Hydrolysis chlorophyll

An important representative of diterpenoid alcohols is phytol (2 ,3,7ff,llff,15)-3,7,ll,15-tetramethylhexadec-2-en-l-ol, a constituent of chlorophylls, tocopherols and K group vitamins. Free phytol arises during chlorophyll hydrolysis by chlorophyUase as an integral part of plant catabolism in fruit ripening and yellowing of leaves. Microbial decomposition of phytol creates some unusual branched fatty acids, such as pristanic and phytanic acids (see Section 3.2.3.3.2). Acyclic diterpenic alcohol is also retinol (vitamin Aj) (see Section 5.2.1). 

All organisms seem to have an absolute need for magnesium. In plants, the magnesium complex chlorophyll is the prime agent in photosynthesis. In animals, magnesium functions as an enzyme activator the enzyme which catalyses the ATP hydrolysis mentioned above is an important example. 

Hydrolysis of chlorophyll using sodium hydroxide produces the moderately water-soluble sodium salts of chlorophyllin, phytol and methanol (145). The magnesium ia chlorophyllin may be replaced by copper. The sodium copper chlorophyllin salt is heat stable, and is ideal for coloring foods where heat is iavolved, such as ia canning (146). 

Esterification increases the lipophilic character of the pigments that has been recogiuzed as an important factor for interactions with the peptide chains of proteins. The hydrolysis of this side chain results in chlorophyllides and the concomitant removal of the Mg + ion in pheophorbides. Only a Umited number of natural chlorophylls in plants and photosynthetic organisms has been described and is well... 

Commercial food grade water-soluble Cu-chlorophyllin is the most notable among these preparations. Copper chlorophyllins are produced from crude natural chlorophyll extracts followed by the hydrolysis of the phytyl and methyl esters, cleavage of the cyclopentanone (E) ring in dilute alkali, and the replacement of magnesium by copper. ... 

Alkaline hydrolysis (saponification) has been used to remove contaminating lipids from fat-rich samples (e.g., pahn oil) and hydrolyze chlorophyll (e.g., green vegetables) and carotenoid esters (e.g., fruits). Xanthophylls, both free and with different degrees of esterification with a mixture of different fatty acids, are typically found in fruits, and saponification allows easier chromatographic separation, identification, and quantification. For this reason, most methods for quantitative carotenoid analysis include a saponification step. 

The automated EXAMS model consists of a set of FORTRAN programs which calculates the fate, exposure and dissipation of the chemical from input environmental data such as 1) Global parameters (rainfall, irradiance, latitude), 2) Biological parameters (biomass, bacterial counts, chlorophyll), 3) Depths and in-lows, 4) Sediment characteristics, 5) Wind, 6) Evaporation, 7) Aeration, 8) Advective and turbulent interconnections, 9) Water flow, 10) Sediment flow, 11) pH and pOH, and 12) Temperature. Also characteristics of the chemical are taken into account such as hydrolysis photolysis, oxidation, biolysis, and volatility. 

This enzyme [EC 3.1.1.14] catalyzes the hydrolysis of chlorophyll to produce phytol and chlorophyllide. The enzyme has also been reported to catalyze chlorophyllide transfer reactions (for example, in converting chlorophyll to methylchlorophyllide). 

Chlorophyll. Chemically pure chlorophyll is difficult to prepare, since it occurs mixed with other colored substances such as carotenoids. Commercially it is solvent extracted from the dried leaves of various plants such as broccoli or spinach. Chlorophyll is water-iosoluble. It has none of the characteristics of a dye in that it has no aflinity for the usual libers such as cotton or wool. Chlorophyll is properly classified as a pigment tCI Natural Green 3 Cl 75810), As such. It finds use lor coloring soaps, waxes, inks. fats, or nils. Chlorophyll is an ester composed of an acidic pint, chlorophyllin, esterilied by an aliphatic alcohol known as phylol. Hydrolysis of chlorophyll using sodium hydroxide produces the moderately water-soluble sodium salts of chlorophyllin. phytol. and methanol. The magnesium in chlorophyllin may be replaced by copper. The sodium copper chlorophyllin salt is heat-stable, and is ideal for coloring foods where heat is involved, such as in canning. 

More details of the plastein reaction and its application to remove pigments such as chlorophyll, or to remove off-flavor components such as the beany taste of soybeans, are shown in Figure 2. The protein of the food system is solubilized and denatured (in order to achieve proteolysis), a protease is added, and the hydrolytic reaction is allowed to proceed. On partial hydrolysis of the protein the pigments and flavor constituents are released from the protein they are removed, the hydrolyzate is concentrated, and resynthesis and/or rearrangement of the amino acid sequence of the polypeptides is catalyzed by the same or a different protease. Resynthesis also can be carried out in the presence of added amino acid esters in order to improve the nutritional/functional properties of the protein. 

Other reactions that may be influenced by water activity are hydrolysis of protopectin, splitting and demethylation of pectin, auto-catalytic hydrolysis of fats, and the transformation of chlorophyll into pheophytin (Loncin et al. 1968). 

Chlorophylls and Iron porphyrins are prevalent In plant and animal matter whereas only nickel (as Nl(II)) and vanadium (as oxovanadlum V(IV), V 0) metalloporphyrlns are found In petroleum. To determine a plausible reaction sequence for these conversions, we are studying hydrolysis and metallatlon reactions of metal complexes of pheophytlns (the demetallated ligands of chlorophylls) and of porphyrins. The pheophytlns and metal pheophytlnates, Including the chlorophylls and the most abundant natural porphyrins, are highly llpophyllc and have very low solubilities In aqueous... 

Figure 4. A mechanistic scheme for the hydrolysis of chlorophyll a that is consistent with the observed rate law.

Table I. Rate Constants For Chlorophyll A Hydrolysis in Media Of Different Composition.

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