Photosynthetic pigments, determination

For comparison with other plant samples, take 0.05 or 0.1 ml of this concentrated pigment extract, dilute to 5 ml with 100% acetone or diethyl ether, and determine the amount of photosynthetic pigments using the absorption coefficients and equations given in UNITF4.3. 

UNESCO,1966. Determination of photosynthetic pigments in sea-water. Monographs on Oceanographic Methodology, Vol.l, pp. 1-69. 

Photosynthetic pigments, chlorophylls, and carotenoids have a clear hydro-phobic character and are usually analyzed by C18-reversed-phase (RP) columns. A C30-RP appeared on the market. The C30-RP is particularly efficient in the separation of carotenoids because the interactions of the pigments and the stationary phase are maximized by the similar size. With this phase, many cis isomers of the same carotenoid are separated from each other (Emenhiser et al., 1995 Lacker et al., 1999 Sharpless et al., 1996). This C30-RP has been successfully applied to the determination of saponified carotenoids in orange juice (Rousseff et al., 1996). However, when a mixture is complex, coelutions may become rapidly limiting and less selective stationary phases, such as the C18-RP, are therefore preferably... 

The compounds included in this section have mainly been detected in the particulate fractions of seawater and are su ested to correlate with biological activity. The oldest determined compounds in this class are the photosynthetic pigments, mainly the chlorophylls. The methods for the determination of the plant pigments have been standardised by international agreements (UNESCO, 1966) and the published methods of Strickland and Parsons (1972). A review of the methods for the determination of both total and individual p ments has been presented by Rai (1973). 

Rai, H., 1973. Methods involving the determination of photosynthetic pigments using spectrophotometry. Verh. Int. Ver. Theor. Angew. Limnol., 18 1864—1875. 

In the next section we take a quick look at the triplet state and discuss the origin and significance of the ZFS. This is followed by an outline of some of the ODMR experiments that are in common use to determine static and dynamic triplet state properties in biopolymers. After a description of experimental equipment and methods used in ODMR spectroscopy, we conclude with some examples that illustrate the wealth of information provided by the application of ODMR to the study of tryptophan triplet states in proteins. Because this chapter is intended to focus on methods, we present neither a historical development of ODMR spectroscopy, nor an extensive review of its application to biopolymer studies. We refer the interested reader, instead, to some early reviews on the general methods and results of ODMR spectroscopy, as well as to a book and to additional reviews that deal more specifically with biological applications of ODMR. Applications to photosynthetic pigments and the reaction centers, in particular, have been reviewed thoroughly by Hoff. - ... 

Our knowledge of the stereochemistry of porphyrins and related tetrapyrrole macrocycles has expanded rapidly since the first reported x-ray structure determination in 1959 The structures of metallotetrapyrrole complexes are of interest because of the common occurrence of this type of macrocycle in biological systems. As is well known, foremost among these are the heme proteins (iron derivatives), the various photosynthetic pigments (magnesium complexes), the vitamin Bn coenzyme (cobalt corrinoids), and coenzyme F430 (nickel corphinoids) of the methanogenic bacteria. 

Determination of concentrations of the photosynthetic pigments (protocols available in Dauchet et al., 2015 that are based on the measurement of the pigments dry-mass fraction and the volume fraction of intracellular water). 

Other TLC studies on fat-soluble chloroplast pigments from plant tissues include the following. Suzuki et al. (1987) studied the retention of chlorophylls, pheophytins, and pheophorbides in C,g TLC and HPLC systems. Stauber and Jeffrey (1988) examined the photosynthetic pigments of 51 species of tropical and subtropical diatoms by normal- and reversed-phase TLC. Cserhati (1988) determined the lipophilicity of some photosynthetic pigments using reversed-phase TLC on various impregnated layers with acetone and ethanol as the mobile phase. Heimler et al. (1989) quantitatively determined chlorophylls in spruce needles by densitometry on cellulose layers. 

Cserhati, T. (1988). Lipophilicity determination of some photosynthetic pigments by re-versed-phase thin-layer chromatography. The effect of support and the organic phase in the eluent. Chromatographia 25 908-914. 

The aim of this chapter also is the introduction of the photo physical study of model system ( 3-carotene in RTILs) mimicking very well spectroscopic data of this photosynthetic pigment in situ in the photosynthetic system Unique fluorescence properties of P-carotene in room temperature ionic liquids (RTIL) (Bialek-Bylka et al., 2007) and new (P-carotene) electronic states (3Ag- and 1B -) of both impxjrtant in photosynthesis isomers all-frans and 15-cis in ionic liquid with dimethylformamide (DMF) were found (Bialek-Bylka et al., 2008) and also a sensor detecting the methoxy group in the cation part of imidazolium ionic liquid was developed by us (Pawlak et al., 2009). In order to determine a detailed answer to the unique fluorescence properties, aroimd 100 times higher fluorescence yield of P-carotene in (ILl) (l-methyl-3-octyloxymethylimidazolium tetrafluoroborate) than in standard solvent n-hexane, the designed structures of RTILs were synthesized and carefully purified 1-methyl-3-octyloxymethylimidazolium tetrafluoroborate (ILl), l-methyl-3-... 

The analysis of carotenoid identity, conformation, and binding in vivo should allow further progress to be made in understanding of the functions of these pigments in the photosynthetic machinery. One of the obvious steps toward improvement could be the use of continuously tuneable laser systems in order to obtain more detailed resonance Raman excitation profiles (Sashima et al 2000). This technique will be suitable for the investigation of in vivo systems with more complex carotenoid composition. In addition, this method may be applied for the determination of the energy of forbidden Sj or 2 Ag transition. This is an important parameter, since it allows an assessment of the energy transfer relationship between the carotenoids and chlorophylls within the antenna complex. 

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