scholarly journals Investigation of Chlorophyl-a Derived Compounds as Photosensitizer for Photodynamic Inactivation

2021 ◽  
Vol 16 (1) ◽  
pp. 161-169
Author(s):  
Listiana Oktavia ◽  
Irma Mulyani ◽  
Veinardi Suendo
Keyword(s):  
Physicochemical Properties ◽  
Chlorophyll A ◽  
Fluorescence Intensity ◽  
Energy Region ◽  
Metal Ion ◽  
Soret Band ◽  
Photodynamic Inactivation ◽  
Inhibition Activity ◽  
Pheophytin A ◽  
Chlorophyll A And B

Chlorophyll has unique physicochemical properties which makes them good as photosensitizer of Photodynamic Inactivation (PDI). The physicochemical properties of chlorophyll as photosensitizer can be optimized through several routes.  One of the possible route is by replacing the metal ion center of chlorophyll with other ions. In this research, the effect of coordinated metal ion in the natural chlorophyll-a was studied for bacterial growth (S. aureus) inhibition. The replacement of metal in the center of chlorophyll hopefully can improve the intensity of Intersystem Crossing Mechanism (ISC) lead to the formation of singlet oxygen species. The chlorophyll a and b were isolated from spinach via precipitation technique using 1,4 dioxane and water. The chlorophyll a and b were separated using sucrose column chromatography. The thin layer chromatography result showed that chlorophyll a (Rf: 0.57) had been well separated with chlorophyll b (Rf: 0.408). The absorption spectra of chlorophyll a and b showed that the Soret band was observed at 411 and 425 nm, while the Q band appeared at 663 and 659 nm. Replacement of metal ion center shifted the Soret band of chlorophyll- a derivatives to lower energy region, while Q-band was slightly shifted to the higher energy region. The absorption and the fluorescence intensity were  also observed decreasing after ion replacement. The Inhibition activity investigation over S. aureus showed the highest inhibition activity was exhibited by Zn-pheophytin-a (66.8%) followed by chlorophyll a (30.1 %) and Cu-pheophytin-a (0%). The inhibition activity is correlated with decreasing fluorescence intensity. The formation of singlet oxygen by ISC mechanism is hypothesized to deactivate the excitation state of Cu-pheophytin-a. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

scholarly journals Assessment of the effect of heavy metal salts on the photosynthetic activity of aquatic plants

2021 ◽  
pp. 310-318
Author(s):  
G. V. Lobkova ◽  
E. I. Tikhomirova ◽  
Z. A. Simonova
Keyword(s):  
Chlorophyll A ◽  
Fluorescence Intensity ◽  
Aquatic Plants ◽  
Lemna Minor ◽  
Control Level ◽  
Lead Salt ◽  
Chlorophyll B ◽  
Chlorophylls A And B ◽  
Chlorophyll A And B ◽  
Effect Of Copper

The status of the photosynthetic pigments in the aquatic plants Lemna minor L. and Elodea canadensis Michx. under the action of Ni2+, Co2+, Cu2+ and Pb2+ acetate in concentrations 5.00, 2.50, 1.25, 0.62, 0.31, 0.15, 0.07, and 0.03 mg/L was assessed by changes in the fluorescence intensity of chlorophyll a and b and their ratio. It was established that nickel acetate in original solutions in all the above concentrations caused an increase in the fluorescence intensity of chlorophylls a and b in L. minor in relation to the control while the lead salt suppressed it. Co2+ acetate inhibits the fluorescence of chlorophyll a with concentrations in the initial solutions of 0.03 to 0.15 and 2.50 mg/L and that of chlorophyll b at all concentrations, except 0.62, 1.25 and 2.50 mg/L. For E. canadensis it was found that the salts of all metals at all concentrations caused a reduction of the fluorescence intensity of chlorophyll a relative to the control and increased it in the case of chlorophyll b. The exception is the effect of copper and lead acetates with a concentration of 1.25 mg/L, when the fluorescence intensity of chlorophyll b is maintained at the control level. The presence of Ni2+, Co2+, Cu2+, and Pb2+ acetates in all concentrations in the culture medium influences the quantitative and qualitative characteristics of chlorophyll a and b, which indicates a violation of the photosynthesis process. Our data on the change in the chlorophyll a / b ratio leads to a conclusion about degradation of chlorophyll a relative to chlorophyll b after the effect of heavy metals.

scholarly journals THE INFLUENCE OF STRONG AND WEAK ACID UPON AGGREGATION AND PHEOPHYTINIZATION OF CHLOROPHYLL A AND B

2010 ◽  
Vol 9 (1) ◽  
pp. 70-76
Author(s):  
Lia Kusmita ◽  
Leenawaty Limantara
Keyword(s):  
Chlorophyll A ◽  
Higher Plants ◽  
Soret Band ◽  
Weak Acid ◽  
Spectral Difference ◽  
Green Pigment ◽  
Double Beam ◽  
Plant Chloroplast ◽  
Chlorophyll A And B ◽  
Green Pigments

Chlorophyll is green pigment that can be found in plant chloroplast. Higher plants usually have two kinds of chlorophylls, chlorophyll a and b. These green pigments are easily degraded by temperature, light intensity, oxygen, acid, and water. Water causes aggregation of chlorophyll, while acid causes pheophytinization of chlorophyll. Aggregation and pheophytinization process of chlorophyll are influenced by solvents. This study was conducted to observe the spectral difference of aggregated chlorophyll in acetone and methanol upon pheophytinization by strong (HCl) and weak acid (CH3COOH), in comparison to the non-aggregated chlorophyll. Observation of spectral pattern was carried out using double beam spectrophotometer CARY 50 at 350-1100 nm. The result shows that pheophytinization of chlorophyll a and b causes hypsochromic shift, particularly at Soret band. There are new peak formations in Qx region, specifically at 506 and 535 nm for pheophytinized-chlorophyll a, and at 371, 435, 526 and 599 nm for pheophytinized-chlorophyll b.   Keywords: aggregation, chlorophyll a and b, pheophytinization

scholarly journals An extended PROSPECT: Advance in the leaf optical properties model separating total chlorophylls into chlorophyll a and b

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Yao Zhang ◽  
Jingfeng Huang ◽  
Fumin Wang ◽  
George Alan Blackburn ◽  
Hankui K. Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Chlorophyll A ◽  
Leaf Optical Properties ◽  
Chlorophyll A And B

Effects of metal ion in cationic Pd(II) and Ni(II) phthalocyanines on physicochemical and photodynamic inactivation properties

2021 ◽  
pp. 131288
Author(s):  
Irem Kulu ◽  
Vanya Mantareva ◽  
Vesselin Kussovski ◽  
Ivan Angelov ◽  
Mahmut Durmuş
Keyword(s):  
Metal Ion ◽  
Photodynamic Inactivation

scholarly journals A study of the low-lying singlet and triplet electronic states of chlorophyll A and B

2013 ◽  
Vol 78 (11) ◽  
pp. 1775-1787 ◽  
Author(s):  
Mihajlo Etinski ◽  
Milena Petkovic ◽  
Miroslav Ristic
Keyword(s):  
Chlorophyll A ◽  
Density Functional ◽  
Chlorophyll B ◽  
Fluorescence Lifetimes ◽  
Functional Theory ◽  
Chlorophyll A And B ◽  
Vertical Ionization Potentials ◽  
Density Functional Theory Optimization ◽  
Triplet Formation ◽  
Good Agreement

Chlorophylls have been extensively investigated both experimentally and theoretically owing to the fact that they are essential for photosynthesis. We have studied two forms of chlorophyll, chlorophyll a and chlorophyll b, by means of density functional theory. Optimization of S0, S1 and T1 states was performed with the B3-LYP functional. The computed fluorescence lifetimes show good agreement with the available experimental data. The electronic adiabatic energies of S1 and T1 states are 2.09/2.12 and 1.19/1.29 eV for chlorophyll a and chlorophyll b respectively. We discussed the implications of this results on the triplet formation. Also, the calculated vertical ionization potentials shows good agreement with the experimental results.

Light-Induced Accumulation and Stability of Chlorophylls and Chlorophyll-Proteins during Chloroplast Development in Radish Seedlings

1981 ◽  
Vol 36 (5-6) ◽  
pp. 421-430 ◽  
Author(s):  
H. K. Lichtenthaler ◽  
G. Burkard ◽  
G. Kuhn ◽  
U. Prenzel
Keyword(s):  
Chlorophyll A ◽  
Early Stage ◽  
Continuous Darkness ◽  
Suitable Parameter ◽  
Chlorophyll Accumulation ◽  
Chlorophylls A And B ◽  
Sds Page ◽  
Chlorophyll Protein ◽  
Chlorophyll A And B ◽  
Radish Seedlings

Abstract Illumination of 3 day old etiolated radish seedlings with continuous white light results in a progressive accumulation of chlorophyll a and b. Both pigments are bound in a different way to the thylakoid chlorophyll-proteins, which appear parallel to the formation of chlorophylls. By applying the SDS-PAGE method to SDS-digested chloroplasts, it was possible to show that the chloroplasts of radish cotyledons contain the typical chlorophyll proteins LHCP1-3, CPa, CPI and CPIa which have been found in other plants. Between LHCP1 and CPI an additional chlorophyll protein is detected with the spectral properties of a LHCP; it is termed here LHCPy. When the green plants are transferred to continuous darkness, chlorophylls and the chlorophyll-proteins are progressively degraded. At an early stage of greening chlorophyll b is destroyed at a much higher rate in darkness than chlorophyll a, which yields high chlorophyll a/b ratios. This is paralleled by a faster decrease in the level of the corresponding chloro­phyll a/b-protein LHCP3 than of CPI. At a later stage of greening, after the end of the logarithmic chlorophyll accumulation, the chlorophylls a and b and also the LHCP3 and CPI are destroyed in continuous darkness at equal rates; the a/b ratios and the LHCP3/CPI ratios are then little different from the light control. The data indicate that at an early stage of greening the light-harvesting chlorophyll a/b-protein LHCP3 is less stable than the other chlorophyll-proteins (CPI, CPIa, CPa), which contain pre­ dominantly chlorophyll a. The ratio chlorophyll a to β-carotene (a/c ratio) of CPIa, CPI and CPa is about 10, while that of the LHCP1-3 is found to be between 150 to 300. We therefore propose using the a/c ratio to define the chlorophyll-proteins which, besides the absorption spectra, is the most suitable parameter.

scholarly journals Technical Note: Multispectral lidar time series of pine canopy chlorophyll content

2015 ◽  
Vol 12 (5) ◽  
pp. 1629-1634 ◽  
Author(s):  
T. Hakala ◽  
O. Nevalainen ◽  
S. Kaasalainen ◽  
R. Mäkipää
Keyword(s):  
Chlorophyll A ◽  
Point Cloud ◽  
Laser Scanning ◽  
Technical Note ◽  
Tree Canopy ◽  
Tree Level ◽  
Spatial Changes ◽  
New Instrument ◽  
Leaf Level ◽  
Chlorophyll A And B

Abstract. We present an empirical application of multispectral laser scanning for monitoring the seasonal and spatial changes in pine chlorophyll (a + b) content and upscaling the accurate leaf-level chlorophyll measurements into branch and tree level. The results show the capability of the new instrument for monitoring the changes in the shape and physiology of tree canopy: the spectral indices retrieved from the multispectral point cloud agree with laboratory measurements of the chlorophyll a and b content. The approach opens new prospects for replacing destructive and labour-intensive manual sampling with remote observations of tree physiology.

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