Yuan, Xingyi; Tan, Yanji; Wei, Xiaoping; Li, Jianping
A novel molecular imprinting electrochemiluminescence sensor for detecting chiral cinchonine molecules was developed with a molecularly imprinted polymer membrane on the surfaces of magnetic microspheres. Fe 3 O 4 @Au nanoparticles modified with 6-mercapto-beta-cyclodextrin were used as a carrier, cinchonine as a template molecule, methacrylic acid as a functional monomer and N,N'-methylenebisacrylamide as a cross-linking agent. Cinchonine was specifically recognized by the 6-mercapto-beta-cyclodextrin functional molecularly imprinted polymer and detected based on enhancement of the electrochemiluminescence intensity caused by the reaction of tertiary amino structures of cinchonine molecules with Ru(bpy) 3 2+ . Cinchonine concentrations of 1 × 10 -10 to 4 × 10 -7 mol/L showed a good linear relationship with changes of the electrochemiluminescence intensity, and the detection limit of the sensor was 3.13 × 10 -11 mol/L. The sensor has high sensitivity and selectivity, and is easy to renew. It was designed for detecting serum samples, with recovery rates of 98.2% to 107.6%. Copyright © 2017 John Wiley & Sons, Ltd.
Wang, Hui-Ting; Wu, Wen-Jie; Liu, Jiang; Chen, Meng; Qian, Dong-Jin; Zhang, Li; Liu, Minghua
We report here the synthesis and spectroscopic properties of two enantiomeric chiral tridentate ligands (TPyCCD and TPyCCN) composed of terpyridine (TPy) and cinchonidine (CCD) or cinchonine (CCN) substituent, as well as their metal complexes with Zn 2+ , Fe 2+ , Eu 3+ , and Tb 3+ ions. For the pure ligands, the fluorescent emission intensity increased as their concentrations increased in the dilute solutions, but they decreased when the concentrations were greater than 6.9×10 −6 mol/l due to concentration quenching. No significant influence on ligand luminescence was observed for the Zn 2+ /Fe 2+ –TPyCCD and –TPyCCN metal complexes. Their lanthanide (Eu 3+ and Tb 3+ ) complexes displayed both ligand and lanthanide ion emissions, suggesting that the excited energy of both ligands could be transferred to the central Eu 3+ and Tb 3+ ions. Mirror-image circular dichroism spectra were recorded, with several signals centered at about 230, 250–270, 296, and 320 nm; the first ones corresponded to the chiral CCD and CCN substituents, while the latter ones corresponded to the TPy substituent and the metal–TPy (M-TPy) coordination units. It is suggested that the chirality of TPy and the metal complexes was induced by the coexisting chiral CCD and CCN substituents. In addition, due to formation of the metal complexes, the relative intensity of the chiral signals of M–TPy coordination units was enhanced at about 320 nm. - Highlights: • Cinchona alkaloid-terpyridine derivatives and metal complexes were prepared. • Cinchona alkaloid-terpyridine derivatives gave off luminescence at 362 nm. • Ligand excited energy could efficiently transferred to lanthanide ions. • Chirality of terpyridine and metal complexes was induced.
Rapid and Green Analytical Method for the Determination of Quinoline Alkaloids from Cinchona succirubra Based on Microwave-Integrated Extraction and Leaching (MIEL Prior to High Performance Liquid Chromatography
Full Text Available Quinas contains several compounds, such as quinoline alkaloids, principally quinine, quinidine, cinchonine and cichonidine. Identified from barks of Cinchona, quinine is still commonly used to treat human malaria. Microwave-Integrated Extraction and Leaching (MIEL is proposed for the extraction of quinoline alkaloids from bark of Cinchona succirubra. The process is performed in four steps, which ensures complete, rapid and accurate extraction of the samples. Optimal conditions for extraction were obtained using a response surface methodology reached from a central composite design. The MIEL extraction has been compared with a conventional technique soxhlet extraction. The extracts of quinoline alkaloids from C. succirubra obtained by these two different methods were compared by HPLC. The extracts obtained by MIEL in 32 min were quantitatively (yield and qualitatively (quinine, quinidine, cinchonine, cinchonidine similar to those obtained by conventional Soxhlet extraction in 3 hours. MIEL is a green technology that serves as a good alternative for the extraction of Cinchona alkaloids.
Rapid and green analytical method for the determination of quinoline alkaloids from Cinchona succirubra based on Microwave-Integrated Extraction and Leaching (MIEL) prior to high performance liquid chromatography.
Fabiano-Tixier, Anne-Sylvie; Elomri, Abdelhakim; Blanckaert, Axelle; Seguin, Elisabeth; Petitcolas, Emmanuel; Chemat, Farid
Quinas contains several compounds, such as quinoline alkaloids, principally quinine, quinidine, cinchonine and cichonidine. Identified from barks of Cinchona, quinine is still commonly used to treat human malaria. Microwave-Integrated Extraction and Leaching (MIEL) is proposed for the extraction of quinoline alkaloids from bark of Cinchona succirubra. The process is performed in four steps, which ensures complete, rapid and accurate extraction of the samples. Optimal conditions for extraction were obtained using a response surface methodology reached from a central composite design. The MIEL extraction has been compared with a conventional technique soxhlet extraction. The extracts of quinoline alkaloids from C. succirubra obtained by these two different methods were compared by HPLC. The extracts obtained by MIEL in 32 min were quantitatively (yield) and qualitatively (quinine, quinidine, cinchonine, cinchonidine) similar to those obtained by conventional Soxhlet extraction in 3 hours. MIEL is a green technology that serves as a good alternative for the extraction of Cinchona alkaloids.
Zhang, Yu; Yu, Haixia; Wu, Yujiao; Zhao, Wenyan; Yang, Min; Jing, Huanwang; Chen, Anjia
In this paper, a new capillary electrophoresis (CE) separation and detection method was developed for the chiral separation of the four major Cinchona alkaloids (quinine/quinidine and cinchonine/cinchonidine) using hydroxypropyl-β-cyclodextrin (HP-β-CD) and chiral ionic liquid ([TBA][L-ASP]) as selectors. Separation parameters such as buffer concentrations, pH, HP-β-CD and chiral ionic liquid concentrations, capillary temperature, and separation voltage were investigated. After optimization of separation conditions, baseline separation of the three analytes (cinchonidine, quinine, cinchonine) was achieved in fewer than 7 min in ammonium acetate background electrolyte (pH 5.0) with the addition of HP-β-CD in a concentration of 40 mM and [TBA][L-ASP] of 14 mM, while the baseline separation of cinchonine and quinidine was not obtained. Therefore, the first-order derivative electropherogram was applied for resolving overlapping peaks. Regression equations revealed a good linear relationship between peak areas in first-order derivative electropherograms and concentrations of the two diastereomer pairs. The results not only indicated that the first-order derivative electropherogram was effective in determination of a low content component and of those not fully separated from adjacent ones, but also showed that the ionic liquid appeared to be a very promising chiral selector in CE. Copyright © 2014 Elsevier Inc. All rights reserved.
Full Text Available Cinchona alkaloids are in extensive uses, not only for drugs but also for soft drink industries. They are harvested from the bark of trees Cinchona spp. after certain ages and therefore are available over a limited time. Cell culture is an alternative way to continuously produce such secondary metabolites in a much shorter time. Various substances were added in the normal growth media to promote quinoline alkaloids production by cell cultures of Cinchona ledgeriana. At the sixth week of culture, quinine and cinchonine contents were suppressed by paclobutrazol (PBZ, abscisic acid (ABA, or even by precursor tryptophan, while cinchonidine content was enhanced by 0.2 mg/l tryptophan to 43 fold of that produced by untreated cells (2.8% dry weight. At the seventh week of culture, the production of quinine and quinidine started to grow whereas the production of cinchonine and cinchonidine tended to decrease. An addition of 5 mg/l PBZ to culture media yielded the highest level of total quinine/quinidine after seven weeks, e.g. quinine 11 times more abundant and quinidine 23 fold higher compared to the untreated cells. Particularly the level of quinine which is the most demanded for medical and industrial purposes still need to be improved to approach to or even higher than that of extracted from the conventional source.
Murauer, Adele; Ganzera, Markus
Chinoline alkaloids found in Cinchona bark still play an important role in medicine, for example as antimalarial and antiarrhythmic drugs. For the first time Supercritical Fluid Chromatography has been utilized for their separation. Six respective derivatives (dihydroquinidine, dihydroquinine, quinidine, quinine, cinchonine and cinchonidine) could be resolved in less than 7 min, and three of them quantified in crude plant extracts. The optimum stationary phase showed to be an Acquity UPC 2 Torus DEA 1.7 μm column, the mobile phase comprised of CO 2 , acetonitrile, methanol and diethylamine. Method validation confirmed that the procedure is selective, accurate (recovery rates from 97.2% to 103.7%), precise (intra-day ≤2.2%, inter-day ≤3.0%) and linear (R 2 ≥ 0.999); at 275 nm the observed detection limits were always below 2.5 μg/ml. In all of the samples analyzed cinchonine dominated (1.87%-2.30%), followed by quinine and cinchonidine. Their total content ranged from 4.75% to 5.20%. These values are in good agreement with published data, so that due to unmatched speed and environmental friendly character SFC is definitely an excellent alternative for the analysis of these important natural products. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.
Abbasi, M. A.; Hussain, G.; Rehman, A. U.; Shahwar, D.; Mohyuddin, A.; Ashraf, M.; Rahman, J.; Lodhi, M. A.; Khan, F. A.
In the present study, in vitro enzyme inhibitory studies on cinchonidine (1), cinchonine (2), quinine (3), noscapine (narcotine, 4) and santonine (5) were carried out. The various enzymes included in the study were lipoxygenase, xanthine oxidase, acetyl cholinesterase, butyryl cholinesterase and protease. The results revealed that 2, 3, and 4 were moderate active against lipoxygenase and xanthine oxidase enzymes. The molecule 3 possessed weak activity against butyryl cholinesterase enzyme while remaining molecules were inactive against this enzyme. However, all these compounds were inactive against acetyl cholinestrase and protease enzymes. The synthesized compounds were computationally docked into the active site of lipoxygenase enzyme. The compounds 3 and 4 showed decent interactions, hence strengthening the observed results. (author)
Hansen, Frederik André; Hansen, Steen Honoré; Petersen, Nickolaj J.
We have recently in our group at the University of Copenhagen developed a robust and simple sheatless CE-ESI-MS interface (capillary electrophoresis – electrospray ionization-mass spectrometry). In this presentation the interface is characterized and compared with HPLC-MS for studying...... a submicron fracture in the capillary close the ESI tip. The fracture provides a zero dead volume and excellent conducting properties due to the large amount of ions in the electric double layer. Electric current exceeding the upper limit of CE instrumentation of up to 300 µA can easily be obtained....... Furthermore, the increased conductivity of the buffer in the fracture generates field free pumping of the analytes towards the ESI spray tip. In this study the device was used to analyze the four major alkaloids (diastereomeric pairs of quinine/quinidine and cinchonine/cinchonidine) in Cinchona bark samples...
Zhang, Wen-Hua; Young, David J.
Naturally occurring molecules offer intricate structures and functionality that are the basis of modern medicinal chemistry, but are under-represented in materials science. Herein, we review recent literature describing the use of abundant and relatively inexpensive, natural products for the synthesis of ligands for luminescent organometallic complexes used for organic light emitting diodes (OLEDs) and related technologies. These ligands are prepared from the renewable starting materials caffeine, camphor, pinene and cinchonine and, with the exception of caffeine, impart performance improvements to the emissive metal complexes and resulting OLED devices, with emission wavelengths that span the visible spectrum from blue to red. The advantages of these biologically-derived molecules include improved solution processibility and phase homogeneity, brighter luminescence, higher quantum efficiencies and lower turn-on voltages. While nature has evolved these carbon-skeletons for specific purposes, they also offer some intriguing benefits in materials science and technology.
Saito, Morimasa; Yamada, Kei; Okochi, Haruno; Hirose, Fumio
Tungsten in high-alloy steels and heat-resisting alloys was determined by isotope dilution method combined with spark source mass spectrometry by using 183 W enriched tungsten. The spike solution was prepared by fusing tungsten trioxide in sodium carbonate. A high-alloy steel sample was dissolved in the mixture of sulfuric acid and phosphoric acid together with the spike solution; a sample of heat resisting alloy was similarly dissolved in the mixture of hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. The solution was evaporated to give dense white fumes. Tungsten was separated from the residue by a conventional cinchonine salt-precipitation method. The salt was ignited, and the residue was mixed with graphite powder and pressed into electrodes. The isotope 183 W and 184 W were measured. The method was applied to the determination of tungsten in JSS and NBS standard high-alloy steels and JAERI standard nickel- and NBS standard cobalt-base heat resisting alloys containing more than 0.05% tungsten. The results were obtained with satisfactory precision and accuracy. However, the results obtained for JSS standard high- speed steels containing molybdenum tended to be significantly lower than the certified values. (author)
Cai, Yong-Feng; Li, Li; Luo, Meng-Xian; Yang, Ke-Fang; Lai, Guo-Qiao; Jiang, Jian-Xiong; Xu, Li-Wen
A detailed experimental investigation of an aza-Michael reaction of aniline and chalcone is presented. A series of Cinchona alkaloid-derived organocatalysts with different functional groups were prepared and used in the aza-Michael and retro-aza-Michael reaction. There was an interesting finding that a complete reversal of stereoselectivity when a benzoyl group was introduced to the cinchonine and cinchonidine. The chirality amplification vs. time proceeds in the quinine-derived organocatalyst containing silicon-based bulky group, QN-TBS, -catalyzed aza-Michael reaction under solvent-free conditions. In addition, we have demonstrated for the first time that racemization was occurred in suitable solvents under mild conditions due to retro-aza-Michael reaction of the Michael adduct of aniline with chalcone. These indicate the equilibrium of retro-aza-Michael reaction and aza-Michael reaction produce the happening of chirality amplification in aza-Michael reaction and racemization via retro-aza-Michael reaction under different conditions, which would be beneficial to the development of novel chiral catalysts for the aza-Michael reactions. Copyright © 2011 Wiley-Liss, Inc.
Sundowo, Andini; Artanti, Nina; Hanafi, M.; Minarti, Primahana, Gian
C ledgeriana is a medicinal plant that contains alkaloids, especially on the barks for commercial production of quinine as antimalarial. The main alkaloids in this plant are cinchonine, cinchonidine, quinine and quinidine. Besides for antiamalarial this plant is also commonly used to treat whooping cough, influenza and dysentery. Compare to other medicinal plants, nowadays only very few studies were conducted in Cinchona species. Our current study aims to determine the content of phytochemical, total phenol and total flavonoids from C. ledgeriana leaves 70% ethanol extract. The extraction was performed by maceration method using 70% ethanol solvent and then fractionated into hexane, ethylacetate and butanol. Phytochemical screening was performed to determine the content of alkaloids, flavonoids, terpenoids, tannins and saponins. Total phenol and flavonoid contents of the extract were determined by Folin-Ciocalteu and alumunium chloride colorimetric methods using gallic acid and quercetin as standards. The antioxidant activity was determined by using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The results of phytochemical screening showed that the 70% ethanol extract of C. ledgeriana leaves contained alkaloids, flavonoids, terpenoids, tannins and saponins. The total phenol and total flavonoids analysis showed that ethyl acetate fraction had the highest total phenol (40.23%) and total flavonoids (65.34%).