Recombinant protein G/Au nanoparticles/graphene oxide modified electrodes used as an electrochemical biosensor for Brucella Testing in milk.

In this study, a simple label-free biosensor for Brucella was constructed, which based on the screen-printed carbon electrode (SPCE) modified by Recombinant protein G/gold nanoparticles/graphene oxide (RpG/Au/GO). The impedance responses of the proposed biosensor were measured by electrochemical AC impedance method in Brucella antigen gradient concentration solutions. The results showed that the linear range of this biosensor was from 1.6 × 102 CFU/mL to 1.6 × 108 CFU/mL with the minimum detection limit of 3.2 × 102 CFU/mL (S/N = 3). Moreover, the biosensor for Brucella detection possessed acceptable reproducibility with a relative standard deviation of 5.15% and acceptable stability with a relative standard deviation of 4.68%. The spiked recovery rate in actual pasteurized milk samples was more than 92%. Therefore, the developed biosensor exhibits excellent prospects in the selective quantification detection of Brucella abortus. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05544-8.

Design, synthesis, biological evaluation, homology modeling and docking studies of (E)-3-(benzo[d][1,3]dioxol-5-ylmethylene) pyrrolidin-2-one derivatives as potent anticonvulsant agents.

A series of (E)-3-(benzo[d][1,3]dioxol-5-ylmethylene)pyrrolidin-2-one derivatives were designed, synthesized, and evaluated for their anticonvulsant activities. In the preliminary screening, compounds 5, 6a-6f and 6h-6i showed promising anticonvulsant activities in MES model, while 6f and 6g represented protection against seizures at doses of 100 mg/kg and 0.5 h in scPTZ model. The most active compound 6d had a high-degree protection against the MES-induced seizures with ED50 value of 4.3 mg/kg and TD50 value of 160.9 mg/kg after intraperitoneal (i.p.) injection in mice, which provided 6d in a high protective index (TD50/ED50) of 37.4 comparable to the reference drugs. Beyond that, 6d has been selected and evaluated in vitro experiment to estimate the activation impact. Apparently, 6d clearly inhibits the Nav1.1 channel. Our preliminary results provide new insights for the development of small-molecule activators targeting specifically Nav1.1 channels to design potential drugs for treating epilepsy. The computational parameters, such as homology modeling, docking study, and ADME prediction, were made to exploit the results.

Synthesis and Evaluation of 5-(o-Tolyl)-1H-tetrazole Derivatives as Potent Anticonvulsant Agents.

A series of 5-(o-tolyl)-1H-tetrazole derivatives were synthesized and evaluated for their anticonvulsant activities. 1-(2-Methylbenzyl)-5-(o-tolyl)-1H-tetrazole (3h) showed important anticonvulsant activity against the MES-induced seizures, as well as lower neurotoxicity with an ED50 value of 12.7 mg/kg and a TD50 value of over 500 mg/kg after intraperitoneal injection into mice, providing 3h with a high protective index (TD50 /ED50 ) of over 39.4. The achieved results prove that the distinctive compounds could be valuable as a model for future development, adaptation, and investigation to construct more active analogues.

[Study on Chemical Components of Tripterospermum chinense ( â ¡)].

Objective: To investigate the chemical components of Tripterospermum chinense. Methods: Various column chromatography were used in the isolation and purification,and physiochemical constant determination and spectral analysis were adopted to determine the chemical structures. Results: A novel monoterpenoid and seven known compounds were isolated and identified as tripterospermum acid ester A( 1),strychnovoline( 2),p-hydroxybenzaldehyde( 3),isovitexin( 4),7-O-rhamnopyransoyl-isoorientin( 5),trifoliside( 6),2″-O-rhamnopyransoyl-trifoliside( 7) and sweroside( 8). Conclusion: Compound 1 is a new monoterpenoid,compounds 2,3 are isolated from this plant for the first time.

[Chemical Constituents from Roots and Rhizome of Trillium tschonoskii( â £)].

Objective: To investigate the chemical constituents from the roots and rhizome of Trillium tschonoskii. Methods: The85% methanol elution parts from the roots and rhizome of Trillium tschonoskii were separated and purified by polyamide,silica gel,RPC18,Sephadex LH-20 column chromatography and the preparation of high performance liquid. Chemical structures were identified by MS,1D and 2D-NMR experiment. Results: Ten steroidal saponins compounds were isolated and identified as diosgenin-3-O-α-L-rhamnopyranosyl-( 1→4)-α-L-rhamnopyranosyl-( 1→4)-[α-L-rhamnopyranosyl( 1 →2) ]-ß-D-glucopyranoside( 1),trikamsteroside E( 2),deoxytrikamsteroside E( 3),( 23 S,24S,25S)-spirostan-5-ene-1ß,3ß,21,23,24-pentahydroxy-1ß-O-α-L-rhamnopyranosyl-( 1 →2)-[O-ß-D-xylopyranosyl( 1→3) ]-O-α-L-pyranarabinoside( 4),trikamsteroside B( 5),27-hydroxy-trikamsteroside B( 6),3-acetyl-pennogenin( 7),dioscoreanoside I( 8),sileneoside G( 9) and intergristerone B( 10). Conclusion: Compounds 8 ~ 10 are isolated from this genus for the first time,compounds 1,3,4,6,7 are isolated from this plant for the first time.

[Preliminary Study on the Detection of Pork Tenderness by Three-Dimensional Diffuse Reflectance Spectroscopy].

Tenderness is an important index to evaluate the pork's quality, in this paper a method called three-dimensional diffuse reflectance spectroscopy was proposed to detect pork tenderness. Because pork has a strong scattering impact on light, this method introduced more scattering information of pork samples into spectral analysis of tenderness. Using the special data acquisition system, three-dimensional diffuse reflectance spectra of 64 pork samples were constructed by collecting the emergent light signals of different distances away from the light incident point. And n-way partial least squares (NPLS) regression was applied to establish the calibration model between the pork tenderness and three-dimensional diffuse reflectance spectra which were denoised by wavelet transform. The determination coefficient of model for the calibration set (R2(Cal)) is 0.883 1, and the root mean squared error of calibration (RMSEC) is 3.685 0N. The determination coefficient of model for the prediction set (R2(Pred)) is 0.874 7, and the root mean squared error of prediction (RMSEP) is 3.975 6N. The result indicates that the NPLS model of pork tenderness built by three-dimensional diffuse reflectance spectra has higher calibration accuracy and prediction stability than the traditional diffuse reflectance spectra. Three-dimensional diffuse reflectance spectroscopy can be expected to be a new method to quickly detect the tenderness and the other qualities of pork.

[Chemical Constituents from Saururus chinensis].

OBJECTIVE: To investigate the chemical constituents of active components of Saururus chinensis on anti-nicotine withdrawal symptoms. METHODS: Various column chromatography were used in the isolation and purification, and physiochemical constant determination and spectral analysis were adopted to determine the chemical structures. RESULTS: Six chemical compounds were isolated from the active part of anti-withdrawal symptoms, and were identified as 4'-hydroxyl-3,3',4,5,5'-pentamethoxy-7,7'-epoxylignan (1) ,3-(2-nitroethyl)-1-methoxyindole(2), elemicin (3), erythro-(7R, 8S) - (-) - (3,4,5-trimethoxy-7-hydroxy-1'-allyl-3', 5'-dimethoxy)-8-O-4'-neolignan (4), 3,4,5-trimethoxy-phenylacrylaldehyde (5) and dibutyl phthalate (6). CONCLUSION: Compound 1 is a novel lignan, compounds 2 - 6 are firstly isolated from this plant.

[Study on Phenylpropanoids of Gardenia jasminoides].

OBJECTIVE: To investigate the phenylpropanoids constituents of Gardenia jasminoides. METHODS: Various column chromatography were used in the isolation and purification, physiochemical constant determination and spectral analysis were adopted to determine the chemical structures. RESULTS: Eight compounds were isolated from Gardenia jasminoides, including 4-hydroxy-cinnamic acid methylester (1), 3, 5-dimethoxy-4-hydroxy-cinnamic acid methylester (2), pisoninol II (3), 7-hydroxy-orebiusin A (4), (E) -3-(4'-hydroxyphenyl) -acrylic acid n-butyl ester (5), (E) -3-(4'-methoxyphenyl) -acrylic acid n-butyl ester (6), 4-methoxyl-phenylpropanol n-butyl ether (7) and cycloolivil (8). CONCLUSION: All compounds are firstly isolated from this plant.

[Phenylpropanoids constituents of Eucommia ulmoides leaves].

OBJECTIVE: To investigate phenylpropanoids constituents from Eucommia ulmoides leaves. METHODS: Various column chromatographic methods were used in isolation and purification. Physiochemical constant determination and spectral analysis were adopted to determine the chemical structures of phenylpropanoids. RESULTS: Nine phenylpropanoids were isolated and identified as caffeic acid (1), chlorogenic acid methylester (2), syringin (3), guaiacylglycerol (4), 5-methoxy-guaiacylglycerol (5), 5,9-dimethoxy-guaiacylglycerol (6), 9-n-butyl-guaiacylglycerol (7), 9-n-butyl-isoguaiacylglycerol (8), 8'-methoxy-olivil (9). CONCLUSION: Compounds 5 - 9 are isolated from this plant for the first time.

[Study on chemical constituents of iridoids from eucommiae folium].

OBJECTIVE: To investigate the chemical constituents of iridoids from Eucommiae Folium. METHODS: The compounds were isolated and purified by various column chromatography, the structures were identified on the basis of physiochemical properties and spectral analysis. RESULTS: Nine iridoids were isolated and identified as asperuloside (1), daphylloside (2), scandoside methyl ester (3), loganin (4), 8-epi-loganin (5), 7-epi-loganin (6), deacetyl asperulosidic acid methyl ester (7), geniposide (8) and geniposidic acid (9). CONCLUSION: Compounds 2 - 7 are isolated from this plant for the first time, compounds 4 - 6 are isolated from this genus for the first time.

[Study on chemical constituents of Gardenia jasminoides(III)].

OBJECTIVE: To investigate the chemical constituents of Gardenia jasminoides fruits. METHODS: Various column chromatography were used in the isolation and purification, and physiochemical constant determination and spectral analysis were adopted to determine the chemical structures. RESULTS: Twelve compounds were isolated from Gardenia jasminoides including jasminoside I (1), gardenoside (2), gardaloside (3), 3-hydroxy-urs-12-ene-11-ketone(4), 5, 4'-dihydroxyl-7, 3', 5'-trimethoxyflavone (5), 5, 7, 3', 4', 5'-pentamethoxyflavone(6), 3, 5, 6, 4'-tetrahydroxy-3', 5'-dimethoxyflavone (7), shikimic acid (8), 1, 2, 4-benzenetriol (9), 3, 4-dimethoxy-benzoic acid (10), dibutyl phthalate (11) and diisobutyl phthalate (12). CONCLUSION: Compounds 4 - 7 and 9 -10 were isolated from this plant for the first time.

[Study on chemical components of Tripterospermum chinense].

OBJECTIVE: To investigate the chemical components of the whole herb of Tripterospermum chinense. METHODS: Various column chromatography methods were used in the isolation and purification. Physio-chemical constant determination and spectral analysis were adopted to determine the chemical structures. RESULTS: Ten compounds were isolated and identified as 1, 7-dihydroxy-3,8-dimethoxyxanthone(1),1,3-dihydroxy-7,8-dimethoxyxanthone (2) 1,3,6,7-tetrahydroxyxanthone (3),1,8-dihydroxyxanthone(4),2'-deoxythymidine(5), 4-hydroxyphthalide(6),2,4-dihydroxy benzyl alcohol (7),2,5-dihydroxyphenetole (8), saponarin (9) and 4'-methoxysaponarin(10). CONCLUSION: Compounds 2 - 8 and 10 are isolated from this plant for the first time.

[Study on chemical constituents of Eucommia ulmoides leaves].

OBJECTIVE: To investigate the chemical constituents of Eucommia ulmoides leaves. METHODS: Various column chromatography were used in the isolation and purification, physiochemical constant determination and spectral analysis were adopted to determine the chemical structures. RESULTS: Ten compounds were isolated and identified as borreriagenin (1), n-butyl-O-ß-D-fructopyranoside (2), α-D-glucopyranosyl-(1-->1')-3'-amino-3'-deoxy-ß-D-glucopyranoside (3), ß-D-fructofuranosyl-α-D-galactopyranoside (4), ß-D-fructose (5), diisobutyl phthalate (6), 5-hydroxy-9-isopropylether-guaiacylglycerol (7), 4-hydroxyphenylethanol-8-O-ß-D-apiofuranosyl(1-->6)-ß-D-glucopyranoside (8), lariciresinol (9), and (3S,5R,6R,9S)-tetrahydroxy-7-ene-megastigmane (10). CONCLUSION: All compounds are isolated from this genus for the first time.

[Study on the chemical components of Gardenia jasminoides (II)].

OBJECTIVE: To investigate the chemical components of Gardenia jasminoides. METHODS: Various column chromatography were used in the isolation and purification, and physiochemical constant determination and spectral analysis were adopted to idenitify the chemical structures. RESULTS: Ten compounds were isolated and identified as jasminoside A(1), epijasminoside A(2), 6-O-methylscandoside methyl ester (3), 6-O-methyldeacetylasperulosidic acid methyl ester (4), gardenoside (5), phenylmethol (6), 4-hydroxy-phenylmethol-O-beta-D-glucopyranosyl- (1-->6) -beta-D-glucopyranoside (7), 3,4-dihydroxy-phenylmethol-O-beta-D-glucopyranosyl-(1-6)-beta-D-glucopyranoside (8), 3-hydroxy4-methoxy-phenylmethol-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (9), 3-hydroxy-4-methoxyphenylmethol-O-beta-D-glucopyranoside (10). CONCLUSION: Compounds 6 -10 are isolated from this plant for the first time.

[Study on the chemical components of Gardenia jasminoides].

OBJECTIVE: To investigate the chemical components of Gardenia jasminoides. METHODS: Various column chromatography were used in the isolation and purification. Physiochemical constant determination and spectral analysis were adopted to determine the chemical structures. RESULTS: Ten compounds were isolated and elucidated as syringic acid (1), syringaldehyde (2), vanillic acid (3), 3-hydroxy-vanillic acid (4), 3, 4, 5-trimethoxy-phenol (5), 4-hydroxy-3,5-dimethoxy-phenol (6), 4-methoxy-benzaldehyde (7), 7-hydroxy-5-methoxy-chromone (8), crocin-1 (9), crocin-2 (10). CONCLUSION: Compounds 2, 4 - 8 are first isolated from this plant.

Rapid quantitative detection of Brucella melitensis by a label-free impedance immunosensor based on a gold nanoparticle-modified screen-printed carbon electrode.

A rapid and simple method for quantitative monitoring of Brucella melitensis using electrochemical impedance spectroscopy (EIS) is reported for the first time. The label-free immunosensors were fabricated by immobilizing Brucella melitensis antibody on the surface of gold nanoparticle-modified screen-printed carbon electrodes (GNP-SPCEs). Cyclic voltammetry (CV) and EIS were used to characterize the Brucella melitensis antigen interaction on the surface of GNP-SPCEs with antibody. A general electronic equivalent model of an electrochemical cell was introduced for interpretation of the impedance components of the system. The results showed that the change in electron-transfer resistance (Rct) was significantly different due to the binding of Brucella melitensis cells. A linear relationship between the Rct variation and logarithmic value of the cell concentration was found from 4 × 10(4) to 4 × 10(6) CFU/mL in pure culture. The label-free impedance biosensor was able to detect as low as 1 × 10(4) and 4 × 10(5) CFU/mL of Brucella melitensis in pure culture and milk samples, respectively, in less than 1.5 h. Moreover, a good selectivity versus Escherichia coli O157:H7 and Staphylococcus aureus cells was obtained for our developed immunosensor demonstrating its specificity towards only Brucella melitensis.

[Study on chemical constituents in the roots and rhizome of Trillium tschonoskii (III)].

OBJECTIVE: To investigate the chemical constituents in the roots and rhizome of Trillium tschonoskii. METHODS: The roots and rhizome of Trillium tschonoskii were extracted with 70% ethanol and purified by polyamide, silica gel, RP-C18 and Sephadex LH-20 column chromatography. Chemical structures were identified by MS, 1D and 2D NMR experiments. RESULTS: Twelve compounds were isolated and identified from the ethyl acetate and n-butanol as 7,11-dimethyl-3-methylene-10, 11-dihdroxyl-1,6-dodecadien-diol(1),2, 6,10-trimethyl-2,10-dihdroxyl-6-dodecene-diol(2),3,7,11-trimethyl-3,9,11-trihydroxyl-1,6-dodecadiene-glycerol(3),p-hydroxymethyl-benzyl alcohol(4),20betaF, 22alphaF, 25alphaF-spirostan-5,13-ene-3beta,21alpha-diol(5), 2-methyl-3,4-dihydroxy-hexanedioic acid(6), alpha-Lrhamnopyranosyl(7), epitrillenogenin-24-O-acetate-1-O-[2,3,4,-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside] (8),epitrillenogenin-24-O-acetate-1-O-[2,4, -di-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside](9), epitrillenogenin1-O-[2,3,4,-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside] (10), epitrillenogenin-1-O-[2,4, -di-O-acetyl-alpha-Lrhamnopyranosyl-(1-->2) -alpha-L-arabinopyranoside] (11) and epitrillenogenin-1-O-[4-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2) -alpha-L-arabinopyranoside] (12). CONCLUSION: Compounds 4-6 are isolated from this genus for the first time, compounds 1-3, 11, 12 are isolated from this plant for the first time.

Compounds from the roots and rhizomes of Valeriana amurensis protect against neurotoxicity in PC12 cells.

Three new germacrane-type sesquiterpenoids, heishuixiecaoline A-C (compounds 1-3), were isolated along with ten known compounds 4-13 from fraction of Valeriana amurensis roots and rhizomes effective against Alzheimer's disease (AD). The structures of 1-3 were elucidated on the basis of their spectroscopic data. We also investigated the protective effect of compounds 1-13 on the neurotoxicity of PC12 cells induced by amyloid-beta (Aß(25-25)), respectively. As a result, germacrane-type sesquiterpenoids 1-4 and lignans 5-7 were seen to afford protection against Aß-induced toxicity in PC 12 cells. This study will contribute to revealing the chemical basis for the therapeutic effect of V. amurensis against AD.

[Influence of foliar dust on crop reflectance spectrum and nitrogen monitoring].

More researches were carried out to investigate the application of spectral technology on crop nutrition diagnosis. However, the complex conditions in the field results in the uncertainty of spectrum. In this paper, the influence of foliar dust on spectral of the crop beside the nation road was studied, the differences of the raw spectral reflectance and first derivative spectral reflectance between the foliar with dust and the foliar washed with deionised water were analyzed, nitrogen prediction models were built on the disturbance of foliar dust. Result showed that the dust foliar spectral reflectance increased in the visible light (350-720 nm) and shortwave infrared (SWIR) (1 360-2 500 nm) regions whereas the spectral reflectance in the near infrared (NIR) (720-1 360 nm) wavelength regions decreased. There were no change rules for blue edge position, yellow edge position, red edge position, blue edge slope and yellow edge slope on the effect of foliar dust, but red edge slope, blue edge area, yellow edge area, red edge area decreased. Determinate coefficient (R2) of nitrogen prediction models reduced in the condition of foliar dust. The primary research work about the condition of foliar dust was studied which helps to provide foundation for evaluating effect of foliar dust and proposing foliar dust modification model in the future.

[Study on recognition of the true or false red wine based on visible-near infrared spectroscopy].

This study selected 90 samples from different brands of red wine. In order to eliminate the impact of spectral curve's baseline, the first derivatives of all of spectral curves were calculated and the principal component analysis was carried out on the first derivative spectra. The result showed that the contribution rate of the first two principal components was over 80 percent. By the first two principal components, all the red wine samples were obviously divided into two classes. Furthermore a 3-layer artificial neural network predictive model was built with the first four principal components as input variables and 100 percent correct prediction rate was gained. The research showed that the visible-near infrared spectroscopy combined with principal component analysis provides an accurate and reliable new method to rapidly and nondestructively recognize the true or false red wines.