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
TL;DR: The role of 2D NMR spectroscopy in CASE is discussed and the methods a natural product chemist may apply to elucidate the structure of a complex natural product are highlighted.
62 citations
TL;DR: The detection in Rhodopetudomonas 8pheroides and the isolation of magnesium protoporphyrin monomethyl ester as a normal metabolite indicated that the pathways of chlorophyll biosynthesis in green plants and bacteriochlorophyll synthesis in photosynthetic bacteriamay be similar.
Abstract: The identification of intermediates in the biosynthesis of chlorophyll has been largely dependent upon the use ofmutants of Chlorella that are unable to synthesize chlorophyll but accumulate in the medium various tetrapyrrole compounds assumed to be precursors (for a review see Granick & Mauzerall, 1961). In particular, Granick (1950) identified magnesium vinylphaeoporphyrin a5 monomethyl ester (Scheme 1, formula V) as an intermediate and it now seems likely that it is this compound and not its phytyl ester (protochlorophyll) that is reduced to the oxidation level of chlorophyll. Esterification with phytol follows, yielding chlorophyll a (formula VII) (cf. Smith, 1960). The detection in Rhodopetudomonas 8pheroides of an enzyme system which methylates magnesium protoporphyrin (formula II) (Tait & Gibson, 1961) and the isolation of magnesium protoporphyrin monomethyl ester (formula III) as a normal metabolite of R. 8pheroides (Jones, 1963a) indicated that the pathways of chlorophyll biosynthesis in green plants and bacteriochlorophyll synthesis in photosynthetic bacteriamay be similar, although chlorophyll a and bacteriochlorophyll differ not only in the reduction state of ring II but also in substituents at position 2 of the tetrapyrrole
62 citations
TL;DR: Three similar and apparently previously unrecorded viruses were studied and found to be most like viruses of the turnip yellow mosaic group, and all three viruses are readily transmitted by sap inoculation.
Abstract: SUMMARY: Three similar and apparently previously unrecorded viruses were studied and found to be most like viruses of the turnip yellow mosaic group. Andean potato latent virus (APLV) was obtained from primitive cultivated potatoes collected in the high tropical Andes, dulcamara mottle virus (DMV) from Solanum dulcamara L. growing near Rothamsted, and Ononis yellow mosaic virus from Ononis repens L. growing in many parts of England. All three viruses are readily transmitted by sap inoculation; APLV and DMV are transmitted through the seed of infected plants; DMV is transmitted by the flea beetle Psylloides affinis Paykull. Plants infected by one of the viruses are not protected against infection by the others.
Purified preparations of these viruses have many common properties. Each virus has isometric particles 25-30 mμ in diameter, indistinguishable in appearance from one another and from the particles of turnip yellow mosaic virus. Preparations of each contain mainly two types of particles with sedimentation coefficients of about 115S and 55S, corresponding to infective nucleoprotein particles and non-infective “empty” particles respectively. Each contains nucleic acid with a molar base composition of about G 16% A 22% C 33% U 29%. The three viruses are serologically related; antisera titres are 8-128 times greater with homologous than with the heterologous viruses. No serological relationship was found between these viruses and turnip yellow mosaic, wild cucumber mosaic, cocoa yellow mosaic, squash mosaic and red clover mottle viruses.
Plants infected with APLV or DMV when sprayed with solutions of 2-thiouracil or 6-azauracil produced fewer nucleoprotein particles and more “empty” protein particles, than plants sprayed with water.
62 citations
TL;DR: The investigated seeds were rich in minerals such as Na, P, Mg, Zn and Fe and Antinutritional substances, total free phenols, tannins, L-DOPA and haemagglutinating activity, were also analysed/assayed.
62 citations
TL;DR: The desired yolk colours are achieved by the in-situ processing of eggs with a distinct aversion to pale, orange-red and off-coloured yolks.
Abstract: Consumers prefer eggs with yolk colours ranging from golden-yellow to orange. There is a distinct aversion to pale, orange-red and off-coloured yolks.The desired yolk colours are achieved by the in...
62 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