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.
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TL;DR: Acid hydrolysis of cell wall-rich material from young leaves of the lycophyte Selaginella apoda (L.) Spring yielded substantial amounts of 3-O-methyl-D-galactose (1) in addition to the usual major monosaccharides (glucose, galactose, arabinose, xylose and galacturonic acid).
41 citations
TL;DR: The relationship between chitin content and activity of the chit in synthetase enzyme was investigated in final instar larvae and pupae of Prodenia eridania and a correlation was found between changes in Chitin concentration and activity.
41 citations
TL;DR: It is found that plasma membrane H(+)-ATPase hydrolytic and pumping activities were not affected by application of 150 mM NaCl, and apoplastic pH was also not affected under salt stress, but a decrease in plant growth was observed.
41 citations
01 Jan 1961-Progress in the chemistry of organic natural products. Progrès dans la chimie des substances organiques naturelles
TL;DR: The flowers of the herbaceous perennial Chrysanthemum cinerariaefolium Vis, a member of the Compositae family, are valued for their insecticidal properties: the history of their employment has been discussed by Gnadinger and to-day the principal world source is Kenya where a rationally administered industry provides standardised products.
Abstract: The flowers of the herbaceous perennial Chrysanthemum cinerariaefolium Vis (synonym, Pyrethrum cinerariaefolium Trev), a member of the Compositae family, are valued for their insecticidal properties: the history of their employment has been discussed by Gnadinger (77,78) Commercial supplies were originally obtained from Dalmatia and Japan, but to-day the principal world source is Kenya where a rationally administered industry provides standardised products Other Compositae flowers have insecticidal activity but of these only Chrysanthemum coccineum Willd (synonyms, C carneum Steud and C roseum Adam) has commercial value, though it is cultivated on a restricted scale The active insecticidal principles, the Pyrethrins, are contained mostly in the achenes of C cinerariaefolium (19–21) Harvesting the crop requires much hand labour as maximum yields are obtained by gathering the flower (Fig I) when four or five rows of disc florets are open The flowers are artificially dried and baled and are known commercially as “pyrethrum” As insecticides, the Pyrethrins have the advantage of low mammalian toxicity and so far insects have not easily developed resistance towards them They are also well known for their rapid “knock-down” or paralytic properties which are valuable in dealing with flying insects
41 citations
TL;DR: A comparison between two sampling methods based on sample concentration (purge and trap) and solid phase micro-extraction (SPME) applied to gas sensors (electronic nose) for wine discrimination is performed as mentioned in this paper.
41 citations
References
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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