Diketopyrrolopyrrole Derivatives as Photosensitizing Agents against Staphylococcus aureus.

Diketopyrrolopyrrole (DPP) derivatives containing sulfonamide (Sulfonamide-DPP), pyridyl (Dipyridyl-DPP) and N-methylpyridyl (MePyridyl-DPP) substituents were assessed as antibacterial photosensitizers. Non-charged DPPs showed an intense absorption band centered at about 480 nm and green fluorescence emission (Φ  ~ 0.7) in acetonitrile.

Amphiphilic tricationic Zn(II)phthalocyanine provides effective photodynamic action to eradicate broad-spectrum microorganisms.

A novel tricationic Zn(II)phthalocyanine derivative, (NCH)ZnPc, was synthesized by ring expansion reaction of boron(III) [2,9(10),16(17)-trinitrosubphthalocyaninato]chloride. First, the reaction of this subphthalocyanine with 2,3-naphthalenedicarbonitrile and Zn(CHCOO) catalyzed by 8-diazabicyclo[5.4.

Magnetic Nanoplatforms for Modification of Macromolecules: Synthesis, Characterization, and Photoinactivating Power of Cationic Nanoiman-Porphyrin Conjugates.

A nanoplatform concept was developed to synthesize accessible photoactive magnetic nanoparticles (MNPs) of FeO coated with silica. This approach was based on the covalent binding of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPPF) to aminopropyl-grafted MNPs by nucleophilic aromatic substitution reaction (SAr) to obtain conjugate MNP-P1. After modification, the remaining pentafluorophenyl groups of TPPF attached to MNPs were substituted by dimethylaminoethoxy groups to form MNP-P2.

Methods to Unravel Pathways of Reactive Oxygen Species in the Photodynamic Inactivation of Bacteria.

Different experimental conditions can be used to detect the presence of reactive oxygen species (ROS) in the photodynamic inactivation of microorganisms. Here, we describe the effect of the media and the addition of ROS scavengers to obtain insight about the oxidative processes that take place during the photokilling of bacteria. In addition, 9,10-dimethylanthracene was used to sense the generation of singlet molecular oxygen, O(Δ), in microbial cells.

Diketopyrrolopyrrole-fullerene C architectures as highly efficient heavy atom-free photosensitizers: synthesis, photophysical properties and photodynamic activity.

Chromophore-fullerene C60 hybrids possess interesting properties that enable them to act as heavy atom-free photosensitizers and reactive oxygen species (ROS) producers. Here, two new diketopyrrolopyrrole-C60 conjugates were efficiently synthesized and characterized. The conjugates show broadband absorption in the visible spectral region, in which diketopyrrolopyrrole dyes act as light-harvesting antenna with very high capacity to populate excited triplet states.

Light-Harvesting Antenna and Proton-Activated Photodynamic Effect of a Novel BODIPY-Fullerene C Dyad as Potential Antimicrobial Agent.

A covalently linked BODIPY-fullerene C dyad (BDP-C ) was synthesized as a two-segment structure, which consists of a visible light-harvesting antenna attached to an energy or electron acceptor moiety. This structure was designed to improve the photodynamic action of fullerene C to inactivate bacteria. The absorption spectrum of BDP-C was found to be a superposition of the spectra of its constitutional moieties, whereas the fluorescence emission of the BODIPY unit was strongly quenched by the fullerene C .

Porphyrins containing basic aliphatic amino groups as potential broad-spectrum antimicrobial agents.

New porphyrin derivatives bearing basic aliphatic amino groups were synthesized from the condensation of meso-4-[(3-N,N-dimethylaminopropoxy)phenyl]dipyrromethane, pentafluorobenzaldehyde and 4-(3-N,N-dimethylaminopropoxy)benzaldehyde. The reaction was catalyzed by trifluoroacetic acid in acetonitrile. This approach was used to obtain porphyrins with different patterns of substitution, of which three of them were isolated: 5,15-di(4-pentafluorophenyl)-10,20-di[4-(3-N,N-dimethylaminopropoxy)phenyl]porphyrin (FAPP), 5-(4-pentafluorophenyl)-10,15,20-tris[4-(3-N,N-dimethylaminopropoxy)phenyl]porphyrin (FAPP) and 5,10,15,20-tetrakis[4-(3-N,N-dimethylaminopropoxy)phenyl]porphyrin (TAPP).

On the Simultaneous Identification and Quantification of Microalgae Populations Based on Fluorometric Techniques.

In this study, the phytoplankton structure of a freshwater reservoir located in central Argentina (Embalse Río Tercero) was analyzed using Beutler's method (Photosynthesis Research 72: 39-53, 2002), aiming to provide water quality control agencies with a reliable tool for early detection of algae blooms, particularly cyanobacteria. The method estimated the concentration of chlorophyll a (Chl a) contributed by individual algal groups in a real sample by fitting its fluorescence excitation spectrum to a linear combination of norm spectra of relevant algae groups. To this purpose, norm spectra for five algae genera usually found in Embalse Río Tercero, Microcystis, Chlorella, Cyclotella, Ceratium and Porphyridium, were constructed and posteriorly used to analyze samples collected in the reservoir in years 2014-2016.

Proton-Dependent Switching of a Novel Amino Chlorin Derivative as a Fluorescent Probe and Photosensitizer for Acidic Media.

A novel chlorin derivative (TPCF -NMe ) has been synthesized as a syn adduct of a pyrrolidine-fused chlorin bearing a C-linked N,N-dimethylaminophenyl residue. The absorption spectrum of TPCF -NMe is essentially identical to that of TPCF in N,N-dimethylformamide, indicating a very weak interaction between the chlorin macrocycle and the amine group in the ground state. However, the fluorescence emission of the chlorin moiety in TPCF -NMe is effectively quenched by the attached amine unit.

Approaches to unravel pathways of reactive oxygen species in the photoinactivation of bacteria induced by a dicationic fulleropyrrolidinium derivative.

The photodynamic mechanism sensitized by N,N-dimethyl-2-[4-(3-N,N,N-trimethylammoniopropoxy)phenyl]fulleropyrrolidinium (DPC) was investigated in Staphylococcus aureus cells. Different experimental conditions were used to detect reactive oxygen species (ROS) in S. aureus cell suspensions.

Photodynamic inactivation of bacteria using novel electrogenerated porphyrin-fullerene C60 polymeric films.

A porphyrin-fullerene C60 dyad (TCP-C60) substituted by carbazoyl groups was used to obtain electrogenerated polymeric films on optically transparent indium tin oxide (ITO) electrodes. This approach produced stable and reproducible polymers, holding fullerene units. The properties of this film were compared with those formed by layers of TCP/TCP-C60 and TCP/ZnTCP.

Effects of divalent cations, EDTA and chitosan on the uptake and photoinactivation of Escherichia coli mediated by cationic and anionic porphyrins.

The effect of divalent cations, EDTA and chitosan (CS) on the uptake and photoinactivation of Escherichia coli produced by 5,10,15,20-tetrakis(4-N,N,N-trimethylammoniumphenyl)porphyrin (TMAP(4+)), 5,10-di(4-methylphenyl)-15,20-di(4-N,N,N-trimethylammoniumphenyl)porphyrin (MPAP(2+)) and 5,10,15,20-tetra(4-sulphonatophenyl)porphyrin (TPPS(4-)) were examined under different conditions. These porphyrins were rapidly bound to E. coli cells (<2.