Photodynamic properties of naphthosulfobenzoporphyrazines, novel asymmetric, amphiphilic phthalocyanine derivatives.

Metallo naphthosulfobenzoporphyrazines sulfonated to different degrees (M-NSBP) were prepared, and their potential as photosensitizers for the photodynamic therapy (PDT) of cancer was evaluated. M-NSBP can be viewed as hybrid molecules between sulfophthalocyanines and naphthalocyanines resulting in distinct differences in the absorption spectra between the mono-through tetrasulfonated derivatives. This feature greatly facilited their purification. Using V-79 Chinese hamster cells in vitro, the disulfonated derivatives were found slightly more photoactive than the hydrophilic trisulfonated derivatives while the monosulfonated derivative was inactive, in spite of a sixfold higher cell uptake. In the case of the di- and trisulfonated derivatives, differences in phototoxicity correlated well with their relative cell uptake. Substitution of Al for Zn had little effect on the extent of phototoxicity of the M-NSBP. In vitro PDT of the EMT-6 cells after in vivo dye administration, revealed a similar potency for direct cell killing between the di- and trisulfonated AlOH-NSBP, while the monosulfonated analog was inactive. PDT with the amphiphilic disulfonated AlOH-NSBP on the EMT-6 mammary tumor in BALB/c mice induced a significant tumor response, while the monosulfonated derivative was much less active.     

BIOLOGICAL ACTIVITIES OF PHTHALOCYANINES–VII. PHOTOINACTIVATION OF V-79 CHINESE HAMSTER CELLS BY SELECTIVELY SULFONATED GALLIUM PHTHALOCYANINES

Abstract Gallium chloride phthalocyanines sulfonated to different degrees were tested for their ability to inactivate V-79 Chinese hamster cells in the presence of red light. The mono- and disulfonated compounds were the most active whereas the tri- and tetrasulfonated complexes were completely void of photoactivity. In addition, large variations in photoactivity were observed among the four isomeric disulfonated derivatives with the most hydrophobic isomer exhibiting the highest photoactivity. Prolonged exposure to the disulfonated complex resulted in increased photosensitization. Complexing the dye with Al instead of Ga resulted in a slightly increased photosensitizing effect.     

BIOLOGICAL ACTIVITIES OF PHTHALOCYANINES—VIII. CELLULAR DISTRIBUTION INV–79 CHINESE HAMSTER CELLS AND PHOTOTOXICITY OF SELECTIVELY SULFONATED ALUMINUM PHTHALOCYANINES

Abstract— Water soluble chloro aluminum phthalocyanines sulfonated to different degrees are studied for phototoxicity and cellular distribution inV–79 Chinese hamster cells. The more hydrophobic disulfonated dyes, with sulfonate substituents on adjacent benzyl groups of the phthalocyanine ring structure, exhibited the best cell penetrating properties and the highest phototoxicity. Fluorescence microscopy revealed that the dye was uniformly distributed in the cytoplasm but absent in the nucleus. The greater cell membrane penetrating properties of the lower as compared to the higher sulfonated dyes are attributed to the amphiphilic nature of the former.     

Biological activities of phthalocyanines--III. Photoinactivation of V-79 Chinese hamster cells by tetrasulfophthalocyanines

Abstract— Tetrasulfophthalocyanine and a series of its metal chelates were tested for their ability to photoinactivate V-79 Chinese hamster cells. Incubation of cells for 1 h with tetrasulfophthalocyanine at 5 μM effectively sensitized cells towards red light. At the 1% survival level, the dye was 4 x more efficient than hematoporphyrin, efficiency being defined in terms of drug concentration in the medium and incident light fluence rather than on the basis of quanta absorbed. Chelation of the dye with metal ions resulted in most cases in a greatly diminished photosensitizing effect, except for cerium. The cerium complex was about 5 x more effective for cell killing than the metal free tetrasulfophthalocyanine and 20 x more efficient as compared to hematoporphyrin. Hypoxic conditions resulted in total loss of photoactivity indicating the involvement of oxygen in the action mechanism. The inactivation by near-UV light by these drugs was also investigated. The potential of sulfonated phthalocyanines as novel photosensitizers for photodynamic cancer therapy is discussed.     

THE PREPARATION OF RADIOLABELED PORPHYRINS and THEIR USE IN STUDIES OF PHOTODYNAMIC THERAPY

Abstract— We tested water-soluble sulfonated phthalocyanine and three metal chelate derivatives for their tumoricidal effect on the EMT-6 mammary tumor in mice exposed to red light. The metal-free sulfophthalocyanine had little effect, whereas the aluminum complex and the lower sulfonated fraction of the gallium complex exhibited tumoricidal activity similar to hematoporphyrin-based photosensitizer (Photofrin II). The higher sulfonated fractions of the gallium complex were less active as compared to the lower sulfonated fraction. The cerium complex was the most active sensitizer in terms of dye and light doses required to induce tumor necrosis and cure but also showed the highest phototoxicity towards healthy skin. These results suggest that sulfonated phthalocyanines will offer a new alternative in photodynamic therapy of light-accessible neoplasms.     

Cytotoxicity of Amino-BODIPY Modulated via Conjugation with 2-Phenyl-3-Hydroxy-4(1H)-Quinolinones

The combination of cytotoxic amino-BODIPY dye and 2-phenyl-3-hydroxy-4(1H)-quinolinone (3-HQ) derivatives into one molecule gave rise to selective activity against lymphoblastic or myeloid leukemia and the simultaneous disappearance of the cytotoxicity against normal cells. Both species′ conjugation can be realized via a disulfide linker cleavable in the presence of glutathione characteristic for cancer cells. The cleavage liberating the free amino-BODIPY dye and 3-HQ derivative can be monitored by ratiometric fluorescence or by the OFF-ON effect of the amino-BODIPY dye. A similar cytotoxic activity is observed when the amino-BODIPY dye and 3-HQ derivative are connected through a non-cleavable maleimide linker. The work reports the synthesis of several conjugates, the study of their cleavage inside cells, and cytotoxic screening.     

First Highly Efficient and Photostable E and C Derivatives of 4,4‐Difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) as Dye Lasers in the Liquid Phase,Thin Films,and Solid‐State Rods

A new library of E‐ and C‐4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) derivatives has been synthesized through a straightforward protocol from commercially available BODIPY complexes, and a systematic study of the photophysical properties and laser behavior related to the electronic properties of the B‐substituent group (alkynyl, cyano, vinyl, aryl, and alkyl) has been carried out. The replacement of fluorine atoms by electron‐withdrawing groups enhances the fluorescence response of the dye, whereas electron‐donor groups diminish the fluorescence efficiency. As a consequence, these compounds exhibit enhanced laser action with respect to their parent dyes, both in liquid solution and in the solid phase, with lasing efficiencies under transversal pumping up to 73 % in liquid solution and 53 % in a solid matrix. The new dyes also showed enhanced photostability. In a solid matrix, the derivative of commercial dye PM597 that incorporated cyano groups at the boron center exhibited a very high lasing stability, with the laser emission remaining at the initial level after 100 000 pump pulses in the same position of the sample at a 10 Hz repetition rate. Distributed feedback laser emission was demonstrated with organic films that incorporated parent dye PM597 and its cyano derivative. The films were deposited onto quartz substrates engraved with appropriate periodical structures. The C derivative exhibited a laser threshold lower than that of the parent dye as well as lasing intensities up to three orders of magnitude higher.     

Small Iminocoumarin Derivatives as Red Emitters: From Biological Imaging to Highly Photoluminescent Non‐doped Micro‐ and Nanofibres

The fluorescence properties of four derivatives of 3‐thienyl‐2‐(N‐dicyanovinyl)iminocoumarin, bearing a diethylamino group in the 7‐position or a methoxy group in the 6, 7 and 8 positions, were compared in solution and in the solid state. The 7‐diethylamino derivative was strongly fluorescent in various solvents, with marked solvatochromism. Its fluorescence was quenched by aggregation. In contrast, the methoxy derivatives were only moderately or weakly fluorescent in solution, but two of them were strongly photoluminescent in the crystalline state, owing to favourable molecular packing. The 6‐methoxy derivative even exhibited spectacular crystallization‐enhanced emission, examples of which are particularly rare for this type of dyes. Dyes were tested for biological use. The 7‐diethylamino derivative led to particularly strong fluorescence staining of the cytoplasm of HCT‐116 colon cancer cells. No fading was observed over prolonged illumination by the microscope light beam, but a phototoxic effect was detected. The use of the dyes as red‐emitting materials was also investigated. Using easy‐to‐implement preparation methods, the compounds self‐ assembled to give one‐dimensional nano‐ and microsized particles, including millimeter‐long microfibres that exhibited clear wave‐guiding properties. This study shows the value of these low molecular‐weight molecules for the preparation of new orange and red‐emitting fluorescent materials based on totally pure dye.     

Efficient One‐pot Synthesis,Antimicrobial and Docking Studies of Some Newer Tetrahydro‐4H‐benzo [1,3‐e]oxazines and Related β‐Acylamino Ketone Derivatives

A concise one‐step procedure was developed for the synthesis of some newer tetrahydro‐4H‐benzo[1,3‐e ]oxazines and β‐acylamino ketone derivatives via condensation of cyclohexanone derivative with different aromatic aldehydes and nitriles in the presence of tetrachlorosilane/zinc chloride (TCS/ZnCl₂) reagent mixture under ambient conditions. Docking studies for the synthesized benzo‐oxazine derivatives were designed and a model of highly active derivatives was mapped for the antimicrobial screening.     

Silylation Improves the Photodynamic Activity of Tetraphenylporphyrin Derivatives In Vitro and In Vivo

The effects of silyl and hydrophilic groups on the photodynamic properties of tetraphenylporphyrin (TPP) derivatives have been studied in vitro and in vivo. Silylation led to an improvement in the quantum yield of singlet oxygen sensitization for both sulfo and carboxy derivatives, although the silylation did not affect other photophysical properties. Silylation also improved the cellular uptake efficiency for both sulfo and carboxy derivatives, enhancing the in vitro photodynamic activity of the photosensitizer in U251 human glioma cells. The carboxy derivative (SiTPPC₄) was found to show higher cellular uptake efficiency and in vitro photodynamic activity than the corresponding sulfo derivative (SiTPPS₄), which indicates that the carboxy group is a more promising hydrophilic group than the sulfo group in the silylated porphyrin. SiTPPC₄ was found to show high selective accumulation efficiency in tumors, although almost no tumor selectivity was observed for the nonsilylated porphyrin. The concentration of SiTPPC₄ in tumors was 13 times higher than that in muscle 12 h after drug administration. We also studied tumor response after treatment and found that silylation enhanced in vivo photodynamic activity significantly. SiTPPC₄ shows higher photodynamic activity than NPe6 with white light irradiation.     

Impact of the Metal Center and Leaving Group on the Anticancer Activity of Organometallic Complexes of Pyridine-2-carbothioamide

Ru^II(cym)Cl (cym = η⁶-p-cymene) complexes of pyridinecarbothioamides have shown potential for development as orally active anticancer metallodrugs, underlined by their high selectivity towards plectin as the molecular target. In order to investigate the impact of the metal center on the anticancer activity and their physicochemical properties, the Os(cym), Rh- and Ir(Cp*) (Cp* = pentamethylcyclopentadienyl) analogues of the most promising and orally active compound plecstatin 2 were prepared and characterized by spectroscopic techniques and X-ray diffraction analysis. Dissolution in aqueous medium results in quick ligand exchange reactions; however, over time no further changes in the ¹H NMR spectra were observed. The Rh- and Ir(Cp*) complexes were investigated for their reactions with amino acids, and while they reacted with Cys, no reaction with His was observed. Studies on the in vitro anticancer activity identified the Ru derivatives as the most potent, independent of their halido leaving group, while the Rh derivative was more active than the Ir analogue. This demonstrates that the metal center has a significant impact on the anticancer activity of the compound class.     

Green synthesis,molecular docking and pharmacological evaluation of new triazolo-thiadiazepinylcoumarine derivatives as sedative-hypnotic scaffold

4-Amino-5-mercapto-4H-1,2,4-triazole derivative 1 was used as a key intermediate for the preparation of 1,2,4-triazolo[3,4-b][1,3,4]thiadiazepine derivatives 5a-d , 12a-g , and 16 via reactions with the appropriate chalcones 2a-d , α,β-unsaturated carbonitrile derivatives 9a-g and 13 , respectively. The identity of the synthesized compounds was elucidated via their spectral data and elemental analysis. Moreover, the sedative-hypnotic activity of the newly synthesized compounds were evaluated and showed excellent activities especially compounds 12b , 12f , and 16 . Also, their structure activity relationship (SAR) was clearly demonstrated and showed that the electron-donating groups enhance activities while electron-withdrawing groups decrease activities. The molecular docking of the most active derivative 16 against γ-amino butyric acid (GABA) receptor was performed by the MOE 2014 0901program. The acquired outcomes demonstrated that the most active compounds could be a helpful model for future structure, adjustment, and examination to build more active analogs.     

A Fluorescence Polarization Assay of Erythrocyte Membrane Fluidity on the Abbott TDx Analyzer

Four fluorescein dye derivatives (attached to cholic acid, deoxycholic acid, lithocholic acid, and 5-cholenic acid-3β-ol) were studied as a means of detecting alterations in erythrocyte membrane fluidity. In addition, membrane fluidity using these novel dye derivatives was correlated to nonenzymatic glycation of erythrocyte membrane ghosts. These dyes have excitation and emission wavelengths suitable for analysis on an Abbott TDx analyzer. Both the lithocholic acid and the 5-cholenic acid-3β-ol fluorescein derivatives were capable of detecting erythrocyte membrane fluidity with an increase in polarization of approximately 34% over the range of glycation studied, and the fluidity was strongly correlated with the degree of glycation. The cholic acid and deoxycholic acid fluorescein derivatives were unable to enter the erythrocyte membrane since no alteration in fluorescence intensity or polarization was observed upon incubation with the membrane preparations. The results obtained indicate that the lithocholic acid and 5-cholenic acid-3β-oI fluorescein derivatives are potential new reagents for the development of routine assays for membrane fluidity on the Abbott TDx analyzer.     

CELLULAR UPTAKE AND RELATIVE EFFICIENCY IN CELL INACTIVATION BY PHOTO ACTIVATED SULFONATED meso-TETRAPHENYLPORPHINES

The cellular uptake, relative fluorescence quantum yields and photosensitizing efficiencies of meso-tetraphenylporphines sulfonated to different degrees (TPPSn) have been investigated using the human carcinoma cell line NHIK 3025. The efficiencies of these dyes in photoinactivation of cells were highly dependent on the number of sulfonate groups on the derivatives. These differences in phototoxicity were primarily due to different abilities to be taken up by cells, but were also dependent upon the cellular localization of the dyes. TPPS1 and TPPS2a were more efficiently taken up by the cells than TPPS2o and TPPS4. Plasma membrane associated TPPS4 was less efficient in cell inactivation per quantum of fluorescence emitted than intracellularly located dye. This was also to some extent the case for TPPS1 but not for TPPS2a and TPPS2o. The results presented here indicate that TPPS2a and TPPS1 are the most promising of the TPPSns for possible future use in photodynamic therapy.     

Influence of the substitution of 3-vinyl by 3-formyl group on the photodynamic properties of chlorin P6: molecular, cellular and in vivo studies

Molecular in vitro and in vivo properties of 3-devinyl-3-formylchlorin p6 (FCp6) were examined in order to characterize this derivative as a new prospective photosensitizer. The long-wavelength absorption maximum of FCp6 was 690-696 nm (depending on environment). FCp6 was found to bind readily to membranous structures and form complexes with some proteins. The dye was associated with the plasmalemma and distributed rather diffusely along the cytoplasm with ca a three-fold higher accumulation within mitochondria in A549 human adenocarcinoma cells. The spectral analysis revealed that the major part of FCp6 was bound to membranes within cells. The membrane-bound FCp6 was shown to generate singlet oxygen efficiently. The average cytoplasmic concentration of FCp6 in A549 cells achieved ca 80% of its extracellular concentration in complete medium. The dye was characterized by a very fast efflux (16-fold decrease in 2 h). The ex vivo analysis of FCp6 fluorescence in mice revealed that the maximal dye content in blood, tissues, organs and tumor was achieved in less than 1 h after injection, followed by a considerable (ca six-fold) decrease during the next 23 h and a long-term persistence at low level. A preferential accumulation of FCp6 in subcutaneously implanted Ehrlich carcinoma along with its higher retention level comparing to the surrounding skin and muscles were observed in mice treated with different dye doses. In vitro cytotoxic assays with A549 and Raji B-cell lymphoma cells as well as in vivo analyses using Ehrlich carcinoma in mice revealed the very low toxicity of FCp6 without light irradiation and the significant photodynamic activity of this compound.     

Supramolecular Structure in s‐Block Metal Complexes of Sulfonated Monoazo Dyes: Discrepant Packing and Bonding Behavior of ortho‐Sulfonated Azo Dyes

The first solid‐state structures of ortho‐sulfonated monoazo dyestuffs are reported and compared to those of their para‐ and meta‐sulfonated analogues. The structures of the 16 Na, K, Cs, Mg, Ca, Sr, and Ba ortho‐sulfonated salts are found to have fewer M? O₃S bonds than their isomeric equivalents and this in turn means that the metal type is no longer the prime indicator of which structural type will be adopted. M? O₃S bonds are replaced by M? OH₂, M? HOR and M–π interactions, apparently for steric reasons. As well as new bonding motifs, the changed dye shape also leads to new packing motifs. The simple organic/inorganic layering ubiquitous to the para‐ and meta‐sulfonated dye salt structures is replaced by variations (organic bilayers, inorganic channels), each of which correlates with a different degree of molecular planarity in the sulfonated azo dye anion.     

Synthesis,Antimicrobial Activity and Molecular Modeling of Some Novel 5‐Aminopyrazole,Pyrazolo[1,5‐a]pyrimidine,Bispyrazole and Bispyridone Derivatives Containing Antipyrinyl Moiety

2‐Cyano‐N‐(antipyrin‐4‐yl)‐3‐(ethylthio)‐3‐(naphthalen‐1‐ylamino)acryl‐amide 4 was achieved via a one‐pot, three‐component reactions of cyanoacetamide derivative 2 , 2‐naphthyl isothiocyanate, and diethyl‐sulphate. The cyano acrylamide derivative 4 was hydrazinolysis to furnish 5‐aminopyrazole 5 ; many pyrazolo[1,5‐a ]pyrimidines 10a,b, 14, 15, 16, 18, and 20 have been synthesized via treatment of 5 with some electrophilic reagents. Also, ternary condensation of cyanoacetamide derivative 2 , terephthalaldehyde, and active methylene derivatives afforded bispyridone derivatives 21a,b . The structures of the new compounds were confirmed on the basis of elemental analysis and spectral data. Representative compounds of the synthesized products were tested and evaluated as antimicrobial. In general, the novel‐synthesized compounds showed a good antimicrobial activity against Gram‐positive bacteria, Gram‐negative bacteria, and antifungal activity against Azithromycin and Ketoconazole . The molecular modeling of the 21a and 21b as representative examples of the synthesized compounds has been drawn, and their molecular parameters were calculated.     

Synthesis of Small‐Molecule Fluorescent Probes for the In Vitro Imaging of Calcium‐Activated Potassium Channel KCa3.1

Small‐molecule probes for the in vitro imaging of K_Ca3.1 channel‐expressing cells were developed. Senicapoc, showing high affinity and selectivity for the K_Ca3.1 channels, was chosen as the targeting component. BODIPY dyes 15 – 20 were synthesized and connected by a Cu^I‐catalyzed azide–alkyne [3+2]cycloaddition with propargyl ether senicapoc derivative 8 , yielding fluorescently labeled ligands 21 – 26 . The dimethylpyrrole‐based imaging probes 25 and 26 allow staining of K_Ca3.1 channels in NSCLC cells. The specificity was shown by removing the punctate staining pattern by pre‐incubation with senicapoc. The density of K_Ca3.1 channels detected with 25 and by immunostaining was identical. The punctate structure of the labeled channels could also be observed in living cells. Molecular modeling showed binding of the senicapoc‐targeting component towards the binding site within the ion channel and orientation of the linker with the dye along the inner surface of the ion channel.     

Antituberculous compounds. XXVIII. Synthesis of pyrazolopyridines

In a previous paper it was reported that N′-alkyl derivative of isonicotinic acid hydrazide (INH) was more active against tuberele bacilli than the acyl derivative containing the same number of carbon atoms. The authors subsequently reported that the pyrido[2, 3-d]pyridazine was closely related to the acyl derivative of INH except that the terminal carbonyl group was cyclized to the pyridine nucleus, therefore these derivatives were not effective against tubercle bacilli; however, pyridopyridazine, which is similar to the alkyl derivatives of INH, will be more effective against tubercle bacilli. According to the similar expectation, some pyrazolopyridines were prepared.     

Proton‐conducting polymers based on benzimidazoles and sulfonated benzimidazoles

A sulfonated derivative of polybenzimidazole is reported, and its properties are analyzed in comparison with related polybenzimidazole proton‐conducting materials. Poly(2,5‐benzimidazole), poly(m‐phenylenebenzobisimidazole), and poly[m‐(5‐sulfo)‐phenylenebenzobisimidazole] were prepared by condensation of the corresponding monomers in polyphosphoric acid. Several adducts of these polymers with phosphoric acid were prepared. The resulting materials were characterized by chemical analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis; also, the dc conductivity of doped and undoped derivatives was measured. Similar to what has been observed for the commercial polybenzimidazole polymer (also examined here for comparison), the title polymers exhibit high thermal stability. Furthermore, their doping with phosphoric acid leads to a significant increase in conductivity from less than 10^?11 Scm^?1 for the undoped polymers to 10^?4 Scm^?1 (both at room temperature) for their acid‐loaded derivatives. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3703–3710, 2002