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PubMed2006

Heme and chlorophyll intake and risk of colorectal cancer in the Netherlands cohort study.

BACKGROUND: The evidence for red meat as a determinant of colorectal cancer remains equivocal, which might be explained by differences in heme content. Heme is the pro-oxidant, iron-containing porphyrin pigment of meat and its content depends on the type of meat. Chlorophyll from green vegetables might modify this association. METHODS: The Netherlands Cohort Study was initiated in 1986 when a self-administered questionnaire on risk factors for cancer was completed by 120,852 subjects ages 55 to 69 years. After 9.3 years of follow-up through the Cancer Registry, 1,535 incident colorectal cancer cases (869 men and 666 women) were available. Nineteen of the 150 items in the validated dietary questionnaire related to consumption of specific types of fresh and processed meat. Heme iron content was calculated as a type-specific percentage of the total iron content and chlorophyll content of vegetables was derived from the literature. RESULTS: Multivariate rate ratios for quintiles of heme iron intake and colon cancer were 1.00, 0.98, 1.04, 1.13, and 1.29 (P(trend) = 0.10) among men and 1.00, 1.31, 1.44, 1.18, and 1.20 (P(trend) = 0.56) among women, respectively. No consistent associations were observed for rectal cancer. Rate ratios for colon cancer increased across successive quintiles of the ratio of heme/chlorophyll among men only (1.00, 1.08, 1.01, 1.32, and 1.43; P(trend) = 0.01). No associations were observed between fresh meat and colorectal cancer. CONCLUSION: Our data suggest an elevated risk of colon cancer in men with increasing intake of heme iron and decreasing intake of chlorophyll. Further research is needed to confirm these results.

Aged↗
PubMed2004

Modeling the optical properties of mineral particles suspended in seawater and their influence on ocean reflectance and chlorophyll estimation from remote sensing algorithms.

The optical properties of mineral particles suspended in seawater were calculated from the Mie scattering theory for different size distributions and complex refractive indices of the particles. The ratio of the spectral backscattering coefficient to the sum of the spectral absorption and backscattering coefficients of seawater, b(b)(lambda)/[a(lambda) + b(b)(lambda)], was analyzed as a proxy for ocean reflectance for varying properties and concentrations of mineral particles. Given the plausible range of variability in the particle size distribution and the refractive index, the general parameterizations of the absorption and scattering properties of mineral particles and their effects on ocean reflectance in terms of particle mass concentration alone are inadequate. The variations in the particle size distribution and the refractive index must be taken into account. The errors in chlorophyll estimation obtained from the remote sensing algorithms that are due to the presence of mineral particles can be very large. For example, when the mineral concentration is 1 g m(-3) and the chlorophyll a concentration is low (0.05 mg m(-3)), current global algorithms based on a blue-to-green reflectance ratio can produce a chlorophyll overestimation ranging from approximately 50% to as much as 20-fold.

Algorithms↗
PubMed2003

Origin of chlorophyll fluorescence in plants at 55-75 degrees C.

The origin of heat-induced chlorophyll fluorescence rise that appears at about 55-60 degrees C during linear heating of leaves, chloroplasts or thylakoids (especially with a reduced content of grana thylakoids) was studied. This fluorescence rise was earlier attributed to photosystem I (PSI) emission. Our data show that the fluorescence rise originates from chlorophyll a (Chl a) molecules released from chlorophyll-containing protein complexes denaturing at 55-60 degrees C. This conclusion results mainly from Chl a fluorescence lifetime measurements with barley leaves of different Chl a content and absorption and emission spectra measurements with barley leaves preheated to selected temperatures. These data, supported by measurements of liposomes with different Chl a/lipid ratios, suggest that the released Chl a is dissolved in lipids of thylakoid membranes and that with increasing Chl a content in the lipid phase, the released Chl a tends to form low-fluorescing aggregates. This is probably the reason for the suppressed fluorescence rise at 55-60 degrees C and the decreasing fluorescence course at 60-75 degrees C, which are observable during linear heating of plant material with a high Chl a/lipid ratio (e.g. green leaves, grana thylakoids, isolated PSII particles).

Chlorophyll↗
PubMedDate not supplied

Determination of stereochemistry of bacteriochlorophyll gF and 8(1)-hydroxy-chlorophyll aF from Heliobacterium modesticaldum.

The reaction center complex of heliobacteria contains three kinds of chlorophyll pigments, bacteriochlorophyll gF (BChl gF), its 13(2)-epimer BChl gF' and 8(1)-hydroxy-chlorophyll aF (8(1)-OH-Chl aF). Because the full stereochemistry of these naturally occurring chlorophyllous pigments has remained unknown, we determined the stereochemistry of both BChl gF and 8(1)-OH-Chl aF extracted from Heliobacterium modesticaldum. The configurations of the specific functional groups at ring-B as well as those at ring-D and -E were investigated by use of nuclear Overhauser effect correlations in their 1H-NMR spectra and circular dichroism spectra, as well as by modified Mosher's method in their chemical modification: (1) E-configuration was confirmed for the 8-ethylidene group at ring-B in BChl gF, (2) R-configuration was identified for the 1-hydroxyethyl group at ring-B in 8(1)-OH-Chl aF and (3) 13(2)-(R)-, 17-(S)- and 18-(S)-configurations at ring-D and -E in both BChl gF and 8(1)-OH-Chl aF were confirmed. These stereochemistries enabled us to discuss their biosynthesis and to propose possible routes for preparation of ethylidene and 1-hydroxyethyl groups at the 8-position.

Bacteriochlorophylls↗
PubMed2005

Global changes of chlorophyll excitonic interactions in photosystem II during thermal denaturation.

Photosystem II (PSII) is a multisubunit chlorophyll-binding enzyme that absorbs light to catalyze water oxidation and plastoquinone reduction. Chlorophyll excitonic interaction changes in PSII were studied by absorption and circular dichroism spectra from 25 degrees C to 80 degrees C, and protein subunit denaturation was monitored by differential scanning calorimetry. A four-stage process of chlorophyll excitonic interaction change was observed being correlated with the denaturation of protein subunits.

Chlorophyll↗
PubMed1999

Identification of oxidized chlorophylls and metallochlorophyllic complexes of copper in table olives (cv. Gordal) with green staining alteration.

In Spanish green table olives showing the alteration known as green staining, new chlorophyll derivatives have been identified: the copper complexes of 3(1),3(2)-didehydrorhodochlorin-15-glyoxylic acid-17(3)-phytyl ester a and b (Cu-15-glyoxylic acid pheophytins a and b), and 3(1),3(2)-didehydro-15(1)-hydroxy-15(1)-hydroxyrhodochlorin- 15-acetic acid delta-lactone-15(2)-methyl-17(3)-phytyl ester a and b (Cu-15(1)-OH-lactone-pheophytins a and b). These compounds were isolated by normal phase thin-layer chromatography and identified from their UV-visible and mass spectra and by co-chromatography with authentic standards. The chromatographic and spectroscopic characteristics and the molecular mass for a new allomerized chlorophyll derivative and its copper complex are reported. The corresponding molecular structure according to the molecular mass has been proposed. The characterization of the latter compounds enables their possible detection in processed fruits and vegetables. The present work gathers new advances in the study of the color alteration in table olives and this is the first time that copper complexes of oxidized chlorophylls are detected in foodstuffs.

Chlorophyll↗
PubMed1998

Mechanisms of regulation and interplastid localization of chlorophyll biosynthesis.

The current concepts of chlorophyll biosynthesis, its interplastid localization, biosynthetic and biochemical heterogeneity, mechanisms of regulation of the key reactions, formation of 5-aminolevulinic acid and incorporation of magnesium into protoporphyrin IX, are reviewed. The literature and author's data demonstrate the existence of in vivo multienzyme systems synthesizing chlorophyll and its precursors as monovinyl and divinyl chemical species. Both types of the multienzyme systems synthesize 5-aminolevulinic acid and regulate this process independently. A hypothesis is considered that the function of the magnesium branch of chlorophyll biosynthesis in vivo is controlled by a mechanism through inhibition of the enzymes by their products because of the limitation of the binding sites for them in the membrane. An additional influence of light on the Mg-chelatase activity not only via the photosynthetic supply with ATP but also through the light-induced synthesis of the enzyme molecules de novo is described. Efficient energy migration from protoporphyrin IX and Mg-protoporphyrin IX (monomethyl ester) molecules to the protochlorophyllide active form detected by the author is discussed considering a close location of these pigments in plastid membranes and the enzymes participating in their formation.

Chlorophyll↗
PubMed1999

[Effect of concentration temperature of kiwi fruit pulp on color, chlorophyll and ascorbic acid].

A study was established to evaluate concentration temperatures (25, 30, 35, 40 and 45 degrees C) on kiwi fruit pulp concentrated to 32 degrees Brix, with vacuum regulation. Munsell and sensorial colour, ascorbic acid and chlorophyll amount remanent were analyzed. Both, 25 and 30 degrees C concentration temperatures treatments, in the most of variables, experimented low deteriorate and differ with the other treatments. Ascorbic acid measurements had not significative differences (P < 0.95). Chlorophyll assays showed a decreased (70%) in the amount remanent over 35 degrees C in comparison to 25 degrees C treatments. 40 and 45 degrees C treatments showed traces of chlorophyll. Sensorial colour did not showed variations on 25 and 30 degrees C treatments; they were classified as bright green. Other treatments present colour deteriorate: 35 degrees C treatment was green-yellowish classified, and 45 degrees C treatments brown-greenish categories. Munsell colour showed the same relations, were increasing the concentration temperatures, decrease the green colour and increase the yellow colour.

Ascorbic Acid↗
PubMed2000

Pheophorbide a, a moiety of chlorophyll a, induces apoptosis in human lymphoid leukemia molt 4B cells.

The exposure of human lymphoid leukemia Molt 4B cells to pheophorbide a (PPB a), a moiety of chlorophyll a, led both to growth inhibition and induction of programmed cell death (apoptosis). The growth inhibition by PPB a was much stronger than that by chlorophyll a. Morphological change showing apoptotic bodies was observed in the Molt 4B cells treated with PPB a. The fragmentation by PPB a of DNA to oligonucleosomal-sized fragments, that are characteristics of apoptosis, was observed to be concentration- and time-dependent. These findings suggest that growth inhibition by PPB a of Molt 4B cells results from the induction of apoptosis and that PPB a, moiety of chlorophyll a, is essential for exertion of antitumor and apoptosis-inducing activity in these cells.

Apoptosis↗
PubMed2002

The mapping of QTLS for chlorophyll content and responsiveness to gibberellic (GA3) and abscisic (ABA) acids in rye.

Genetic maps containing molecular markers are useful tools for the identification of genes underlying quantitative traits (QTLs). Three traits important for plant physiology, i.e. chlorophyll content, sensitivity to GA and sensitivity to ABA, were evaluated for 99 F2 families of the DS2 x RXL10 rye mapping population. The observed variation in the chlorophyll content in rye leaves was shown to be under the genetic control of four independent QTLs. They were located on the following chromosome arms: 1RL (QChc-1R.1), 3RS (QChc-3R.1), 4RL (QChc-4R.1) and 5RL (QChc-5R.1) The marker-assisted selection of recombinants comprising positively-acting alleles at these loci may significantly increase the chlorophyll content in rye leaves, which should result in a higher efficiency of photosynthesis. A decreasing of plant height in rye is one of the major aims of breeders selecting for lodging resistance. The polymorphism of genes controlling sensitivity to gibberellic acid may be the basis for a potential selection strategy. Three QTLs underlying the sensitivity of rye seedlings to GA were located on chromosomes 5RL (QGar-5R.1), 1RL (QGar-1R.1) and on 7RL (QGar-7R.1). The dwarfing allele of a Dw1 locus present in line RXL10 was mapped in the same position as the QGar-5R.1 gene. Sensitivity to ABA plays an important role in imposing dormancy in rye grain. Three QTLs affecting sensitivity to ABA were found. They were mapped on chromosomes 1RS (QAbr-1R.1), 2R in the centromeric region (QAbr-2R.1) and on 5RL (QAbr-5R.1). QAbr-5R.1, Dw1 and QGar-5R.1 are located in the same position on the distal part of the 5RL chromosome arm, which suggests that they belong to a single locus for a major regulatory gene controlling the development of rye plants.

Abscisic Acid↗
PubMedDate not supplied

[Pigment accumulation and functional activity of chloroplasts in common Pisum sativum L. mutants with low chlorophyll level (chlorotica)].

Pea mutants chlorotica 2004 and 2014 with a low content of chlorophyll were studied. The mutant 2004 has light green leaves and stem, and the mutant 2014 has yellow green leaves and stem. They accumulate approximately 80 and 50% chlorophylls of the parent form of pea Torsdag cv. The content of carotene in carotenoids of the mutant 2004 was much lower, and the accumulation of lutein and violaxanthine was increased. The accumulation of all carotenoids in the mutant 2014 decreased almost proportionally to a decrease in the chlorophyll content. The rate of CO2 evolution in mutant chlorotica 2004 and 2014 was established to be lower. The quantum efficiency of photosynthesis in the mutants was 29-30% lower as compared to the control, and in hybrid plants it was 1.5-2-fold higher. It is assumed that the increase in the activity of the night-time respiration in gas exchange of chlorotica mutants and the drop of photosynthesis lead to a decrease in biomass increment. The results obtained allow us to conclude that the mutation of chlorotica 2004 and 2014 affects the genes controlling the formation and functioning of different components of the photosynthetic apparatus.

Carotenoids↗
PubMed1992

Characterization of chlorophyll a/b proteins of photosystem I from Chlamydomonas reinhardtii.

In this study we have isolated the chlorophyll a/b-binding proteins from a photosystem I preparation of the green alga Chlamydomonas reinhardtii and characterized them by N-terminal sequencing, fluorescence, and absorption spectroscopy and by immunochemical means. The results indicate that in this organism, the light-harvesting complex of photosystem I (LHCI) is composed of at least seven distinct polypeptides of which a minimum number of three are shown to bind chlorophyll a and b. Both sequence homology and immunological cross-reactivity with other chlorophyll-binding proteins suggest that all of the LHCI polypeptides bind pigments. Fractionation of LHCI by mildly denaturing methods showed that, in contrast to higher plants, the long wavelength fluorescence emission typical of LHCI (705 nm in C. reinhardtii) cannot be correlated with the presence of specific polypeptides, but rather with changes in the aggregation state of the LHCI components. Reconstitution of both high aggregation state and long wavelength fluorescence emission from components that do not show these characteristics confirm this hypothesis.

Amino Acid Sequence↗
PubMedDate not supplied

[The ontogenetic approach to chlorophyll fluorescence studies of plant photosynthetic apparatus under stressful conditions].

Based on the analysis of reasons limiting the application of the method of chlorophyll fluorescence induction for estimating the state of the leaf photosynthetic apparatus under prolonged stress, the necessity of the ontogenetic approach consisting in a more exact determination of leaf age was substantiated. A comparison of the calendar and ontogenetic ways of determination of age of cucumber leaves under controlled conditions revealed essential distinctions in the estimation of plant leaf photosynthetic apparatus by the method of chlorophyll fluorescence induction for two variants distinguishing by the cultivation light regime ("white", 400-700 nm, and "red", 600-700 nm). It was shown that, in the case of prolonged effect of the stress factor on the plant, the unambiguity of the interpretation of chlorophyll fluorescence induction parameters in the estimation of the state of their photosynthetic apparatus depends essentially on the choice of the ontogenetic period of leaves of plants being compared and the accuracy of determination of leaf age.

Chlorophyll↗
PubMed2005

[Dynamics of water retaining capacity and chlorophyll content of two-line hybrid rice during heading-grain filling stage and their relations with grain yield].

The study with 25 two-line hybrid rice strains showed that their water retaining capacity was different with their combinations. On the whole, the water content in leaf and stem-sheath decreased during heading-grain filling stage, while that in panicle increased first and then decreased, with a peak at 7th day after heading. Stem-sheath was the main organ for water retaining. The correlation of panicle yield with both leaf and stem-sheath water content was positive at the 1st day after heading but became negative later, and that with whole stem-plant water content was positive after heading. The chlorophyll content of the two-line hybrids increased first and then decreased, with a peak at the 7th day after heading. Comparing with normal rice (male parent), the chlorophyll content of most two-line hybrids was lower, and the decreasing rate was faster than that of normal rice after heading. For two-line hybrid rice breeding, it should preferentially consider to select those hybrids which have a clearer dominance of plant water retaining capacity and a higher chlorophyll content at earlier and middle heading-grain filling stage, and an obvious dry matter transportation from leaf and stem-sheath at later heading-grain filling stage. For two-line hybrid rice planting, it should not only pay attention to the supply of water and nutrients, especially nitrogen at earlier and middle heading-grain filling stage, but also control nitrogen and water in time to prevent leaf green clinging and to promote dry matter transportation from leaf and stem-sheath to grain at later heading-grain filling stage.

Biomass↗
PubMed2005

Influence of pH on lead uptake, chlorophyll and nitrogen content of Nasturtium officinale R. Br. and Mentha aquatica L.

In the present study, effects of pH (5.0, 7.0 and 9.0) and lead (1, 5, 10, 25, 50 and 100 microg mL(-1)) were investigated on uptake of lead, content of chlorophyll and nitrogen in Nasturtium officinale and Mentha aquatica. Total chlorophyll and nitrogen contents were adversely affected from Pb2+ concentrations dose dependently at each pH. The macrophytes were adversely affected by pH 5.0 or more than 9.0. After 12-days Pb2+ treatment, results showed that lead accumulation of macrophyte tissues was variable. According to the parts of the macrophytes, Pb2+ amounts were generally found at all tested pH levels and the metal concentrations for M. aquatica in the following order: root > stem > leaf and for N. officinale root > leaf > stem. Pb2+ concentrations in plant tissues (root, stem, leaf) in relation to pH were generally found for both macrophytes in following order: 7.0 > 9.0 > 5.0. Despite of the fact that high Pb2+ accumulation was observed in root tissues of the macrophytes, low metal accumulation was measured in the above-ground parts indicating low root-leaf translocation. The study indicated that uptake rate of Pb2+ and its toxicity on Chlorophyll and nitrogen contents in the macrophytes were dependent upon pH value of solutions.

Analysis of Variance↗
PubMed2006

Impact of fertilizer factory effluent on seed germination, seedling growth and chlorophyll content of gram (Cicer aeritenum).

In the present study effect of fertilizer factory effluent on seed germination, seedling growth and chlorophyll content of gram (Cicer aeritenum) has been carried out, at different concentration of the effluent and time intervals. The effluent is alkaline in nature with strong ammonia odour. The germination percentage of seed, seedling growth and chlorophyll content showed a gradual decline with increase in effluent concentration. At 25% concentration of the effluent, growth promotion in terms of root, shoot length and increase in chlorophyll content recorded at 21 days. However, at higher concentrations of the effluent toxic effects were observed at 21 days. The study suggests that the effluent can be used safely for Cicer aeritenum cultivation, only after proper treatment and dilution.

Chlorophyll↗
PubMed2004

[Effect of accumulating fluorine and sulphur compounds on the content of chlorophyll in pine needles (Pinus sylvestris L.) from some areas of southern Poland in 2001-2003].

Concentrations of F(-), S and chlorophyll in needles of pines growing near metallurgical works and power plants were determined. A statistically significant positive correlation between F(-) (in the range of 4.32 to 21.98 microg F(-)/g d.m.) and chlorophyll and a negative correlation between S (in the range of 1094 to 2150 microg S/g d.m.) and chlorophyll was found. This result suggests an antagonistic interaction between F(-) and S in pine needles.

Chlorophyll↗
PubMed1990

Immunological identification and quantification of light harvesting chlorophyll a/b protein of Chlorella protothecoides.

The alteration of photosynthetic membrane proteins in relation to the disappearance of pigments during the heterotrophic growth of Chlorella protothecoides was investigated. Chlorophylls and certain polypeptides associated with the LHC II disappeared after 50 hr of heterotrophic growth but the 24 kDa apoprotein constituting LHC II was not affected. Immunological analysis indicated that the chlorophylls and the light harvesting complex proteins of the thylakoid membranes are not tightly coupled and the latter is retained in its native form irrespective of the presence or absence of the former. The circumstantial evidence that the other photosynthetic membrane polypeptides are degraded along with the pigments due to increased proteolytic activity in the rapidly dividing heterotrophic cells indicate that chlorophyll synthesis is not a pre-requisite for the synthesis of the LHC II apoprotein.

Chlorella↗