Chlorophyllide

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... 

Chlorophyll b occurs as an accessory pigment of the light-harvesting systems in land plants and green algae, and comprises one-third (or less) of total chlorophyll. The biosynthesis of chlorophyll b has been an area of active research particularly regarding its compartmentalization in chloroplast membranes, identification of the gene for chlorophyllide a oxidase, and characterization of the enzymes involved. ... 

Folly, P, Catabolisme de la chlorophyllide b, structures, mecanismes et syntheses. These presentee a la Faculte des Sciences de I Universite de Fribourg pour I obtention du grade de Doucteur es sciences naturelles, Fribourg, 2000. 

In the past, no snitable analytical methodologies were capable of investigating these multiple reactions and even today, the complete extraction and analysis of all the componnds is still a difficult task. The methods for extraction must be optimized for each sample according to the solubility of either phytylated (chlorophylls and pheophytins) or dephytylated (chlorophyllides and pheophorbides) derivatives, often requiring several repeated steps and the use of a single or a mixture of organic solvents. 

Fig. 2.130. Elution profile by RP-HPLC of the chlorophyll derivative pigments analysed. The pigments were detected spectrophotometrically at 660 nm and fhiorimetrically using excitation and emission wavelengths at 440 and 660 nm, respectively. Peak identification (numbers in parentheses are retention times in min) 1 = chlorophyllide-b (3.10) 2 = chlorophyllide-a (4.98) 3 = pheophorbide-b (7.44) 4 = pheophorbide-a (8.85) 5 = chlorophyll-b (14.74) 6 = chlorophyll-a (16.40) 7 = pheophytin-b (21.49) 8 = pheophytin-a (23.38). Reprinted with permission from L. Almela et al. [301].

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). 

This enzyme [EC 1.3.1.33], also known as NADPH-pro-tochlorophyllide oxidoreductase, catalyzes the reaction of chlorophyllide a with NADP+ to produce protochloro-phyUide, having the (75, 85)-configuration, and NADPH. It catalyzes a light-dependent trans-reduction of the D-ring of protochlorophyllide. 

The crystal structure of the corresponding chlorophyllide has been solved [10], the chemical synthesis was developed by Woodward [11] and a recent review on the biosynthesis has been published by Rudiger and Schoch [12]. 

An alternative example has been reported by Boxer et al. 201 202 They formed well-defined complexes of chlorophyll and bacteriochlorophyllide with apomyo-globin. The chlorophyllide and its derivatives substitute for heme in the hydrophobic... 

Development of fast, accurate, and reproducible high-performance liquid chromatography (HPLC) methods has offset the use of traditional open-column and TLC methods in modern chlorophyll separation and analysis. A number of normal and reversed-phase methods have been developed for analysis of chlorophyll derivatives in food samples (unit F4.4), with octadecyl-bonded stationary phase (C]8) techniques predominating in the literature (Schwartz and Lorenzo, 1990). Inclusion of buffer salts such as ammonium acetate in the mobile phase is often useful, as this provides a proton equilibrium suitable for ionizable chlorophyllides and pheophorbides (Almela et al., 2000). 

White, R.C., Jones, I.D., and Gibbs, E. 1963. Determination of chlorophylls, chlorophyllides, pheo-phytins and pheophorbides in plant material. J. FoodSci. 28 431-436. 

Polar chlorophyll derivatives such as chlorophyllides and pheophorbides. 

Figure F4.4.2 HPLC chromatogram of chlorophyll derivatives separated using the Alternate Protocol. Peak identifications 1, chlorophyllide if 2, chlorophyllide a 2, chlorophyllide a" 3, pheophorbide tr, 3, pheophorbide if 4, pyropheophorbide b 5, pheophorbide a 5, pheophorbide a 6, pyropheophorbide a 7, chlorophyll tr, 7, chlorophyll if 8, chlorophyll a 8, chlorophyll a 9, pheophytin tr, 9, pheophytin tf 10, pyropheophytin tr, 11, pheophytin a 11, pheophytin a 12, pyropheophytin a. Reproduced from Canjura et al. (1991) with permission from the Institute of Food Technologists.

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