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Stover-covered no-tillage (NT) is of great significance to the rational utilization of stover resources and improvement of cultivated land quality, and also has a profound impact on ensuring groundwater, food and ecosystem security. However, the effects of tillage patterns and stover mulching on soil nitrogen turnover remain elusive. Based on the long-term conservation tillage field experiment in the mollisol area of Northeast China since 2007, the shotgun metagenomic sequencing of soils and microcosm incubation were combined with physical and chemical analyses, alkyne inhibition analysis to elucidate the regulatory mechanisms of NT and stover mulching on the farmland soil nitrogen emissions and microbial nitrogen cycling genes. Compared with conventional tillage (CT), NT stover mulching significantly reduced the emission of N 2 O instead of CO 2 , especially when 33% mulching was adopted, and correspondingly the nitrate nitrogen of NT33 was higher than that of other mulching amounts. The stover mulching was associated with higher total nitrogen, soil organic carbon and pH. The abundance of AOB (ammonia-oxidizing bacteria)-amoA (ammonia monooxygenase subunit A) was substantially increased by stover mulching, while the abundance of denitrification genes was reduced in most cases. Under alkyne inhibition, the tillage mode, treatment time, gas condition and interactions between them noticeably influenced the N 2 O emission and nitrogen transformation. In CT, NT0 (no mulching) and NT100 (full mulching), the relative contribution of AOB to N 2 O production was markedly higher than that of ammonia oxidizing archaea. Different tillage modes were associated with distinct microbial community composition, albeit NT100 was closer to CT than to NT0. Compared with CT, the co-occurrence network of microbial communities was more complex in NT0 and NT100. Our findings suggest that maintaining a low-quantity stover mulching could regulate soil nitrogen turnover toward proficiently enhancing soil health and regenerative agriculture, and coping with global climate change., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Da-Cheng HAO reports financial support was provided by National Natural Science Foundation of China. Lian-Feng Wang reports financial support was provided by National Natural Science Foundation of China. Lian-Feng Wang reports financial support was provided by Scientific Research Funds Project of Liaoning Education Department. Da-Cheng HAO reports financial support was provided by China Scholarship Council., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Optimal exposure to fluoride and calcium from tap water is beneficial for dental caries prevention. Water fountains may be an important source of drinking water in work and educational settings. The aims of this study were to quantify the fluoride and calcium concentrations of drinking water samples collected from public water fountains on the Indiana University-Purdue University Indianapolis campus; compare the fluoride and calcium concentrations in water collected at 2 different times; and determine whether the presence or absence of a visible external filter affects fluoride and calcium concentrations. Ninety samples were collected from 45 water fountains accessible to the public, and 90 duplicate samples were collected 1 month later. A fluoride ion-selective electrode was used in conjunction with an ion-specific meter to determine fluoride concentration, while atomic absorption spectrometry in an air-acetylene flame was implemented to quantify the calcium concentration. The fluoride and calcium concentration of drinking water samples displayed ranges of 0.62 mg/L to 0.97 mg/L and 56.61 mg/L to 89.11 mg/L, respectively. The concentrations of fluoride and calcium in drinking water were slightly lower at the second collection period (P < 0.001; Wilcoxon signed rank test). No statistically significant differences were observed in the fluoride or calcium concentration of drinking water collected from water fountains with an external filter cartridge in comparison with fountains that did not have a filter. Fluoride concentrations were within the optimal range recommended by the US Public Health Service for fluoridated drinking water, and calcium concentrations were consistent with those reported in previous surveillance studies.

This study focused on an ozone pollution event occurring in winter (January) in Guangzhou. Various influencing factors were analyzed, including various atmospheric trace gases, meteorological conditions during the whole pollution process, as well as the characteristics of the main O 3 precursor volatile organic compounds (VOCs). The main sources of VOCs and the O 3 formation regime were analyzed using an array of tools:the ozone potential formation (OFP), positive matrix factorization (PMF) model, and empirical kinetic modeling approach (EKMA) curve. Feasible strategies for O 3 control were suggested. The results showed that O 3 and NO 2 exceeded the corresponding standards in this winter pollution event, when the concentrations of PM 10 and PM 2.5 were also high, differing from the air pollution characteristics in summer and autumn. Low boundary layer height (<75 m) and high atmospheric stability at night exacerbated the accumulation of ozone precursors and fine particles. Meteorological conditions such as the increased daytime temperature (5℃), stronger solar radiation (10%), and low horizontal wind speed (<1 m·s -1 ) favored photochemical reactions and promoted the formation of ozone and fine particles. VOCs were mainly composed of alkanes, and the proportions of alkanes and alkynes in winter were higher than those in the other seasons. Aromatics (xylenes and toluene) and propylene were the key VOCs species leading to O 3 formation. The main VOCs sources were vehicle exhaust (22.4%), solvent usage (20.5%), and industrial emissions (17.9%); however, the source with highest OFP was identified as solvent usage. O 3 formation in this event was in the VOCs-limited regime, and reducing O 3 precursors in the VOCs/NO x ratio of 3:1 was effective and feasible for O 3 control. This study explored the causes of an O 3 pollution event in winter, which will serve as reference for the synergistic control of O 3 and PM 2.5 in heavy pollution seasons.

Triacylglycerols (TAGs) containing less common fatty acids (FAs) were isolated from the seeds of three plants (Santalum album, Crepis foetida, and Leucas aspera). These FAs had allenic (laballenic acid, Lb) and acetylenic (crepenynic, C; ximenynic acids, Xi) bonds. TAGs were analyzed on reversed-phase and chiral columns. High-resolution tandem mass spectrometry identified TAGs by positive electrospray ionization (ESI + ). Twenty-two molecular species of TAGs isolated from the seed oil of Santalum album were separated by RP-HPLC and chiral HPLC methods and identified by positive electrospray ionization tandem MS detection (ESI + -MS). Two major enantiomers, i.e., sn-OOLb and sn-LLLb (O represents oleic acid; and L represents linoleic acid), were synthesized from the appropriate phosphatidylcholines. This allowed the identification of enantiomers after separation by chiral chromatography by tandem mass spectrometry. Similarly, TAGs from the seeds of Crepis foetida, and Leucas aspera were analyzed by reversed-phase chromatography and identified by mass spectrometry. Four enantiomers (sn-OOC, sn-LLC, sn-OOXi, and sn-LLXi) were synthesized. A total of six and three enantiomers of TAGs containing crepenynic and ximenynic acids, respectively, were identified by chiral column analysis. The retention times of TAGs containing allenic and acetylenic bonds were always greater on the reversed-phase column than TAGs with the same number of carbon atoms and the same unsaturation (e.g., LLL versus LLLb). From the chiral column, the regioisomers and enantiomers were eluted in the order of symmetric-asymmetric-asymmetric (i.e., sn-OCO, sn-COO, and sn-OOC). Through tandem mass spectrometry, we were able to identify and distinguish regioisomer [DAG] + -type ions, i.e., [MNH 4 NH 3 RCOOH] + , that can be considered diagnostic. Unfortunately, enantiomers and TAGs with the same numbers of carbon atoms and the same unsaturation levels have identical mass spectra, such as LLL and LLLb., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A new application of stimulated Raman scattering (SRS) uses the benefit of a label-free molecular fingerprint to image the uptake and distribution of an alkyne-based drug in living cells. This method delivers information on cellular molecular composition and drug-cell interaction, showing the potential of SRS in drug development.

The present paper describes the successful synthesis and application of a ternary hybrid consists of gold nanoparticles decorated on titania-polyaniline (TiO 2 -PANI-AuNPs) for A 3 -coupling between aldehydes, terminal alkynes and amines under visible irradiation. The synthesis of ternary hybrid involved the coating of PANI on TiO 2 via an oxidative polymerization method followed by the deposition of AuNPs on TiO 2 -PANI using trisodium citrate as a reducing agent. The synthesized photocatalyst was characterized by various techniques like FT-IR, SEM, HR-TEM, XRD, UV-VIS, ICP-AES, TGA, XPS and PL spectroscopy. The synthesized photocatalyst exhibited higher efficiency which was presumed due to the suppressed electron-hole recombination and better electron mobility at the surface of the photocatalyst. In the hybrid, polyaniline was found to enhance the activity as well as stability of the photocatalyst owing to its chemical interaction with titania and gold. Furthermore, after the reaction, the photocatalyst could readily be recovered and recycled for several runs with consistent photoactivity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: Artemisia capillaris (Yin-Chen) is a famous traditional Chinese medicine (TCM) for treating acute and chronic hepatitis in China. Enynes are one type of characteristic constituents in this herb, while their anti-hepatitis B virus (anti-HBV) properties have not been systemically investigated., Aim of the Study: This study is to reveal the active part of A. capillaris, and systemically investigate the enynes and their anti-HBV activity., Materials and Methods: The total extract and each fraction of A. capillaris were assayed for the anti-HBV activity to reveal the active part. Bioassay-guided fractionation using various chromatographic techniques yielded the enynes, whose structures were elucidated by spectroscopic analyses and ECD calculations. The anti-HBV properties inhibiting HBsAg and HBeAg secretions and HBV DNA replication were evaluated on HepG 2.2.15 cell line in vitro., Results: ACT-2 and ACT-3 was revealed to be the respective active and toxic part of A. capillaris. Twelve enynes (1-12) involving four new ones (1-4) and two unusual enyne analogs (13-14) were isolated from the active part (ACT-2). All the isolates were assayed for their anti-HBV activity, and the preliminary structure-activity relationships were summarized based on the structural features. In particular, compound 4 could significantly inhibit the secretions of HBsAg and HBeAg, and HBV DNA replication with IC 50 values of 197.2 (SI > 5.1), 48.7 (SI > 20.5) and 9.8 (SI > 102) μM., Conclusions: Enynes are responsible for the anti-HBV effects of A. capillaris. Hydroxyl and glycosyl groups are preferable for maintaining activity. This is the first time to systematically investigate the anti-HBV activity of enynes in A. capillaris, which provides valuable information for understanding the ethnopharmacological application of Yin-Chen., (Copyright © 2018. Published by Elsevier B.V.)

Driven by a necessity for confident molecular identification at high spatial resolution, a new time-of-flight secondary ion mass spectrometry (TOF-SIMS) tandem mass spectrometry (tandem MS) imaging instrument has been recently developed. In this paper, the superior MS/MS spectrometry and imaging capability of this new tool is shown for natural product study. For the first time, via in situ analysis of the bioactive metabolites rubrynolide and rubrenolide in Amazonian tree species Sextonia rubra (Lauraceae), we were able both to analyze and to image by tandem MS the molecular products of natural biosynthesis. Despite the low abundance of the metabolites in the wood sample(s), efficient MS/MS analysis of these γ-lactone compounds was achieved, providing high confidence in the identification and localization. In addition, tandem MS imaging minimized the mass interferences and revealed specific localization of these metabolites primarily in the ray parenchyma cells but also in certain oil cells and, further, revealed the presence of previously unidentified γ-lactone, paving the way for future studies in biosynthesis.

A surface-enhanced Raman scattering (SERS) method for in situ detection and analysis of the intranuclear biomolecular information of a cell has been developed based on a small, biocompatible, nuclear-targeting alkyne-tagged deoxyribonucleic acid (DNA) probe (5-ethynyl-2'-deoxyuridine, EDU) that can specially accumulate in the cell nucleus during DNA replications to precisely locate the nuclear region without disturbance in cell biological activities and functions. Since the specific alkyne group shows a Raman peak in the Raman-silent region of cells, it is an interior label to visualize the nuclear location synchronously in real time when measuring the SERS spectra of a cell. Because no fluorescent-labeled dyes were used for locating cell nuclei, this method is simple, nondestructive, non- photobleaching, and valuable for the in situ exploration of vital physiological processes with DNA participation in cell organelles. Graphical abstract A universal strategy was developed to accurately locate the nuclear region and obtain precise molecular information of cell nuclei by SERS.

The lipophilicity of a series of anticancer propargylquinoline derivatives is investigated using both chromatographic and computational methods. The parameters of the tested compounds' relative lipophilicity (logkw) are determined experimentally by the high-performance liquid chromatographic method (RP-HPLC, Accucore C18 column), using mixtures of acetonitrile and water as mobile phases. Mobile phase acetonitrile concentrations range between 50 and 80%. The logk values of the investigated compounds are linearly dependent upon the acetonitrile concentration. The analysis led to the calculation of the logkw parameter values for each of the tested compounds. The parameter logkw is discussed in terms of the relationship between structure and lipophilicity and consequently, transformed into the parameter logPHPLC using the calibration curve. The partition coefficients of the tested compounds (logPcalc) are also calculated by selected computer programs. A regression analysis and the sum of ranking differences are used to compare the lipophilic parameters of 15 acetylenequinoline derivatives, which were experimentally obtained (logPHPLC) and calculated using different mathematical methods (logPcalc). The 13C NMR spectra are used to examine the electronic relationships between properties and lipophilicity for the studied compounds. A regression study conducted on 15 compounds exhibits a linear correlation between lipophilicity and electronic properties, expressed as the 13C NMR chemical shift (R2 = 0.98)., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Alkynes are a key component of click chemistry and used for a wide variety of applications including bioconjugation, selective tagging of protein modifications, and labeling of metabolites and drug targets. However, challenges still exist for detecting alkynes because most 1,2,3-triazole products from alkynes and azides do not possess distinct intrinsic properties that can be used for their facile detection by either fluorescence or mass spectrometry. To address this critical need, a novel brominated coumarin azide was used to tag alkynes and detect alkyne-conjugated biomolecules. This tag has several useful properties: first, it is fluorogenic and the click-chemistry products are highly fluorescent and quantifiable; second, its distinct isotopic pattern facilitates identification by mass spectrometry; and third, its click-chemistry products form a unique pair of reporter ions upon fragmentation that can be used for the quick screening of data. Using a monoclonal antibody conjugated with alkynes, a general workflow has been developed and examined comprehensively.

To understand the biogeochemical roles of microorganisms in the environment, it is important to determine when and under which conditions they are metabolically active. Bioorthogonal noncanonical amino acid tagging (BONCAT) can reveal active cells by tracking the incorporation of synthetic amino acids into newly synthesized proteins. The phylogenetic identity of translationally active cells can be determined by combining BONCAT with rRNA-targeted fluorescence in situ hybridization (BONCAT-FISH). In theory, BONCAT-labeled cells could be isolated with fluorescence-activated cell sorting (BONCAT-FACS) for subsequent genetic analyses. Here, in the first application, to our knowledge, of BONCAT-FISH and BONCAT-FACS within an environmental context, we probe the translational activity of microbial consortia catalyzing the anaerobic oxidation of methane (AOM), a dominant sink of methane in the ocean. These consortia, which typically are composed of anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing bacteria, have been difficult to study due to their slow in situ growth rates, and fundamental questions remain about their ecology and diversity of interactions occurring between ANME and associated partners. Our activity-correlated analyses of >16,400 microbial aggregates provide the first evidence, to our knowledge, that AOM consortia affiliated with all five major ANME clades are concurrently active under controlled conditions. Surprisingly, sorting of individual BONCAT-labeled consortia followed by whole-genome amplification and 16S rRNA gene sequencing revealed previously unrecognized interactions of ANME with members of the poorly understood phylum Verrucomicrobia This finding, together with our observation that ANME-associated Verrucomicrobia are found in a variety of geographically distinct methane seep environments, suggests a broader range of symbiotic relationships within AOM consortia than previously thought.

The RP-HPLC-based method of determination of the activity of cystathionine β-synthase and γ-cystathionase was undertaken in mouse liver, kidney and brain. Products of the reactions, such as cystathionine, α-ketobutyrate, cysteine and glutathione, were measured using the RP-HPLC method. A difference in the cystathionine level between homogenates with totally CTH-inhibiting concentrations of DL-propargylglycine and without the inhibitor was employed to evaluate the activity of cystathionine β-synthase. Gamma-cystathionase activity was measured using DL-homoserine as a substrate and a sensitive HPLC-based assay to measure α-ketobutyrate. The results confirmed high cystathionine β-synthase activity and no γ-cystathionase activity in brain, and high γ-cystathionase activity in mouse liver. The method presented here allows for evaluating the relative contribution of CBS and CTH to generation of H2S in tissues. Additionally, it provides results, which reflect the redox status (GSH/GSSG) of a tissue., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Although Codonopsis pilosula (C. pilosula) has long been considered as an important herbal medicine, no analytical method of marker compounds for quality assessment is registered in the Korean Pharmacopoeia. We developed a simple and robust analytical method of three marker components lobetyolin (1), lobetyol (2), and tangshenoside I (3) using HPLC-UV method. We also confirmed the three marker components using UPLC-qTOF/MS method. Various extraction conditions were optimized to achieve three marker compounds with faster extraction kinetics and higher recovery. The analytical condition was then validated by determining the linearity, accuracy, precision, limit of detection, limit of quantification, recovery, repeatability, robustness, and stability. By this method, the three markers were successfully quantified in 38 commercial samples along with three related species that are sometimes used as alternatives to C. pilosula. Finally, principal component and hierarchical clustering analyses were conducted to show the practicality of the method developed for the quality evaluation of C. pilosula.

The development of a chemical probe for identifying the protein targets of reactive electrophilic α-oxoaldehydes such as methylglyoxal is presented. The probe is evaluated against methylglyoxal using human serum albumin as well as using living cells and lysates.

Increasing production and disposal of organic light-emitting diode (OLED) displays for smartphones and tablets may have impact on the environment depending on the aqueous solubility of the pertinent chemicals. Here, aqueous solubilities are presented for several compounds, mostly aromatic amines, used as hole transport materials in the OLED displays. Solute selection includes 1,4-bis(diphenylamino)benzene, tetra-N-phenylbenzidine, 4,4'-bis(N-carbazolyl)-1,1'-biphenyl, 1,3,5-tris(diphenylamino)benzene, and 9,10-bis(phenylethynyl)anthracene. The solubilities are those in pressurized hot water (PHW), i.e., measured at elevated temperature (up to 260 °C) and pressure. The semi-quantitative estimates of room-temperature solubilities of the solutes have been obtained from extrapolations of the solubilities in PHW. For the compounds studied, the estimated aqueous solubilities at room temperature do not exceed 2×10(-11) g of the solute per 1 kg of water. Aqueous solubilities of triphenylamine have also been measured and used to upgrade a recent group-contribution model of aqueous solubilities of organic nonelectrolytes with the parameters for the nitrogen atom in aromatic amines., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Functionalized alkynyl polyvinyl alcohol magnetic microspheres (PVA MMs) were developed for the specific enrichment of sialic acid-rich glycoproteins by click chemistry. The capture capability for proteins was evaluated through a novel dual-labeled bovine serum albumin (BSA) that utilizes fluorescence resonance energy transfer (FRET). The PVA MM parameters, including the size and coverage of functionalized groups, were optimized by response surface methodology. The optimal parameters obtained were 1.25-6.31 μm in size and 48.53-73.05% in coverage. Then, the optimal PVA MMs were synthesized, and the morphology and surface chemical properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). To capture glycoproteins from the cell surface, a bioorthogonal chemical method was applied to metabolically label them with an azide group. The functionalized alkynyl PVA MMs showed a high specificity and strong binding capability for glycoproteins through a [3 + 2] cycloaddition reaction. The results indicated that the functionalized alkynyl PVA MMs could be applied to the enrichment of cell glycoproteins, and the merits of the MMs suggested an attractive and potential way to facilitate glycoprotein research.

Alkyne-functionalized cellulose fibers have been generated through etherification under basic water or hydroalcoholic conditions (NaOH/H(2)O/isopropanol). For a given NaOH content, the medium of reaction and, more particularly, the water/IPA ratio, were shown to be of crucial importance to derivatize the fibers without altering their integrity and their crystalline nature. It was shown that the degree of substitution (DS) of the fibers increases concomitantly with isopropanol weight ratio and that, contrary to water or water-rich conditions, derivatization of fibers under isopropanol-rich conditions induces an alteration of the fibers. Optimization of etherification conditions in aqueous media afforded functionalized cellulose materials with DS up to 0.20. Raman confocal microscopy on derivatized fibers cross sections stressed that alkyne moieties are incorporated all over the fibers. The resulting fibers were postfunctionalized by molecular probes and macromolecules in aqueous or water-rich conditions. The effectiveness of the grafting was strongly impacted by the nature of the coupling agents.

A new brominated C(17) acetylenic acid (1) designated as bromotheoynic acid has been isolated from the marine sponge Theonella swinhoei, collected off the coast of Tanegashima, Kagoshima Prefecture, Japan. The structure was determined on the basis of the analysis of its extensive 2D NMR spectroscopic data as well as HRMS. Bromotheoynic acid (1) inhibited maturation of starfish oocytes and cell division of fertilised starfish eggs. Bromotheoynic acid (1) also inhibited proliferation of human leukaemia U937 and HL60 cells, human lung cancer A549 and H1299 cells, and human embryonic kidney 293 (HEK293) cells.

Alkyne has a unique Raman band that does not overlap with Raman scattering from any endogenous molecule in live cells. Here, we show that alkyne-tag Raman imaging (ATRI) is a promising approach for visualizing nonimmobilized small molecules in live cells. An examination of structure-Raman shift/intensity relationships revealed that alkynes conjugated to an aromatic ring and/or to a second alkyne (conjugated diynes) have strong Raman signals in the cellular silent region and can be excellent tags. Using these design guidelines, we synthesized and imaged a series of alkyne-tagged coenzyme Q (CoQ) analogues in live cells. Cellular concentrations of diyne-tagged CoQ analogues could be semiquantitatively estimated. Finally, simultaneous imaging of two small molecules, 5-ethynyl-2'-deoxyuridine (EdU) and a CoQ analogue, with distinct Raman tags was demonstrated.

Roots of Echinacea purpurea and Echinacea pallida cultivated for 4 years in a North European climate were analyzed for seasonal variations in the concentrations of lipophilic constituents (alkamides, ketoalkenes, and ketoalkynes) and phenolic acids by harvesting five times during 1 year to establish the optimal time for harvest. A total of 16 alkamides, three ketoalkenes, two ketoalkynes, and four phenolic acids (echinacoside, cichoric acid, caftaric acid, and chlorogenic acid) were identified in aqueous ethanolic (70%) extracts by liquid chromatography-mass spectrometry and quantified by reverse-phase high-performance liquid chromatography. The major alkamides in the roots of E. purpurea were at their lowest concentration in the middle of autumn and early winter, and the total concentration of lipophilic compounds in E. pallida showed the same pattern. Moreover, all of the major phenolic acids in E. purpurea were at their highest concentrations in spring. The optimal harvest time in spring is in contrast to normal growing guidelines; hence, this specific information of seasonal variations in the concentrations of lipophilic and phenolic compounds in E. purpurea and E. pallida is valuable for research, farmers, and producers of medicinal preparations.

Context: Carlinae radix is an herbal drug, commonly used by the locals in southeastern Serbia for the treatment of respiratory and urogenital diseases and, externally, for various skin conditions. There still seems to be no detailed studies correlating the chemical composition of this drug and its ethnopharmacological uses., Objective: Chemical composition, antimicrobial activity and mode of action of C. radix essential oil, isolated from commercial samples (confirmation of whose true biological identity was also the aim of this work) were analyzed. Antimicrobial potential of decoctions (extracts prepared by boiling plant material in a given solvent), used in ethnomedicine preferentially to the pure essential oil, was also investigated., Materials and Methods: The essential oil obtained by hydrodistillation was screened for antimicrobial activity by disc diffusion and broth microdilution methods. Effects of the oil on the growth of Staphylococcus aureus cells were investigated using turbidimetric measurements and visualized using scanning electron microscopy. Analyses of the chemical composition of the oils were done using gas chromatography and gas chromatography/mass spectrometry., Results and Discussion: Both the essential oil and the decocts exhibited a very high antimicrobial activity against all tested strains, with S. aureus as the most sensitive one [e.g., for the oil sample the values for minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were 0.02, 0.04 µL/mL, respectively]. Growth curves of S. aureus demonstrated a significant decrease in turbidity (for the MIC concentration this amounted to ca. 70%) showing a concentration-dependent lysis of the cells, confirmed by scanning electron microscopy. Chemical composition, anatomical and morphological features of the sample pointed to Carlina acanthifolia L. (Asteraceae) instead of Carlina acaulis L. (Asteraceae)., Conclusion: The results showed significant antimicrobial effect of the essential oil and the decoctions and support the use of this plant in ethnomedicine for the treatment of various human infections, especially those caused by S. aureus. Adulteration of the drug would not cause significant differences in its biological activity, since chemical composition of the sample showed high similarity with those containing C. acaulis roots.

Conyza canadensis (L.) Cronquist syn. (horseweed) is a problematic and invasive weed with reported allelopathic properties. To identify the phytotoxic constituents of the aerial parts, a systematic bioactivity-guided fractionation of the dichloromethane extract was performed. Three active enyne derivatives, (2Z,8Z)-matricaria acid methyl ester, (4Z,8Z)-matricaria lactone, and (4Z)-lachnophyllum lactone, were identified. The lactones inhibited growth of the monocot Agrostis stolonifera (bentgrass) and the dicot Lactuca sativa (lettuce) at 1 mg mL(-1), while the (2Z,8Z)-matricaria acid methyl ester was less active. In a dose-response screening of the lactones for growth inhibitory activity against Lemna paucicostata , (4Z)-lachnophyllum lactone was the most active with an IC50 of 104 μM, while the (4Z,8Z)-matricaria lactone was less active (IC50 of 220 μM). In a fungal direct bioautography assay, the two lactones at 10 and 100 μg/spot inhibited growth of the plant pathogenic fungi Colletotrichum acutatum , Colletotrichum fragariae , and Colletotrichum gloeosporioides . In a dose-response screening of the lactones against six different plant pathogenic fungi, (4Z,8Z)-matricaria lactone was more active than the commercial fungicide azoxystrobin on Col. acutatum , Col. fragariae , and Col. gloeosporioides at 30 μM and about as active as the commercial fungicide captan against Col. gloeosporioides , while (4Z)-lachnophyllum lactone was less active.

The diffusion coefficients of a series of closely matched pairs of macrocyclic and linear molecules have been compared using NMR spectroscopy. The macrocyclic series was designed both to overlap with and extend beyond the molecular weight range typically employed for drug-like molecules. The linear molecules each represent a carbogenic fission of their macrocyclic counterparts, designed to minimize differences in functionality and physicochemical properties. Each series of molecules was prepared using copper catalyzed azide-alkyne cycloaddition (CuAAC) reactions conducted in a flow using a copper tube. The macrocyclic series exhibited consistently higher diffusion across the entire molecular weight range studied. The fold difference in diffusion coefficients between the macrocyclic and linear analogues appeared to be independent of either solvent viscosity or dielectric environment.

A simple and practical procedure for the synthesis of aza- and oxacycles, which possess an array of stereogenic functionalities, is described. This protocol relies on tandem Cu-catalyzed coupling of suitably functionalized terminal alkyne with diazoester followed by isomerization and subsequent aza or oxa-Michael reaction, thus generating the required scaffold with high diastereoselectivity.

Extraction and pre-concentration of a bioactive marker compound, phenyl-1,3,5-heptatriyne from Bidens pilosa, prior to HPLC has been demonstrated using both organic and ecofriendly solvents. Non-ionic surfactants, viz. Triton X-100, Triton X-114 and Genapol X-80, were used for extraction. No back-extraction or liquid chromatographic steps were required to remove the target phytochemical from the surfactant-rich extractant phase. The optimized cloud point extraction procedure has been shown to be a potentially useful methodology for the preconcentration of the target analyte, with a preconcentration factor of 4-99. Moreover, the method is simple, sensitive, rapid and consumes lesser solvent than traditional methods. An isocratic chromatographic separation and quantitation was accomplished on a C(18) column with acetonitrile-acidified aqueous as mobile phase at a flow rate of 1.0 mL/min, UV detection at 254 nm and specificity with photo diode-array detector (PDA) and MS. Under the optimum experimental conditions recovery was satisfactory (99.18-100.33%) without interference from the surfactant. The method seems to be reliable with intraday precision and interday precision below 2.0%. Good linearity was obtained in the working range from 7.5 to 30 µg/mL with correlation coefficient >0.99. The limits of detection and quantitation were 1.84 and 6.13 µg/mL, respectively. The method was validated following international guidelines and successfully applied for quantitative assays of cytotoxic compound phenyl-1,3,5-heptatriyne in Bidens pilosa., (Copyright © 2010 John Wiley & Sons, Ltd.)

Aims: This study is aiming at characterizing antifungal substances from the methanol extract of Prunella vulgaris and at investigating those substances' antifungal and antioomycete activities against various plant pathogens., Methods and Results: Two polyacetylenic acids were isolated from P. vulgaris as active principles and identified as octadeca-9,11,13-triynoic acid and trans-octadec-13-ene-9,11-diynoic acid. These two compounds inhibited the growth of Magnaporthe oryzae, Rhizoctonia solani, Phytophthora infestans, Sclerotinia sclerotiorum, Fusarium oxysporum f. sp. raphani, and Phytophthora capsici. In addition, these two compounds and the wettable powder-type formulation of an n-hexane fraction of P. vulgaris significantly suppressed the development of rice blast, tomato late blight, wheat leaf rust, and red pepper anthracnose., Conclusions: These data show that the extract of P. vulgaris and two polyacetylenic acids possess antifungal and antioomycete activities against a broad spectrum of tested plant pathogens., Significance and Impact of the Study: This is the first report on the occurrence of octadeca-9,11,13-triynoic acid and trans-octadec-13-ene-9,11-diynoic acid in P. vulgaris and their efficacy against plant diseases. The crude extract containing the two polyacetylenic acids can be used as a natural fungicide for the control of various plant diseases., (© 2010 The Authors. © 2010 The Society for Applied Microbiology.)

Although bisacetylenic oxylipins have been demonstrated to exhibit diverse biological activities, the chemical structures of many representatives of this class of phytochemicals still remain elusive. As carrots play an important role in our daily diet and are known as a source of bisacetylenes, an extract made from Daucus carota L. was screened for bisacetylenic oxylipins, and, after isolation, their structures were determined by means of LC-MS and 1D/2D NMR spectroscopy. Besides the previously reported falcarinol, falcarindiol, and falcarindiol 3-acetate, nine additional bisacetylenes were identified, among which six derivatives are reported for the first time in literature and three compounds were previously not identified in carrots. To determine the absolute stereochemistry of falcarindiol in carrots, the (3R,8R)-, (3R,8S)-, (3S,8R)-, and (3S,8S)-stereoisomers of falcarindiol were synthesized according to a novel 10-step total synthesis involving a Cadiot-Chodkiewicz cross-coupling reaction of (S)- and (R)-trimethylsilanyl-4-dodecen-1-yn-3-ol and (R)- and (S)-5-bromo-1-penten-4-yn-3-ol, respectively. Comparative chiral HPLC analysis of the synthetic stereoisomers with the isolated phytochemical led to the unequivocal assignment of the (Z)-(3R,8S)-configuration for falcarindiol in carrot extracts from Daucus carota L.

The peptide ligase subtiligase, derived from subtilisin, has been employed in the identification of protein N-termini in complex mixtures. Here, the peptide ester substrates for the ligation reaction were optimized with respect to solubility, resulting in greater incorporation of the N-terminal tags. Additionally, the quantitation of the incorporated tags was explored, and a 'click' chemistry-based derivatization provided the ability to quantitate the tag to low nanomolar concentrations by sandwich ELISA. These new tags should expand the utility of subtiligase for the proteomic study of N-termini.

Hypoxoside is a norlignan diglucoside present in the corms of African potato, Hypoxis hemerocallidea, used as a popular African traditional medicine for its nutritional and immune boosting properties. A specific analytical method employing capillary zone electrophoresis has been developed and validated for the quantitative determination of this analyte. Sulfafurazole was used as internal standard, and electrophoretic separation of both analytes could be achieved within 12 min. Linearity of the method was established within the range 5-60 microg/mL and provided a high degree of accuracy (100 +/- 3%). The recovery of the method was found to be 100 +/- 5% and the RSDs of the intra- and inter-day precision were better than 5.19 and 2.52%, respectively. The limits of detection and quantification were calculated to be 0.5 and 2 microg/mL, respectively. The described method was used for the analysis and quality control of two commercially available products containing African potato. The method can also be used to determine product stability since it could separate the hypoxoside peak from its degraded products obtained from degradation studies., (Copyright (c) 2007 John Wiley & Sons, Ltd.)

African potato (AP) is widely used as an immune booster for the treatment of various ailments. The norlignan glycoside hypoxoside, a major phytoconstituent of AP, its aglycon rooperol, and an aqueous preparation of lyophilized AP corms were screened for in vitro antioxidant activity using the DPPH (1,1-diphenyl-2-picryl hydrazine) and FRAP (ferric reducing ability of plasma) tests. Inhibition of quinolinic acid (QA) induced lipid peroxidation in rat liver tissue was studied in vitro using the thiobarbituric assay (TBA). Superoxide free radical scavenging activity was determined by the nitroblue tetrazolium assay. An isocratic HPLC method was developed to quantitatively determine both hypoxoside and rooperol concurrently. While rooperol and AP extracts reduced QA-induced lipid peroxidation in rat liver homogenates and significantly scavenged the superoxide anion at pharmacological doses, in comparison, hypoxoside was virtually devoid of activity. Since hypoxoside is converted to rooperol in vivo following administration of AP, the results indicate that the hypoxoside component in AP could have value as an antioxidant prodrug.

Liquid chromatography-mass spectrometry (LC-MS) analysis of methanol extracts of Oenanthe crocata roots revealed that oenanthotoxin co-eluted with another major polyalkyne, 2,3-dihydro-oenanthotoxin, using the existing high performance liquid chromatography (HPLC) method (isocratic elution from C18 with aqueous methanol) for investigating Oenanthe poisoning. Positive ES or APCI gave [(M+H)-H(2)O](+) and its methanol adduct as major ion species for oenanthotoxin, whereas 2,3-dihydro-oenanthotoxin formed [M+H](+) and its methanol adduct. The two polyalkynes could be chromatographically resolved on C18 by gradient elution with aqueous acetonitrile. This provides superior analysis for oenanthotoxin using HPLC with photodiode array (PDA) detection alone, but for LC-MS/MS aqueous acetonitrile was less suitable due to poor ionisation and, with APCI, an increase in the relative abundance of a [M-1](+) species, which could confuse compound assignment. HPLC-PDA and LC-MS/MS methods using an aqueous acetonitrile or aqueous methanol mobile phase, respectively, were successful when applied to the analysis of the stomach contents of a pony suspected to have eaten O. crocata. Relevant product ion spectra, by ion trap MS/MS, accurate mass data and complete sets of (1)H and (13)C NMR spectral assignments are given for the two compounds.

Hypoxoside is a norlignan diglucoside present in the corms of African potato (Hypoxis hemerocallidea). The latter is used as a popular African traditional medicine for it's nutritional and immune-boosting properties. A reverse phase high-performance liquid chromatography method was developed and validated for the determination of hypoxoside using a mobile phase consisting of acetonitrile:water (20:80, v/v). The method was linear throughout the range of 10-100 microg/mL and provided a high degree of accuracy (100 +/- 4%). The recovery of the method was found to be 100 +/- 5%, and the precision of the study, % relative standard deviation intraday and interday (over three separate days), was better than 6.15 and 5.64%, respectively. The limits of detection and quantification were calculated to be 0.75 and 3.5 microg/mL, respectively. This method was applied to the analysis and quality control of African potato corms as well as 12 commercially available products. The daily intake of hypoxoside through traditionally prepared African potato decoction was also evaluated.

To date, chloroethyne in the environment has been proposed to occur as a reactive intermediate during the reductive dechlorination of tri- and tetrachloroethene with zerovalent metals. Such artificial conditions might possibly be found at organohalide-contaminated sites that are surrounded by remediation barriers made of metallic iron. In this paper, it is shown that the highly reactive chloroethyne is also a product of natural processes in soil. Soil air samples from three differentterrestrial ecosystems of Northern Germany showed significant chloroethyne concentrations, besides other naturally produced monochlorinated compounds, such as chloromethane, chloroethane and chloroethene. Measured amounts range from 5 to 540 pg chloroethyne in air purged from 1 L of soil. A possible route of chloroethyne formation in soil is discussed, where chloroethyne is probably produced as a byproduct of the oxidative halogenation of aromatic compounds in soil. A series of laboratory studies, using the redox-sensitive catechol as a discrete organic model compound, showed the formation of chloroethyne when Fe3+ and hydrogen peroxide were added to the system. We therefore propose that the natural formation of chloroethyne in soil proceeds via oxidative cleavage of a quinonic system in the presence of the ubiquitous soil component chloride.

Ensiling plant material with the aid of lactic acid bacteria (LAB) is a common agricultural practice for conserving forages independently of the time point of harvest. Despite ensiling being a natural process, it can be improved by the treatment of the harvested forage with starter cultures before storage. Within this context, Lactobacillus plantarum (L. plantarum) is the most frequently used LAB in commercially available starter cultures. In order to enable the monitoring of the population dynamics of L. plantarum in silage, methods for species-specific detection based on the 16S ribosomal DNA (rDNA) sequence were developed by applying a quantitative real-time polymerase chain reaction (QRT-PCR) approach. The QRT-PCR assay was also applied to estimate the development of the L. plantarum population within experimental grass silages. In addition, a multiplex QRT-PCR assay was developed to estimate the amount of L. plantarum 16S rDNA in relation to total bacterial 16S rDNA. This multiplex QRT-PCR assay was applied to monitor the influence of different silage additives on the L. plantarum population.

Two series of new oligo(p-phenyleneethynylene)s (OPEs) O1-O4 and O5-O8, which have been proven to be one of the chief classes of molecules mainly used as the wires and other potential backbones of molecular electronic devices, have been synthesized by stepwise synthetic approach. The characterization of these oligomers was performed on MALDI TOF MS. Different cationization salts have been applied to investigate the ionization processes of these series of oligomers under MALDI conditions. The experimental results show that these oligomers display a strong tendency to undergo radical cationization and varied ionization efficiency with different cationization agents attributable to their difference in cationic diameters. Furthermore, we found that these two series of oligomers differed in ionization properties because of their different end-groups even when the same cationization agent was used.

A dichloromethane extract of root celery yielded falcarinol, falcarindiol, panaxydiol, and the new polyacetylene 8-O-methylfalcarindiol. The structure of the new compound was established by one- and two-dimensional (1D and 2D) NMR, mass spectrometry, and optical rotation data. Nonpolar extracts of roots and bulbs of carrots, celery, fennel, parsley, and parsnip were investigated for their content of polyacetylenes by high-performance liquid chromatography with diode array detection (HPLC-DAD). All five species contained polyacetylenes, although carrots and fennel only in minor amounts. Additionally, the cytotoxicity of the four polyacetylenes against five different cell lines was evaluated by the annexin V-PI assay. Falcarinol proved to be the most active compound with a pronounced toxicity against acute lymphoblastic leukemia cell line CEM-C7H2, with an IC(50) of 3.5 micromol/L. The possible chemopreventive impact of the presented findings is discussed briefly.

Tonghaosu (1), a lead for a botanical antifeedant, and its 22 analogues were synthesized according to a previously reported concise and straightforward procedure. The structures of all new compounds were confirmed by NMR, IR, MS, and HREIMS or elemental analysis. Their insect antifeedant activities against the large white butterfly (Pieris brassicae L.) were examined, and six analogues (Z- and E-6h and Z-isomers of 6i-l), which contain 1,3-diyn or 3,4-methylenedioxyphenyl acetylene group, showed considerable antifeedant activity. Interestingly, Z-isomers of 6i-k are much more active than their corresponding E-isomers.

A 33-year-old man died after intentionally inhaling a gaseous mix of methyl acetylene (propyne) and propadiene (allene) commonly known as MAPP, which is used for soldering and welding. He was found with a plastic bag securely placed over his head and a cylinder of MAPP alongside his head. The cylinder had been vented into the bag using a flexible hose. A comprehensive toxicological analysis revealed only a trace of diphenhydramine in the liver and 0.02 mg/L of morphine in the urine. Analysis of blood by headspace gas chromatography (HS-GC) detected two unknown peaks. These were determined to be the components of MAPP gas. MAPP was quantitated in femoral blood (59.6 mg/L) and brain (43.6 mg/kg) using a HS-GC method. The cause of death was attributed to acute MAPP intoxication, and the manner was determined to be suicide. A discussion on the analytical and interpretive considerations commonly encountered when analyzing volatile compounds is also presented.

Hexyn-1-yl silver shows broad signals in 1H, 13C and 109Ag NMR. In the presence of 1 equiv. of triphenylphosphane, the signals are much sharper and at low temperature 109Ag,31P and 107Ag,31P coupling can be observed. On 109Ag decoupling, the 31P spectrum still shows the 107Ag,31P coupling indicating the formation of a coordination complex., (2004 John Wiley & Sons, Ltd.)

Only 2% of the known natural products with acetylenic bonds are alpha-alkynoates. Their polarized, conjugated triple bond is an optimal target for an enzymic hydration. Therefore they are good substrates for the enzymes involved in metabolism of acetylenic compounds, resulting in products that are suitable for bacterial growth. We isolated a Pseudomonas putida strain growing on 2-butynedioate as well as on propynoate, and determined the metabolic pathways of these two alpha-alkynoates. The triple bonds in both compounds were initially hydrated and 2-ketobutandioate as well as 3-ketopropanoate were formed. These two beta-keto acids were decarboxylated resulting in pyruvate and acetaldehyde, respectively. Pyruvate was further hydrolysed mainly to acetate and formate, whereas minor amounts were reduced to lactate. In the other biotransformation, acetaldehyde was oxidized to acetate accompanied by the reduction of 3-ketopropanoate to 3-hydroxypropanoate. Analyses of these metabolic processes were performed by in situ 1H-NMR spectroscopy in 1H2O, although the substrates, propynoate and 2-butynedioate, carried only one or even no detectable protons, respectively. However, while protons from the solvent are incorporated in the course of the pathway, the metabolites can be detected and identified. Therefore a detailed determination of the metabolic process is possible.

Complexation of 3-iodo-L-tyrosine with 9-borabicyclo[3.3.1]nonane (9-BBN) provides a convenient substrate for a palladium-catalyzed coupling reaction. The complex is stable to silica gel chromatography (hexanes/ethyl acetate), dilute triethylamine in THF, and potassium fluoride in DMF. The desired product, 3-ethynyl-L-tyrosine, was released from the complex by simply diluting its solution in methanol with chloroform. Interestingly, the complex remains stable in solutions of either methanol or chloroform individually.

The fidelity of translation is dependent on the specificity of the aminoacyl-tRNA synthetases (aaRSs). The aaRSs that activate the hydrophobic amino acids leucine, isoleucine, and valine employ a proofreading mechanism that hydrolyzes noncognate aminoacyl adenylates and misaminoacylated tRNAs. Discrimination between structurally similar amino acids by these AARSs is believed to operate by a double-sieve principle, wherein a separate editing domain governs hydrolysis on the basis of the size and hydrophilicity of the amino acid side chain. Leucyl-tRNA synthetase (LeuRS) relies on its editing function to correct misaminoacylation of tRNA(Leu) by isoleucine and methionine. Thr252 of Escherichia coli LeuRS has been shown previously to be important in defining the size of the editing cavity. Here we report the isolation and characterization of three LeuRS mutants with point mutations at this position (T252Y, T252L, and T252F). The proofreading activity of the synthetase is significantly impaired when an amino acid bulkier than threonine is introduced. The rate of misaminoacylation of tRNA(Leu) by isoleucine and valine increases with the increasing size of the amino acid substituent at position 252, and the noncognate amino acids norvaline and norleucine are inserted efficiently at the leucine sites of recombinant proteins under conditions of constitutive overexpression of the T252Y mutant in E. coli. In addition, the unsaturated amino acids allylglycine, homoallylglycine, homopropargylglycine, and 2-butynylalanine all support protein synthesis in E. coli hosts harboring the mutant synthetase. These results demonstrate that programmed manipulation of the editing cavity can allow in vivo incorporation of novel protein building blocks.

Variation of phenylheptatriyne (PHT) in leaves of Bidens alba (Linn.) var. radiata (Shultz-Bip.) was investigated across its Florida range, throughout the year, and in response to the photoenvironment. A survey of PHT in B. alba leaves was done at 13 sites in Florida and three sites throughout the year. PHT concentrations differed among populations (P < 0.001), but little of the variation was explained by latitude (R2 = 0.024) or longitude (R2 = 0.022). Leaf concentrations of PHT fluctuated throughout the year (P < 0.001); they were highest in October and lowest in January and April. Experimental manipulations of light quality and quantity caused increased PHT accumulation when UV wavelengths were filtered out and decreased accumulation under low R/FR treatments. Low light levels did not significantly influence the concentration of PHT on a dry weight basis, but did decrease leaf biomass and PHT levels on a leaf area basis. The results suggest that PHT in B. alba leaves varies in nature and that light quality affects PHT biosynthesis in situ.

We present a comprehensive study of the physical and chemical conditions along the TMC-1 ridge. Temperatures were estimated from observations of CH3CCH, NH3, and CO. Densities were obtained from a multitransition study of HC3N. The values of the density and temperature allow column densities for 13 molecular species to be estimated from statistical equilibrium calculations, using observations of rarer isotopomers where possible, to minimize opacity effects. The most striking abundance variations relative to HCO+ along the ridge were seen for HC3N, CH3CCH, and SO, while smaller variations were seen in CS, C2H, and HCN. On the other hand, the NH3, HNC, and N2H+ abundances relative to HCO+ were determined to be constant, indicating that the so-called NH3 peak in TMC-1 is probably a peak in the ammonia column density rather than a relative abundance peak. In contrast, the well-studied cyanopolyyne peak is most likely due to an enhancement in the abundance of long-chain carbon species. Comparisons of the derived abundances to the results of time-dependent chemical models show good overall agreement for chemical timescales around 10(5) yr. We find that the observed abundance gradients can be explained either by a small variation in the chemical timescale from 1.2 x 10(5) to 1.8 x 10(5) yr or by a factor of 2 change in the density along the ridge. Alternatively, a variation in the C/O ratio from 0.4 to 0.5 along the ridge produces an abundance gradient similar to that observed.

Photolysis of germane (GeH4) in the presence of acetylene (C2H2), propyne (C3H4) or phosphine (PH3) with a 185 nm mercury lamp has been studied. The volatile products formed in these reactions are characterized by 1H, 31P and 13C NMR. Vinylgermanes are the first reaction products formed in the photolysis of GeH4 with alkynes. A reaction pathway is proposed. The initial step is the dissociation of germane 1 to hydrogen and GeH3 radicals. Addition of the germyl radical on alkyne is proposed as the next step. Vinyl-germanes are then formed by radical combination. Photolysis of ethenylgermane 2 gives diethenylgermane 3 in the presence of acetylene and digermaethane 4 in the presence of GeH4. The application of these findings to Jovian and Saturn atmospheric chemistry is discussed.

Methanol extracts of the corms of Hypoxis rooperi and H. latifolia were studied for their hypoxoside content by an in-line sorption enrichment HPLC technique [Kruger et al., J. Chromatogr., 612 (1993) 191]. Hypoxoside is the trivial name for (E)-1,5-bis(3'-hydroxy-4'-O-beta-D-glucopyranosyl-phenyl) pent-1-en-4-yne and rooperol the aglucone obtained from beta-glucosidase treatment. Hypoxoside and rooperol analogues containing 4, 3 and 2 hydroxyl groups resolved as separate peaks with the proportion of the latter two markedly higher in H. latifolia than in H. rooperi. After oral ingestion of hypoxoside by humans, no hypoxoside or rooperol appeared in the serum. Only rooperol was present in the faeces. The serum and urine contained at least three phase II metabolite peaks. Selective enzyme hydrolysis showed that they represent the diglucuronide, disulfate and glucuronide-sulfate conjugates of all three rooperol analogues.