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1.
Sensitive, rapid, and simple spectrophotometric methods were developed for determination of the anticancer drugs vinblastine sulfate (VBS) and vincristine sulfate (VCS), which belong to the class of vinca alkaloids. The first method is based on the reaction of VBS and VCS with diazotized dapsone, forming yellow azo products with absorption maxima at 430 nm. The colored species obey Beer's law in the concentration range of 0.5-24 microg/mL for VBS and 0.5-12 microg/mL for VCS. The second method describes the reaction of VBS and VCS with iron(III) and subsequent reaction with ferricyanide in hydrochloric acid medium to yield blue products with absorption maxima at 750 nm. The Beer's law range for this method is 0.1-4 microg/mL for VBS and 0.5-10 microg/mL for VCS. With both methods, colored species were stable for 1 h. The methods are simple and reproducible and are applied for determination of VBS and VCS in pharmaceutical formulations. Commonly encountered pharmaceuticals added as excipients do not interfere in the analysis and the results obtained in the analysis of dosage forms agree well with the labeled contents. 相似文献
2.
The reaction of gaseous H2S with aqueous ammonium heptamolybdate in the presence of triethylenetetramine (trien) gave a red complex. The complex was recrystallized in hot water and characterized by element analysis and UV, visible, IR, and 1H NMR spectroscopy. PMR has revealed accidental magnetic equivalence, resulting from the proximity of [MoS4]2- species in one complex molecule to the open triethylenetetramine ligand of another molecule. (TrienH2)[MoS4] crystallizes in the orthorhombic crystal system, space group Pca21, a=13.045(2), b=16.461(3), c=13.754(2) , =90, =90, =90°, V=2953.5(9) 3, Z=8, R1=0.0323, wR2=0.0730. The structure consists of the tetrahedral tetrathiomolybdate anions, forming an extended 3D framework in solids due to the interactions with triene cations via Mo-S...H-N hydrogen bonds. 相似文献
3.
A sensitive, rapid, and simple spectrophotometric method is described for the determination of sulfa drugs. The method is based on the formation of a red-colored product by the diazotization of sulfonamides such as sulfathiazole (SFT), sulfadiazine (SFD), sulfacetamide (SFA), sulfamethoxazole (SFMx), sulfamerazine (SFMr), sulfaguanidine (SFG), and sulfamethazine (SFMt), followed by complexation with dopamine in the presence of molybdate ions in (1 + 1) H2SO4 medium. Absorbance of the resulting red product is measured at 490-510 nm, and the product is stable for 2 days at 27 degrees C. Beer's law is obeyed in the concentration range of 0.04-8.0 microg/mL at the wavelength of maximum absorption. The method was used successfully for the determination of some sulfonamides in tablets and eye drops. Common excipients used as additives in pharmaceuticals do not interfere in the proposed method. The method offers the advantages of simplicity, rapidity, and sensitivity without the need for extraction or heating. The limits of detection and quantitation were calculated for SFT, SFD, SFA, SFMx, SFMr, SFG, and SFMt. 相似文献
4.
T. Vijay T. Narasimhamurthy H. S. Yathirajan R. S. Rathore P. Nagaraja 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(1):o36-o38
In the crystal structure of the title salt, C7H7Cl2N2O2+·Cl−, the chloride anions participate in extensive hydrogen bonding with the aminium cations and indirectly link the molecules through multiple N+—H⋯Cl− salt bridges. There are two independent molecules in the asymmetric unit, related by a pseudo‐inversion center. The direct intermolecular coupling is established by C—H⋯O, C—H⋯Cl and C—Cl⋯Cl− interactions. A rare three‐center (donor bifurcated) C—H⋯(O,O) hydrogen bond is observed between the methylene and nitro groups, with a side‐on intramolecular component of closed‐ring type and a head‐on intermolecular component. 相似文献
5.
Sreenivasa Nayak Meghashyama P. Bhat A.C. Udayashankar T.R. Lakshmeesha Nagaraja Geetha Sudisha Jogaiah 《应用有机金属化学》2020,34(4):e5567
Dillenia indica L. is a traditional medicinal plant well known for its ability to cure various human diseases. In the current study, silver nanoparticles have been synthesized by simple and eco-friendly method using Dillenia indica extract. The green synthesized nanoparticles were characterized by Fourier transform infrared (FTIR), UV–visible spectroscopy, Atomic force microscopy (AFM), High-resolution transmission electron microscopy (HR-TEM), Zeta Potential and Size Distribution. UV–visible and FTIR spectra, AFM, HR-TEM and Zeta Potential readings and size distribution conformed that the synthesized silver particles were in the size of nano. The green synthesized silver nanoparticles were subjected for antibacterial activity against Gram-positive bacteria Enterococcus faecalis and Gram-negative bacteria Escherichia coli by agar well diffusion method. The synthesized AgNPs exhibited significant inhibition of 27 and 16 mm against the test bacteria at 0.25 mg/ml. Further the antibacterial activity was confirmed by live and dead cell assay by fluorescence microscopy and morphological changes of bacteria were studied by Scanning electron microscope (SEM). The study recommends that the synthesized silver nanoparticles using Dillenia indica extract have potential application in inhibition of bacteria owing to their potent antibacterial activity. 相似文献
6.
Gundibasappa K. Nagaraja Vijayavittala P. Vaidya Koodamara Sheshappa Rai Kittappa M. Mahadevan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2797-2806
A novel and efficient method for the synthesis of substituted thiazepines and diazepines has been developed. A simple one-pot reaction of chalcones 1a–f with 1-amino-2-mercapto-5-phenyl-1,3,4-triazole and o-phenylenediamine in the presence of a catalytic amount of sodium acetate under microwave irradiation gave 2-(3,8-diphenyl-7,8-dihydro[1,2,4]triazolo[3,4-b][1,3,4]thiadiazepin-6-yl)phenoles 2a–f and 2-(2-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-4-yl)phenoles 3a–f, respectively. The structure of all the synthesized compounds was elucidated on the basis of elemental analysis, IR, 1H and 13C NMR, and mass spectral data. 相似文献
7.
Kalkote Uttam Ramrao Choudhary Anil Ramkumar Natu Arvind Anant Ayyangar Nagaraja Ramanuja 《合成通讯》2013,43(10-11):1129-1135
1-Alkylaminoanthraquinones ( 2 a-f) and 1,4-bisalkylaminoanthraquinones ( 4 a-c) were prepared from aminoanthraquinones ( 1,3 ) by alkylation with alkyl sulphate/alkyl halide in presence of powdered sodium hydroxide, potassium carbonate and phase transfer catalyst. 相似文献
8.
M. P. Telenkov Yu. A. Mityagin V. V. Agafonov K. K. Nagaraja 《Bulletin of the Lebedev Physics Institute》2015,42(12):343-345
Kinetics of intrasubband energy relaxation of electrons in the system of Landau levels lying below the optical phonon energy is studied. Extraordinary behavior of the relaxation of electronic subsystem excitation energy is detected. Despite the fact that its main channel is optical phonon emission, the total relaxation time exceeds the characteristic times of scattering on optical phonons by several orders of magnitude. 相似文献
9.
B. N. Lakshminarayana C. R. Gnanendra T. N. Mahadeva Prasad M. A. Sridhar Nagaraja Naik D. Chenne Gowda J. Shashidhara Prasad 《Journal of chemical crystallography》2010,40(8):686-690
Abstract
The novel 3-methyl-2,6-dip-toylpiperidine-4-one was acylated by 3-chloropropanoychloride and subjected for dehydrohalogenation. The synthesized compound was characterized by spectroscopic techniques and finally confirmed by X-ray diffraction studies. The molecule crystallizes in the monoclinic crystal class in the space group C 2/c with cell parameters a = 18.538(2) ?, b = 9.9050(1) ?, c = 22.954(2) ?, β = 94.486(8)° and Z = 8. The piperidine ring adopts a twist boat conformation. 相似文献10.
Snehasish Panigrahy Jinhu Liang Shashank S. Nagaraja Zhaohong Zuo Gihun Kim Shijun Dong Goutham Kukkadapu William J. Pitz Subith S. Vasu Henry J. Curran 《Proceedings of the Combustion Institute》2021,38(1):479-488
To improve our understanding of the combustion characteristics of propyne, new experimental data for ignition delay times (IDTs), pyrolysis speciation profiles and flame speed measurements are presented in this study. IDTs for propyne ignition were obtained at equivalence ratios of 0.5, 1.0, and 2.0 in ‘air’ at pressures of 10 and 30 bar, over a wide range of temperatures (690–1460 K) using a rapid compression machine and a high-pressure shock tube. Moreover, experiments were performed in a single-pulse shock tube to study propyne pyrolysis at 2 bar pressure and in the temperature range 1000–1600 K. In addition, laminar flame speeds of propyne were studied at an unburned gas temperature of 373 K and at 1 and 2 bar for a range of equivalence ratios. A detailed chemical kinetic model is provided to describe the pyrolytic and combustion characteristics of propyne across this wide-ranging set of experimental data. This new mechanism shows significant improvements in the predictions for the IDTs, fuel pyrolysis and flame speeds for propyne compared to AramcoMech3.0. The improvement in fuel reactivity predictions in the new mechanism is due to the inclusion of the propyne + H?2 reaction system along with ?H radical addition to the triple bonds of propyne and subsequent reactions. 相似文献