Regioselective reduction of 5-aryl-10,15,20-tris(pyridyl) porphyrin to 5-aryl-10,15,20-tris(pyridyl)dihydroporphyrin (chlorin)

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1380-1397
Author(s):  
Frédérique Brégier ◽  
Jérémy Godard ◽  
Jordan Thiais ◽  
Soukaina Bouramtane ◽  
Alexia Moulin ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Double Bond ◽  
Absorption Band ◽  
Structural Difference ◽  
Chloride Dihydrate

Dihydroporphyrins or chlorins differ from porphyrins only by saturation of a peripheral double bond of the macrocycle. However, this small structural difference leads to a significant increase of the absorption band at approximately 650 nm, which makes them very interesting candidates for photodynamic therapy applications. The reduction of porphyrins bearing two, three or four pyridyl substituents with tin(II) chloride has been developed for the synthesis of dihydroporphyrins in yields of 15–73%. The reduction of 5-(aryl)-10,15,20-tris(2 or 4-pyridyl)porphyrin with tin(II) chloride dihydrate demonstrated good regioselectivity. Porphyrins with one meso-aryl bearing one electron-donating group (EDG) gave 5-aryl-10,15,20-tris(2- or 4-pyridyl)-17,18-dihydroporphyrins in 17–72% yield. Porphyrins with one meso-aryl bearing one or more electron-withdrawing groups (EWG) gave 5-aryl-10,15,20-tris(4-pyridyl)-17,18-dihydroporphyrins or 5-aryl-10,15,20-tris(4-pyridyl)-7,8-dihydroporphyrins in 15–21% yield and isobacteriochlorin. We have also proven the possibility of functionalizing these compounds to design new regioisomerically pure photosensitizers.

THE SIGNIFICANCE OF AN ABSORPTION BAND AT 968 CM.−1 IN THE INFRARED SPECTRUM OF METHYL ISOLINOLEATE

1949 ◽  
Vol 27b (7) ◽  
pp. 610-615 ◽  
Author(s):  
H. W. Lemon ◽  
C. K. Cross
Keyword(s):  
Fatty Acids ◽  
Absorption Spectrum ◽  
Double Bond ◽  
Absorption Band ◽  
Linseed Oil ◽  
Infrared Absorption Spectrum ◽  
Methyl Esters ◽  
Trans Configuration ◽  
Double Bonds ◽  
Identical Band

The infrared absorption spectrum of methyl isolinoleate, separated from the methyl esters of hydrogenated linseed oil fatty acids, has a well defined absorption band with maximum absorption at about 968 cm.−1 As an identical band was found in the spectra of fatty acids or esters after isomerization with selenium, it is attributed to the presence of double bonds with a trans-configuration. It was found that the same band was present in the spectra of samples taken during hydrogenation of oils, and that its intensity increased to a maximum, then decreased as hydrogenation proceeded. It is concluded that hydrogenation is accompanied by a cis-to-trans change in some of the double bonds of the fatty acids, and that methyl isolinoleate has at least one double bond with a trans-configuration.

Synthesis of highly water soluble tetrabenzoporphyrins and their application toward photodynamic therapy

2020 ◽  
Vol 24 (01n03) ◽  
pp. 456-464
Author(s):  
Austen Moss ◽  
Zehua Zhou ◽  
Lin Jiang ◽  
M. Graça H. Vicente ◽  
Hong Wang
Keyword(s):  
Photodynamic Therapy ◽  
Absorption Band ◽  
Methyl Iodide ◽  
Water Soluble ◽  
Ionic Groups ◽  
Benzene Rings

Novel tetraaryl-(pyridinium-4-yl)-tetrabenzoporphyrins have been successfully synthesized via a Heck-based sequence reaction. These tetrabenzoporphyrins were substituted with eight pyridyl groups at the fused benzene rings. Methylation of the pyridyl groups with methyl iodide afforded highly water soluble tetrabenzoporphyrins carrying eight ionic groups. The extended [Formula: see text]-conjugation broadened and red-shifted the absorption band of these porphyrins to 650–750 nm. These cationic tetrabenzoporphyrins showed non-toxicity in the dark up to 100 uM. High phototoxicity with IC[Formula: see text] values lower than 18 [Formula: see text]M were obtained for these tetrabenzoporphyrins.

scholarly journals Spectrophotometrical purity and stability testing of a photosensitizer based on an indotricarbocyanine dye

2020 ◽  
pp. 17-23
Author(s):  
Nikita V. Belko ◽  
Michael P. Samtsov ◽  
Dzmitry S. Tarasau
Keyword(s):  
Mass Spectrometry ◽  
Absorption Spectrum ◽  
Photodynamic Therapy ◽  
Liquid Chromatography ◽  
Absorption Band ◽  
Stability Testing ◽  
Liquid Chromatography Mass Spectrometry ◽  
Express Method ◽  
Chromatography Mass Spectrometry ◽  
Purity Testing

The express method for testing purity and stability of an indotricarbocyanine dye based photosensitizer for photodynamic therapy was developed. Storage of the hydrophilic photosensitizer under unfavorable conditions resulted in contamination with a hydrophobic dye. The absorption spectrum of the hydrophobic dye was characterized by a new band at 514 nm that was absent in the absorption spectrum of the photosensitizer. There was no spectral overlap between this absorption band and the absorbance of the photosensitizer. Therefore, presence of the band at 514 nm allowed us to detect contamination of the photosensitizer substance with the hydrophobic dye. It was established that the optimal photosensitizer concentration for purity testing is ca. 0.8 mmol/L, when as little as 0.6 wt. % of the impurity can be detected. The developed method is not time consuming and requires accessible equipment only. Data obtained with this method was verified with the aid of liquid chromatography-mass spectrometry.

Theranostics of skin neoplasms based on luminescence diagnostics in combination with photodynamic therapy in the absorption band of porphyrin

2022 ◽  
Vol 52 (1) ◽  
pp. 56-62
Author(s):  
I P Shilov ◽  
A S Gorshkova ◽  
A V Ivanov ◽  
V D Rumyantseva ◽  
G L Danielyan ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Absorption Band ◽  
Therapeutic Effect ◽  
Extinction Coefficient ◽  
Photophysical Properties ◽  
Skin Neoplasms ◽  
Dmso Solution ◽  
Experimental Animals ◽  
Laser Fluorimeter

Abstract We report the results of developing a technique for theranostics of skin neoplasms based on luminescence diagnostics in combination with photodynamic therapy (PDT) in the absorption band of porphyrin. It is shown that the therapeutic effect is achieved exclusively due to PDT, without the participation of the hyperthermia process, which occurs at temperatures above 42 °C. The Fluroscan gel [based on the dipotassium salt of the ytterbium complex of 2,4-di-(a-methoxyethyl)deuteroporphyrin IX (Yb-DMDP)] is used as a preparation for theranostics. The main photophysical properties and possible mechanisms of accumulation of nanosized low-toxic photosensitisers based on this compound are studied. It is shown that the Yb-DMDP compound in a DMSO solution (30% aqueous DMSO) enhances photophysical characteristics (luminescence lifetime 5-10 ms, luminescence quantum yield up to 1%, extinction coefficient ~1.96 × 105 M-1 cm-1 at a wavelength of 398 nm). Experimental animals are used to test the proposed technique for theranostics of tumours using the Fluroscan gel and a fibre-optic laser fluorimeter.

Infrared evidence for the occurrence of SiO groups with double-bond character in antigorite, sepiolite and palygorskite

Clay Minerals ◽  
1986 ◽  
Vol 21 (5) ◽  
pp. 925-935 ◽  
Author(s):  
S. Yariv
Keyword(s):  
Double Bond ◽  
Absorption Band ◽  
Ir Spectra ◽  
Inductive Effect ◽  
High Order ◽  
Octahedral Sheet ◽  
Tetrahedral Sheet ◽  
Double Bond Character ◽  
Layer Silicates ◽  
Bond Character

AbstractIR spectra of antigorite and sepiolite show an absorption band at ∼ 1200 cm−1. Spectra of palygorskite show several small absorptions between 1140–1200 cm−1. Since these three minerals are the only layer-silicates which show this absorption this band was assigned to Si-O-Si groups which serve as bridges between alternating alumino-Mg-silicate ribbons. By comparing the location of this band to bands observed in the spectra of P=O groups it was concluded that the contribution of π bonding in the bridging Si-O-Si group is of a high order. Similar conclusions were drawn after comparing the spectra of antigorite, sepiolite and palygorskite with those of various pyrosilicates. An inversion of the tetrahedral sheet requires an Si-O-Si angle of 180° which can be stabilized by dπ-pπ bonding in the Si-O-Si group. Due to the inductive effect of the octahedral sheet this type of bonding may occur in trioctahedral clay silicates, but is not to be expected in dioctahedral clay silicates.

Construction of a near-infrared responsive upconversion nanoplatform against hypoxic tumors via NO-enhanced photodynamic therapy

Nanoscale ◽  
2020 ◽  
Vol 12 (14) ◽  
pp. 7875-7887 ◽  
Author(s):  
Ying Lan ◽  
Xiaohui Zhu ◽  
Ming Tang ◽  
Yihan Wu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Near Infrared ◽  
Upconversion Nanoparticles

A near-infrared (NIR) activated theranostic nanoplatform based on upconversion nanoparticles (UCNPs) is developed in order to overcome the hypoxia-associated resistance in photodynamic therapy by photo-release of NO upon NIR illumination.

Porphyrin-functionalized coordination star polymers and their potential applications in photodynamic therapy

2019 ◽  
Vol 10 (45) ◽  
pp. 6116-6121 ◽  
Author(s):  
Tan Ji ◽  
Lei Xia ◽  
Wei Zheng ◽  
Guang-Qiang Yin ◽  
Tao Yue ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Self Assembly ◽  
Star Polymers ◽  
New Family ◽  
Potential Applications

We present a new family of porphyrin-functionalized coordination star polymers prepared through combination of coordination-driven self-assembly and post-assembly polymerization. Their self-assembly behaviour in water and potential for photodynamic therapy were demonstrated.

A nitroreductase-activatable near-infrared theranostic photosensitizer for photodynamic therapy under mild hypoxia

2020 ◽  
Vol 56 (43) ◽  
pp. 5819-5822
Author(s):  
Jing Zheng ◽  
Yongzhuo Liu ◽  
Fengling Song ◽  
Long Jiao ◽  
Yingnan Wu ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Triplet State ◽  
Near Infrared ◽  
Mild Hypoxia

In this study, a near-infrared (NIR) theranostic photosensitizer was developed based on a heptamethine aminocyanine dye with a long-lived triplet state.

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