Properties of Chlorophyll and Derivatives in Homogeneous and Microheterogeneous Systems

Aluminum Chloride Phthalocyanine (AlPcCl) can be used as a photosensitizer (PS) for Photodynamic Inactivation of Microorganisms (PDI). The AlPcCl showed favorable characteristics for PDI due to high quantum yield of singlet oxygen (ΦΔ ) and photostability. Physicochemical properties and photodynamic inactivation of AlPcCl incorporated in polymeric micelles of tri-block copolymer (P-123 and F-127) against microorganisms Staphylococcus aureus, Escherichia coli and Candida albicans were investigated in this work. Previously, it was observed that the AlPcCl undergoes self-aggregation in F-127, while in P-123 the PS is in a monomeric form suitable for PDI. Due to the self-aggregation of AlPcCl in F-127, this formulation did not show any effect on these microorganisms. On the other hand, AlPcCl formulated in P-123 was effective against S. aureus and C. albicans and the death of microorganisms was dependent on the PS concentration and illumination time. Additionally, it was found that the values of PS concentration and illumination time to eradicate 90% of the initial population of microorganisms (IC90 and D90 , respectively) were small for the AlPcCl in P-123, showing the effectiveness of this formulation for PDI.

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“…The Φ F was calculated by the Eq. .

{normalΦ}_{F} = \frac{{Abs}_{normalStd} F_{C} n_{Std}^{2}}{{Abs}_{C} F_{normalStd} n_{C}^{2}} {normalΦ}_{normalStd}

where Std: standard and C : AlPcCl ; n : refractive index; F : emission spectra area.…”

Section: Methodsmentioning

confidence: 99%

Formulation of Aluminum Chloride Phthalocyanine in Pluronic^™ P‐123 and F‐127 Block Copolymer Micelles: Photophysical properties and Photodynamic Inactivation of Microorganisms

Vilsinski

Gerola

Enumo

et al. 2015

Photochem & Photobiology

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“…ZnChl was prepared by addition of Zn to pheophorbide a (Frontier Scientific) as described [67]. DMSO-solubilized ZnChl stock concentrations were determined by dilution in methanol using an extinction coefficient of 64 000 M 21 cm 21 at 656 nm [68].…”

Section: Pigment Purificationmentioning

confidence: 99%

De novo synthetic biliprotein design, assembly and excitation energy transfer

Mancini

Sheehan

Kodali

et al. 2018

J. R. Soc. Interface.

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Bilins are linear tetrapyrrole chromophores with a wide range of visible and near-visible light absorption and emission properties. These properties are tuned upon binding to natural proteins and exploited in photosynthetic light-harvesting and non-photosynthetic light-sensitive signalling. These pigmented proteins are now being manipulated to develop fluorescent experimental tools. To engineer the optical properties of bound bilins for specific applications more flexibly, we have used first principles of protein folding to design novel, stable and highly adaptable bilin-binding four-α-helix bundle protein frames, called maquettes, and explored the minimal requirements underlying covalent bilin ligation and conformational restriction responsible for the strong and variable absorption, fluorescence and excitation energy transfer of these proteins. Biliverdin, phycocyanobilin and phycoerythrobilin bind covalently to maquette Cys A blue-shifted tripyrrole formed from maquette-bound phycocyanobilin displays a quantum yield of 26%. Although unrelated in fold and sequence to natural phycobiliproteins, bilin lyases nevertheless interact with maquettes during co-expression in to improve the efficiency of bilin binding and influence bilin structure. Bilins bind and to Cys residues placed in loops, towards the amino end or in the middle of helices but bind poorly at the carboxyl end of helices. Bilin-binding efficiency and fluorescence yield are improved by Arg and Asp residues adjacent to the ligating Cys on the same helix and by His residues on adjacent helices.

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“…The pheophytinization takes place at low pH. Mg 2+ is replaced by 2H + and this reaction results in a shift in the absorption wavelength [35]. If a strongly green product is desired, it is likely that increasing the pH again to neutral would stabilize the chlorophyll.…”

Section: Colormentioning

confidence: 99%

pH-shift processing of Nannochloropsis oculata microalgal biomass to obtain a protein-enriched food or feed ingredient

2015

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Keywords:Microalgae Nannochloropsis Food Acid/alkaline solubilization and precipitation Protein n-3 fatty acids Fractionation of plant and animal raw materials by pH-shift processing has been widely applied to purify proteins. The principle is to solubilize proteins at high or low pH, removing debris and precipitating the proteins near their isoelectric point. We here describe the pH-shift process on commercially available Nannochloropsis oculata. The partitioning of major nutrients into the various fractions of the process was studied. Proteins were found to exhibit maximal solubility between pH 7 and 10, with a minimal solubility below pH 4. Two process versions were investigated in this study, with solubilization at either pH 7 (native pH) or 10; both versions were precipitated at pH 3. Up to 85% of both the protein and total fatty acids were recovered in the final product, compared to the initial algal slurry. Protein, total fatty acids and carbohydrates were concentrated in the final product, while the ash content was lower compared to the starting material. From a processing point of view, solubilization of Nannochloropsis at native pH was found to be preferable, since less chemicals were consumed compared to high-pH solubilization. Owing to its content of protein and (total) fatty acids (23 and 12% of dry weight, respectively), the latter enriched in eicosapentaenoic acid (EPA), the product of the pH-shift process has potential as a functional food ingredient.

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Properties of Chlorophyll and Derivatives in Homogeneous and Microheterogeneous Systems

Cited by 64 publications

References 47 publications

Formulation of Aluminum Chloride Phthalocyanine in Pluronic^™ P‐123 and F‐127 Block Copolymer Micelles: Photophysical properties and Photodynamic Inactivation of Microorganisms

Formulation of Aluminum Chloride Phthalocyanine in Pluronic^™ P‐123 and F‐127 Block Copolymer Micelles: Photophysical properties and Photodynamic Inactivation of Microorganisms

De novo synthetic biliprotein design, assembly and excitation energy transfer

pH-shift processing of Nannochloropsis oculata microalgal biomass to obtain a protein-enriched food or feed ingredient

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Properties of Chlorophyll and Derivatives in Homogeneous and Microheterogeneous Systems

Cited by 64 publications

References 47 publications

Formulation of Aluminum Chloride Phthalocyanine in Pluronic™ P‐123 and F‐127 Block Copolymer Micelles: Photophysical properties and Photodynamic Inactivation of Microorganisms

Formulation of Aluminum Chloride Phthalocyanine in Pluronic™ P‐123 and F‐127 Block Copolymer Micelles: Photophysical properties and Photodynamic Inactivation of Microorganisms

De novo synthetic biliprotein design, assembly and excitation energy transfer

pH-shift processing of Nannochloropsis oculata microalgal biomass to obtain a protein-enriched food or feed ingredient

Contact Info

Product

Resources

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Formulation of Aluminum Chloride Phthalocyanine in Pluronic^™ P‐123 and F‐127 Block Copolymer Micelles: Photophysical properties and Photodynamic Inactivation of Microorganisms

Formulation of Aluminum Chloride Phthalocyanine in Pluronic^™ P‐123 and F‐127 Block Copolymer Micelles: Photophysical properties and Photodynamic Inactivation of Microorganisms