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Chinese Journal of Chemistry 2023年第10期41卷 1191-1197页

作者： Linhua Xu Qishuai Li Dongwei Li Xin Zhou Ni Song Peng Wang Ming Li Molecular Synthesis Center Key Laboratory of Marine MedicineChinese Ministry of EducationSchool of Medicine and PharmacyOcean University of ChinaQingdaoShandong 266003China Laboratory for Marine Drugs and Bioproducts National Laboratory for Marine Science and TechnologyQingdaoShandong 266237China

A direct oxidative radical decarboxylative cyanomethylation of carboxylic acids is described using 3-azido-2-methylbut-3-en-2-ol as the carbon-centered radical acceptor.The transformation is applicable to structurally diverseα-amino acids,α-oxy acids,α-keto ac-ids,pentofuranuronic acids,and hexopyranuronic acids.The mechanistic investigations suggest that a radical process is involved in the transformation.This work provides a potential approach toβ-amino acid,5-deoxy-hexofuranose,and 6-deoxy-heptose con-structs of biological relevance.

关键词： cyanides Carboxylic acids Carbohydrates Radical decarboxylation Cyanomethylation

Unveiling anomalous lattice shrinkage induced by Pi-backbonding in Prussian blue analogues

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Journal of Energy Chemistry 2022年第7期31卷 121-128,I0004页

作者： Ju-Hyeon Lee Jin-Gyu Bae Hyeon Jeong Lee Ji Hoon Lee School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Department of Materials University of OxfordOxford OX13PHUnited Kingdom

Transition-metal(TM)-based Prussian blue and its analogues(TM-PBAs) have attracted considerable attention as cathode materials owing to their versatile ion storage capability with tunable working voltages. TM-PBAs with different crystal structures, morphologies, and TM combinations can exhibit excellent electrochemical properties because of their unique and robust host frameworks with well-defined ionic diffusion channels. Nonetheless, there is still a lack of understanding regarding the performance dependence of TM-PBAs on structural changes during charging/discharging processes. In this study, in situ X-ray diffraction and X-ray absorption fine structure analyses elucidate the TMdependent structural changes in a series of TM-PBAs during the charging and discharging processes.During the discharging process, the lattice volume of Fe-PBA increased while those of Ni-and Cu-PBAs decreased. This discrepancy is attributed to the extent of size reduction of the cyanometallate complex([Fe(CN)_(6)]) via pi-backbonding from Fe to C due to redox flips of the low-spin Fe^(3+/2+) ion. This study presents a comprehensive understanding of how TM selection affects capacity acquisition and phase transition in TM-PBAs, a promising class of cathode materials.

关键词： Prussian blue analogues X-ray diffraction X-ray absorption fine structure Pi-backdonation cyanides

Granular activated carbons from palm nut shells for gold di-cyanide adsorption

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International Journal of Minerals,Metallurgy and Materials 2013年第2期20卷 172-179页

作者： William K.Buah Paul T.Williams Energy Research Institute The University of LeedsLeeds LS2 9JTUnited Kingdom

Granular activated carbons were produced from palm nut shells by physical activation with steam. The proximate analysis of palm nut shells was investigated by thermogravimetric analysis, and the adsorption capacity of the activated carbons, produced as a result of shell pyrolysis at 600℃ followed by steam activation at 900℃ in varying activation times, was evaluated using nitrogen adsorption at 77 K. Applicability of the activated carbons for gold dicyanide adsorption was also investigated. Increasing the activation hold time with the attendant increase in the degree of carbon burn-off results in a progressive increase in the surface area of the activated carbons, reaching a value of 903.1 m2/g after activation for 6 h. The volumes of total pores, mieropores, and mesopores in the activated carbons also increase progressively with the increasing degree of carbon burn-off, resulting from increasing the activation hold time. The gold di-cyanide adsorption of the activated carbons increases with the rise of pore volume of the activated carbons. The gold di-cyanide adsorption of palm nut shell activated carbon obtained after 6-h activation at 900℃ is superior to that of a commercial activated carbon used for gold di-cyanide adsorption.

关键词： activated carbon adsorption gold cyanides processing pyrolysis

A phytochemical study on Dichocarpum auriculatum, an endangered medicinal plant peculiar to China

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Chinese Herbal Medicines 2019年第4期11卷 364-368页

作者： Pei Li Shuang-shuang Liu Qing Liu Jie Shen Chun-nian He Pei-gen Xiao Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine Ministry of EducationInstitute of Medicinal Plant DevelopmentChinese Academy of Medical SciencesPeking Union Medical CollegeBeijing 100193China

Objective:Dichocarpum auriculatum,an endangered perennial herb,is endemic to China and has been used as folk medicines for the treatment of cough,hepatitis,scrofula,and epilepsy.However,there is no phytochemical report on this herbal so far.For the resource development and protective importance of this endangered medicinal plant,a phytochemical study was undertaken.Methods:The chemical constituents were purified by silica gel column,Sephadex LH-20 column,and semi-preparative reversed phase HPLC.NMR and MS spectra were used for structural identification.Results:Thirteen compounds were isolated from D.auriculatum.Their structures were characterized as jatrorrhizine(1),berberine(2),steponine(3),magnoflorine(4),coclauril(5),menisdaurin(6),menisdaurilide(7),aquilegiolide(8),(6 R,9 S)-3-oxo-α-ionol-β-D-glucopyranoside(9),blumenol C glucoside(10),palmitic acid(11),dibutylphthalate(12),and auriculatum A(13).Conclusion:Compound 13 is a new diester terephthalate derivative.All the compounds are obtained from the genus Dichocarpum for the first time,and compounds 9 and 10 have potential chemotaxonomic significance to the genus Dichocarpum.

关键词： benzylisoquinoline alkaloids chemical constituents cyanides Dichocarpum auriculatum(Franch.)W.T Wang et Hsiao megastigmane glycosides

Recovery of Silver from Cyanide Solutions Using Electrochemical Process Like Alternative for Merrill-Crowe Process

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Materials Sciences and Applications 2014年第12期5卷 863-870页

作者： Víctor Vázquez José Parga Jesús L. Valenzuela Gabriela Figueroa Alejandro Valenzuela Guillermo Munive Department of Chemical Engineering and Metallurgy University of Sonora Hermosillo Mexico Department of Materials Science and Metallurgy Technological Institute of Saltillo Saltillo Mexico

The conventional processes for recovery of silver from cyanide leach solutions are the carbon adsorption, the Merrill-Crowe zinc dust cementation, the Ion Exchange, and Solvent Extraction processes;among other available options for recovery of precious metals from cyanide solutions, Electrocoagulation (EC) is a very promising electrochemical process that does not require high concentrations of silver in cyanide solutions to yield excellent results and neither pretreatment of cyanide solutions like Merrill-Crowe process (deoxygenating and clarification). The present study has been done for the recovery of silver contained in pregnant solution from the cyanidation process using the electrocoagulation technology with iron electrodes, and therefore develops an alternative technology for Merril-Crowe process. The average silver content in pregnant solution was of 52 ppm, recovery was obtained of 99% of silver, with this optimum operating parameters, pH = 8, residence time = 20 minutes and conductivity by addition of sodium chloride = 4 grs/L. Finally the characterization of the solid products formed during the EC process with X-ray Diffraction and Scanning Electronic Microscope was performed, results suggest that magnetite particles and amorphous iron oxyhydroxides are present (Lepidocrocite).

关键词： Electrochemical Process Silver cyanides Magnetic Fields Merrill-Crowe

Recovery of Gold and Silver and Removal of Copper, Zinc and Lead Ions in Pregnant and Barren Cyanide Solutions

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Materials Sciences and Applications 2015年第2期6卷 171-182页

作者： Gabriela Figueroa Jesus L. Valenzuela Jose R. Parga Victor Vazquez Alejandro Valenzuela Department of Chemical Engineering and Metallurgy University of Sonora Hermosillo Mexico Department of Materials Science Technological Institute of Saltillo Saltillo Mexico

Over the past decade the concern about toxic metals in freshwater has increased. Environmental laws such as the Clean Water Act have forced industries that produce metal containing wastewater to treat their wastewater prior to discharge. The purpose of this study was to investigate the use of a novel method for the minimization of heavy metals in the wastewater from the mining industry. A very promising electrochemical treatment technique that does not require chemical additions is electrocoagulation (EC) and sulphide precipitation. The present study has been done for the recovery of gold and silver contained in pregnant solution from the cyanidation process using the electrocoagulation technology with iron electrodes;that is a developed alternative technology for the Merril-Crowe process. The average gold and silver content in pregnant solution was 4.27 and 283 ppm respectively and the recoveries were 92% for gold and 95% for silver, with optimum operating parameters of pH 10, residence time of 20 minutes and addition of sodium chloride of 4 gr/L. The results of precipitation process show that the elimination of lead, zinc, cooper and iron ions from the barren solution was successful, with optimum operating parameters of pH 3 and residence time of 15 minutes, and the recoveries were 99% of these ions. Finally the characterization of the solid products of gold and silver formed during the EC process with Scanning Electronic Microscope was performed. Results suggest that magnetite particles and amorphous iron oxyhydroxides (lepidocrocite) were present.

关键词： Electrochemical Process Precipitation Process Gold and Silver cyanides

Cassava Flour: Quantification of Cyanide Content

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Food and Nutrition Sciences 2016年第7期7卷 592-599页

作者： André Rinaldi Fukushima Maria Aparecida Nicoletti Almir Junior Rodrigues Caroline Pressutti Jeandro Almeida Tamires Brandão Rosilene Kinue Ito Luis Antônio Bafille Leoni Helenice De Souza Spinosa USJT-Pharmacy Course Universidade S&#227o Judas Tadeu Campus Capital S&#227o Paulo Brazil FMVZ-School of Veterinary Medicine and Animal Science Universidade de S&#227o Paulo Campus Capital S&#227o Paulo Brazil Pharmacy Course Universidade Guarulhos-Ser Educacional Campus Centro S&#227o Paulo Brazi Departamento de Farmácia Faculdade de Ciências Farmacêuticas Universidade de S&#227o Paulo Campus Capital S&#227o Paulo Brazil

Cassava flours are obtained from the roots of Manihot esculenta Crantz and daily fairly consumed by the Brazilian population considering it comes to hum food, and also inserted into food baskets, besides to present low cost and easy access, in addition to being plant easily cultivated by the population. However, the food obtained with cassava may contain hydrocyanic acid, in the form of cyanogenic glycoside when those meals are not cooked properly. The oral toxicity can range 30 - 210 mg/kg body, the average daily consumption per capita in larger rural areas than in urban areas for cassava flour 19.1 g against 4.7 g, respectively. Brazil’s North and Northeast have higher consumption of cassava flour, associated with family monthly monetary income, making this region more vulnerable to poisoning. The objective of this study was to quantify cyanogenic glycosides present in some types of Brazilian cassava foods by means of spectrophotometric technique (reading at a wavelength of 530 nm). For quantitative determination of cyanide content, linamarase hydrolysis was used. The amount of cyanide was determined, and results were: artisan toasted cassava flour: 15 mg/500g, sweet cassava starch: 32.5 mg/500g, artisan dried cassava flour: 37.5 mg/500g, “bijuzada” cassava flour: 60 mg/500g, industrialized, toasted cassava flour: 115 mg/500g, industrialized, raw cassava flour: 140 mg/500g, and wet cassava flour: 225 mg/500g. Considering the chronic ingestion of cyanide present in these foods, they can cause public health problems.

关键词： Manihot esculenta Crantz Manihot Flour cyanides Toxicity Spectrophotometry Konigi Method