Modern methods of plant analysis
01 Jan 1964-
About: The article was published on 1964-01-01 and is currently open access. It has received 1991 citations till now.
Citations
More filters
01 Jan 2010
TL;DR: In this article, the antioxidant properties of hydro-alcohlic extract of Calotropis gigantea leaves (HECGL) were investigated using DPPH (1,1-Diphenyl-2-Picryl-Hydrazyl) free radical scavenging activity.
Abstract: Antioxidants play an important role to protect human against infections and degenerative
diseases. The aim of this study is to verify the In-vitro antioxidant properties and to calculate the
total polyphenol contents, total tannins, flavonoid contants of hydroalcohlic extract. The
powdered crude drugs were extracted with hydro-alcoholic solvent (70:30) by double
maceration process. Phytochemical tests of hydro-alcoholic extract reveals the presence of
carbohydrate, alkaloid, flavonoid, steroids, protein, amino-acids and tannins. The antioxidant
activity of hydroalcohlic extract of Calotropis gigantea leaves (HECGL) was investigated using
in-vitro models like DPPH (1,1-Diphenyl-2-Picryl-Hydrazyl) free radical scavenging activity.
Reducing power assay using ascorbic acid, nitric oxide scavenging activity using curcumin
equivalents. At the same time the phenolic content of the extracts was determined using Folin-
Ciocalteau reagent, total tannins and total flavonoids using rutine to evaluate their contribution
to total antioxidant activity. HECGL at 400AŽÂ¼g/ml concentration showed maximum DPPH radical
scavenging activity (85.17%) and for nitric oxide scavenging (54.55%) at 100AŽÂ¼g/ml
concentration. Reducing power of HACGL was increases with increasing the concentration of
extract. Phenolic contents, expressed as gallic acid equivalents 63.08 A‚± 4.17 /100 mg of the dried
weight of cg. Tannin 0.52% and Flavonoids 46.97A‚± 1.95 AŽÂ¼g mg-1.It is concluded that, this study
is to verify the antioxidant properties of hydroalcohlic extract, and to define the total polyphenol
contents, flavonoids and tannins in Calotropis gigantea leaves.
19 citations
TL;DR: The relatively low and moderatesalinization levels resulted in a promotion rather than inhibition of the dry weight and in the content of most of the investigated elements in the different organs of the test plants, but with the rise of salinization level from 60 to 100 meq l−1, thedry weight and the contentof these nutrient elements were mostly reduced.
Abstract: Using water culture technique, some experiments have been performed to investigate the effect of 60 days salinization treatments (0.0–100 meq 1−1 NaCl) on dry weight and on the content of some nutrient elements (Na, K, Ca, Mg, P, N) in castor bean, sunflower and flax plants. In general the content of sodium increased progressively with the rise of salinity level. The relatively low and moderate salinization levels (20 and 40 meq I−1 NaCl) resulted in a promotion rather than inhibition of the dry weight and in the content of most of the investigated elements in the different organs of the test plants. However with the rise of salinization level from 60 to 100 meq l−1, the dry weight and the content of these nutrient elements were mostly reduced.
19 citations
TL;DR: The culture of two Kluyveromyces species in the presence of subinhibitory doses of amphotericin B leads to the selection of mutants which are resistant to this polyene, showing an alteration of their cell wall composition with the main change corresponding to an increase of chitin.
Abstract: The culture of two Kluyveromyces species, Kluyveromyces lactis (ATCC 96897) and Kluyveromyces bulgaricus (ATCC 96631), in the presence of subinhibitory doses of amphotericin B leads to the selection of mutants which are resistant to this polyene. The mutants show an alteration of their cell wall composition with the main change corresponding to an increase of chitin. The enzyme activities involved in the metabolism of this polymer, i.e. chitin synthases and chitinase, were measured. The results demonstrate that in both mutants the activity of chitinase was drastically decreased by 99% in comparison with the activity measured in the corresponding wild-type strain while no significant change of the chitin synthase I, II and III activities could be detected.
19 citations
01 Jan 1994
TL;DR: regulation of transit, lowering of blood cholesterol, etc.
Abstract: regulation of transit, lowering of blood cholesterol, etc.) of dietary fibre intake are generally accepted.
19 citations
TL;DR: The structure of the acidic polysaccharide of Klebsiella pneumoniae type A (strain 1265) is reported on.
Abstract: PREVIOUS investigations1,2 have shown that the capsular polysaccharides of Klebsiella pneumoniae types A and B are glucose-containing polyuronides. Eriksen and Henriksen3 have tentatively identified glucose, fucose and a uronic acid as components of type A capsular polysaccharide. Hitherto, little work has been directed towards elucidation of the structure of these polysaccharides and we now report briefly on the structure of the acidic polysaccharide of Klebsiella pneumoniae type A (strain 1265).
19 citations
References
More filters
01 Jan 1963
TL;DR: In this article, a physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln.
Abstract: Kann ein physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), so besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln. Hierzu gehoren die Bestimmung der Reaktions- und Substratspezifitat sowie die Ermittlung der Bedingungen, unter denen eine optimale Wirkung des Enzyms gegeben ist. Wesentlich zur Charakterisierung ist ferner die Untersuchung der Stabilitat des Enzyms und dabei insbesondere die Feststellung, ob es sich um ein Ferment handelt, das zur vollen Aktivitat dialysable Cofaktoren benotigt. Falls diese Frage bejaht wird, ist auch die Bestimmung der unerlaslichen Cofaktoren anzuschliesen. Uberdies bietet auch der Nachweis der Lokalisation des Enzyms in der Zelle (oder im Zellverband) eine entscheidende Moglichkeit zur Charakterisierung des Fermentes. Hinzu kommt schlieslich noch die Untersuchung der Wirkung einzelner Inhibitoren1 auf das Enzym, die zu weitgehender Klarung des Reaktionsmechanismus beitragen kann und eine Abgrenzung der Eigenschaften des untersuchten Fermentes gegenuber ahnlichen Enzymen erlaubt.
2 citations
01 Jan 1962
TL;DR: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins and rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
Abstract: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins. Generally speaking denaturation can be defined as a process or sequence of processes in which the spatial arrangement of the polypeptide chains within the molecule is changed from that typical of the native protein to a more disordered arrangement (Kauzmann 1959). The terms “configuration”, “conformation” and “state of folding” are widely used for spatial arrangement. It is probably best to follow the suggestion of Blout (1960) and restrict the use of “configuration” to its original sense, i.e. the spatial arrangement around an asymmetric carbon atom, and to use “conformation” for the shape of the molecule in its entirety. The properties discussed in the previous Chapter i.e., viscosity, diffusion, sedimentation, and light scattering — can all furnish information on the overall shape of proteins or other macromolecules and changes in this shape with environment. Thus Doty, Bradbury and Holtzer (1956) were able to show using these methods, together with streaming birefringence, that poly-γ-benzyl-L-glutamate could exist in two conformations, the α-helix and the solvated randomly coiled form, depending on the solvent. The change from α-helix to random coil was accompanied by marked changes in the optical rotatory properties of the polypeptides. It is to be expected that an α-helical structure should contribute to the rotatory power of a polypeptide since helices are asymmetric and not superimposable on their mirror images. The work on polypeptides has shown that rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
1 citations