Isolation and Structural Identification of Herbicidal Active Substance from Root of Flaveria bident(L.) Kuntze

In order to understand the composition and structure of herbicidal active substance from the root of Flaveria bidentis （L.） Kuntze, the isolation and structural identification were researched in this paper. The crude extract from the root ofF. bidentis （L.） Kuntze was extracted by petroleum ether, ethyl acetate, and water saturation of n-butyl alcohol, respectively, and the extraction fluid was separated by using the method of TLC, then the main fraction was separated by HPLC, and the structure of the herbicidal active substance was analyzed by LC-MS, elemental analysis and ~H-NMR. The results showed that the petroleum extraction had the strongest herbicidal activity, and the purple blue stripe separated by TLC had the strongest effect on Digitaria sanguinalis. The herbicidal active substance was identified as ct-terthienyl according to the data of LC-MS, elemental analysis and 1H-NMR.

Isolation and Identification of Staphylococcus chromogenes and 3 D Structural Analysis of the katA Gene

[Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from arthritis and named as the strain Gg1.[Result]It was then identified as Staphylococcus chromogenes by the biochemical tests and phylogenetic tree analysis based on 16S rDNA sequence.Furthermore,the catalase（katA）gene was amplified by PCR using the designed primers,and the expected fragment was 1 232 bp long encoding a protein of 410 amino acids that shares the conserved motifs including catalase,heme-binding ligand and active center motif.Six phosphorylation sites（Ser95,Thr96,Ser241,Ser242,Thr281,Ser338）,four conserved residues（Ser95,His216,Tyr281,Asp341）and two active sites（His56,Asn129）were demonstrated by multiple sequence alignment and homology comparisons.The homology modeling of 3D structure of katA protein was done by SWISSMODEL server based on the template retrieved from the catalase（PDB：2ISA_A）of Vibrio salmonicida.The katA protein represents a four-domain globular protein,the quality and reliability of the resulting protein structure was further verified by Ramachandran plot.[Conclusion]To our knowledge,this is the first report of S.chromogenes linked to arthritis in chicken and the bioinformatic characterization of its katA gene.

Separation, Purification and Identification of Antioxidant Compositions in Black Rice

To separate, purify and identify the antioxidative compositions of black rice, using total antioxidation capacity （TAC） as an activity-monitoring parameter, different fractions of black rice antioxidative extracts were obtained using solvents of different polarities such as petroleum ether, chloroform, ethyl acetate and normal butyl alcohol. The main anfioxidative components were separated from the strongest antioxidative fractions by using Sephadex LH-20 resin and the structures were analyzed by ultraviolet-vis, infra-red, ESI-MS, ^1H-NMR and ^13C-NMR spectrums. Results showed that the water fraction and normal butyl alcohol antioxidafive extract fraction of black rice had the strongest antioxidation capacities and their TACs reached 383 and 392 ku g^-1, respectively. Four main antioxidative components were separated from the water fraction and their TACs reached 976, 878, 1 134 and 1087 ku g^-, respectively. The spectroscopy analysis indicated that the four active components of the antioxidative extract of black rice were four anthocyanin compounds of malvidin, pelargonidin- 3, 5-diglucoside, cyaniding-3-glucoside and cyaniding-3, 5-diglucoside. It is concluded that the anthocyanin compounds are the most important substantial foundations for antioxidation.

Isolation and Structural Indentification of Herbicidal Toxin Fractions Produced by Pythium aphanidermatum

In order to understand the compsition and structure of herbicidal component of Pythium aphanidermatum,the isolation and structural indentification were researched.The culture filtrate was extracted by ethyl acetate,petroleum,and chloroform with the same volume respectively and the activity of the crude toxin was bioassayed.The toxin was separated by using the method of thin layer chromatography（TLC）,then the main fraction was separated by HPLC,and the structure was analyzed by the sepctrum of IR,13C-NMR and 1HNMR.The results showed that the ethyl acetate extracts had the strongest herbicidal activity.Using the method of TLC,the bioassay results showed that the extracts with Rf 0.19 had the strongest effect on weeds and the inhibition to Digitaria sanguinalis and Amaranthus retroflexus reached five levels,and the component was proved to be dimethyl o-phthalate from the spectrum of IR,13C-NMR and 1HNMR,which was one of the components from the toxin,and it had herbicidal activity.

Parameter Estimation and Topology Identification of Uncertain General Fractional-order Complex Dynamical Networks with Time Delay

Complex networks have attracted much attention from various fields of sciences and engineering in recent years.However, many complex networks have various uncertain information, such as unknown or uncertain system parameters and topological structure, which greatly affects the system dynamics.Thus, the parameter estimation and structure identification problem has theoretical and practical importance for uncertain complex dynamical networks. This paper investigates identification of unknown system parameters and network topologies in uncertain fractional-order complex network with time delays(including coupling delay and node delay). Based on the stability theorem of fractional-order differential system and the adaptive control technique, a novel and general method is proposed to address this challenge. Finally two representative examples are given to verify the effectiveness of the proposed approach.

Structure identification of an uncertain network coupled with complex-variable chaotic systems via adaptive impulsive control

In this paper, structure identification of an uncertain network coupled with complex-variable chaotic systems is in- vestigated. Both the topological structure and the system parameters can be unknown and need to be identified. Based on impulsive stability theory and the Lyapunov function method, an impulsive control scheme combined with an adaptive strategy is adopted to design effective and universal network estimators. The restriction on the impulsive interval is relaxed by adopting an adaptive strategy. Further, the proposed method can monitor the online switching topology effectively. Several numerical simulations are provided to illustrate the effectiveness of the theoretical results.

Purification and Structure Identification of Hyaluronic Acid

Polysaccharide produced by mutated strain of Streptococcus zooepidemicus was purified by the procedures including Savage method, quaternary ammonium compound precipitation, DEAE-cellulose(DE52) chromatography and Sephadex G-75 gel filtration. The structure of the purified polysaccharide has been characterized by means of chemical composition analysis,13C NMR spectrum, infrared spectrum and circular dichroism (CD). All the results showed that the purified polysaccharide was hyaluronic acid (HA). The single helix conformation of the purified HA was determined by Congo red experiment. The molecular weight of the HA was about 1.16×106D, which was measured by viscosity method.

Identification of the Concealed Structures in the Beiya Area of Western Yunnan

The interpretation of regional gravity and magnetic data, especially the extracted information about concealed targets and structures, provide important evidence for geological structure research, oil-gas resource assessment, mineral potential forecast and prospective area delineation. Several interpretation methods have been proposed to determine structural boundary, including vertical derivative, horizontal first-order derivative, total horizontal derivative, total gradient modulus, tilt derivative, and theta graph, and each have their advantages and disadvantages. This study used the tilt derivate method to obtain bouguer gravity anomalies in the Beya area, as shown in Fig. 1a.

Identification of impurities in nafamostat mesylate using HPLC-ITTOF/MS:A series of double-charged ions

Nafamostat mesylate is a serine protease inhibitor used in the treatment of acute pancreatitis.The impurities in nafamostat mesylate,the active pharmaceutical ingredient(API),were profiled via high performance liquid chromatography tandem ion trap coupled with time-of-flight mass spectrometer(HPLC-IT-TOF/MS).The chromatography was performed on an ACE-3 C18 column(200 mm4.6 mm,3 mm)using methanol and 0.1%formic acid in purified water as mobile phase at a flow rate of 1.0 mL/min.The ions were detected by IT-TOF/MS with a full-scan mass analysis from m/z 100 to 800.In total,eleven impurities were detected in nafamostat mesylate API.The impurity profile was estimated based on the HPLC-IT-TOF/MS data,including accurate masses,MSn fingerprints of fragmentation pathways and a series of double-charged ions.Finally,seven impurities were identified and reported for the first time.The results will provide technical support for the quality control and clinical safety of nafamostat mesylate.

Crosscumulants Based Approaches for the Structure Identification of Volterra Models

In this paper, we address the problem of structure identification of Volterra models. It consists in estimating the model order and the memory length of each kernel. Two methods based on input-output crosscumulants are developed. The first one uses zero mean independent and identically distributed Caussian input, and the second one concerns a symmetric input sequence. Simulations are performed on six models having different orders and kernel memory lengths to demonstrate the advantages of the proposed methods.

A MODEL IDENTIFICATION METHOD OF VIBRATING STRUCTURES FROM INCOMPLETE MODAL INFORMATION

The accurate mathematical models for complicated structures are very difficult to construct.The work presented here provides an identification method for estimating the mass.damping,and stiffness matrices of linear dynamical systems from incomplete experimental data.The mass,stiffness and damping matrices are assumed to be real,symmetric,and positive definite The partial set of experimental complex eigenvalues and corresponding eigenvectors are given.In the proposed method the least squares algorithm is combined with the iteration technique to determine systems identified matrices and corresponding design parameters.Seeveral illustative examples,are presented to demonstrate the reliability of the proposed method .It is emphasized that the mass,damping and stiffness matrices can be identified simultaneously.

Non Ideal Schottky Barrier Diode’s Parameters Extraction and Materials Identification from Dark I-V-T Characteristics

Several parameters of a commercial Si-based Schottky barrier diode (SBD) with unknown metal material and semiconductor-type have been investigated in this work from dark forward and reverse I-V characteristics in the temperature (T) range of [274.5 K - 366.5 K]. Those parameters include the reverse saturation current (Is), the ideality factor (n), the series and the shunt resistances (Rs and Rsh), the effective and the zero bias barrier heights (ΦB and ΦB0), the product of the electrical active area (A) and the effective Richardson constant (A**), the built-in potential (Vbi), together with the semiconductor doping concentration (NA or ND). Some of them have been extracted by using two or three different methods. The main features of each approach have been clearly stated. From one parameter to another, results have been discussed in terms of structure performance, comparison on one another when extracted from different methods, accordance or discordance with data from other works, and parameter’s temperature or voltage dependence. A comparison of results on ΦB, ΦB0, n and NA or ND parameters with some available data in literature for the same parameters, has especially led to clear propositions on the identity of the analyzed SBD’s metal and semiconductor-type.

Chemical Constituents from Ethnic Medicine Laportea bulbifera

[Objectives]This study was conducted to study the chemical constituents from Laportea bulbifera. [Methods] The 60% ethanol extract from L. bulbifera was isolated and purified by silica, Sephadex LH-20, ODS, semi-preparative HPLC and recrystallization. Their chemical structures were elucidated by physicochemical properties and spectroscopic methods. [Results] These compounds were determined as kaempferol-3-O-α-L-(3-O-acetyl)-rhamnoside-7-O-α-L-rhamnoside(1), sutchuenoside A(2), kaempferol-3-O-[β-D-glucopyranosyl-(1→3)]-α-L-(4-O-acetyl)-rhamnopyranoside-7-O-α-L-rhamnopyranoside(3). Compounds 1-3 are isolated from genus Laportea for the first time. Compound 3 is a new compound. [Conclusions] This study lays a foundation for improving the quality standard of L. bulbifera and the development and utilization of its resources.

Study on Chemical Constituents from Phellodendron chinense

[Objectives]To isolate and identify chemical constituents from Phellodendron chinense.[Methods]Compounds were isolated by silica gel,Sephadex LH-20,and ODS column chromatography,and their structures were determined by means of the spectral analysis and physicochemical properties.[Results]Eleven compounds were isolated and identified as berberine(1),obaculactone(2),shihulimonin A(3),N-p-coumaroyltyramine(4),1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxy-propyl)-2-methoxyphenoxy]-propane-1,3-diol(5),phellodendrine(6),magnoflorine(7),palmatine(8),jatrorrhizine(9),columbamine(10),and obacunone(11).[Conclusions]Compounds 3 and 5 were isolated from Phellodendron for the first time,and compound 4 was isolated from this plant for the first time.

Structure elucidation,immunomodulatory activity,antitumor activity and its molecular mechanism of a novel polysaccharide from Boletus reticulatus Schaeff

A new water-soluble heteropolysaccharide with a molecular weight of 15 k Da was isolated from the fruiting bodies of Boletus reticulatus Schaeff.Structural characterization results revealed that B.reticulatus Schaeff polysaccharide(BRS-X)had a backbone of 1,6-linkedα-D-galactose and 1,2,6-linkedα-D-galactose which branches were mainly composed of a terminal 4-linkedβ-D-glucose and the ratio of D-galactose and D-glucose was 5:1.Bioactivity assays indicated that BRS-X displayed a strong proliferative activity in T cells and B cells and promoted the secretion of immunoglobulin G(Ig G),Ig E,Ig D and Ig M.In addition,BRS-X could facilitate the proliferation and phagocytosis of RAW264.7 cells and could significantly inhibit the growth of tumors in S180-bearing mice.The results of transcriptome sequencing analysis illustrated that total 46 genes enriched in MAPK and total 34 genes enriched in PI3 K/Akt signaling pathways in BRS-X group.The protein VEGF and VEGFR expression were significantly reduced under the treatment with BRS-X.These findings provide a scientific basis for the edible and medicinal value of BRS-X.

Two new saponins from Anemarrhena asphodeloides Bge.

Two new saponins 3-O-β-d-glucopyranosyl (1 → 2)-β-d-mannopyranosyl sarsasapogenin, named timosaponin A IV(1) and (5β, 25S)-26-O-β-d-glucopyranosyl-furost-20(22)-en-3,26-diol-3-O-β-d-glucopyranosyl (1 → 4) glucopyranosyl (1 → 2)-β-d-galacopyranoside, named timosaponin B IV(2), were isolated by silica gel column chromatography and preparative HPLC from Anemarrhena asphodeloides Bge. Their structures were elucidated by chemical characters and spectroscopic analysis.

A new isoquinoline derivative from the leaves of Magnolia sieboldii K.Koch

Magnoline（1）,a new isoquinoline derivative,was isolated from the leaves of Magnolia sieboldii K.Koch（Magnoliaceae）.Its structure was elucidated on the basis of spectral analysis including 1D,2D NMR and HR-TOF-MS.

Isolation and characterization of lignans from the leaves of Isatis indigotica Fortune

A phytochemical investigation of 80%EtOH exact of Isatis indigotica Fortune leaves yielded ten lignans(1-10),including six furofurans lignans(1-6),one arylnaphthalenes lignans(7)and three tetrahydrofurans lignans(8-10).Their structures were determined by HRESIMS spectroscopic data and extensive NMR analyses.Among them,compounds 6,9 and 10 were isolated from the genus oi Isatis for the first time.

Composition and antioxidant activity of anthocyanins isolated from Yunnan edible rose(An ning)

Edible roses(An ning)are a good source of anthocyanins and grown widely in Yunnan Province of China.In this study,the contents of anthocyanins and total phenol as well as the antioxidant activity of methanol extract from specific variety of rose were systematically investigated.The results showed that anthocyanins and total phenolic content of the petals were(353.56±2.50)mg cyanidin 3,5-diglucoside(Cy-3,5-diglu)equivalents and(2087.43±17.37)mg gallic acid equivalents(GAE)per 100 g fresh weight(FW),respectively.Totally,3 kinds of anthocyanins were detected and Cy-3,5-diglu was the predominant constituent which accounted for approximately 94.9%of total anthocyanins according to the analysis results of high performance liquid chromatography-photodiode array detection(HPLC-PAD).Data demonstrated that the extract from edible rose exhibited excellent ferric reducing capacity and free radical scavenging activity against both 2,2-diphenyl-1-picrylhydrazyl(DPPH)and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt(ABTS).The equivalents of anthocyanins from roses on DPPH,ABTS and ferric reducing ability were 2089,639 mg and 1400 mg GAE per 100 g FW,respectively.The high anthocyanins content and excellent antioxidant activity suggested that Yunnan edible roses could be applied in food industry as a good source of natural pigments.©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.