The Conversion of Chlorophyll to Pheophytin

Mackinney, G.; Joslyn, M. A.

doi:10.1021/ja01858a508

Cited by 50 publications

(29 citation statements)

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“…All food preparation and cooking procedures caused a significantly higher degradation of chlorophyll a than chlorophyll b (45.6 ± 8.0% compared with 32.8 ± 9.8%), which is in line with earlier reports on chlorophyll degradation (Mackinney and Joslyn 1940;Schanderl and others 1962;Siefermann-Harms and Ninnemann 1983). However, as chlorophyll content and enzyme activities differ between plant parts and plant species, degradation pathways and rate of chlorophyll degradation may differ.…”

Section: Discussionsupporting

confidence: 90%

Chlorophyll‐bound Magnesium in Commonly Consumed Vegetables and Fruits: Relevance to Magnesium Nutrition

Bohn¹,

Walczyk²,

Leisibach³

et al. 2004

Journal of Food Science

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Magnesium is bound as the central atom of the porphyrin ring of the green plant pigments chlorophyll a and b. It has been suggested that chlorophyll-bound magnesium may play an important role in magnesium nutrition because when iron is similarly bound in the porphyrin ring of heme, it is absorbed to a greater extent than non-heme iron. We have analyzed 22 frequently consumed fruits and vegetables for the chlorophyll content by high-pressure liquid chromatography and for magnesium with atomic absorption spectroscopy. Chlorophyll concentrations ranged from 6 g/g (grape) to 790 g/g (spinach) (median 63 µg/g). Magnesium concentrations ranged from 48 g/g (grape) to 849 g/g (spinach) (median 122 g/g). In the green leafy vegetables, such as spinach and lettuce, chlorophyll-bound magnesium represented 2.5% to 10.5% of total magnesium whereas other common green vegetables, pulses and fruits contained <1% chlorophyll-bound magnesium. The chlorophyll content of spinach was further decreased by about 35% on thawing frozen spinach or on chopping fresh spinach, and this degradation increased to about 50% after boiling and steaming. Based on the present results and published food consumption data, we estimate that chlorophyll-bound magnesium represents a very low fraction of total magnesium intake in industrialized countries, less than 1% in the case for data obtained from Switzerland. Thus, chlorophyll-bound magnesium is of little relevance to magnesium nutrition.

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Section: Discussionsupporting

confidence: 90%

Chlorophyll‐bound Magnesium in Commonly Consumed Vegetables and Fruits: Relevance to Magnesium Nutrition

Bohn¹,

Walczyk²,

Leisibach³

et al. 2004

Journal of Food Science

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“…8,9 Though this may be a clue for the choice of Zn, quantitative comparison has been done in only a limited number of works on the pheophytinization of Mg-(B)Chls. [10][11][12][13][14][15][16][17] In this work, we compared the pheophytinization rate of Zn-(B)Chl a with that of Mg-(B)Chl a as a function of pH, to find a remarkably high resistance of Zn-BChl a to acid.…”

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confidence: 99%

Acid Resistance of Zn-Bacteriochlorophyll a from an Acidophilic Bacterium Acidiphilium rubrum

et al. 1998

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The major pigments of both antenna and reaction centers (RCs) are chlorophylls (Chls) in higher plants and bacteriochlorophylls (BChls) in photosynthetic bacteria. Except for the metal-free pheophytin (Pheo) a, bacteriopheophytin (BPheo) a (see Fig. 1) and BPheo b acting as primary electron acceptors in RCs 1-3 , only Mg has been known as the central metal of Chls and BChls until we recently found a novel Zn-containing BChl a in an aerobic bacterium Acidiphilium rubrum growing at low pH (ca. 3) 4 and confirmed its structure to be identical with that of BChl a esterified with phytol.

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“…Previous attempts to determine the reaction order n produced contradictory results. Early studies conclude that this reaction is first-order in proton concentration (n ϭ 1) (34,35), whereas more recent work indicates that it is a second-order reaction (n ϭ 2) (36,37). In this work the reaction was studied at sufficiently high acid concentrations, so that it shows exponential kinetics with a pseudo-first-order rate constant kЈ that is given by kЈ…”

Section: Optimizing the Instrument Parameters For Stoppedflow Esi Msmentioning

confidence: 99%

From Small-Molecule Reactions to Protein Folding: Studying Biochemical Kinetics by Stopped-Flow Electrospray Mass Spectrometry

Kolakowski

Konermann

2001

Analytical Biochemistry

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The Conversion of Chlorophyll to Pheophytin

Cited by 50 publications

References 0 publications

Chlorophyll‐bound Magnesium in Commonly Consumed Vegetables and Fruits: Relevance to Magnesium Nutrition

Chlorophyll‐bound Magnesium in Commonly Consumed Vegetables and Fruits: Relevance to Magnesium Nutrition

Acid Resistance of Zn-Bacteriochlorophyll a from an Acidophilic Bacterium Acidiphilium rubrum

From Small-Molecule Reactions to Protein Folding: Studying Biochemical Kinetics by Stopped-Flow Electrospray Mass Spectrometry

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