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SummaryEndophytes constitute a remarkably multifarious group of microorganisms ubiquitous in plants and maintain an imperceptible association with their hosts for at least a part of their life cycle. Their enormous biological diversity coupled with their capability to biosynthesize bioactive secondary metabolites has provided the impetus for a number of investigations on endophytes. Here, we highlight the possible current and future strategies of understanding the chemical communication of endophytic fungi with other endophytes (fungi and bacteria) and with their host plants, which might not only allow the discovery and sustainable production of desirable natural products but also other mostly overlooked bioactive secondary metabolites.

A series ten novel analogs based on a novel template pyrrolo-quinazolino-quinolines, containing Luotonin-A (Luot-A) and 14-aza-camptothecin (14-aza-CPT) molecular core as well as their inclusion complexes in the native α- (α-CD), β- (β-CD) and γ- (β-CD) cyclodextrins were obtained. The physical properties of the alkaloids and corresponding molecular complexes with cyclodextrins are elucidated experimentally by the electronic absorption and CD-spectroscopy, electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry and nuclear magnetic resonance method. The experimental data are supported by the theoretical quantum chemical calculations of the molecular and electronic structures as well as physical properties in condense phase.

The experimental and theoretical spectroscopic and spectrometric elucidation in solid-state and gas-phase on the interacting ionic species of applied oriented synthetic derivatives on the base of the stilbazolium salts as molecular template was reported. The correlation between the molecular structure, and vibrational properties within THz-regime (10-0.3 THz) was performed. The collective vibrations, and gas-phase stabilized ionic species were comprehensive studied by the Raman spectroscopy and matrix-assisted laser desorption/ionization mass spectrometry, using the embedded organic dyes in host matrixes. The performed solid-state quantum chemical calculations contributed to further understanding of the nature of the guest–host interacting systems as well as to explain the observed optical phenomena within the THz-region.

Experimentally and theoretically were studied the physical properties of 19 new Schiff’s bases and their different protonated forms, depending on reaction conditions. It was elucidated the correlation between the type of molecular architecture, substituents and pH of the medium on first hyperpolarizability (β) with regard to the potential application of these compounds as organic nonlinear optical materials. The structure and optical properties were also studied, comparing quantum chemical data and experimental results from the mass spectrometry, electronic absorption, diffuse reflectance, and fluorescence spectroscopy, vibrational spectroscopy in condense phase, nuclear magnetic resonance, as well as thermal methods.

(2012). Crystal structures and physical properties of 5-sulfosalicylate and violurate metal–organic crystals – experimental versus theoretical study. Journal of Coordination Chemistry: Vol. 65, No. 12, pp. 2055-2073.

A comprehensive study of the coordination ability of the Ag(I) ion with biologically oriented synthetic derivatives of naturally occurring molecular targets of antimycins and actinomycins, with potential anticancer activity, is presented. The physical properties and molecular structures of the isolated series of 15 coordination compounds, depending on the experimental conditions, modelling the unique in vivo physiological environment, within relatively common utilized factors such as the pH of the medium, the type of solvent, the molar ratio of the metal to ligand (M:L) and more, were discussed. Electronic absorption, fluorescence, CD and vibrational spectroscopy, including IR- and Raman methods, nuclear magnetic resonance, mass spectrometric, X-ray diffraction, ICP and thermal methods were applied. Quantum chemical DFT calculations and NBO analysis were performed as well. The competitive contribution of the peptide residues in the naturally occurring antimycins and actinomycins to the observed polydentate chelation and the effect on the spectroscopic properties and unique T-shaped AgIX2Y, and AgIX3 polyhedra of the metal-chromophores were discussed.

Sixteen new metal–organic Ag I -compounds of organic dyes are synthesized, isolated spectroscopic and structurally elucidated by means of single crystal and powder X-ray diffraction, high resolution ESI mass spectrometry (MS), electronic absorption (EAs) and vibrational spectroscopy, diffuse reflectance (Ds) and fluorescence (Fs) spectroscopy in condense phases, nuclear-magnetic resonance, ICP, and thermal methods. Quantum chemical DFT calculations, as well as NBO analysis are performed of the novel complexes and ligands. Structurally related model metal–organic chromophores are also studied. The obtained correlation between the theoretical and experimental data marked the studied complexes as promising novel nonlinear optical (NLO) materials.

The molecular architecture design and physical properties of seven camptothecin (CPT) alkaloids, structurally related to irinotecan (CPT-11), substituted with the cyclic bulk N-aliphatic substituents at A-ring as well as their different protonated forms were studied. The correlation between the molecular geometry and physical properties of the neutral lactone form and different possible cationic forms was elucidated, using the electronic absorptions (EAs), circular dichroic (CD) and Raman spectroscopy within the far -IR region as well as electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry and nuclear magnetic resonance methods. The electronic structures, and properties of the neutral CPTs, their mono- and diprotonated forms as well as molecular ion fragments, obtained by the mass spectrometric data are predicted theoretically using the DFT method.

Despite enormous instrumental mass spectrometric (MS) developments, providing sufficient advantages towards highly selective and sensitive analytical protocols, including those related to different ionization techniques, the presented paper aimed to study the ionization UV-MALDI-MS process and to describe the chemical aspects and essential role of the types of the matrixes. Organic salts appeared promising as matrixes for analysis of natural products (NPs), including the imaging techniques, versus the co-crystals of neutral polyfunctional carboxylic acids. Seven model crystals of organic salts, and their matrix–analyte polycrystals, were comprehensively studied using the MALDI-MS and ESI-MS methods. The MS data were compared and supported by theoretical and experimental data, using quantum chemical methods, optical spectroscopy, and single crystal X-ray diffraction. The role of proton transfer (PT) effects in the desorption/ionization UV-MALDI processes was clarified.

The paper reported a matrix-assisted laser desorption/ionization (MALDI) mass spectrometric (MS) protocol for determination of herbicides, improving the analytical sample preparation step, making a significant contribution to the reproducibility and precision of the method. Matrix-analyte sampling is performed, employing low molecular weight (LMW) dication-containing organic crystals. Considering environmental control applications, six of the best selling herbicides, such as aclonifen (1), bifenox (2), diclofop-methyl (3), racemic mixture of diclofop (4), alachlor (5) and metolachlor (6) as well as their mixtures are quantified successively through the replacement of the polyfunctional benzoic acids with dication-containing organic matrices. The application of classical matrices for UV-MALDI-MS for the analysis of 1–6 caused their competitive chemical transformation, thus leading to spurious results and inaccurate analytical information, due to the wide variety of experimental conditions depending on the chemical, physico-chemical and physical nature of the herbicide analytes. The full method and technique validation, based on UV-MALDI-MS employing an Orbitrap analyser, are presented, achieving to our knowledge promising measurements for LMW analytes. These latter are judged by a fully validated analytical protocol based on positive electrospray ionization (ESI) mass spectrometry in a single and tandem (MS/MS) mode of operation. The chemical modifications, polymorph transformations of the UV-MALDI-MS crystal matrices and/or matrix-analyte samples, as well as ion-process formation upon solution → crystalline state and crystalline state → gas-phase transitions is controlled by joint application of unique and robust instrumental analytical methods for absolute structural determination, such as single crystal X-ray diffraction and mass spectrometry. As direct experimental qualitative, quantitative and structural evidence regarding the analytes was provided, the reported protocol is a fully validated one at each of the analytical steps. The additional quantum chemical data allowed correlation of the thermodynamic stability and MS abundances of observed ionic species in the gas-phase as well as the structure of crystals. Since environmental analysis involves a broad variety of analytes, conditions and degree of matrix complexity, only an individual certification method development may achieve meaningful analytical information. In this respect, the reported UV-MALDI-MS method for herbicides significantly impacts the field of environmental analytical chemistry, quality assurance and control; moreover the analytical protocol is constructed to deal with a real environmental problem. Therefore the reported method ensures real practical efficiency and reliability in the results for the human health safety, environmental monitoring and control programs.

A new analytical procedure using solid-state Raman spectroscopy within the THz-region for the quantitative determination of mixtures of different conformations of trifloxystrobin (EE, EZ, ZE and ZZ), tebuconazole (1), and propiconazole (2) as an effective method for the fungicide product quality monitoring programmes and control has been developed and validated. The obtained quantities were controlled independently by the validated hybrid HPLC electrospray ionization (ESI) tandem mass spectrometric (MS) and matrix-assisted laser desorption/ionization (MALDI) MS methods in the condensed phase. The quantitative dependences were obtained on the twenty binary mixtures of the analytes and were further tested on the three trade fungicide products, containing mixtures of trifloxystrobin-tebuconazole and trifloxystrobin-propiconazole, as an emissive concentrate or water soluble granules of the active ingredients. The present methods provided sufficient sensitivity as reflected by the metrologic quantities, evaluating the concentration limit of detection (LOD) and quantification (LOQ), linear limit (LL), measurement accuracy and precision, true quantity value, trueness of measurement and more.

The structure and properties of the 11 Camptothecin derivatives (CPTs) and their different mono-, di-, and triprotonated forms, depending on the number of proton accepting centers in the molecules are studied both theoretically and experimentally by quantum chemical approaches, electronic absorption, and CD spectroscopy. The study of the protonated forms of the CPTs and search of the electron-withdrawing groups is crucial of the water-solubility of the novel medications. Thus, the model interaction of the different protonated molecular species with the Topoisomerase I–DNA complex are elucidated and discussed with a view to understand the mode of binding of the CPTs depending on the type of the substituents and pH of the medium. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 134–144, 2012.

The distribution and co-occurrence of four Fusarium species and their mycotoxins were investigated in maize samples from two susceptible cultivars collected at 14 localities in South Africa during 2008 and 2009. Real-time PCR was used to quantify the respective Fusarium species in maize grain, and mycotoxins were quantified by multi-toxin analysis using HPLC-MS. In 2008, F. graminearum was the predominant species associated with maize ear rot in the eastern Free State, Mpumalanga and KwaZulu-Natal provinces, while F. verticillioides was predominant in the Northwest, the western Free State and the Northern Cape provinces. In 2009, maize ear rot infection was higher and F. graminearum became the predominant species found in the Northwest province. Fusarium subglutinans was associated with maize ear rot in both years at most of the localities, while F. proliferatum was not detected from any of the localities. Type B trichothecenes, especially deoxynivalenol, and zearalenone were well correlated with the amount of F. graminearum, fumonisins with F. verticillioides, and moniliformin and beauvericin with F. subglutinans. This information is of great importance to aid understanding of the distribution and epidemiology of Fusarium species in South Africa, and for predicting mycotoxin contamination risks and implementing preventative disease management strategies.

The conformational analysis, determination of absolute configurations (ACs) as well as elucidation of the electronic absorption and CD spectra of chiral molecules 2′,3′-O-isopropylideneadenosine (1), 5′-carboxy-2′,3′-O-isopropylidene-D-adenosine (2), 2-chloro-2′,3′-O-isopropylideneadenosine-5′-N- ethylcarboxamide (3) and 1-[6-(6-Amino-2-methyl-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-ylmethyl]-3-carbamoyl-pyridinium chloride (4), 9-(6-aminomethyl-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-yl)-9H-purin-6-ylamine (5) and acetic acid 6-(6-amino-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-ylmethyl ester (6) are performer. The methods such as electronic absorption (EAs), diffuse reflectance (DSs) spectroscopy as well as electronic circular dichroism (ECD) are applied. The theoretical density functional theory (DFT) calculations are carried out to evaluate the optical phenomena of isolated molecules as well as dimeric associates. We are demonstrated the significance and the advances of the stereo chemical experimental and theoretical characterization of natural products and their functional synthetic derivatives, vitha a view to further elucidation of unknown extracts of same chemical class. Special attention is devoted to the role of intermolecular interactions in condense phases on the theoretical and experimental optical properties, studying the corresponding dimeric associates. These results are a key in the drug discovery, and structure-based design of functionalized nucleosides. The methods as single crystal X-ray diffraction and MALDI Orbitrap mass spectrometric imaging (MALDI Orbitrap MSI) are also applied.

Rohitukine is a chromane alkaloid possessing anti-inflammatory, anti-cancer and immuno-modulatory properties. The compound was first reported from Amoora rohituka (Meliaceae) and later from Dysoxylum binectariferum (Meliaceae) and Schumanniophyton problematicum (Rubiaceae). Flavopiridol, a semi-synthetic derivative of rohitukine is a potent CDK inhibitor and is currently in Phase III clinical trials. In this study, the isolation of an endophytic fungus, Fusarium proliferatum (MTCC 9690) from the inner bark tissue of Dysoxylum binectariferum Hook.f (Meliaceae) is reported. The endophytic fungus produces rohitukine when cultured in shake flasks containing potato dextrose broth. The yield of rohitukine was 186 μg/100 g dry mycelial weight, substantially lower than that produced by the host tissue. The compound from the fungus was authenticated by comparing the LC-HRMS and LC-HRMS/MS spectra with those of the reference standard and that produced by the host plant. Methanolic extract of the fungus was cytotoxic against HCT-116 and MCF-7 human cancer cell lines (IC(50) = 10 μg/ml for both cancer cell lines).

A discussion on the possible application of the organic 5-sulfosalicylates as organic materials with tunable optical and non-linear-optical (NLO) properties is performed on the basis of the experimental crystallographic and spectroscopic methods such as single crystal X-ray diffraction, electronic absorption, diffuse reflectance and fluorescence spectroscopy in condense phase, conventional and linear-polarized IR- and Raman spectroscopy in solid-state. The model systems 5-sulfosalicylic acid dihydrate ( 1 ), 4-aminobenzamidinium bis(5-sulfosalicylicilate) monohydrate ( 2 ) and 5-sulfosalicylicilate salt of glycinamide ( 3 ), comparing with the as well as theoretical quantum chemical calculations of the systems neutral 5-sulfosalicylic acid ( I ), its mono-( Ia ) and dianion ( Ib ), respectively.

A series of 14 new metal–organic compounds of Ag(I) and Zn(II), i.e. trichloro(1-(2-hydroxyethyl)piperazinium)zinc(II) (1), 1-[2-(2-hydroxyethoxy)-ethyl]-piperazinium tetrachlorozincate(II) (2), tetrachlorozincate(II) salt of 4-(2-aminoethyl)morpholine (3), 1,4-bis(2-hydroxyethyl)piperazinium tetrachlorozincate(II) (4), 5-sulfosalicylate coordination polymer of Ag(I) (5) [3dd] , mandelate coordination polymer of Ag(I) (6) [1r] , hexa-aqua zinc(II) 5-sulfosalicylate monohydrate (7), cyclic quaternary N-ethylmorpholine tetrachlorozincate(II) monohydrate (8), 2,2′:6′,2″-terpyridinium tetrachlorozincate(II) (9), bis(guaninium) tetrachlorozincate(II) dihydrate (10), bis(8-hydroxyquinolinium) tetrachlorozincate(II) (11), zinc(II) complexes of 2,4-dihydroxy-(12) and 2,3-dihydroxy-(13) benzoic acid, silver(I) complex of 2,4-dihydroxybenzoic acid (14), as well as cyclic quaternary N-ethylmorpholine chloride monohydrate (8a), are synthesized, isolated spectroscopic and structurally characterized by the mass spectrometry, electronic absorption and vibrational spectroscopy, diffuse reflectance and fluorescence spectroscopy in condense phases, single crystal X-ray diffraction, ICP and thermal methods. Quantum chemical DFT calculations, including NBO analysis are performed for all of the obtained complexes, their ligands as well as series of structurally related model metal–organic chromophores. The obtained correlation dependences between the theoretical and experimental structural and spectroscopic data both in gas- and condense phases, underlying an explanation of the experimentally observed mass spectrometrically stable metal–organic species in the gas phase as well as the atypical CT bands in excited state.

The objective of this study was to investigate how the camptothecin (CPT) producing endophyte, Fusarium solani, ensures self-resistance before being incapacitated by its own and the host’s CPT biosynthesis. The primary structure of endophyte topoisomerase I (Topo 1, encoded by Top1 gene) was studied with emphasis on the CPT-binding and catalytic domains. Known Topo 1 amino acid residues conferring CPT resistance were screened in CPT-producing and CPT-lacking endophytes and the possible role of Topo 1 alteration in fungal resistance towards CPT was evaluated. Based on known nucleotide polymorphisms of Top1 associated with CPT resistance, the current findings indicate that fungal endophytes intrinsically possess resistance features against CPT produced by the associated host, irrespective of their indigenous biosynthetic capabilities. They might later develop further co-evolutionary resistance features against host and indigenous CPT. This study signifies the importance of resistance mechanisms employed by endophytes to tolerate toxic host-specific metabolites, and might provide deeper understanding of host–microbe co-evolution and further development of anticancer drugs.

Camptothecin (CPT), 9-methoxycamptothecin (9-MeO-CPT), and 10-hydroxycamptothecin (10-OH-CPT) are potent antineoplastic metabolites. We analyzed these metabolites in Camptotheca acuminata sampled from Germany and China, using LC–MS/MS and LC-ESI–HRMS/MS, coupled with chemometrics. Multivariate analysis revealed that fresh stems of C. acuminata from China had the highest comprehensive metabolite load. Significant positive correlations of CPT with 9-MeO-CPT and 10-OH-CPT were observed by Kruskal's multidimensional scaling and principal component analysis. Linear discriminant analysis and hierarchical agglomerative cluster analysis revealed that C. acuminata from China was separated from others. These positive correlations indicate that these metabolites are biosynthesized similarly and operate synergistically in planta .

Fungal endophytes inhabit healthy tissues of all terrestrial plant taxa studied and occasionally produce host-specific compounds. We recently isolated an endophytic fungus, Fusarium solani, from Camptotheca acuminata, capable of biosynthesizing camptothecin (CPT, 1), but this capability substantially decreased on repeated subculturing. The endophyte with an impaired 1 biosynthetic capability was artificially inoculated into the living host plants and then recovered after colonization. Although the host-endophyte interaction could be reconstituted, biosynthesis of 1 could not be restored. Using a homology-based approach and high-precision isotope-ratio mass spectrometry (HP-IRMS), a cross-species biosynthetic pathway is proposed where the endophyte utilizes indigenous G10H (geraniol 10-hydroxylase), SLS (secologanin synthase), and TDC (tryptophan decarboxylase) to biosynthesize precursors of 1. However, the endophyte requires host STR (strictosidine synthase) in order to condense the nitrogen-containing moiety (tryptamine, 2) with the carbon-containing moiety (secologanin, 3) to form strictosidine (4) and complete the biosynthesis of 1. Biosynthetic genes of 1 in the seventh subculture generation of the endophyte revealed random and unpredictable nonsynonymous mutations. These random base substitutions led to dysfunction at the amino acid level. The controls, Top1 gene and rDNA, remained intact over subculturing, revealing that instability of biosynthetic genes of 1 was not reflected in the primary metabolic processes and functioning of the housekeeping genes. The present results reveal the causes of decreased production of 1 on subculturing, which could not be reversed by host-endophyte reassociation.

Four novel AgI-complexes with DL-mandelic acid (MA) (1), squaric acid (H2Sq) (2), 3-pyridin aldehyde (3PyA) (3) and 2-amino-8-hydroxyquinoline (2A8H) (4) as well as two ZnII-ones with 3PyA (5) and 2A8H (6) are synthesized, isolated, spectroscopic and structural characterized by single crystal X-ray diffraction, UV–vis–NIR, and IR-spectroscopy. The experimental data of the complex (1) were compared with the analogous of the neutral MA. Quantum chemical calculations are carried out, and the electronic structures and optical properties of neutral MA and its anion, with a view to assign the vibrational properties of (1).

Crystal structures, spectroscopic and NLO properties of 8 novel organic salts with aromatic amines, i.e. tyrammonium iodide (1), tyrammonium benzene-1,2,4-tricarboxilate (2), octopammonium 5-sulfosalicylate monohydrate (3), octopammonium hydrogen squarate (4), dopammonium 5-sulfosalicylate dihydrate (5), ephedrinium mandelate (6), dopammonium hydrogen squarate (7) and bis(ephedrinium) squarate (8) are reported and discussed with a view of their application in optical technologies. The conformations of the cations of the aromatic amines are discussed comparing the experimental and theoretical data.

The photodegradation kinetics and the break down pathway of fenhexamid were studied in aqueous systems using [phenyl-UL- 14 C]- and [carbonyl- 14 C]-labelled compounds. The photolysis of fenhexamid followed first-order kinetics. The degradation rate of fenhexamid was significantly influenced by the solution pH with rate constants ( k ) of 2.11 × 10 −2 , 4.47 × 10 −2 , 6.11 × 10 −1 and 1.69 h −1 at pH 5.0, 6.6, 7.3 and 9.0, respectively. Fenhexamid exhibited no significant change in degradation rate in the presence of acetone and hydrogen peroxide, while humic and fulvic acids retarded the degradation rate, because they shielded the active molecules from light. However, in phosphate medium, the photolysis rate was significantly enhanced as a function of concentration. About 3–8% and 10–25% photo mineralization were observed, using [carbonyl- 14 C]- and [phenyl-UL- 14 C]-labelled fenhexamid in aqueous solutions at different pH, respectively. In addition to four known metabolites, one major and five minor photoproducts out of which one is reported for the first time, were identified using high resolution LC–MS/MS and NMR. The toxicity of the new metabolite was tested against the fish Oncorhynchus mykiss with no lethal effect at 100 mg L −1 .

A model heterogeneous mixture of a hydrophilic tripeptide (phenylalanine-glycine-glycine, PGG) and hydrophobic organic acids ((12)C- and (13)C-octanoic acid and pentadecanoic acid) was subjected to electrospray ionization mass spectrometry (ESI-MS). The objective was to verify the previously noted inconsistencies in ESI-MS of complex environmental samples such as humic materials from either aquatic or terrestrial origins. The hydrophobic organic acids, either alone or together, reduced significantly the ESI-MS detection of the tripeptide molecular and self-associated ions at a concentration that was an order of magnitude lower than that of PGG. The most intense peaks were invariably those of the octanoic acid as either deprotonated, self-associated, or acetate-clustered molecules. The presence of equimolar amounts of PGG and organic acids yielded similar results, but with a significant increased detection of PDA and a smaller depression of the PGG signals. This behaviour is attributed to a different electrospray ionization of the mixture compounds depending on their most probable positioning at the surface of the evaporating droplet. The most favoured positioning of hydrophobic molecules at the aqueous-gas interphase allows preferential evaporation of hydrophobic ions whereas the hydrophilic molecules are retained in the droplet interior, and, their ESI-MS detection depressed. These findings suggest that the electrospray ionization of different molecules present in complex heterogeneous mixtures of environmental significance such as humic substances is limited by their concentration and reciprocal attracting forces.

Papaverine is one of the earliest opium alkaloids for which a biosynthetic hypothesis was developed on theoretical grounds. Norlaudanosoline (=tetrahydropapaveroline) was claimed as the immediate precursor alkaloid for a multitude of nitrogen containing plant metabolites. This tetrahydroxylated compound was proposed to be fully O-methylated. The resulting tetrahydropapaverine should then aromatize to papaverine. In view of experimental data, this pathway has to be revised. Precursor administration to 8-day-old seedlings of Papaver followed by direct examination of the metabolic fate of the stable-isotope-labeled precursors in the total plant extract, without further purification of the metabolites, led to elucidation of the papaverine pathway in vivo. The central and earliest benzylisoquinoline alkaloid is not the tetraoxygenated norlaudanosoline, but instead the trihydroxylated norcoclaurine that is further converted into (S)-reticuline, the established precursor for poppy alkaloids. The papaverine pathway is opened by the methylation of (S)-reticuline to generate (S)-laudanine. A second methylation at the 3' position of laudanine leads to laudanosine, both known alkaloids from the opium poppy. Subsequent N-demethylation of laudanosine yields the known precursor of papaverine: tetrahydropapaverine. Inspection of the subsequent aromatization reaction established the presence of an intermediate, 1,2-dihydropapaverine, which has been characterized. The final step to papaverine is dehydrogenation of the 1,2-bond, yielding the target compound papaverine. We conclusively show herein that the previously claimed norreticuline does not play a role in the biosynthesis of papaverine.

A novel PCR primer system that targets a wide range of polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHD α ) genes of both Gram-positive and Gram-negative bacteria was developed and used to study their abundance and diversity in two different soils in response to phenanthrene spiking. The specificities and target ranges of the primers predicted in silico were confirmed experimentally by cloning and sequencing of PAH-RHD α gene amplicons from soil DNA. Cloning and sequencing showed the dominance of phnAc genes in the contaminated Luvisol. In contrast, high diversity of PAH-RHD α genes of Gram-positive and Gram-negative bacteria was observed in the phenanthrene-spiked Cambisol. Quantitative real-time PCR based on the same primers revealed that 63 days after phenanthrene spiking, PAH-RHD α genes were 1 order of magnitude more abundant in the Luvisol than in the Cambisol, while they were not detected in both control soils. In conclusion, sequence analysis of the amplicons obtained confirmed the specificity of the novel primer system and revealed a soil type-dependent response of PAH-RHD α gene-carrying soil bacteria to phenanthrene spiking.

High year-to-year variability in the incidence of Fusarium spp. and mycotoxin contamination was observed in a two-year survey investigating the impact of maize ear rot in 84 field samples from Germany. Fusarium verticillioides, F. graminearum, and F. proliferatum were the predominant species infecting maize kernels in 2006, whereas in 2007 the most frequently isolated species were F. graminearum, F. cerealis and F. subglutinans. Fourteen Fusariumrelated mycotoxins were detected as contaminants of maize kernels analyzed by a multi-mycotoxin determination method. In 2006, a growth season characterized by high temperature and low rainfall during anthesis and early grain filling, 75% of the maize samples were contaminated with deoxynivalenol, 34% with fumonisins and 27% with zearalenone. In 2007, characterized by moderate temperatures and frequent rainfall during the entire growth season, none of the 40 maize samples had quantifiable levels of fumonisins while deoxynivalenol and zearalenone were detected in 90% and 93% of the fields, respectively. In addition, 3-acetyldeoxynivalenol, 15-acetyldeoxnivalenol, moniliformin, beauvericin, nivalenol and enniatin B were detected as common contaminants produced in both growing seasons. The results demonstrate a significant mycotoxin contamination associated with maize ear rots in Germany and indicate, with regard to anticipated climate change, that fumonisins-producing species already present in German maize production may become more important. Keywords Deoxynivalenol . Ear rot . F. verticillioides . F. graminearum . Fumonisin . Zearalenone

The application of organic salts of mandelic acid (MA) as new materials for optical and non-linear-optical (NLO) application is discussed, using four novel organic salts, i.e. pyridinium-4-aldoxime mandelate (1), 1-aminoisoquinolinium mandelate mandelic acid (2), 2-amino-8-hydroxyquinolinium mandelate (3) and phenylalaninamide mandelate monohydrate (4). The crystal structures, optical and NLO properties are studied by the application of single crystal X-ray diffraction, UV–VIS–NIR spectroscopy, conventional and linear polarized infrared (IR-LD) spectroscopy, thermal methods as well as quantum chemical (ab initio and DFT) calculations.

The self-assembly, crystal structures, and optical properties are reported for eight novel organic crystals of derivatives of barbituric acid, i.e. 4-methoxypyrydinium barbiturate dihydrate (1), 1,10-phenanthrolinium barbiturate monohydrate (2), 1-amino isoquinolinium barbiturate monohydrate (3), 5-hydrohy-L-tryptophan barbituric acid complex (4), 5-hydroxy-L-tryptophan 1,3-dimethylbarbituric acid dihydrate molecule complex (5), 1,10-phenanthrolinium (thio)barbiturate (6), 1-amino-1,2,4-triazole violuric acid monohydrate (7), and pyridine-3-aldoxime violuric acid complex (8). Compounds 1−8 were synthesized and characterized by means of single crystal X-ray diffraction, solution and solid-state UV/vis/NIR spectroscopy, and linear-polarized infrared (IR-LD) spectroscopy. Quantum chemical ab initio and DFT calculations were performed with a view to understanding the optical properties of these species. The potential application of these derivatives as NLO-phores is discussed by comparison with the correspond...

Ephedrinum violurate dihydrate was synthesized, spectroscopically and structural elucidated. The data are compared with those of the free-base ephedrine hemihydrate. Discussion on the stable conformer of the ephedrinum cation is carried out. Quantum chemical calculations were performed for the theoretical elucidation of the conformational preference of the ephedrinum cation and its vibrational properties. The model systems neutral ephedrine hemihydrate ( 1 ) and violurate salt dihydrate ( 2 ) are elucidated.

It has been firmly established that humans excrete a small but steady amount of the isoquinoline alkaloid morphine in their urine. It is unclear whether it is of dietary or endogenous origin. There is no doubt that a simple isoquinoline alkaloid, tetrahydropapaveroline (THP), is found in human and rodent brain as well as in human urine. This suggests a potential biogenetic relationship between both alkaloids. Unlabeled THP or [ 1,3,4-D 3 ]-THP was injected intraperitoneally into mice and the urine was analyzed. This potential precursor was extensively metabolized (96%). Among the metabolites found was the phenol-coupled product salutaridine, the known morphine precursor in the opium poppy plant. Synthetic [7D]-salutaridinol, the biosynthetic reduction product of salutaridine, injected intraperitoneally into live animals led to the formation of [7D]-thebaine, which was excreted in urine. [ N -CD 3 ]-thebaine was also administered and yielded [ N -CD 3 ]-morphine and the congeners [ N -CD 3 ]-codeine and [ N -CD 3 ]-oripavine in urine. These results show for the first time that live animals have the biosynthetic capability to convert a normal constituent of rodents, THP, to morphine. Morphine and its precursors are normally not found in tissues or organs, presumably due to metabolic breakdown. Hence, only that portion of the isoquinoline alkaloids excreted in urine unmetabolized can be detected. Analysis of urine by high resolution-mass spectrometry proved to be a powerful method for tracking endogenous morphine and its biosynthetic precursors.

Exophialin, a previously unknown indole alkaloid, was isolated from the human-pathogenic fungus Exophiala dermatitidis upon cultivation on a medium containing tryptophan as sole nitrogen source. Its structure has been elucidated by 1D and 2D NMR experiments and mass spectrometry. When the mutant strain Mel-1 was used in place of the wild-type strain, the new indole alkaloid 8-hydroxyexophialin was generated instead of exophialin. This result indicates that the aromatic moiety of exophialin originates from 2-hydroxyjuglone, a shunt product of the 1,8-dihydroxynaphthalene melanin biosynthesis, which is only produced by the wild-type strain, but not by the mutant. In contrast, the mutant accumulates flavioline, which acts as precursor leading to the generation of 8-hydroxyexophialin instead of exophialin.

The crystal structures and optical properties of the novel (1R,2R)-(-)-1,2-diammoniumocyclohexane squarate trihydrate (1) and bis(hydrogen squarate) (2) were elucidated and reported. Physical methods, single crystal X-ray diffraction, UV-vis-NIR, polarized IR spectroscopy of oriented colloids, mass spectrometry, and thermal methods were used. Quantum chemical DFT calculations were performed with a view to predict the optical and NLO properties of the systems (1) and (2). Both compounds are characterized with the noncentrosymmetric orthorhombic space groups C222(1) (1) and P2(1)2(1)2(1) (2), indicating nonlinear optical properties in the bulk. These organic salts are thermal stable up to 400 degrees C and transparent over the range from 270 to 1100 nm.

Soil, the “Earth’s thin skin” serves as the delicate interface between the biosphere, hydrosphere, atmosphere, and lithosphere. It is a dynamic and hierarchically organized system of various organic and inorganic constituents and organisms, the spatial structure of which defines a large, complex, and heterogeneous interface. Biogeochemical processes at soil interfaces are fundamental for the overall soil development, and they are the primary driving force for key ecosystem functions such as plant productivity and water quality. Ultimately, these processes control the fate and transport of contaminants and nutrients into the vadose zone and as such their biogeochemical cycling. The definite objective in biogeochemical-interface research is to gain a mechanistic understanding of the architecture of these biogeochemical interfaces in soils and of the complex interplay and interdependencies of the physical, chemical, and biological processes acting at and within these dynamic interfaces in soil. The major challenges are (1) to identify the factors controlling the architecture of biogeochemical interfaces, (2) to link the processes operative at the individual molecular and/or organism scale to the phenomena active at the aggregate scale in a mechanistic way, and (3) to explain the behavior of organic chemicals in soil within a general mechanistic framework. To put this in action, integration of soil physical, chemical, and biological disciplines is mandatory. Indispensably, it requires the adaption and development of characterization and probing techniques adapted from the neighboring fields of molecular biology, analytical and computational chemistry as well as materials and nano-sciences. To shape this field of fundamental soil research, the German Research Foundation (DFG) has granted the Priority Program “Biogeochemical Interfaces in Soil”, in which 22 individual research projects are involved.

The correlation between the structural and the physical properties in solid state of two novel salts of cinchonine, cinchoninium violurate monohydrate (1) and cinchoninium squarate tetrahydrate (2), has been studied in dependence on protonation mode, using the methods of single crystal X-ray diffraction, IR-LD spectroscopy of oriented samples as a suspension in nematic liquid crystals, UV–vis spectroscopy and 1

The epiphyte Pantoea agglomerans 48b/90, which has been isolated from soybean leaves, belongs to the Enterobacteriaceae , as does the plant pathogen Erwinia amylovora , which causes fire blight on rosaceous plants such as apples and leads to severe economic losses. Since P. agglomerans efficiently antagonizes phytopathogenic bacteria, the P. agglomerans strain C9-1 is used as a biocontrol agent (BlightBan C9-1). Here we describe the bioassay-guided isolation of a peptide antibiotic that is highly active against the plant pathogen E. amylovora and pathovars of Pseudomonas syringae , and we elucidate its structure. Bioassay-guided fractionation using anion-exchange chromatography followed by hydrophobic interaction liquid chromatography yielded the bioactive, highly polar antibiotic. The compound was identified as 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine by using high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance techniques. This peptide was found to be produced by three of the nine P. agglomerans strains analyzed. Notably, the biocontrol strain P. agglomerans C9-1 also produces 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine. Previously, 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been characterized only from Serratia plymuthica . 2-Amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been shown to inhibit the growth of the human pathogen Candida albicans efficiently, but its involvement in the defense of epiphytes against phytopathogenic bacteria has not been investigated so far.

The interaction of seven novel substituted merocyanine dyes, i.e. 1-methyl-4-[2-(3-methoxy-4-hydroxyphenyl)ethenyl)]pyridinium iodide, 1-methyl-4-[2-(3,5-dimethoxy-4-hydroxyphenyl)ethenyl)]pyridinium iodide, 1-methyl-4-[2-(4-dimethylaminophenyl)ethenyl)]pyridinium iodide, their quinoide forms as well as 1-methyl-4-[2-(3-methoxy-4-oxocyclohexadienilydene)ethylidene]-1,4-dihydropyridine, 1-methyl-4-[2-(3,5-dimethoxy-4-oxocyclohexadienilydene)ethylidene]-1,4-dihydropyridine, with α-CD, γ-CD as well as functionalized γ-cyclodextrin phosphate sodium salt is studied by the methods such as UV–Vis and fluorescence spectroscopy, linear-polarized infrared (IR-LD) spectroscopy of oriented colloids in nematic host, 1H- and 13C-NMR spectroscopy, HPLC ESI tandem mass spectrometry, scanning electron and tunneling microscopy, powder X-ray diffraction as well as thermal methods. A formation of the 1D and 2D “supramolecular polymers” with nanosizes is found. The dyes are adsorbed on the CDs surface and form a hexagonal microcrystalline sub-structures. Remarkable fluorescence properties depending of the type of the substituent in the dyes, in solid-state are observed.

We describe the semi-synthesis of dihydrochalcone derivatives and their IN VITRO antimicrobial activities. These compounds were prepared by modifying two naturally occurring antimicrobial dihydrochalcones, erioschalcones A and B, reported by us earlier. The structures of the compounds were assigned on the basis of spectroscopic evidence and by comparing their physical and spectroscopic data with those reported in the literature. All the compounds were subjected to IN VITRO antimicrobial assays against a panel of pathogenic microorganisms, including gram-positive and gram-negative bacteria, and fungi. The antimicrobial efficacies of this class of compounds were established by correlating the activity profile of each compound with its structure and by comparing the activities of all the compounds with each other based on their structure. This should enable the development of other derivatives of the dihydrochalcone family that would serve as more potent antimicrobial agents against specific pathogens.

The photodegradation of two fluoroquinolone veterinary antibiotics, difloxacin (DIF) and sarafloxacin (SARA) has been explored for the first time in aqueous systems. The study was performed to evaluate the influence of pH, inorganics, humic substances, and other additives. The drugs followed first-order degradation kinetics in matrix free aqueous medium with a rate constant ‘ k ’ value of 0.82 and 0.26 h −1 for DIF and SARA, respectively. Studies performed at various pH revealed that the photolysis rates dropped sharply at pH >7 for DIF, while SARA dissipated faster with increasing pH. Humic substances acted as light barriers by attenuating the light intensity, to retard the drug degradation process. However, rapid drug dissipation was observed in the presence of additives like acetone, hydrogen peroxide, and phosphates, while inorganics such as fluoride, nitrate, and sulfate did not influence the drug photodegradation. Studies on the photolysis of DIF and SARA in river water revealed that both the drugs degraded rapidly under conditions that were relevant to natural systems, following direct photolysis mechanism. It was observed that SARA was the primary photoproduct of DIF and showed relatively a higher persistence than DIF. The findings were also substantiated by the quantum yield ( Ф c ) calculations. The analytical measurements were carried out with LC–MS/MS.

Fluoroquinolones like difloxacin (DIF) and sarafloxacin (SARA) are adsorbed in soil and enter the aquatic environment wherein they are subjected to photolytic degradation. To evaluate the fate of DIF and SARA, their photolysis was performed in water under stimulated natural sunlight conditions. DIF primarily degrades to SARA. On prolonged photodegradation, seven photoproducts were elucidated by HR-LC–MS/MS, three of which were entirely novel. The residual anti-bacterial activities of DIF, SARA and their photoproducts were studied against a group of pathogenic strains. DIF and SARA revealed potency against both Gram-positive and -negative bacteria. The photoproducts also exhibited varying degrees of efficacies against the tested bacteria. Even without isolating the individual photoproducts, their impact on the aquatic environment could be assessed. Therefore, the present results call for prudence in estimating the fate of these compounds in water and in avoiding emergence of resistance in bacteria caused by the photoproducts of DIF and SARA.

The possible microbial mechanism of hypericin (1) and emodin (2) biosynthesis was studied in axenic submerged culture conditions in the endophytic fungus Thielavia subthermophila, isolated from Hypericum perforatum. The growth and secondary metabolite production of the endophyte remained independent of the illumination conditions. This production remained unaltered on spiking the medium with 3 or 5 mM 2, although the biomass accumulation was reduced. Neither emodin anthrone (3) nor protohypericin (4) could be detected at any stage of fermentation, irrespective of either spiking or illumination conditions. The endophytic metabolites exhibited photodynamic cytotoxicity against the human acute monocytic leukemia cell line (THP-1), at 92.7 vs 4.9%, and 91.1 vs 1.0% viability by resazurin and ATPlite assays, in light and in the dark, respectively. In trying to ascertain the presence/expression of the candidate hyp-1 gene in the endophyte, it was revealed that the hyp-1 gene was absent in T. subthermophila, indicating that the biosynthetic pathway in the endophytic fungus might be different and/or governed by a different molecular mechanism than the host plant or host cell suspension cultures. We have discussed the biosynthetic principles and evolutionary implications relating to endophytic T. subthermophila based on the results obtained.

Two novel anyles of 4-benzolylpyridine, namely N , N -diethyl- N ′-[( Z )-phenyl(pyridin-4-yl)methylidene]benzene-1,4-diamine and its N -ethylpyridinium salt were synthesized and elucidated in detail spectroscopically, thermally and structurally, using linear polarized solid-state IR-spectroscopy, UV-spectroscopy, TGA, DSC, DTA and positive and negative ESI MS. Quantum chemical calculations were used to obtain the electronic structure, vibrational data and electronic spectra of the compounds. The crystal structure of an anyle-pyridine derivative, N , N -diethyl- N ′-[( Z )-phenyl(pyridin-4-yl)methylidene]benzene-1,4-diamine, is reported for the first time; the material crystallized in the triclinic P -1 space group and only one short contact of length 3.16 A was observed between two neighbouring pyridine fragments. A bathochromic shift in λ max of 170 nm resulted from N -anylation and a 95 nm solvatochromic shift of N , N -diethyl- N ′-[( Z )-phenyl(pyridin-4-yl)methylidene]benzene-1,4-diamine were obtained depending on solvent type.

The novel salt of a geminal diol 4-(dihydroxymethyl)pyridinium hydrogensquarate was derived from isonicotinaldehyde and squaric acid in water. Two polymorphs were characterized by means of single crystal X-ray diffraction and linear-polarized infrared (IR-LD) spectroscopy of oriented colloids in nematic host. UV spectroscopy was employed to confirm the stabilization of the geminal diol form in aqueous solution. Depending of the reaction conditions two polymorphs of 4-(dihydroxymethyl)pyridinium hydrogensquarate are determined – monoclinic (1) and a triclinic (2) polymorph. The monoclinic (1) crystallizes in the centrosymmetric space group P21/c, while (2) crystallizes in the centrosymmetric space group P 1 ¯ , respectively. The hydrogensquarate anions in both forms form the α chain motif via interanionic hydrogen bonding interactions 2.664(7) A (1) and 2.517(5) A (2), respectively. The geminal diol group of the cations in (1) are directed to an adjacent hydrogensquarate ion via two O–H···O hydrogen bonds with an averaged donor–acceptor distances forming an eight membered ring. In contrast to (1), in (2) the infinite hydrogen bonded two-dimensional layers formed by cations and anions are connected via a hydrogen bond between hydroxyl groups of adjacent symmetry related cations.

Two novel hydrogensquarates of 3-nicotinoyl (1) and 3-isonicotinoyl (2) coumarin have been synthesized and their structures and properties elucidated spectroscopically and structurally, using single crystal X-ray diffraction, linear-polarized solid-state IR-spectroscopy, UV-spectroscopy and negative ESI MS. Quantum chemical calculations were used to obtain the electronic structure, vibrational data and electronic spectra. The IR-spectroscopic elucidation is carried out by a comparison with the characteristics of corresponding neutral 3-nicotinoyl and 3-isonicotinoyl coumarins.

A spectrum of eight pharmacologically important secondary compounds, all putatively belonging to the polyketide pathway (hypericin, pseudohypericin, emodin, hyperforin, hyperoside, rutin, quercetin, and quercitrin) were analyzed in several hypericin-producing species of Hypericum by LC-MS/MS. Different organs such as leaves, stems and roots of wild-grown plants of Hypericum hirsutum L., Hypericum maculatum Crantz s. l., Hypericum montanum L., Hypericum tetrapterum Fr. collected in Slovakia and of Hypericum perforatum L. collected in India were examined individually. Highest contents of hypericin, pseudohypericin, and emodin were found in H. montanum, suggesting that there are alternative species to H. perforatum with high pharmaceutical value. Amounts of hyperforin and quercetin were highest in H. perforatum, whereas highest contents of hyperoside and quercitrin were found in H. maculatum. A significant positive correlation between hypericin and pseudohypericin as well as between hypericin and emodin was observed by Kruskal's multidimensional scaling (MDS), indicating a parallel enhancement of emodin as a common precursor in the biosynthetic pathways of hypericin and pseudohypericin. Furthermore, MDS combined with principal component analysis (PCA) revealed strong correlations in the occurrence of pseudohypericin and emodin, pseudohypericin and quercitrin, hypericin and quercitrin, emodin and quercitrin, hyperoside and quercitrin, rutin and quercetin, and, hyperforin and quercetin. On the other hand, rutin showed a negative correlation with emodin as well as with quercitrin. Furthermore, hierarchical agglomerative cluster analysis (HACA) clustered hypericin and pseudohypericin, grouping emodin at equal distance from both. Considerable infraspecific variability in secondary compound spectrum and load of different populations of H. maculatum from Slovakia underscores the need for detailed studies of genotypic variation and environmental factors in relation to polyketide biosynthesis and accumulation.

The self-assembly and properties of six novel violurates with organic counterions, that is, cyclohexylammonium violurate (1), piperidinium violurate 2.5 hydrate (2), tetrahydroisoquinolinium violurate monohydrate (3), quinuclidinium violurate tetrahydrate (4), pyridinium violurate (5), and 3-aminopyridinium violurate (6) are reported. Compounds 1−6 were synthesized and characterized in detail by means of single crystal X-ray diffraction, solution and solid-state UV/vis spectroscopy, linear-polarized infrared (IR-LD) spectroscopy of oriented colloids in a nematic host, mass spectrometry, and thermal methods. Quantum chemical ab initio and density functional theory (DFT) calculations were performed with a view to understanding the optical properties of the studied species. New phenomenon of the origin of the color in the solid state is observed and elucidated.

The degradation of a chiral nonylphenol isomer, 4-(1-ethyl-1,4-dimethylpentyl)phenol (NP(112)), in two agricultural soils from Monheim and Dortmund, Germany has been studied. The degradation of NP(112) and the formation of a nitro-nonylphenol metabolite were determined by means of GC-MS analysis. The degradation followed bi-exponential order kinetics, with half-life of less than 5 days in both soils. The nitro-metabolite was found at different concentration levels in the two soils. The nitro-metabolite of NP(112) was more persistent than its parent compound. After 150 days about 13% of the initially applied NP(112) remained in the Monheim soil as its nitro-metabolite. Results of the E-screen assay revealed that the nitro-NP(112) has oestrogenic potency of 85% of that of NP(112). Furthermore, the results of chiral GC-MS analysis revealed that no chiral degradation of NP(112) occurred in this study.

Fluoroquinolones are amongst the most important antibiotics used in veterinary medicine. On this account the behavior of difloxacin (DIF) and its metabolites was investigated by administering the (14)C-labeled and non-labeled veterinary drug to fattening pigs. The excretion kinetics were determined after daily collection of manure. Sarafloxacin (SAR) was found to be the major metabolite, three further trace metabolites were also recovered, applying high-resolution (HR) mass spectrometric technique. The identification of DIF and SAR was confirmed by comparison with the spectroscopic and chromatographic data of the authentic references. The identification of the three trace metabolites was performed by HR-MS/MS. Only 8.1% of the administered radioactivity remained in the pig after 10 days and DIF accounted for 95.9% of the radioactivity excreted. More than 99% of the labeled compounds were detected and identified in the manure. The mean recoveries for all single electrolytes were 94%. Linearity was established over concentration range 10-10,000 microg/kg manure with a correlation coefficient 0.99. By using in vitro antimicrobial activity tests against a group of standard pathogenic control strains, the results showed that the residual antibiotic concentrations in the manure of pigs are high enough to exhibit antibacterial activity.

We report the synthesis, spectroscopic and structural elucidation of two prolinamide derivatives of squaric acid, i.e. prolinamide ester amide of squaric acid ethyl ester (1) and prolinamide diamide of squaric acid dihydrate (2). Both compounds crystallize in non-centrosymmetric space groups, monoclinic P2(1) (1) and orthorhombic P2(1)2(1)2(1) (2), respectively. For first time in the literature the crystal structure of homodiamide of amino acid amide of squaric acid is reported. The data for heterodiamides is also absent. Supramolecular zig-zag chains by hydrogen bonds of H(2)N-C=O ..., HNH (3.020 A) and HNH ..., OC((S(q))) (2.972 A) types with the participation of amide and squaric acid (S(q)) fragments, -CO=NH(2) and O=C((S(q))) are refined in (1). A helix supramolecular structure is formed in (2) by moderate intermolecular HNH ... O=C(NH(2)) hydrogen bond with length of 2.947A. The two crystallographical non-equivalent water molecules stabilized the helix by interactions of types HOH...OC((Sq)) (2.917A), HOH...O=C(NH(2)) (2.899A), H(2)O...NH(2)(C=O) (2.972A), respectively. Optical and magnetic properties are investigated with a view to explain the correlation structure-properties of the newly synthesized molecules.