Isolation of chlorophyll and

Isolation of Chlorophyll and Carotenoid Pigments from Spinach... 

The chlorophylls produced by bacteria, algae and plants are a natural source of chlorins. The isolation of chlorophylls from natural material is known to be difficult because of their extreme sensitivity to various reactions, such as enolization, epimerization, allomerization, de-methoxycarbonylation, solvolysis, demctalation, dephytylation, photooxidation, etc. Often the... 

The clastogenic effects of male Swiss albino mice fed chromium(VI) trioxide (20 mg/kg body weight) by gavage were studied after 24 hours, bone marrow cells were isolated and 500 metaphase plates were scored for chromosomal aberrations (Sarkar et al. 1993). The treated cells showed a significant increase in aberrations per cell over controls by 4.4-fold. When animals were treated simultaneously with chlorophyllin (1.5 mg/kg), a sodium-copper derivative of chlorophyll and an antioxidant, numbers of aberrations were reduced to nearly background levels. 

Proteins of all organisms are based on the 20 common amino acids, generally referred to as protein amino acids. In some cases, these amino acids are modified post-translationally, e.g. the hydroxyproline moieties in several cell wall proteins. Apart from these protein amino acids, numerous other amino acids occur in plants. Some of them are known to be intermediates in various pathways of primary metabolism, e.g. ornithine as a metabolite in arginine bios)m-thesis, 8-aminolevulinic acid as a precursor of chlorophyll and 0-acetylserine as an S-acceptor to yield cysteine. In addition, about 900 other amino acids, which are not thought to be involved in primary metabolism, have been isolated from plants. These non-protein amino acids (NPAAs) are regarded as typical secondary metabolites with corresponding ecological functions. 

The isolation of an active, structurally intact complex was obtained using an association of cholate and octylglucoside and sucrose gradient centrifugation [111]. This preparation did not contain cytochrome 6-559 and possessed a plastoquinol-plastocyanine oxidoreductase activity, inhibited by specific inhibitors (DBMIB, UHDBT). The complex was essentially free of chlorophyll and contaminations by other membrane components, specifically of the ATPase complex. 

Two Batfish profiles of chlorophyll and copepods (sampled in the eastern Canadian Arctic) were separated by volume into their component species and are shown in Figure 5. The separation shows that both Calanus finmarchicus Stage V and Calanus glacialis Stage V are situated 5 m above the chlorophyll maximum, whereas Calanus hyperboreus Stages V and VI were situated primarily at or below the chlorophyll maximum. Such examples illustrate the species identification potential of the electronic counter and the resolution capabilities of the system for isolating species in the water column. 

The nature of the petroporphyrins found in a variety of crude oils, oil shales, ancient and recent sediments have been a subject of continual interest since these compounds were first isolated from such materials by Treibs (l) some fifty years ago. It is now generally agreed ( 2) that the petroporphyrins represent the degradation products of chlorophyll and that they consist predominantly of homologous series of deoxophyllo-erythroetioporphyrin (DPEP) and aetio porphyrins. However, as yet unidentified porphyrin compounds which do not belong to either of these two classes have been observed (JO in some samples and the proposition that all petroporphyrins are derived from chlorophyll has also been questioned (4). 

Adsorptive separations have been in use well before the twentieth century. Tswett (1905, 1906), however, was the first who coined the term Chromatography in 1903 for the isolation of chlorophyll constituents. Kuhn and Brockmarm, in the course of their research recognized the need for more reproducible and also more selective adsorbents, specially tuned for specific separation problems. This recognized demand for reproducible stationary phases led to the development of first materials standardized for adsorption strength and describes the first attempt toward reproducible separations (Unger et al., 2010). 

Progress in the synthesis of chlorophylls and bacteriochlorophylls (di- and tetra-hydro porphyrins) has been relatively slow, but the recent isolation of new reduced porphyrins, such as the physiologically active marine pigment bonellin" and sirohydrochlorin (an intermediate in vitamin B12 biosynthesis) is likely to stimulate attempts to synthesize these compounds directly from partially reduced open chain precursors rather than by reduction of preformed porphyrins (see Section 11). Considerable progress has already been made in the development of new methods for synthesizing the partially reduced bile pigments (Section 9). 

Tswett s research involved the isolation of chlorophyll from plant material. Whilst carrying out his work, he found a difference in polar and nonpolar solvents as to how well the isolation occurred. He concluded that this... 

Import incubations were as previously described (5, 6). Translations (50 Ail) were diluted with 950 /j1 import medium (250 mM sorbitol, 35 mM HEPES/KOH pH 7.8 ImM MgC12 ImM MnC12, 2 mM K-EDTA, 5 mM methionine 0.4 mM other amino acids). Chloroplasts isolated from normal and heat shocked cells were resuspended in the diluted translation mixture to 0.3 mg/ml of chlorophyll and incubated in the light for 45 min at 25 C. Chloroplasts were treated with trypsin (0.25 mg/ml), washed and recovered as described (5f 6). 

Rose-bengal is a well known 02 sensitizer which when applied to leaf tissue or isolated chloroplasts leads to rapid light-dependent, bleaching of chlorophylls and carotenoids [4]. There is a more rapid loss of chlorophylls than carotenoids during treatment with rose-bengal, so that after only 24 hours treatment almost 20% of the carotenoid and 40% of the chlorophyll are destroyed (Fig. 2a). 

The first result demonstrating the uptake of chlorophyll derivatives by human intestinal cells was in 2001 by Schwartz s group [61]. Up to then, only a few studies focussed on the isolation of chlorophyll derivatives in feces of humans and animals assuming negligible absorption. 

Inhibition of fatty acid biosynthesis in chloroplasts The de novo synthesis of fatty acids proceeds in the chloroplasts (plastids) (35). The biosynthesis of total fatty acids in isolated maize chloroplasts is inhibited by sethoxydim (Table 7). The Igg-value is lower than 10 molar. Thus in grass weeds the major biochemical target appears to be the fatty acid synthetase. Sethoxydim acts in a similar way to the structurally different herbicide diclofopmethyl (36). The block of chlorophyll and carotenoid... 

Comparative studies of the separation of chlorophyll-protein complexes either by LiDS-PAGE or digitonin treatment followed by sucrose-density gradient, have led to the isolation of four and three complexes respectively. These complexes have been characterized by their spectral properties and their polypeptides separated. These new data are in agreement with the structural scheme previously proposed. 

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