scholarly journals Efek Beta Karoten dan Agregasi Klorofil Pada Fotostabilitas Klorofil a dalam Pelarut Aseton

2012 ◽  
Vol 11 (2) ◽  
pp. 115
Author(s):  
Junet. F. da Costa ◽  
Ferry F Karwur ◽  
Leenawaty Limantara
Keyword(s):  
Chlorophyll A ◽  
Red Light ◽  
Photosynthetic Pigment ◽  
Beta Carotene ◽  
Acetone Solution ◽  
Aggregate Form ◽  
Color Additive ◽  
The Stability

Chlorophyll as photosynthetic pigment has many benefits to human such as antioxidant, antibacterial, color additive,immunity, and photosensitizer. Concerning to these applications, chlorophyll a will react with oxygen and light andreduce its effectiveness. It is then important to understand the stability of chlorophyll a on oxygen and light.Stability of chlorophyll a in the presence of beta-carotene (1:1) in acetone was studied for various waterconcentrations. Each solution was exposed to red light (ë e” 630 nm) for 0.5; 1.0; 2.5; 5.0; 10; 20; 30; 40; 50; and 60minutes and their spectrum were analysed. When water was added (8.33; 16.67; 25; 33.33; 41.67; 50; 58.33; 66.67;75; and 83.33 percent) to the acetone solution of chlorophyll a, the chlorophylls aggregate, and in the presence ofbeta-carotene, the chlorophyll more stable. The water shifts the chlorophyll a spectrum toward red duringillumination with or without the presence of carotene. The formation of oligomeric chlorophyll a aggregate occurswithin 10-20 minutes after the water was applied. This strategy of aggregating the chlorophylls to dissipateexcess energy captured from light does not support the photostability of chlorophyll as much as beta-carotene.Surprisingly, when beta carotene was mixed with 66.7% and 75.0% of water, the chlorophyll a degraded 5.56% and9.71% respectively. In conclusion, the aggregate form of chlorophyll a and the presence of beta-carotene increasephotostability of chlorophyll a in acetone solution.

scholarly journals Stability of Chlorophyll a Monomer Incorporated into Cremophor EL Nano-Micelles under Dark and Moderate Light Conditions

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5059
Author(s):  
Ewa Janik-Zabrotowicz ◽  
Marta Arczewska ◽  
Patrycja Prochniewicz ◽  
Izabela Świetlicka ◽  
Konrad Terpiłowski
Keyword(s):  
Chlorophyll A ◽  
Self Assembly ◽  
Molecular Spectroscopy ◽  
Fluorescence Emission ◽  
Molecular Organization ◽  
Cremophor El ◽  
Light Conditions ◽  
Fluorescence Emission Spectra ◽  
Pigment Stability ◽  
The Stability

In this paper, stability of chlorophyll a monomers encapsulated into the Cremophor EL nano-micelles was studied under dark and moderate light conditions, typical of a room with natural or artificial lighting, in the presence of oxygen. The pigment stability against visible light was determined using the dynamic light scattering and molecular spectroscopy (UV-Vis absorption and stationary fluorescence) methods. Chlorophyll a, at the molar concentration of 10−5 M, was dissolved in the 5 wt% Cremophor emulsion for comparison in the ethanolic solution. The stability of such a self-assembly pigment–detergent nano-system is important in the light of its application on the commercial-scale. The presented results indicate the high stability of the pigment monomeric molecular organization in the nano-emulsion. During the storage in the dark, the half-lifetime was calculated as about 7 months. Additionally, based on the shape of absorption and fluorescence emission spectra, chlorophyll aggregation in the Cremophor EL aqueous solution along with the time was excluded. Moreover, the average size of detergent micelles as chlorophyll carriers was not affected after 70 days of the nano-system storage. Pigment stability against the moderate white light (0.1 mW) did not differ significantly from storage conditions in the dark. The photooxidation products, detected by occurrence of new absorption and fluorescence emission bands, was estimated on the negligible level. The stability of such a self-assembly pigment–detergent nano-system would potentially broaden the field of chlorophyll a (chl a) application in the food industry, medicine or artificial photosynthesis models.

scholarly journals Adaptive Mechanisms in Zilla spinosa and Leptadenia pyrotechnica Plants to Sever Aridity in the Egyptian Deserts

2016 ◽  
Vol 8 (4) ◽  
pp. 498-510 ◽  
Author(s):  
Fawzy Mahmoud SALAMA ◽  
Mohamed Abu El-Ela GADALLAH ◽  
Suzan Abd El-Monem SAYED ◽  
Ayat Abd El Monem ABD EL-GALIL
Keyword(s):  
Water Content ◽  
Chlorophyll A ◽  
Soluble Sugars ◽  
Winter Season ◽  
Stability Index ◽  
Severe Drought ◽  
Adaptive Mechanisms ◽  
Drought Conditions ◽  
Chlorophyll A And B ◽  
The Stability

In the present study two species were selected based on their highest presence values to study the response to the severe drought conditions in desert: these were Zilla spinosa and Leptadenia pyrotechnica. The results showed that soil water content and organic matter of Wadi El-Assiuty were very low over the study period. The estimated pH values in the soil solution at the different studied stands tended to be slight alkaline. Total soluble salts were generally higher during summer versus winter. The water content in the studied plants increased significantly during summer. The selected species increased their content of chlorophyll a and b in summer. The stability index of chlorophyll a and b was significantly higher in summer than that estimated in winter. Calcium and magnesium were accumulated in considerable amounts. Ca+2 was the main accumulated cation whereas its concentration were higher than magnesium. Z. spinosa accumulated more sulphates in summer than in winter. Phosphates appeared in low amounts in all the investigated plants. In L. pyrotechnica tissue, Na+ concentration correlated negatively with those found in soil during summer. In winter Na+ and SO4 correlated positively and K+ correlated negatively in Z. spinosa. The studied species showed slightly increase in soluble sugars accumulation. Soluble protein content in Z. spinosa and L. pyrotechnica decreased significantly during winter season. Amino acids content was low and varied between the two investigated species. It seemed that the Z. spinosa is better adapted than L. pyrotechnica to drought conditions, prevailing in the area under study. This judgement can be concluded by the average metabolic potentiality in the species, whereas soluble metabolites (soluble sugars and soluble proteins) were relatively much higher than in the case of L. pyrotechnica.

scholarly journals Alleviation of nickel toxicity in wheat (Triticum aestivum L.) seedlings by selenium supplementation

2013 ◽  
Vol 50 (2) ◽  
pp. 65-78 ◽  
Author(s):  
Ewa Gajewska ◽  
Daniel Drobik ◽  
Marzena Wielanek ◽  
Joanna Sekulska-Nalewajko ◽  
Jarosław Gocławski ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Chlorophyll A ◽  
Electrolyte Leakage ◽  
Growth Parameters ◽  
Photosynthetic Pigment ◽  
Triticum Aestivum L ◽  
Photochemical Activity ◽  
Wheat Seedlings ◽  
Chlorophyll A And B ◽  
Hydroponically Grown

Abstract Hydroponically grown wheat seedlings were treated with 50 μM N i and/or 15 μM Se. After a 7-day culture period, their growth parameters, N i, Se, F e, and M g contents, electrolyte leakage, photosynthetic pigment concentrations, and photochemical activity of photosystem II were determined. Exposure of wheat seedlings to N i alone resulted in reduction in the total shoot and root lengths, by 22% and 50%, respectively. Addition of Se to the N i-containing medium significantly improved the growth of these organs, compared to the seedlings subjected to N i alone. Application of Se decreased the accumulation of N i in shoots and roots and partially alleviated the N i-induced decrease in F e and M g concentations in shoots. Electrolyte leakage increased in response to N i stress, but in shoots it was diminished by Se supplementation. Exposure to N i led to a decrease in chlorophyll a and b contents and enhancement of chlorophyll a/b ratio, but did not influence the concentration of carotenoids. Enrichment of the N i-containing medium with Se significantly increased chlorophyll b content, compared to the seedlings treated with N i alone. Photochemical activity, estimated in terms of the maximum quantum yield of photosystem II , decreased in response to N i treatment but was significantly improved by simultaneous addition of Se. Results of our study suggest that alleviation of N i toxicity in wheat seedlings by Se supplementation may be related to limitation of N i uptake.

Effects of Low Level Graded I-Layer Doping on the Stability of A-SI:H Solar Cells

1992 ◽  
Vol 258 ◽  
Author(s):  
D. Fischer ◽  
N. Pellaton ◽  
H. Keppner ◽  
A. Shah ◽  
C. M. Fortmann
Keyword(s):  
Numerical Modeling ◽  
Solar Cells ◽  
Electric Field ◽  
Conversion Efficiency ◽  
Red Light ◽  
Degradation Behavior ◽  
Low Level ◽  
Carrier Collection ◽  
The Stability ◽  
Light Conversion Efficiency

ABSTRACTThis work reports on attempts to tailor the electric field of a-Si:H solar cells by the graded low-level doping of the intrinsic layer to optimize conversion efficiency in the degraded state. Based on wavelength dependent collection measurements and numerical modeling, the degradation behavior of doped and undoped cells is explained in terms of the interaction of dopants and the light-induced space-charge. Low level doping is shown to shift the electric field away from the p/i interface towards the bulk of the i-layer. This results in a better carrier collection from the back part of the solar cell, and solar cells with improved stabilized red light conversion efficiency can be realized. These cells can be readily applied as bottom cells of stacked solar cells.

scholarly journals THE EFFECTIVENESS OF THE SPECTRUM IN CHLOROPHYLL FORMATION

1946 ◽  
Vol 29 (3) ◽  
pp. 157-179 ◽  
Author(s):  
Sylvia R. Frank
Keyword(s):  
Chlorophyll A ◽  
Relative Effectiveness ◽  
Red Light ◽  
Absorption Properties ◽  
Constant Amount ◽  
Green Pigment ◽  
Pumpkin Seed ◽  
Pigment Precursor ◽  
Seed Coats ◽  
Chlorophyll Formation

1. Although the carotenoid pigments are present in large concentration in the plastids of etiolated Avena seedlings as compared with protochlorophyll, the pigment precursor of chlorophyll, it is possible to show that the carotenoids do not act as filters of the light incident on the plant in the blue region of the spectrum where they absorb heavily. This suggests that the carotenoids are located behind the protochlorophyll molecules in the plastids. 2. Since the carotenoids do not screen and light is necessary for chlorophyll formation, an effectiveness spectrum of protochlorophyll can be obtained which is the reciprocal of the light energy necessary to produce a constant amount of chlorophyll with different wavelengths. The relative effectiveness of sixteen spectral regions in forming chlorophyll was determined. 3. From the effectiveness spectrum, one can conclude that protochlorophyll is a blue-green pigment with major peaks of absorption at 445 mµ, and 645 mµ, and with smaller peaks at 575 and 545 mµ. The blue peak is sharp, narrow, and high, the red peak being broader and shorter. This differs from previous findings where the use of rougher methods indicated that red light was more effective than blue and did not give the position of the peaks of absorption or their relative heights. 4. The protochlorophyll curve is similar to but not identical with chlorophyll. The ratio of the peaks of absorption in the blue as compared to the red is very similar to chlorophyll a, but the position of the peaks resembles chlorophyll b. 5. There is an excellent correspondence between the absorption properties of this "active" protochlorophyll and what is known of the absorption of a chemically known pigment studied in impure extracts of seed coats of the Cucurbitaceae. Conclusive proof of the identity of the two substances awaits chemical purification, but the evidence here favors the view that the pumpkin seed substance, which is chemically chlorophyll a minus two hydrogens, is identical with the precursor of chlorophyll formation found in etiolated plants.

HPLC analysis of chlorophyll a, chlorophyll b, and beta-carotene in collard greens

1984 ◽  
Vol 61 (3) ◽  
pp. 264 ◽  
Author(s):  
Augustine Silveira ◽  
Jerry A. Koehler ◽  
Edward F. Beadel ◽  
Pearle A. Monroe
Keyword(s):  
Chlorophyll A ◽  
Hplc Analysis ◽  
Beta Carotene ◽  
Chlorophyll B ◽  
Collard Greens

scholarly journals AKTIVITAS TERMOPROTEKSI DAN FOTOPROTEKSI EKSTRAK KASAR KAROTENOID MESOKARP KELAPA SAWIT (Elaeis guineensis Jacq.) TERHADAP KESTABILAN KLOROFIL-A)

2019 ◽  
Vol 12 (1) ◽  
pp. 112-123
Author(s):  
Dece Elisabeth Sahertian ◽  
Indriatmoko Indriatmoko ◽  
Leenawaty Limantara ◽  
Tatas Hardo Panintingjati Brotosudarmo
Keyword(s):  
Absorption Spectrum ◽  
Light Intensity ◽  
Chlorophyll A ◽  
Elaeis Guineensis ◽  
Heating Time ◽  
Protective Function ◽  
Stability And Instability ◽  
In Series ◽  
Elaeis Guineensis Jacq ◽  
The Stability

AbstrakKelapa sawit (Elaeis guineensis Jacq.) merupakan tanaman yang mengandung karotenoid tinggi pada mesokarp yang merupakan bagian dari buah. Cahaya dan suhu dalam proses fotosintesis memberi pengaruh bagi kestabilan dan ketidakstabilan karotenoid dan klorofil. Penelitian ini bertujuan untuk mengetahui aktivitas fotostabilitas dan termostabilitas ekstrak karotenoid mesokarp terhadap klorofil-a yang diiradiasi dengan lampu volpi (intralux 4100) daylight pada intensitas cahaya 31960 lux, 47040 lux dan 76640 lux dalam seri waktu penyinaran 0, 5, 10, 15, 20, 25, dan 30 menit serta dipanaskan pada suhu 25, 50, 65, dan 90 °C dengan seri waktu pemanasan 0, 1, 2, 3, 6, 9, dan 24 jam. Pengukuran spektrum serapan tiap perlakuan diukur menggunakan Spektrofotometer UV-Tampak pada panjang gelombang 300–800 nm. Hasil penelitian menunjukkan bahwa karotenoid tidak melakukan fungsi proteksi dengan baik pada perlakuan pemanasan 65 °C dan 90 °C selama 24 jam, serta perlakuan iradiasi hingga 30 menit pada ketiga intensitas cahaya. Kesimpulan dari penelitian ini adalah klorofil-a murni lebih stabil pada perlakuan pemanasan dan iradiasi. Kemampuan proteksi karotenoid terhadap kestabilan klorofil-a yaitu pada suhu di bawah 50 °C dan pada intensitas cahaya di bawah 31960 lux.Abstract Oil palm (Elaeis guineensis Jacq.) is a plant that contains high carotenoids in its mesocarp which is part of the fruit. Light and temperature in photosynthesis may affect the stability and instability of carotenoid and chlorophyll. The aim of this research was to examine the thermostability and photostability activities of the carotenoids in mesocarp extract on chlorophyll which were irradiated by Volpi lamp (4100 intralux) daylight at light intensity of 31960 lux, 47040 lux and 76640 lux in series of time radiation 0, 5, 10, 15, 20, 25, and 30 minutes and heated at 25, 50, 65, and 90°C with series of heating time 0, 1, 2, 3, 6, 9, and 24 hours. Measurement of the absorption spectrum of each treatment was measured using a UV-Vis Spectrophotometer at a wavelength range of 300–800 nm. The results showed the protective function of carotenoids did not perform well at the heating treatments of 65°C and 90°C in 24 hours and at the irradiation for 30 minutes in all the light intensities. In conclusion, pure chlorophyll-a is more stable in heating and irradiation treatments. Carotenoid protection ability against chlorophyll-a is at temperatures below 50 °C and at a light intensity below 31960 lux.

scholarly journals INFLUENCE OF SPECTRAL FILTERS ON LEAF PIGMENTS AND ANATOMY OF `SPEARS' CHRYSANTHEMUM

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 648g-648
Author(s):  
Margaret J. McMahon ◽  
John W. Kelly
Keyword(s):  
Chlorophyll A ◽  
Unit Area ◽  
Red Light ◽  
Leaf Size ◽  
Blue Dye ◽  
Textile Dye ◽  
Chlorophyll B ◽  
Spectral Filtering ◽  
Spectral Filters ◽  
Β Carotene

`Spears' chrysanthemums were grown in chambers fitted with double-walled exolite filled with spectral filtering solutions: a blue textile dye that absorbed red light, CuSO4·5H2O that absorbed far-red light, and H2O that was spectrally non-selective (control). Leaves of `Spears' grown under CuSO4-filters had increased chlorophyll a (23%), chlorophyll b (26%), xanthophyll (22%), and β-carotene (24%) compared to plants grown under H2O or blue-dye filters. Ratios of total carotenoid: chlorophyll and chlorophyll a: chlorophyll b were not affected by filter. Individual leaf area was reduced 25% under CuSO4 filters compared to other filters. Stomates per unit area were not affected by filters, however stomates per leaf were reduced 25% under CuSO4 filters because of leaf size reduction. Stomate length and width were not affected by filter. Leaves from plants grown under CuSO4-filters had an internal structure resembling that of sun-type leaves. Other filters induced a shade-type leaf.

scholarly journals Spatial Distribution Of Chlorofil-a In Laguna Kabori Manokwari Regency

2020 ◽  
pp. 77-85
Author(s):  
Suci Widya Warnetti ◽  
Thomas Frans Pattiasina ◽  
Fitriyah Irmawati Elyas Saleh ◽  
Alianto Alianto ◽  
Selfanie Talakua ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Chlorophyll A ◽  
Spatial Data ◽  
Water Productivity ◽  
Photosynthetic Pigment ◽  
Quality Data ◽  
Sampling Point ◽  
Water Quality Data ◽  
Depth Measurement ◽  
Chlorophyll A Content

Kabori Lagoon is a lagoon located in Manokwari Regency, West Papua, where the water quality data is still very limited. Chlorophyll-a is the most important photosynthetic pigment for aquatic plants such as phytoplankton. The purpose of this study was to determine the horizontal distribution of chlorophyll-a based on the spatial data approach in the waters of the Kabori Lagoon. The study was conducted from April to May 2019. The sampling point was determined by purposive sampling at eight points for sampling of chlorophyll-a and water parameters including physics and chemistry (temperature, DO, salinity, brightness and depth). Measurement of physical and chemical parameters is carried out in situ. Chlorophyll-a analysis was carried out at the Laboratory of Water Productivity and Quality, Faculty of Marine and Fisheries Sciences, Hasanuddin University. Spatial data processing used ArcGIS 10.4 and Surfer 16 to create chlorophyll-a distribution maps and bathymetry. The results showed that the chlorophyll-a content in Observation I was in the range of 0.12-2.40 mg/m3 and in Observation II it was in the range of 1.43-10.84 mg/m3. Based on the chlorophyll-a content, the Kabori Lagoon is included in the mesotrophic category. Spatially, the distribution of chlorophyll-a content varies, but tends to be higher in the southern part of the lagoon than in the northern part of the lagoon.  Spatial distribution, Chlorophyll-A, Kabori Lagoon, Mesotrophic

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