cells. In addition, we demonstrate that retinyl phytanate was generated by LRAT in the presence of PA and retinol; however, retinyl docosahexaenoate was produced by another enzyme in the presence of DHA and retinol.-Tang, X-H., M-J. Suh, R. Li, and L. J. Gudas. Cell proliferation inhibition and alterations in retinol esterification induced by phytanic acid and docosahexaenoic acid. J. Lipid Res. 2007. 48: 165-176. Supplementary key words mass spectrometry & postsource decay & retinoid metabolism & lecithin:retinol acyltransferase

The vibrational properties of acetyl peroxynitrate CH 3 C(O)OONO 2 (PAN) and trifluoroacetyl peroxynitrate CF 3 C(O)OONO 2 (FPAN) were studied by means of density functional theory (DFT) methods. The previously available experimental data and assignments for these compounds were compared with the theoretical

The chemical analysis of a sample of D 9 -THC, which had been stored in an ethanol/propylene glycol solution for 5 years, resulted in the isolation of several hydroxylated D 9 -THC derivatives, the main of which were trans-cannabitriol monoethyl ether (4) and trans-propanediol ethers 7 and 8. cis-Cannabitriol monoethyl ether (5) and the oxidised derivatives 3 and 6 were detected in lesser amounts. The structure elucidation of the unprecedented cannabinoids 3, 5, 7 and 8 was achieved mainly by NMR techniques. Full NMR assignment of compounds 4 and 6 were also made. The detection of cannabitriol (6) and the corresponding solvent-adduct analogues (compounds 4e8) was in agreement with the decomposition mechanisms previously proposed for D 9 -THC. The isolation of the endoperoxide 3 represents indirect evidence of the existence of unstable precursors that were suspected to be intermediates in the non-enzymatic oxidation pathway of D 9 -THC. Both isomers of cannabitriol monoethyl ether exhibited weak affinity at either CB 1 (K i ¼2.25, 6.30 mM) or CB 2 cannabinoid receptors (K i ¼1.97, 3.13 mM), the trans isomer always being more potent than the cis isomer.

The present paper describes the characterization of Pakistan lignite coal, derived humic acids (HAL) and nitrohumic acids (NHA) along with the standard leonardite humic acids (LHA). The study utilized chromatographic and spectroscopic techniques to characterize the structure of coal and derived materials. Pyrolysis coupled to gc/ms was conducted with and without methylating agent (tetramethyl ammonium hydroxide). The pyrolysis study resulted in releasing mainly fatty acid methyl esters, different series of hydrocarbons and α, ω-dicarboxylic acid methyl esters. Triterpenoids, syringic and ρ-coumaric compounds and aromatic compounds derived from lignin moieties were also detected. Fourier transform infrared (FT-IR) and NMR data helped to evaluate the influence of coal rank on regeneration and nitration processes with respect to chemical structural composition of coal and derived materials. FT-IR spectra of four materials were similar except that NHA showed an absorption band at 1532 cm −1 , thus confirming the presence of -NO 2 groups. 13 C NMR indicated higher aromaticity and less hydroxylalkyl material in HAL than NHA. The elemental composition and acid functional group content of four materials were also reported. The combination of results from different analytical techniques gives an improved understanding of the Pakistan coal nature and helpful for its future utilization.

The Al III -binding abilities of two aldaric acids, d-saccharic acid and mucic acid (the neutral form is denoted as H 2 L), were studied in solution by means of pH potentiometric, 1 H and 13 C NMR, and ESI-MS techniques. The most probable conformations and isomeric binding modes of the complexes formed in solution were determined by density functional theory (DFT) calculations. A solid d-saccharic acid com-plex K 2 [{Al(LH À2 )(H 2 O)} 2 ]¥H 2 O was isolated and crystallographically characterised. The two alcoholic hydroxy groups a to the terminal COO À groups were found to take part in the coordi-nation, but in different ways. One of them coordinates in a bridging mode. Detailed ESI-MS and NMR studies proved that the complex retains its structure in solution. However, depending on the ligand and the pH, such complexes may exist in two isomeric forms. DFT calculations on the ion [{Al(LH À2 )(H 2 O)} 2 ] 2À revealed that several orbitals participate in stabilizing the dimeric arrangement.

The use of a hybrid triple quadrupole-linear ion trap (QqQ LIT ) mass spectrometer system for a comprehensive study of fragmentation mechanisms is described. The anxiolytic drug, buspirone, was chosen as a model compound for this study. With the advent of a QqQ LIT instrument, both the traditional quadrupole and the new linear ion trap scans (LIT) could be performed in a single LC run. In the past, a sample had to be run on two different instruments, namely, a triple quadrupole instrument (QqQ) and a 3D ion trap (3D IT) to obtain similar information. With the new QqQ LIT technology, collision-induced dissociation (CID) occur in a quadrupole collision cell, q2, and fragment ions are trapped and analyzed in Q3 operated in LIT mode. In this work, high-sensitivity product ion spectra of buspirone were obtained from the one-stage 'Enhanced Product Ion' scan (EPI) with rich product ions and no low mass cut-off. Furthermore, detailed fragmentation pathways were elucidated by further dissociation of each of the fragment ions in the EPI spectrum using MS 3 mode in the same run. The MS 3 scan was performed by incorporating CID in q2, and trapping, cooling, isolation, and resonance-excitation in Q3 when operating in LIT mode. This approach allowed unambiguous assignment of all fragment ions quickly with fewer experiments and easier interpretation than the previous approach. The overall sensitivity for obtaining complete fragment ion data was significantly improved for QqQ LIT as compared with that of QqQ and 3D IT mass spectrometers. This is beneficial for structure determination of unknown trace components. The method allowed structure determination of metabolites of buspirone in rat microsomes at 1 µM concentration, which was a 10-fold lower concentration than was needed for QqQ or 3D IT instruments. The QqQ LIT instrument provided a simple, rapid, sensitive and powerful approach for structure elucidation of trace components.

A broad-based characterisation of a pharmacologically active dichloromethane extract from Isatis tinctoria leaves was carried out. For a comprehensive picture we also included the polar constituents of I. tinctoria (MeOH extract) and for comparative purposes, the taxonomically closely related plant I. indigotica. Diode array detector, evaporative light scattering detector, atmospheric pressure chemical ionisation and electrospray ionisation mass spectrometry, and electrospray ionisation time-of-flight mass spectrometry detectors were used in parallel to ensure a wide coverage of secondary metabolites with highly diverging analytical properties. Off-line microprobe nuclear magnetic resonance spectroscopy after peak purification by semi-preparative high-pressure liquid chromatography served for structure elucidation of some minor constituents.

Phenolic compounds in strawberry (Fragaria × ananassa) fruits were identified and characterized by using the complementary information from different high-performance liquid chromatography detectors: diode array, mass spectrometer in positive and negative mode, and coulometric array. Electrochemical profiles obtained from the coulometric array detector contributed to the structural elucidation suggested from the UV-vis and mass spectra. About 40 phenolic compounds including glycosides of quercetin, kaempferol, cyanidin, pelargonidin, and ellagic acid, together with flavanols, derivatives of p-coumaric acid, and ellagitannins, were described, providing a more complete identification of phenolic compounds in strawberry fruits. Quercetin-3-malonylhexoside and a deoxyhexoside of ellagic acid were reported for the first time. Antioxidative properties of individual components in strawberries were estimated by their electrochemical responses. Ascorbic acid was the single most important contributor to electrochemical response in strawberries (24%), whereas the ellagitannins and the anthocyanins were the groups of polyphenols with the highest contributions, 19 and 13% at 400 mV, respectively.

A critical introduction to lipid shortening systems is provided. The review covers types, formulations, functionality, and processing conditions required for the production of lipid shortening systems. Furthermore, lipid shortenings and their production are placed within the context of recent advances in the areas of crystallization, structural elucidation, and mechanical modeling of fat crystal networks in general. The various unit operations involved in the production of lipid shortenings are examined in light of the evolution of structure (both at the crystalline and microstructural levels) and derived physical functionality. #

In situ epoxidation of linseed oil (LO) was carried out as per previously reported method. Epoxidised oil (LOE) was further hydroxylated (HLOE) and cured with butylated melamine formaldehyde (BMF), in varying weight percentages (10-30 wt.% on the weight of epoxy resin) to develop coating materials. Structural elucidation of HLOE and HLOE-BMF system was performed by IR, 1 H NMR and 13 C NMR spectroscopic analyses. Physico-chemical characterization was carried out by standard methods. Thermal stability and curing behaviour of these systems were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. HLOE-BMF systems were applied over mild steel strips of standard sizes to evaluate their physico-mechanical and chemical resistance performance. It was found that, among all resin compositions, HLOE-30 exhibited far better coating properties.

The present paper provides a summary of the collision-induced dissociation of protonated and deprotonated phase II metabolites of drugs and pesticides. This overview is based on published literature and unpublished data from the authors. In particular, glutathione conjugates and their biotransformation products are discussed in detail. In addition, the fragmentation of the major classes of conjugates, i.e. glucuronides, glucosides, malonylglucosides, sulfates, acetates, methyl and glycine conjugates, is reported. Collision-induced dissociation, as studied by tandem mass spectrometry, allows the rapid identification of the type of conjugate, whereas the exact conjugation site can in general be determined only by additional NMR experiments.

A general overview of the advancements and applications of nuclear magnetic resonance (NMR) hyphenated with other analytical techniques is given from a practical point of view. Details on the advantages and disadvantages of the hyphenation of NMR with liquid chromatography as LC-NMR and also with mass spectrometry as LC-MS-NMR are demonstrated with two examples. Current developments of NMR with other analytical separation techniques, especially with capillary liquid chromatography (capLC) are discussed.

The structural elucidation of small molecules using mass spectrometry plays an important role in modern life sciences and bioanalytical approaches. This review covers different soft and hard ionization techniques and figures of merit for modern mass spectrometers, such as mass resolving power, mass accuracy, isotopic abundance accuracy, accurate mass multiple-stage MS(n) capability, as well as hybrid mass spectrometric and orthogonal chromatographic approaches. The latter part discusses mass spectral data handling strategies, which includes background and noise subtraction, adduct formation and detection, charge state determination, accurate mass measurements, elemental composition determinations, and complex data-dependent setups with ion maps and ion trees. The importance of mass spectral library search algorithms for tandem mass spectra and multiple-stage MS(n) mass spectra as well as mass spectral tree libraries that combine multiple-stage mass spectra are outlined. The successi...

Biocatalytic approaches have yielded efficient total syntheses of the major Amaryllidaceae alkaloids, all based on the key enzymatic dioxygenation of suitable aromatic precursors. This paper discusses the logic of general synthetic design for lycoricidine, narciclasine, pancratistatin, and 7-deoxypancratistatin. Experimental details are provided for the recently accomplished syntheses of narciclasine, ent-7-deoxypancratistatin, and 10b-epi-deoxypancratistatin via a new and selective opening of a cyclic sulfate over aziridines followed by aza-Payne rearrangement. The structural core of 7-deoxypancratistatin has also been degraded to a series of intermediates in which the amino inositol unit is cleaved and deoxygenated in a homologous fashion. These truncated derivatives and the compounds from the synthesis of the unnatural derivatives have been tested against six important human cancer cell lines in an effort to further develop the understanding of the mode of action for the most active congener in this group, pancratistatin. The results of the biological activity testing as well as experimental, spectral, and analytical data are provided in this manuscript for all relevant compounds. (6) Isolation and structure elucidation of Amaryllidaceae alkaloids: Lycorine: (a) ref 4. Lycoricidine: (b) Okamoto, T.; Torii, Y.; Isogai, Y. Ramos Martinez, I.; Iglesias Perez, C.; Spengler Salabarria, I.; Velez Castro, H. Rev. Cubana Farm. 1989, 23, 155. (g) Abou-Donia, A. H.; De Giulio, A.; Evidente, A.; Gaber, M.; Habib, A.; Lanzeta, R.; Seif El Din, A. Phytochemistry 1991, 30, 3445. 7-Deoxypancratistatin: (h) Ghosal, S.; Singh, S.; Kumar, Y.; Srivastava, R. S. Phytochemistry 1989, 28, 611. Pancratistatin: (i) Pettit, G. R.; Gaddamidi, V.; Cragg, G. M.; Herald, D. L.; Sagawa, Y. Santos, A.; Alonso, G.; Vazquez, D. Biochim. Biophys. Acta 1976, 425, 342. (d) Pettit, G. R.; Gaddamidi, V.; Herald, D. L.; Singh, S. B.; Cragg, G. M.; Schmidt, J. M.; Boettner, F. E.; Williams, M.; Sagawa, Y. J. Nat. Prod. 1986, 49, 995. (e) Gabrielsen, B.; Monath, T. P.; Huggins, J. W.; Kefauver, D. F.; Pettit, G. R.; Groszek, G.; Hollingshead, M.; Kirsi, J. J.; Shannon, W. M.; Schubert, E. M.; Dare, J.; Ugarkar, B.; Ussery, M. A.; Phelan, M. J.