Properties of Gaseous Deprotonated L-Cysteine S-Sulfate Anion [cysS-SO3]-: Intramolecular H-Bond Network, Electron Affinity, Chemically Active Site, and Vibrational Fingerprints.

L-cysteine S-sulfate, Cys-SSO3H, and their derivatives play essential roles in biological chemistry and pharmaceutical synthesis, yet their intrinsic molecular properties have not been studied to date. In this contribution, the deprotonated anion [cysS-SO3]- was introduced in the gas phase by electrospray and characterized by size-selected, cryogenic, negative ion photoelectron spectroscopy. The electron affinity of the [cysS-SO3]• radical was determined to be 4.95 ± 0.10 eV. In combination with theoretical calculations, it was found that the most stable structure of [cysS-SO3]- (S1) is stabilized via three intramolecular hydrogen bonds (HBs); i.e., one O-H⋯⋯N between the -COOH and -NH2 groups, and two N-H⋯⋯O HBs between -NH2 and -SO3, in which the amino group serves as both HB acceptor and donor. In addition, a nearly iso-energetic conformer (S2) with the formation of an O-H⋯⋯N-H⋯⋯O-S chain-type binding motif competes with S1 in the source. The most reactive site of the molecule susceptible for electrophilic attacks is the linkage S atom. Theoretically predicted infrared spectra indicate that O-H and N-H stretching modes are the fingerprint region (2800 to 3600 cm-1) to distinguish different isomers. The obtained information lays out a foundation to better understand the transformation and structure-reactivity correlation of Cys-SSO3H in biologic settings.

Comprehensive Metabolite Identification of Genipin in Rats Using Ultra-High-Performance Liquid Chromatography Coupled with High Resolution Mass Spectrometry.

Genipin, an aglycone of geniposide, is a rich iridoid component in the fruit of Gardenia jasminoides Ellis and has numerous biological activities. However, its metabolic profiles in vivo and vitro remain unclear. In this study, an effective analytical strategy based on ultra-high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) in positive and negative ion modes was developed to analyze and identify genipin metabolites in rat urine, blood, feces, and fecal fermentation in combination with many methods including post-collection data mining methods, high-resolution extracted ion chromatography (HREIC), and multiple mass defect filtering (MMDF). Simultaneously, the metabolites of genipin in vivo were verified by fecal fermentation of SD rats at different times. Finally, based on information such as reference substances, chromatographic retention behavior, and accurate mass determination, a total of 50 metabolites (including prototypes) were identified in vivo. Among them, 7, 31 and 28 metabolites in vivo were identified in blood, urine, and feces, respectively. Our results showed that genipin could generate different metabolites that underwent multiple metabolic reactions in vivo including methylation, hydroxylation, dehydroxylation, hydrogenation, sulfonation, glucuronidation, demethylation, and their superimposed reactions. Forty-six metabolites were verified in vitro. Meanwhile, 2 and 19 metabolites identified in blood and urine were also verified in fecal fermentation at different times. These results demonstrated that metabolites were produced in feces and reabsorbed into the body. In conclusion, the newly discovered metabolites of genipin can provide a new perspective for understanding its pharmacological effects and build the foundation for thee toxicity and safety evaluations of genipin.

Spectroscopic identification of the low-lying electronic states of S2 molecule.

As is well-known, the S2 molecule is a ubiquitous intermediate in the combustion, atmosphere, and interstellar space. The six low-lying bound states of S2 have been characterized via photoelectron velocity map imaging and a high-level multi-reference configuration interaction method with the Davidson correction. Spectroscopic constants have been extracted by fitting the potential energy curves extrapolated to the complete basis set limit with a series of Dunning's correlation-consistent basis sets: aug-cc-pV(Q, 5)Z. The calculated spectroscopic parameters well reproduce the experimental results in this work. On the basis of the theoretical calculations, Franck-Condon simulations are performed to assign six adjacent electronic states, especially for three higher overlapping electronic states (c1Σu -, A'3Δu, and A3Σu +). The dissociation energy De of the S2 - is evaluated to be 4.111 (4) eV in this work, in agreement with the theoretical prediction (4.056 eV).

Quantitative analysis of nitrogen in ammonium phosphate fertilizers using laser-induced breakdown spectroscopy.

Laser-induced breakdown spectroscopy (LIBS) coupled with the linear multivariate calibration method was applied to analyze nitrogen (N) quantitatively in ammonium phosphate fertilizers. The intensity of lines N (NI:742.4, 744.2, 746.8, 856.7, 859.4, 862.9, 870.3, 871.2, 871.8 nm) and O (OI:777.2, 844.6, 882.0 nm) were used as independent variables for the models. To verify the accuracy of the models, the unary, binary, ternary, and quaternary variables were chosen to establish the linear regression equations. The results of the linear models showed that the quaternary model was better than the other three models. The correlation coefficient of the quaternary linear model was 0.981 and the maximum relative error of the validation samples was 4.32%.

Univariate and Multivariate Analysis of Phosphorus Element in Fertilizers Using Laser-Induced Breakdown Spectroscopy.

Rapid detection of phosphorus (P) element is beneficial to the control of compound fertilizer production process and is of great significance in the fertilizer industry. The aim of this work was to compare the univariate and multivariate analysis of phosphorus element in compound fertilizers and obtain a reliable and accurate method for rapid detection of phosphorus element. A total of 47 fertilizer samples were collected from the production line; 36 samples were used as a calibration set, and 11 samples were used as a prediction set. The univariate calibration curve was constructed by the intensity of characteristic line and the concentration of P. The linear correlation coefficient was 0.854 as the existence of the matrix effect. In order to eliminate the matrix effect, the internal standardization as the appropriate methodology was used to increase the accuracy. Using silicon (Si) element as an internal element, a linear correlation coefficient of 0.932 was obtained. Furthermore, the chemometrics model of partial least-squares regression (PLSR) was used to analysis the concentration of P in fertilizer. The correlation coefficient was 0.977 and 0.976 for the calibration set and prediction set, respectively. The results indicated that the LIBS technique coupled with PLSR could be a reliable and accurate method in the quantitative determination of P element in complex matrices like compound fertilizers.

Spreading a water droplet through filter paper on the metal substrate for surface-enhanced laser-induced breakdown spectroscopy.

To improve the quantitative analysis accuracy of an aqueous solution using surface-enhanced laser-induced breakdown spectroscopy (SENLIBS), the filter paper was used as a transmission medium by placing it onto the surface of a metallic substrate to make the microdroplet spreading more uniform in a fixed region of the substrate surface. The trace elements (Cu, Pb, Cd, and Cr) in an aqueous solution were detected successfully using this method. The results showed that the sample preparation repeatability of SENLIBS was noticeably improved with the aid of filter paper. Moreover, the limit of detection (LoD) values was similar to those without filter paper. Furthermore, the R2 values were improved from 0.6192~0.9321 to 0.9481~0.9766, the RMSECV values were decreased from 0.53~1.95 µg/mL to 0.33~1.06 µg/mL, and the average relative error (ARE) values were decreased from 8.96~22.31% to 4.28~14.37% with the aid of filter paper. This demonstrated that the use of filter paper could improve the quantitative analysis accuracy of SENLIBS by increasing the sample preparation repeatability.

A comparative study on the bond features in CO, CS, and PbS.

Covalent and noncovalent interactions dominate most compounds in the condensed phase and gas phase. For a classical diatomic molecule CO, it is usually regarded as a triple-bond system with one dative bond. In this work, the photoelectron velocity-map imaging spectra of the CS and PbS anions were first measured. The two interactions have been intuitively understood by a comparative investigation of electrostatic potential (ESP) and bond features in CO, CS, and PbS. It is suggested that both electrostatic and dative covalent interactions compete in CO molecules, while dative covalent interaction prevails in CS molecules and electrostatic interaction dominates in PbS molecules. As a consequence, CO has a very small dipole moment (∼0.1 D) compared to the large dipole moment in CS (>1.8 D) and PbS (>4 D). It is indicated that the electron affinity value increases with the increasing dipole moment in the order of CO < CS < PbS. In addition, intriguing ESP with negative bond-ends and positive bond-cylindrical-surface in CO is also revealed by comparing with that in CS and PbS. In the latter, the two molecules present opposite ESP maps. Molecular orbital analyses indicate surprising participation of Pb 5d orbitals in the Pb-S chemical bonding although Pb belongs to main-group elements. Further bond analyses using electron localization function, natural resonance theory, and bond order methods suggest that covalence is dominant in CS and ionicity is a major component in PbS, but somewhere in between for CO molecules. By a comparative study in this work, the CS molecule is also revealed as a promising ligand molecule for the transition-metal coordination chemical synthesis.

Analytical-performance improvement of aqueous solution by chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy.

In this study, chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy (CR-SENLIBS) was introduced for detecting the trace chromium (Cr) element in an aqueous solution, which could use chemical replacement to change the sample from liquid to solid. In order to illustrate the analytical-performance of the CR-SENLIBS, the direct analysis of the liquid surface by LIBS (LSLIBS) was investigated for comparison. The results show that the spectral intensity of Cr I 357.86 nm, plasma lifetime, and spectral stability were improved. Moreover, the limit of detection of Cr I 357.86 nm was 0.018 µg/mL, which was lower than 1.814 µg/mL for LSLIBS. Furthermore, the accuracy and precision were improved more than 60% and 80%, respectively; for example, the root-mean-square error of cross-validation was improved from 1.09 to 0.75 µg/mL, and the average relative standard deviation of the predicted concentration of Cr was reduced from 22.89% to 4.53% by using CR-SENLIBS. These results suggest that CR-SENLIBS has good analytical-performance, which exhibits great potential in water quality monitoring.

BcMctA, a putative monocarboxylate transporter, is required for pathogenicity in Botrytis cinerea.

Monocarboxylate transporters have a central role in mammalian metabolism, but rarely reported in phytopathogenic fungi. In this study, a putative monocarboxylate transporter gene in Botrytis cinerea [B. cinerea MctA (BcMctA)] was identified in the research of a B. cinerea transfer DNA (T-DNA) insertional mutant (74). Disruption of the gene decreased the growth rate on the medium with monocarboxylate (acetate or pyruvate) as the sole carbon sources, but not affected on lactate. The pyruvate contents in BcmctA deletion mutants decreased about 35 % compared with the wild strain. Besides, the conidial yield was increased about two times in BcmctA disruption mutant. The pathogenicity assay indicated that disruption of BcmctA significantly reduced the virulence of B. cinerea on cucumber and tomato leaves. Our results demonstrated that BcMctA is related to pyruvate uptake and pathogenicity of B. cinerea on cucumber and tomato leaves.

[Quantitative Analysis of Mn in Soil Samples Using LIBS].

The trace element of Manganese element in the agricultural farm (Anhui Huaiyuan Nongkang) soil was quantitatively analyzed by Laser-induced breakdown spectroscopy. The line of 403.1 nm was selected as the analysis line of Mn. The matrix element of Fe in soil was chosen as the internal calibration element and the analysis line was 407.2 nm. Ten soil samples were used to construct calibration curves with traditional method and internal standard method, and four soil samples were selected as test samples. The experimental results showed that the fitting correlation coefficient (r) is 0.954 when using the traditional method, the maximum relative error of the measurement samples is 5.72%, and the detection limit of Mn in soil is 93 mg x kg(-1). While using the internal standard method to construct the calibration curve, the fitting correlation coefficient (r) is 0.983, the relative error of measurement samples is reduced to 4.1%, and the detection limit of Mn in soil is 71 mg x kg(-1). The result indicates that LIBS technique can be used to detect trace element Mn in soil. In a certain extent, the internal standard method can improve the accuracy of measurement.

[Quantitative analysis of thiram by surface-enhanced raman spectroscopy combined with feature extraction Algorithms].

Three feature extraction algorithms, such as the principal component analysis (PCA), the discrete cosine transform (DCT) and the non-negative factorization (NMF), were used to extract the main information of the spectral data in order to weaken the influence of the spectral fluctuation on the subsequent quantitative analysis results based on the SERS spectra of the pesticide thiram. Then the extracted components were respectively combined with the linear regression algorithm--the partial least square regression (PLSR) and the non-linear regression algorithm--the support vector machine regression (SVR) to develop the quantitative analysis models. Finally, the effect of the different feature extraction algorithms on the different kinds of the regression algorithms was evaluated by using 5-fold cross-validation method. The experiments demonstrate that the analysis results of SVR are better than PLSR for the non-linear relationship between the intensity of the SERS spectrum and the concentration of the analyte. Further, the feature extraction algorithms can significantly improve the analysis results regardless of the regression algorithms which mainly due to extracting the main information of the source spectral data and eliminating the fluctuation. Additionally, PCA performs best on the linear regression model and NMF is best on the non-linear model, and the predictive error can be reduced nearly three times in the best case. The root mean square error of cross-validation of the best regression model (NMF+SVR) is 0.0455 micormol x L(-1) (10(-6) mol x L(-1)), and it attains the national detection limit of thiram, so the method in this study provides a novel method for the fast detection of thiram. In conclusion, the study provides the experimental references the selecting the feature extraction algorithms on the analysis of the SERS spectrum, and some common findings of feature extraction can also help processing of other kinds of spectroscopy.

Botrytis cinerea chitin synthase BcChsVI is required for normal growth and pathogenicity.

Fungal chitin synthase of classes V and VI (or VII), which contain an additional N-terminal myosin motor domain, have been shown to play important roles in pathogenesis. To study the function of BcChsVI in Botrytis cinerea, BcChs6 gene was disrupted through Agrobacterium tumefaciens-mediated transformation. The Bcchs6 disruption mutant exhibited a 45.5 % increasing in its chitin content when compared with wild strain. The qRT-PCR analysis revealed that in Bcchs6 mutant the expression of BcChs6 was significantly decreased, while the expression of BcChs2 and BcChs3a was increased when compared with wild type. It is probable that the disruption of this gene provoked a compensatory mechanism regulating the cellular response to cell wall damage. Interestingly, the radial growth of Bcchs6 mutant was drastically reduced when 50 % solute was removed from the regular PDA medium, and they were more sensitive to Calcofluor white and other cell wall disturbing chemicals. Pathogenicity assays on tomato leaves indicated that they were significantly reduced in their ability to cause disease. Our results demonstrated that BcChs6 is necessary for proper hyphal growth and pathogenicity of B. cinerea on tomato leaves.

Purification and molecular analysis of a monoamine oxidase isolated from Narcissus tazetta.

Semicarbazide-sensitive amine oxidase activity was detected in Narcissus tazetta. The enzyme was purified to homogeneity by the criterion of native polyacrylamide gel electrophoresis (PAGE) with DEAE-Sephacel, hydroxyapatite, and phenyl-Sepharose columns. The molecular mass of the enzyme, determined using a GS-520 HQ column, was estimated to be 135 kDa. SDS-PAGE yielded two bands of, 75 kDa and 65 kDa. The enzyme, which had catalytic activity for some aliphatic and aromatic monoamines, belongs to a class of monoamine oxidases (MAOs). The K(m) value for n-propylamine was 5.9 × 10⁻5 M. A substrate analog, 2-bromoethylamine, inhibited enzyme activity. Redox-cycling staining detected a quinone in the MAO protein. By inductively coupled plasma mass analysis, it was determined that there were 2.44 moles of copper atoms per mole of the enzyme. Protein sequence analysis revealed that there was no identity between two N-terminal residues of the 75 kDa and 65 kDa proteins of narcissus MAO.

State-dependent photoionization cross-sections of 3d transition metal atoms.

Using the saturation method, we measured the absolute photoionization cross-sections of several excited states of titanium, vanadium, chromium, iron, and cobalt. These results are reported for the first time in this paper. The measured values range from 0.4 ± 0.1 Mb to 6.9 ± 2.0 Mb. The results show that the photoionization cross-section depends on the atomic state and not just on the electronic configuration.

Establishment and characterization of outer root sheath (ORS) cell line from Jining grey goat.

A new line of outer root sheath (ORS) cells was established from hair follicles of Jining grey goat by using a mechanical separation combined with enzyme digestion. Cell morphology is described at different phases. The chromosome analysis of ORS cells, identification of the ORS cells and morphological reversion test were detected at the 4th and 40th passages. The ORS cells were healthy and the growth characteristics were stable with a population doubling time of 52 h. Chromosome analysis showed that >58% of cells were diploid. Test for ORS cell line CK19 expression was positive. This newly established ORS cell line not only lays the foundation for further studying on the growth, regeneration, development law of goat hair follicle but also provides a mirror for the research of human hair in medical field.

Excited-State Dynamics of Crossing-Controlled Energy Transfer in Europium Complexes.

Photosensitized energy transfer (EnT) phenomena occur frequently in a variety of photophysical and photochemical processes and have traditionally been treated with the donor-acceptor distance-dependent Förster and Dexter models. However, incorrect arguments and formulae were employed by ignoring energy resonance conditions and the selection rules of the state-to-state transition in special cases, especially for the sensitive intramolecular EnT of lanthanide complexes. Herein, we proposed an innovative model of energy-degeneracy-crossing-controlled EnT, which can be experimentally confirmed by time-resolved two-dimensional photoluminescence measurements. The computationally determined energy resonance region provides the most effective channel to achieve metal-to-ligand EnT beyond the distance-dependent model and sensitively bifurcates into symmetry-allowed or -forbidden channels for some representative europium antenna complexes. The outcomes of the multidisciplinary treatment contribute to a complementary EnT model that can be tuned by introducing a phosphorescence modulator and altering the antenna-related parameters of the ligand-centered energy level of the 3ππ* state and its spin-orbit coupling for the 3ππ* → S0 * transition through mechanism-guided crystal engineering and should motivate further development of mechanistic models and applications.

Propagation of elegant Laguerre-Gaussian beam in non-Kolmogorov turbulence.

The analytical formulas for the average intensity and the beam width of the elegant Laguerre-Gaussian beam (ELGB) in non-Kolmogorov turbulence have been derived based on the extended Huygens-Fresnel principle. Numerical results reveal that the ELGB converts to Gaussian form quicker for smaller values of beam order and for smaller wavelengths. The root-mean-square (rms) beam width of ELGB increases markedly with the propagation distance for higher beam order, smaller waist width, and larger wavelength. Furthermore, discussions of the influence of ELGB by the non-Kolmogorov turbulence reveal that the normalized intensity distribution of ELGB converts into Gaussian form more quickly and that the rms beam width of ELGB increases more rapidly in non-Kolmogorov turbulence with smaller parameter α, larger outer scale, smaller inner scale and larger structure constant.

[Pleiotropic drug resistance ABC transporters in fungi].

Overexpression of pleiotropic drug resistance (PDR) efflux pumps of the ATP-binding cassette (ABC) transporter superfamily is the major cause of fungal multi-drug resistance and decreased efficacy of antifungal drugs. This review focused on recent progresses in understanding of the PDR efflux pumps of ABC transporter superfamily in Saccharomyces cerevisiae and the fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigates. The mechanisms underlying efflux pump-mediated drug resistance and the regulatory networks involved were discussed. Investigation of the PDR efflux pumps of ABC transporter superfamily and their impact on drug resistance may lead to strategies to overcome fungal multi-drug resistance and improve drug efficacy.

[Analysis of T-DNA integration pattern in Botrytis cinerea genome].

OBJECTIVE: To analyze the T-DNA integration pattern in the genome of grey mold Botrytis cinerea. METHODS: T-DNA (Transfer DNA) inserted mutant library of Botrytis cinerea was created by Agrobactirium tumfacience mediated transformation. By using TAIL-PCR (Thermal asymmetric interlaced polymerase chain reaction), we amplified and cloned the chromosomal regions flanking T-DNA insertions. The obtained T-DNA flanking sequences were subjected to alignment with standard T-DNA border sequence for identification and analysis of integration. RESULTS: Up to 69% T-DNA inserted at noncoding regions and 30% inserted at exons. Recombination including deletion or addition of bases in T-DNA region was observed. The right borders of the T-DNA were frequently truncated, and by contrast the left borders were less prone to degradation and appeared to have been inserted in a relatively integrated manner. Extra sequence additions also occurred in T-DNA integration sites. CONCLUSION: Analysis of T-DNA integration pattern in B. cinerea genome will stimulate the functional genomics study of this fungus.

[Construction of T-DNA insertion mutants of Botrytis cinerea via Agrobacterium tumefaciens mediated transformation and sequence analysis of insertion site].

OBJECTIVE: Construction of Botrytis cinerea T-DNA insertion mutant library through Agrobacterium-mediated transformation and for further understanding of the molecular mechanisms underlying the pathogenicity of Botrytis cinerea. METHODS: Agrobacterium containing the binary vector pCMBIA1390 was used for transformation of Botrytis cinerea. Hygromycin resistant transformants were screened out and subjected to biological and morphological observation, Detached tomato leaves were used for pathogenicity assay. The flanking sequence of T-DNA inserted in mutant genome was cloned and analyzed by using TAIL-PCR. RESULTS: A variety of mutants were obtained and important phenotypes including reduction in growth rate, loss or reduction in conidiation and loss of pathogenicity were screened out. The T-DNA flanking sequence of one of the mutants was successfully amplified with TAIL-PCR. CONCLUSION: Agrobacterium-mediated transformation system of Botrytis cinerea was established and a T-DNA insertion mutants library was constructed. TAIL-PCR was an effective method for isolating the flanking sequence of T-DNA inserted in genome.