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Amphiphilic poly(oxanorbornene)s are promising synthetic polymers that mimic the structural properties and antimicrobial functions of naturally occurring antimicrobial peptides. Here, poly(oxanorbornene)s bearing pendant zinc(II) phthalocyanine and triphenyl(ethyl) phosphonium functionalities are synthesized by ring‐opening metathesis polymerization (ROMP). Fluorescence, singlet oxygen and triplet quantum yields of polymers are measured in dimethyl sulfoxide and aqueous medium. The singlet oxygen quantum yields of copolymers with the highest triphenyl and triethyl phosphonium content are found to be 0.29 and 0.41, respectively. Then, antimicrobial activities of polymers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are investigated under both dark and light conditions. Synergistic effect of zinc(II) phthalocyanine and phosphonium‐containing poly(oxanorbornene) is observed that the conjugate possessing the most triphenyl phosphonium side chains has the highest activity under light against both gram‐positive and gram‐negative bacterial strains after 80 min irradiation, reducing the survival of E. coli or S. aureus by 99.9999%. Hemolytic concentrations of the copolymers are found between 8 and 512 µg mL−1. Scanning electron microscopy (SEM) proves that the bacteria membrane deforms after contacting with the biocidal polymer. [ABSTRACT FROM AUTHOR]

• A new type of phthalocyanines carrying benzimidazole groups. • Investigation of the photophysical-chemical properties. • Investigation of the PDT activities. This study reports on novel phthalocyanines having benzimidazole units which are known to have biological properties. 4-(4-(5-chloro-1H-benzo[ d ]imidazol-2-yl) substituted metal-free, Zn(II), In(III) and Ga(III) phthalocyanines were synthesized, these newly synthesized molecules that were substituted by oxygen bridges were fully characterized. For the purpose of determining their potency for photodynamic therapy, the photophysicochemical properties were investigated in DMSO. The H 2 Pc (4) showed higher fluorescence quantum yield and fluorescence lifetime as compared to metallated phthalocyanines derivatives. However, the highest singlet oxygen (Φ Δ) and triplet state quantum yields (Φ T) values were obtained with the In(III)Pc (5). [ABSTRACT FROM AUTHOR]

The content of this work is based on the introduction of the salicylhydrazone-zinc complexes into the phthalocyanine core. The reaction of the salicylhydrazone substituted ZnPc (1) with the related zinc(II) salt in basic conditions in DMF yielded bis[bis(salicyhydrazone)phenoxy)zinc(II)] phthalocyaninato zinc(II) (5) in which two salicylhydrazone-Zn complexes are linked through oxygen bridges to the macrocyclic core as three-nuclear complex. The novel compound synthesized in this study was fully characterized by general spectroscopic techniques such as FT-IR, UV-vis, 1H NMR, 13C NMR, elemental analysis and mass spectroscopy. In addition, spectral, photophysical (fluorescence quantum yields), and photochemical (generation of singlet oxygen and photo stability under light irradiation) properties of newly synthesized phthalocyanine (5) and the starting Pcs molecules used to obtain this molecule were investigated in DMSO solutions, comparatively. [ABSTRACT FROM AUTHOR]

The context of this study is based on the synthesis of 4-(4-(1H-benzo[d]imidazole-2yl)phenoxy group substituted phthalocyanine ( 4 ) and 4-(4-(1-allyl-1H-benzo[d]imidazole-2yl)phenoxy group substituted phthalocyanine ( 5 ). These phthalocyanine derivatives ( 4, 5 ) are reported for the first time with four functional groups containing benzimidazole derivatives that are linked through oxygen bridges to the macrocyclic core. All novel compounds synthesized in this study were fully characterized by general spectroscopic techniques such as FT-IR, UV–vis, 1 H NMR, 13 C NMR, elemental analysis and mass spectroscopy. The compound 4-(4-(1-allyl-1H-benzo[d]imidazole-2yl)phenoxy)phthalonitrile ( 3 ) was obtained as single crystal and exact structure of these compounds have also been determined using X-ray diffraction technique at 296 K. Weak intra and intermolecular C—H···N interactions and a C—H···π interaction link molecules into a three-dimensional network. Then, spectral, photophysical (fluorescence quantum yields) and photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of the new complexes were investigated in DMSO solutions. These new phthalocyanines ( 4 and 5 ) showed good singlet-oxygen generation (Φ Δ = 0.65 for 4 and Φ Δ = 0.68 for 5 ) in DMSO. [ABSTRACT FROM AUTHOR]

• Neutral (2,3) and cationic (4,5) morpholine containing Schiff base phthalocyanines are reported. • The complexes are used for antimicrobial photodynamic inactivation (aPDI) against bacteria and fungi. • cationic phthalocyanines showed excellent aPDI activity against planktonic cells of all micro-organisms. • Biofilms were susceptible when treated with 200 µM of cationic Pcs at 108 J/cm2. Antimicrobial photodynamic inactivation (aPDI) is a treatment for the eradication of drug-resistant micro-organisms. One of the advantages of this technique, is that there is minimal possibility of microbial resistance. Hence, herein, the preparation and characterization of novel neutral and cationic morpholine containing Schiff base phthalocyanines are reported. The cationic complexes gave moderate singlet oxygen quantum yields (Φ Δ) of ∼0.2 in aqueous media. Conversely, the neutral complexes generated very low Φ Δ values making them very poor candidates for antimicrobial studies. The cationic phthalocyanines showed excellent photodynamic activity against planktonic cells of all micro-organisms (Candida albicans, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella enterica subspecies enterica serovar Choleraesuis , vancomycin-resistant Enterococcus faecium , and methicillin-resistant Staphylococcus aureus). The efficiency of aPDI was shown to be both concentration and light-dose-dependent. Mono biofilms were susceptible when treated with 200 µM of cationic Pcs at 108 J/cm2. However, ∼10% of the mixed biofilm survived after treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Ethyl and propyl pyrrolidine substituted Schiff base phthalocyanines (Pcs) are synthesized. • The Pcs are used for the photoinactivation of Methicillin-resistant Staphylococcus aureus. • The propyl pyrrolidine Pcs are more effective than ethyl for the photoinactivation. New tetra-substituted zinc and indium Schiff base phthalocyanines (ZnPc and InPc, respectively) are synthesized and characterized herein. The ethyl pyrrolidine (ZnPc-2 , InPc-2) and propyl pyrrolidine (ZnPc-3 , InPc-3) substituted Schiff base Pcs were reacted with methyl iodide to form their cationic derivatives (ZnPc-2Q , InPc-2Q , ZnPc-3Q, and InPc-3Q , respectively). The photophysical and photochemical properties of the Pcs were studied. The cationic Pcs generated higher singlet oxygen quantum yield in aqueous media than the neutral Pcs. The photoinactivation of Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA) strains was evaluated. 5 µM ZnPc-3Q and InPc-3Q inactivated 100 % of the MSSA and MRSA while 5 µM ZnPc-2Q and InPc-2Q eradicated 100 % for MSSA and 97.2 % and 98.7 % (respectively) of the MRSA. The photodynamic antimicrobial chemotherapy studies depended on singlet oxygen ability, the charges, and the extension of the alkyl groups. [ABSTRACT FROM AUTHOR]

The emergence of antimicrobial resistance has made the development of photodynamic therapy (PDT) related applications essential, since microorganisms can not form resistance to this method. Porphyrins are well-known photosensitizers for PDT related applications. Thus, the present study outlines the synthesis, characterization and evaluation of the utility of palladium porphyrins and their chitosan inclusion complexes as photosensitizer dye in photodynamic antimicrobial therapy (PACT). Before in vitro cell studies, the photophysical-chemical studies of all obtained structures were performed in solution. It was observed that the immobilization of the porphyrins into the chitosan influenced the photophysical-chemical and PACT activity properties. The determined fluorescence quantum yield was very low, in the range of 0.007–0.028 for all samples indicating the efficient triplet state population to cause high singlet oxygen quantum yield (Φ Δ). The measured Φ Δ values were in the range of 0.51–0.61 for the porphyrins and 0.53–0.66 for porphyrin chitosan immobilization complexes. Our results demonstrate that the PACT activity of cationic porphyrin (P3) and its chitosan immobilization form (P3-Ct) were more efficient in decreasing the number of viable cells up to 100% in vitro. • A new type of metal-free tetra- meso -dibutylaminophenylporphyrin, its palladium complex as neutral form and tetracationic palladium porphyrin were synthesized. • The synthesized porphyrins were conjugated to chitosan. • The photophysical-chemical properties of porphyrins alone and its conjugate form were investigated. • Photodynamic antimicrobial activities for all structures were investigated in comparison with each other. [ABSTRACT FROM AUTHOR]

• Schiff base substituted neutral and cationic indium phthalocyanines were prepared. • Photodynamic inactivation of neutral Pthalocyanines against Staphylococcus aureus and E. coli are very low. • Excellent photodynamic antimicrobial activity with the 100% reduction percentage was observed upon quaternisation of the Schiff base substituted indium phthalocyanine. In this study, the photodynamic antimicrobial activities of a series of new tetra-substituted indium phthalocyanine (InPc) complexes are assessed. An aldehyde substituted complex (2) was initially prepared, which was converted through a condensatioreaction to an imine-pyrrolidine substituted complex (3), which in turn was quaternized to form a tetracationic species (4). Favorable photophysicochemical properties were obtained by incorporating a heavy In(III) ion into the central cavity. Aggregation studies revealed that 2–4 remain non-aggregated in DMSO at concentration below 25 µM. The photodeactivation of S.aureus and E.coli was studied. Log reduction values > 9.0 were obtained for cationic InPc 4 after 30 min of incubation and exposure to light for 75 min. [ABSTRACT FROM AUTHOR]

• Acetophenone substituted phthalocyanines (Pcs) are conjugated to graphene quantum dots (GQDs) by self-assembly. • InPc and its conjugate gave higher singlet oxygen quantum yields compared to the rest. • The photodynamic antimicrobial chemotherapy activity of phthalocyanines and nanoconjugates were tested against S. aureus. • The InPc conjugate with GQDs showed better photoantibacterial activity compared to the rest of the Pcs and conjugates. This work reports on the synthesis and characterization of novel acetophenone substituted phthalocyanines along with the self-assembled nanoconjugates formed via π-π stacking interaction between the synthesized unmetalated (2), zinc (3) and indium (4) phthalocyanines and graphene quantum dots (GQDs) to form 2 @GQDs, 3 @GQDs and 4 @GQDs. The complexes and conjugates exhibited high singlet oxygen ranging from 0.20 to 0.79 in DMSO for Pcs and nanoconjugates where in all cases, the indium complexes showed the highest singlet oxygen quantum yields. The photodynamic antimicrobial chemotherapy activity of both phthalocyanines and nanoconjugates were tested against Staphylococcus aureus. 4 @GQDs was found to be highly effective causing a 9.68 log reduction of the bacteria at 10 μM (based on Pc) when compared to 3.77 log reduction of 3 @GQDs. [ABSTRACT FROM AUTHOR]