Chemical Constituents as Rate Regulating: Initial Variation and Changes during Decomposition. New and Traditional Analytical Techniques

Plant Litter ◽  
2013 ◽  
pp. 109-142
Author(s):  
Björn Berg ◽  
Charles McClaugherty
Keyword(s):  
Chemical Constituents ◽  
Analytical Techniques

scholarly journals Antibacterial potential of new active compounds with biological performances with drugs modeling of pharmacokinetics study as source of bacterial drugs manufacture process and preparations

2021 ◽  
Author(s):  
waseem ahmed ◽  
Rafia Azmant ◽  
Abdul Qayyum ◽  
Shah Masaud Khan ◽  
Rasheed Ahmed ◽  
...  
Keyword(s):  
Chemical Constituents ◽  
Analytical Techniques ◽  
Extraction Methods ◽  
Calotropis Procera ◽  
Cytotoxicity Test ◽  
Bacterial Diseases ◽  
Methanolic Extracts ◽  
Manufacture Process ◽  
Quantitative Analysis Method ◽  
Medical Plants

Abstract Adhatoda vasica and Calotropis procera was popular plants for its traditional medicinal materials as treatment of many bacterial diseases and skin disorders the class of group of chemicals were present in these medical plants as used of various medicines the new bioactive compounds as sources of various medicines the currently study was aim to obtained the higher antibacterial resilient biomolecules were measured through several advanced analytical techniques. The results showed that methanolic extracts and supercritical fluid extraction methods were best for higher yield of new compounds measurement process, after extraction the four structural compounds b-Sitosteryl linoleate, Myristyl diglucoside, D-Triglucopyranoside and S-allylcysteine acid were isolated in herbal plants, while the complete HPLC-DAD analyzed process with accuracy ,precision inter and intraday process all four compounds were done. The new drug design with apply of compartmental modelling of pharmacokinetics were apply on these four compounds check their potential level and capacity of measurements. The cytotoxicity test was analyzed in both plants at three concentrations (1, 0.4 and 8) in which 0.4 % showed the higher activity of LD which was 8 % in Calotropis procera extracts. The best activity of LD was recorded in methanol extracts over other six solvents (Methanol, Ethyl acetate, Chloroform, Hexane, Aqueous, and Ascorbic acid). It was concluded that the both species may act as the best resources of medicines in future uses an efficient and precise combinatorial quantitative analysis method and provided insight into the chemical constituents and development of various antibacterial drugs and explore this medical plants

scholarly journals Counterfeit formulations: analytical perspective on anorectics

2021 ◽  
Author(s):  
Dan Osei Mensah Bonsu ◽  
Constance Afoakwah ◽  
Maria de la Paz Aguilar-Caballos
Keyword(s):  
Method Development ◽  
Legal Status ◽  
Chemical Constituents ◽  
Analytical Techniques ◽  
Drug Analysis ◽  
Counterfeit Drugs ◽  
Preparation Methods ◽  
Specific Chemical ◽  
Counterfeit Drug ◽  
International Agencies

Abstract Purpose This paper examines the scope of anorectics in counterfeit weight-reducing formulations and provides insight into the present state of research in determining such adulterants. Analytical techniques utilised in profiling adulterants found in slimming products, including limitations and mitigation steps of these conventional methods are also discussed. The current legal status of the anorectics and analogues routinely encountered in non-prescription slimming formulations is also explored. Methods All reviewed literature was extracted from Scopus, Web of Science, PubMed, and Google Scholar databases using relevant search terms, such as, ‘counterfeit drugs’, ‘weight loss drugs’, ‘weight-reducing drugs’, ‘slimming drugs’, ‘anorectic agents’, and ‘counterfeit anorexics’. Legislation related to anorectics was obtained from the portals of various government and international agencies. Results Anorectics frequently profiled in counterfeit slimming formulations are mostly amphetamine derivatives or its analogues. Five routinely reported pharmacological classes of adulterants, namely anxiolytics, diuretics, antidepressants, laxatives, and stimulants, are mainly utilised as coadjuvants in fake weigh-reducing formulations to increase bioavailability or to minimise anticipated side effects. Liquid and gas chromatography coupled with mass spectrometric detectors are predominantly used techniques for anorectic analysis due to the possibility of obtaining detailed information of adulterants. However, interference from the complex sample matrices of these fake products limits the accuracy of these methods and requires robust sample preparation methods for enhanced sensitivity and selectivity. The most common anorectics found in counterfeit slimming medicines are either completely banned or available by prescription only, in many countries. Conclusions Slimming formulations doped with anorectic cocktails to boost their weight-reducing efficacy are not uncommon. Liquid chromatography combined with mass spectrometry remains the gold standard for counterfeit drug analysis, and requires improved preconcentration methods for rapid and quantitative identification of specific chemical constituents. Extensive method development and validation, targeted at refining existing techniques while developing new ones, is expected to improve the analytical profiling of counterfeit anorectics significantly.

scholarly journals Extraction, Isolation and Characterization of Phytoconstituents in Urginea wightii

2020 ◽  
pp. 1-11
Author(s):  
M. Smitha Raj ◽  
M. N. Shiva Kameshwari
Keyword(s):  
Chemical Constituents ◽  
Acid Methyl Ester ◽  
Analytical Techniques ◽  
Molecular Structures ◽  
Chemical Components ◽  
Analytical Technique ◽  
Isolation And Characterization ◽  
Screening Study ◽  
Interesting Compound

The Urginea wightii is a well-established squill. The therapeutic activity is determined by the presence of pharmacological component present in the crude extract of Urginea wightii. To screen these active herbal components in a single plant material it requires a sophisticated, sensitive and a reliable analytical technique. As a preliminary screening study infrared spectrum provided information related to active functional groups of bulbous extract. This encouraging result evoked us for further accurate detailing of chemical components by advanced analytical techniques like liquid chromatography mass spectroscopy (LC-MS) and Nuclear magnetic resonance (NMR). The identified chemical constituents with possible molecular structures of pharmacological activity by LC-MS was found to be stigmasterol, hexadecanoic acid methyl ester and 1,3,7,11,15-tetramethyl-2- hexadecenol. Similarly, when 1H NMR was performed an interesting molecule (2,3-dihydro-dihydroxy-6-methyl-4H-pyran-4-one) having potential capability in destroying free radicals (antioxidant) was obtained. The comprehensive and qualitative characterization of these bioactive compounds present in Urginea wightii can be a useful in treating vast disease conditions. This investigation paves the way to explore researchers for further use of Urginea wightii as sources of medicinally interesting compound.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

1978 ◽  
Vol 36 (2) ◽  
pp. 46-47
Author(s):  
Jan Zarzycki ◽  
Joseph Szroeder
Keyword(s):  
Mammary Gland ◽  
Protein Denaturation ◽  
Chemical Constituents ◽  
Freeze Substitution ◽  
Electron Microscopic Examination ◽  
Mouse Mammary Gland ◽  
Electron Microscopic ◽  
Preparation Methods ◽  
Microscopic Studies ◽  
Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

Preferential Sputtering of Ni3Al Single Crystals Studied Using Atom-Probe Field-Ion Microscopy and XPS

1981 ◽  
Vol 39 ◽  
pp. 16-17
Author(s):  
M.P. Thomas ◽  
A.R. Waugh ◽  
M.J. Southon ◽  
Brian Ralph
Keyword(s):  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Depth Profiling ◽  
Analytical Techniques ◽  
Atom Probe ◽  
Probe Field ◽  
Preferential Sputtering ◽  
Argon Ion Bombardment ◽  
Argon Ion

It is well known that ion-induced sputtering from numerous multicomponent targets results in marked changes in surface composition (1). Preferential removal of one component results in surface enrichment in the less easily removed species. In this investigation, a time-of-flight atom-probe field-ion microscope A.P. together with X-ray photoelectron spectroscopy XPS have been used to monitor alterations in surface composition of Ni3Al single crystals under argon ion bombardment. The A.P. has been chosen for this investigation because of its ability using field evaporation to depth profile through a sputtered surface without the need for further ion sputtering. Incident ion energy and ion dose have been selected to reflect conditions widely used in surface analytical techniques for cleaning and depth-profiling of samples, typically 3keV and 1018 - 1020 ion m-2.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

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