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Characterization and Quantification of Phenolic Compounds of Hydroethanolic Extracts and Fractions of Leaves Gnetum africanum (Welv.) and Gnetum buchholzianum (Engl.) (Gnetaceae)

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Open Journal of Applied Sciences 2022年第7期12卷 1304-1318页

作者： Bertin Sone Enone Gisèle Marie-Marguerite Etame-Loe Charles Christian Ngoule Jean-Pierre Ngene Juliette Koube Lahngong Methodius Shinyuy Simone Véronique Fannang Moïse Henri Julien Nko’o Jean Baptiste Hzounda Fokou Hans Denis Bamal Celestine Magne Valdi Steve Djova Wilfred Ndogmo Tekapi Sandrine Sikadeu Josiane Etang Albert Mouelle Sone Laboratory of Microbiology Immunology-Hematology and Morphological Sciences Doctoral Training Unit in Health Sciences Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Department of Pharmaceutical Sciences Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Department of Microbiology University of Yaounde I Yaounde Cameroon Chemistry Laboratory Faculty of Sciences University of Douala Douala Cameroon Department of Biology and plant Organisms Faculty of Science Douala Cameroon

Research for bioactive molecules and not resistant to infectious agents remains topical for science. The total polyphenols (TPP) and total flavonoids (TFv) of the hydroethanolic extracts and fractions obtained were quantified according to the spectrophotometric method described in the literature using the Folin-Ciocalteu reagent and the colorless solutions of sodium nitrite 2.5% and aluminum chloride 10% respectively. The characterization of chemical compounds was made by coupling liquid chromatography (LC) and mass spectroscopy (MS). Thus, 15 chemical compounds were characterized, seven from Gnetum africanum (EBa) and eight from Gnetum buchholzianum (EBb). The majority of which were stilbens, such as Gnetupendin D, Dimethoxygnetulin, Methoxyparvifolol D, Isorhaponcitin from Eba and Gnetuhaidin P, Gnetupendin D, Gnetuhainin C, phenols (Alcohol Homovanillyl, Alcohol Erythro guaiacylglycerol-β-O-4'-coniferyl, and Alcohol Homovanillyl from EBb. The minority were flavonoids such as Dimethoxydihydropyraneriodictyol, Dimethoxyeriodictyol (EBa) and Dimethoxydihydropyraneriodictyol, Trimethoxyluteolin (EBb). The levels of total polyphenolics and total flavonoids content were respectively 14.520 ± 0.557 mg EAA/g Extract and 29.870 ± 2.485 mg EQ/g Extract for EBa. The levels of total polyphenolics and total flavonoids content for EBb were respectively 4.560 ± 0.010 mg EAA/g Extract and 2.233 ± 0.251 mg EQ/g Extract. The high levels of flavonoids content respectively 220.200 ± 35.500 and 335.300 ± 57.810 mg EQ/g Extract were shown in Dichlorometan fraction from EBa and EBb. These bioactive compounds identified and total phenolics compounds quantified can be exploited in pharmacological and pharmacokinetical activities to fight against multi-resistant infectious agents and as well as oxidative stress and antiinflammatory diseases.

关键词： Gnetum africanum Gnetum buchholzianum Phenolic Compounds liquid chromatography Mass Spectroscopy

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Physico-Chemicals Characterization of Quercetin from the <i>Carica papaya</i>Leaves by Different Extraction Techniques

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Open Journal of Physical Chemistry 2021年第3期11卷 129-143页

作者： Muhammad Hidhir Khawory Mohd Ferdaues Mohd Subki Mohd Anuar Shahudin Nurul Hidayatul Afifah Saufi Sofian Nur Hidayah Latif Nurul Hanim Salin Siti Zuraidah Mohamad Zobir Mohamed Ibrahim Noordin Malaysian Institute of Pharmaceutical and Nutraceutical (IPharm) Pulau Pinang Malaysia National Institutes of Biotechnology Malaysia (NIBM) Selangor Malaysia PICOMS International University College Kuala Lumpur Malaysia

Carica papaya leaf extracts from four different extraction methods (cold-water, hot-water, sonication and supercritical fluid), were characterized using physico-chemical analysis. Sonication extraction showed the highest percentage yield of crude extracts (6.76%) and the lowest from the supercritical fluid extraction (1.83%). The Infrared (IR) spectrum of cold-water extract demonstrated the most similarity of functional group to quercetin. Likewise, the thermal analysis indicated that cold-water extract gave a quite similar Endothermic peak to quercetin with the obtained value which was 137°C and onset value which was 118°C. The liquid chromatography (LC) profile indicated that only the cold-water extract exhibited 0.203 ppm of quercetin.

关键词： Carica papaya Extraction Infrared liquid chromatography Thermal Analysis

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Study on the Adsorption of Preservatives by Eyeliner Pen Packaging Materials

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China Detergent & Cosmetics 2022年第2期7卷 68-72页

作者： Liu Li Gong Hui JALA(group)Co.Ltd. China

In order to study adsorption of preservatives by eyeliner pen package,the chemical compositions of the commercially available Eyeliner package were analyzed by infrared *** was found that these package components were PP,PET,modified PP,modified PET,ABS,nylon,PU and so *** adsorption effects of these components on three preservatives,***,Methyl paraben and Propyl paraben have been further studied by high performance liquid *** results demonstrated that the four chemical materials PET,PP,modified PP and ABS had no adsorption on the above three ***,the component named of water diversion core which was composed of modified PET,and nylon-made cotton head have been observed of slight adsorption in this *** components as the function of preventing liquid leakage,which was made of PU,have presented the most serious adsorption on these three preservatives,with the adsorption order as Propyl Paraben>Methyl Paraben>phenoxyethanol.

关键词： eyeliner pen packing material preservative Infra-red spectrometry liquid chromatography adsorption

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Residue of Thiacloprid in Soil and Rice

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Plant Diseases and Pests 2010年第4期1卷 54-57页

作者：侯志广刘丽丹殷丽丹陈超逯忠斌谢文明吉林农业大学资源与环境学院吉林长春130118

[ Objective] Residue condition of thiacloprid in soil and rice was studied. [ Method] The residue decline of 480 g/L thiacloprid SC in rice soil and the final residue in rice was studied through crop field trials and liquid chromatography analysis. [ Result] Crop field trials in Jilin, Hunan and Guangdong during two years showed that the half-life of thiaclopdd in rice soil was 0.1 -0.5 d when application concentration was 315 g/hm^2. Under the dose condition with effective components of 315 and 210 g/hm^2, when insecticide was sprayed for 2 -3 times, the final residue in rice husk was lower than 7.830 mg/kg, the final residue in brown rice was less than 0.1 mg/kg. [ Conclusion] Take multiple factors into consideration, according to the recommended application dose of 210 g/hm^2, MRL value of thiacloprid in rice could be tentatively ascertained as 0.1 mg/kg, the preharvest interval was 7 d. aDolication frequencv was no more than two times.

关键词： Thiacloprid Rice Residual decline liquid chromatography

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Validation of a HPLC Method for Determination of Glutamine in Food Additives Using Post-Column Derivatization

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American Journal of Analytical Chemistry 2012年第2期3卷 113-117页

作者： Marlus Chorilli Herida Regina Nunes Salgado Fabiana De Santana Santos Lucelia Magalhaes Da Silva Departamento de Farmacos e Medicamentos Faculdade de Ciencias Farmaceuticas de AraraquaraUniversidade Estadual Paulista(UNESP)AraraquaraBrazil Faculdade de Americana AmericanaBrazil Programa de Pos-Graduacao em Ciencias Farmaceuticas Faculdade de Ciencias Farmaceuticas de AraraquaraUniversidade Estadual Paulista(UNESP)AraraquaraBrazil

An ion-exchange chromatography (IEC) followed by post-column derivatization method was validated for the determination of glutamine in food additive products. The chromatographic method was carried out on a sodium cation-exchange column and using detection at 570 nm. The mobile phase consisted of sodium eluant, pH 3.15, with 5% sulfolane, sodium eluant, pH 7.40 and sodium column regenerant. The method was linear in the range of 4 - 50 μg/mL (r2 = 0.9999). The accuracy was 99.78%. Moreover, method validation demonstrated acceptable results for precision and robustness. The method was found to be able to use for routine analysis of the glutamine.

关键词： Glutamine Food Additive Product liquid chromatography

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Quantitative Determination of Sphingolipids by HPLC-ESI/MSn

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Agricultural Biotechnology 2022年第5期11卷 134-135,139页

作者： Jin XIE Rong SONG Li ZHOU Siwen PENG Yanning HUANG Xiaoqi ZHU Institute of Agricultural and Biological Resources Utilization Hunan Academy of Agricultural SciencesChangsha 430100China

The most predominant sphingoilipids bases are phytosphingosine(phyto-sph) and phytosphingosine-1-phosphate(phyto-S1 P), followed by dihydrosphingosine(dh-sph) and dihydroshingosine-1-phosphate(dh-S1 P). In this study, a fast, sensitive and selective method for determining those four of sphingolipids by high performance liquid chromatography coupled to electrospray ionization ion trap mass spectrometry was introduced. Comparing two methods, method B’s recovery was better than method A. And the limit of detection(LOD) was between 0.003 to 0.013 μM for 20 μl injection.

关键词： Sphingoilipids liquid chromatography Mass spectrometry

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β-Cyclodextrin/silica Hybrid Spheres as Chiral Stationary Phases for Multiseparation Functions in Broad pH Range

β-Cyclodextrin/silica Hybrid Spheres as Chiral Stationary P...

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中国化学会第十三届全国分析化学年会

作者： Litao Wang Mei Lv Jie Gao Yaqi Wu Qinqin Yang Yanan Liu Yue Li School of Pharmacy Jining Medical University

A kind of β-CD-silica hybrid spheres, as new type of HPLC multifunctional chiral stationary phases, have been successfully prepared by organic-inorganic hybrid polycondensation of β-CD-silica derivatives and 1,2-Bis（triethoxysilyl）ethane under the hydrothermal conditions. β-CD-silica derivatives were bonded and distributed on the surface of the pore channels by propyl carbamate group as linkers and the ethane-silica based support were built into the organic-inorganic hybrid pore wall framework of mesoporous material. The characterization results indicate that the material possesses spherical shape, uniform size, high specific surface area and proper pore size. The multifunctional separation properties of β-CD-silica hybrid spheres were evaluated under the normal phase and reversed phase, which showed multifunctional chiral resolution and achiral separations. More importantly, the enantioseparation of the hybrid spheres was performed under the board pH at 1-10 range. Besides, the propyl carbamate as shorter linker has the more excellent characteristics of enantioseparation.

关键词： Hybrid Spheres Cyclodextrins Multifunctional separations Chiral resolution liquid chromatography

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Growth processes and crystallographic properties of nanographenes synthesized employing in-liquid plasma

Growth processes and crystallographic properties of nanograp...

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第三届微电子及等离子体技术国际会议

作者： Hiroki Kondo Tatsuya Hagino Kenji Ishikawa Keigo Takeda Hiroyuki Kano Makoto Sekine Masaru Hori Department of electrical engineering and computer science graduate school of engineeringNagoya University Plasma nanotechnology research center graduate school of engineeringNagoya University

Nanographene materials have attracted much attention as their unique structures,interesting properties,and promising device ***,we established a high-speed synthesis technique of nanographene employing alcohols and in-liquid plasma,and confirm high crystallinity of synthesized *** this study,growth processes and mechanisms of nanographenes are *** this method,one Ni electrode was immersed into an ethanol,and the other was fixed above the ethanol level at gaseous Ar *** a 9 kV and 60 Hz ac-power to these electrodes,the in-liquid plasma was *** the plasma discharge for 20 minutes,it was found that black-colored nanographenes with a size of microns were dispersed in the *** black substances and yellow-colored extraction liquid were separated by *** sharp G-band peaks at 1581 cm-1 in Raman spectra and the interlayer spacing（3.33 A） between graphite basal planes observed in the transmission electron microscopy（TEM） images revealed the high-crystallinity of synthesized *** the crystallographic properties were not significantly changed owing to the kinds of alcohols and electrode *** the other hand,according to the liquid chromatography analysis,various types of aromatic hydrocarbons were generated in the *** results indicate that the in-liquid plasma discharge induce the dissolution of alcoholic molecules and generation of aromatic hydrocarbons as elementary steps of nanographene ***,the polymerization of the aromatic hydrocarbons results in the nanographene *** results will open the way to further development of high-speed synthesis and precise control of crystallographic properties.

关键词： Nanographene In-liquid plasma transmission electron microscopy Raman spectroscopy liquid chromatography

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liquid Chromatographic Resolution of Racemic ?-Amino Acids,Amines and Amino Alcohols on Two New Improved Chiral Crown Ether Stationary Phases

Liquid Chromatographic Resolution of Racemic ?-Amino Acids,A...

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第21届全国色谱学术报告会及仪器展览会

作者： Song Yanxi Li Hongqi Hyun Myung Ho Cho Yoon Jae School of Environmental Science and Engineering Donghua University College of Chemistry Chemical Engineering & BiotechnologyDonghua University Pusan National University

Two doubly tethered aminoalkyl chiral crown ether stationary phases were prepared by covalently bonding（+）-（18-crown-6）-2,3,11,12-tetracarboxylic acid to doubly tethered aminoalkyl silica gel in order to improve the stability and the enantioselectivity of chiral stationary phases（CSPs） based on（+）-（18-crown-6）-2,3,11,12-tetracarboxylic acid developed previously in our lab. The chiral recognition behavior of the new CSPs was investigated by using racemic primary amino compounds with the variation of the type and content of organic and acidic modifiers in mobile phase and the column temperature. The stability of the CSPs was examined. The results revealed that the new CSPs were more effective in resolving various racemic ?-Amino Acids, Amines and Amino Alcohols than the original ones. Meanwhile, the CSPs showed excellent stability after a month of use.

关键词： Chiral stationary phase Crown ether Enantiomer separation liquid chromatography

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Drug Enantiomer Differenciation Using Cyclodextrin Sensitized Separation/Sensing platforms

Drug Enantiomer Differenciation Using Cyclodextrin Sensitize...

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2018年中国质谱学术大会（CMSC2018）

作者： Yong Wang Tianjin Key Laboratory of Molecular Optoelectronic Science Department of ChemistrySchool of ScienceTianjin University Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)

Differentiation of chiral drug enantiomers is important due to their different even opposite bioactivities in human body. A variety of highly sensitive and efficient analytical methods have been developed for the past few years for enantioselective recognition. However, enantiomer differeciation is still a great challenge in modern-day pharmaceutical industry. Cyclodextrin(CD) is a natural cyclic oligosaccharide formed by linking D-glucopyranose units with α-1,4 glycosidic linkages, which can act the "host"to selectively bind various organic, inorganic, or biological molecules. Therefore they have been widely used in separation, water treatment, drug delivery and sensing. The current work focuses on the design and preparation of novel CD-based novel chiral separation/sensing platforms for fast and effective enantiomer differenciation. Various novel functional CD derivatives were synthesized and immobilized onto solid supports via chemical bonding or physical coating manners with unique techniques. The separation/sensing materials were fully characterized and applied in chromatography or field effect transistor for effective chiral separation or sensing.

关键词： Cyclodextrin Enantioseparation liquid chromatography Field Effect Transistor

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