The Experts below are selected from a list of 9 Experts worldwide ranked by ideXlab platform
W. A. Creasey - One of the best experts on this subject based on the ideXlab platform.
-
Short Communication BIOCHEMICAL EFFECTS OF VINDESINE
2013Co-Authors: W. A. CreaseyAbstract:is a semisynthetic derivative of the Vinca alkaloid group that may be prepared from vinblastine or desacetylvinblastine (Barnett et al., 1978). As a result of its activity against a range of experimental tumours, the alkaloid has been introduced into the clinic, where useful therapeutic results have been obtained; its clinical toxicity includes both neurological impairment of the type seen during treatment with vincristine, and marrow depression like that produced by vinblastine (Dyke & Nelson, 1977). The pharmacokinetic pattern of vindesine in humans closely resembles that of vinblastine, and both are cleared more rapidly than vincristine (Owellen et al., 1977). Vindesine interacts with tubulin and inhibits its polymerization (Owellen et al., 1976), but no studies have yet been made to determine whether the drug interferes with the other biochemical pathways known to be affected by vinblastine, vincristine and Vinleurosine (Creasey, 1979). The present study demonstrates that vindesine does indeed have the capacity to inhibit major biochemical pathways. Sarcoma 180 (S180) cells in the ascites form were maintained in adult Swiss mice (CD-1) and harvested 4-6 days after i.p. inoculation. Erythrocytes were lysed with hypotonic saline and the washed tumour cells resuspended in Krebs phosphate buffer (containing in 125 ml: 0-86 g NaCl; 0-046 g KCI; 0 0073 g CaC12; 0-076
Muhammad Nizammul Hayad Bin Yahya - One of the best experts on this subject based on the ideXlab platform.
-
Characterisation of Silver Nanoparticles using a Standardised Catharanthus Roseus Aqueous extract
Malaysian Journal of Medicine and Health Sciences Universiti Putra Malaysia, 2017Co-Authors: Muhammad Nizammul Hayad Bin YahyaAbstract:The biosynthesis of nanoparticles has been proposed as a cost-effective and environmental friendly alternative to chemical and physical methods. The present study was aimed to characterise Catharanthus roseus (C. roseus)-silver nanoparticles (AgNPs) using a standardised C. roseus aqueous extract. Methods: The standardisation was performed by using Liquid Chromatography/Time-of-Flight ion trap Mass Spectrometry. An optimised C. roseus-AgNPs have been previously synthesised. Further characterisation of C. roseus-AgNPs was evaluated by zeta potential analysis and fourier transform infrared spectroscopy (FTIR). Results: The chromatography analysis has revealed presence of thirteen possible indole alkaloids in C. roseus extract which were lochrovicine, lochnerine, Vinleurosine, vindolinine, tabersonine, catharanthine, serpentine, catharosine, vincristine, catharine, ajmalicine, Vinleurosine, and vindolicine. Zeta potential analysis exhibited the value at -16.6 mV. FTIR spectrum of C. roseus aqueous extract showed the absorption band at 3210.83 cm-1 (C-H stretch), 2934.11 (C-H bond), 1578.15 (N=O stretch), 1388.76 and 1314.89 (N=O bend), 1119.29 (C-O bond) and 729.94 (C-Cl bond). In comparison, FTIR spectrum of C. roseus-AgNP s showed the absorption band at 2925.01 and 2924.97 (C-H bond), 1622.93 (C-C=C symmetric stretch), 1383.19 and 1384.13 (N-O bend), 1037.92/1038.76/1238.3/1117.2 (C-O bond), 3169.4 (O-H bond), 774.59 and 691.53 (C-Cl bond). Conclusion: The present findings have shown that the C. roseus aqueous extract contains alkaloids that may responsible as reducing and stabilising agents in the synthesis of AgNPs
Zilin Chen - One of the best experts on this subject based on the ideXlab platform.
-
Identification and quantification of active alkaloids in Catharanthus roseus by liquid chromatography-ion trap mass spectrometry.
Food Chemistry, 2013Co-Authors: Qinhua Chen, Wenpeng Zhang, Yulin Zhang, Jing Chen, Zilin ChenAbstract:Catharanthus roseus is an important dicotyledonous medicinal plant that produces anticancer compounds. The active alkaloids vinblastine, vindoline, ajmalicine, catharanthine, and Vinleurosine were identified by direct-injection ion trap-mass spectrometry (IT-MS) for collecting MS(1-2) spectra. The determinations of five alkaloids were accomplished by liquid chromatography (LC) with UV and MS detections. The analytes provided good signals corresponding to the protonated molecular ions [M+H](+) and product ions. The precursor ions and product ions for quantification of vinblastine, vindoline, ajmalicine, catharanthine, and Vinleurosine were m/z 825→807, 457→397, 353→144, 337→144 and 809→748 by LC-IT-MS, respectively. Two methods were used to evaluate a number of validation characteristics (repeatability, LOD, calibration range, and recovery). MS provided a high selectivity and sensitivity for determination of five alkaloids in positive mode. After optimisation of the methods, separation, identification and quantification of the five components in C. roseus were comprehensively accomplished by HPLC with UV and MS detection.
Qinhua Chen - One of the best experts on this subject based on the ideXlab platform.
-
Identification and quantification of active alkaloids in Catharanthus roseus by liquid chromatography-ion trap mass spectrometry.
Food Chemistry, 2013Co-Authors: Qinhua Chen, Wenpeng Zhang, Yulin Zhang, Jing Chen, Zilin ChenAbstract:Catharanthus roseus is an important dicotyledonous medicinal plant that produces anticancer compounds. The active alkaloids vinblastine, vindoline, ajmalicine, catharanthine, and Vinleurosine were identified by direct-injection ion trap-mass spectrometry (IT-MS) for collecting MS(1-2) spectra. The determinations of five alkaloids were accomplished by liquid chromatography (LC) with UV and MS detections. The analytes provided good signals corresponding to the protonated molecular ions [M+H](+) and product ions. The precursor ions and product ions for quantification of vinblastine, vindoline, ajmalicine, catharanthine, and Vinleurosine were m/z 825→807, 457→397, 353→144, 337→144 and 809→748 by LC-IT-MS, respectively. Two methods were used to evaluate a number of validation characteristics (repeatability, LOD, calibration range, and recovery). MS provided a high selectivity and sensitivity for determination of five alkaloids in positive mode. After optimisation of the methods, separation, identification and quantification of the five components in C. roseus were comprehensively accomplished by HPLC with UV and MS detection.
Wenpeng Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Identification and quantification of active alkaloids in Catharanthus roseus by liquid chromatography-ion trap mass spectrometry.
Food Chemistry, 2013Co-Authors: Qinhua Chen, Wenpeng Zhang, Yulin Zhang, Jing Chen, Zilin ChenAbstract:Catharanthus roseus is an important dicotyledonous medicinal plant that produces anticancer compounds. The active alkaloids vinblastine, vindoline, ajmalicine, catharanthine, and Vinleurosine were identified by direct-injection ion trap-mass spectrometry (IT-MS) for collecting MS(1-2) spectra. The determinations of five alkaloids were accomplished by liquid chromatography (LC) with UV and MS detections. The analytes provided good signals corresponding to the protonated molecular ions [M+H](+) and product ions. The precursor ions and product ions for quantification of vinblastine, vindoline, ajmalicine, catharanthine, and Vinleurosine were m/z 825→807, 457→397, 353→144, 337→144 and 809→748 by LC-IT-MS, respectively. Two methods were used to evaluate a number of validation characteristics (repeatability, LOD, calibration range, and recovery). MS provided a high selectivity and sensitivity for determination of five alkaloids in positive mode. After optimisation of the methods, separation, identification and quantification of the five components in C. roseus were comprehensively accomplished by HPLC with UV and MS detection.