Novel long alkyl side chain benzo[a]phenoxazinium chlorides: synthesis, photophysical behaviour and DNA interaction

Anticancer Activity of Benzo[a]phenoxazine Compounds Promoting Lysosomal Dysfunction

Specific cancer therapy remains a problem to be solved. Breast and colorectal cancer are among the cancers with the highest prevalence and mortality rates. Although there are some therapeutic options, there are still few effective agents for those cancers, which constitutes a clinical problem that requires further research efforts. Lysosomes play an important role in cancer cells' survival, and targeting lysosomes has gained increased interest. In recent years, our team has been synthetizing and testing novel benzo[a]phenoxazine derivatives, as they have been shown to possess potent pharmacological activities. Here, we investigated the anticancer activity of three of the most potent derivatives from our library, C9, A36, and A42, on colorectal- and breast-cancer-derived cell lines, and compared this with the effect on non-neoplastic cell lines. We observed that the three compounds were selective for the cancer cells, namely the RKO colorectal cancer cell line and the MCF7 breast cancer cell line. In both models, the compounds reduced cell proliferation, cell survival, and cell migration, accumulated on the lysosome, and induced cell death accompanied by lysosomal membrane permeabilization (LMP), increasing the intracellular pH and ROS accumulation. Our results demonstrated that these compounds specifically target lysosomes from cancer cells, making them promising candidates as LMP inducers for cancer therapy.

Visible light-driven photocatalysts, quantum chemical calculations, ADMET-SAR parameters, and DNA binding studies of nickel complex of sulfadiazine

A 3D-supramolecular nickel integrated Ni-SDZ complex was synthesized using sodium salt of sulfadiazine as the ligand and nickel(II) acetate as the metal salt using a condensation process and slow evaporation approach to growing the single crystal. The metal complex was characterized for its composition, functional groups, surface morphology as well as complex 3D structure, by resorting to various analytical techniques. The interacting surface and stability as well as reactivity of the complex were carried out using the DFT platform. From ADMET parameters, human Intestinal Absorbance data revealed that the compound has the potential to be well absorbed, and also Ni-SDZ complex cannot cross the blood-brain barrier (BBB). Additionally, the complex's DNA binding affinity and in-vivo and in-vitro cytotoxic studies were explored utilizing UV-Vis absorbance titration, viscosity measurements, and S. pombe cells and brine shrimp lethality tests. In visible light radiation, the Ni-SDZ complex displayed exceptional photo-degradation characteristics of approximately 70.19% within 70 min against methylene blue (MB).

Novel Benzo[a]phenoxazinium Chlorides Functionalized with Sulfonamide Groups as NIR Fluorescent Probes for Vacuole, Endoplasmic Reticulum, and Plasma Membrane Staining

The demand for new fluorophores for different biological target imaging is increasing. Benzo[a]phenoxazine derivatives are fluorochromophores that show promising optical properties for bioimaging, namely fluorescent emission at the NIR of the visible region, where biological samples have minimal fluorescence emission. In this study, six new benzo[a]phenoxazinium chlorides possessing sulfonamide groups at 5-amino-positions were synthesized and their optical and biological properties were tested. Compared with previous probes evaluated using fluorescence microscopy, using different S. cerevisiae strains, these probes, with sulfonamide groups, stained the vacuole membrane and/or the perinuclear membrane of the endoplasmic reticulum with great specificity, with some fluorochromophores capable of even staining the plasma membrane. Thus, the addition of a sulfonamide group to the benzo[a]phenoxazinium core increases their specificity and attributes for the fluorescent labeling of cell applications and fractions, highlighting them as quite valid alternatives to commercially available dyes.

N-(5-Amino-9H-benzo[a]phenoxazin-9-ylidene)propan-1-aminium chlorides as antifungal agents and NIR fluorescent probes

New benzo[a]phenoxazinium chlorides (λ_emi ≤ 683 nm, Φ_F ≤ 0.24, at pH = 7.4), best MIC 6.25 μM in Saccharomyces cerevisiae, stain vacuolar/perinuclear membranes of cells.

Encapsulation and characterisation of cationic benzo[a]phenoxazines in zeolite HY

Encapsulated benzo[a]phenoxazinium derivatives were synthesized inside of zeolite HY and exhibit excellent fluorescence emission behavior.

Fluorescent probes based on side-chain chlorinated benzo[a]phenoxazinium chlorides: Studies of interaction with DNA

The interaction of DNA with six water soluble benzo[a]phenoxazinium chlorides mono- or di-substituted with 3-chloropropyl groups at the O and N of 2- and 9-positions, along with methyl, hydroxyl and amine terminal groups at 5-positions, was investigated by photophysical techniques. The results indicated that almost all compounds intercalated in DNA base pairs at phosphate to dye ratio higher than 5. At lower values of this ratio, electrostatic binding mode with DNA was observed. Groove binding was detected mainly for the benzo[a]phenoxazinium dye with NH₂·HBr terminal. The set of six benzo[a]phenoxazinium chlorides proved successful to label the migrating DNA in agarose gel electrophoresis assays. These finding proves the ability of these benzo[a]phenoxazinium dyes to strongly interact with DNA.

Ultrasound promoted synthesis of Nile Blue derivatives

Ultrasound irradiation was used for the first time towards the synthesis of new Nile Blue related benzo[a]phenoxazinium chlorides possessing isopentylamino, (2-cyclohexylethyl)amino and phenethylamino groups at 5-position of the heterocyclic system. The efficacy of sonochemistry was investigated with some of our earlier reported synthesis of benzo[a]phenoxazinium chlorides. This newer protocol proved competent in terms of reaction times and enhanced yields. Photophysical studies carried out in ethanol, water and simulated physiological conditions, revealed that emission maxima occurred in the range 644-656 nm, with high fluorescent quantum yields. Other attractive feature exhibited by these materials includes good thermal stability. These properties might be useful in the development of fluorescent probes for biotechnology.

A class of Trp-Trp-AA-OBzl: Synthesis, in vitro anti-proliferation/in vivo anti-tumor evaluation, intercalation-mechanism investigation and 3D QSAR analysis

From the anti-tumor active N-tryptophanyl-β-carboline-3-carboxylic acid benzyl ester and β-carboline-3-carbonyltryptophan benzyl ester, a pharmacophore, Trp-Trp-OBzl, was drawn. Based on the DOCK scores amino acid residue was inserted into the C-terminus of Trp-Trp-OBzl and twenty Trp-Trp-AA-OBzls (AA = amino acid residues) were provided as DNA intercalators. On the in vitro and in vivo models seventeen Trp-Trp-AA-OBzls were anti-tumor active, and twelve Trp-Trp-AA-OBzls were more active than cytarabine. In acute toxicity assay Trp-Trp-AA-OBzls did not damage the immunologic function and had an LD(50) of more than 500 mg/kg. The relationships of structure and activity were analyzed with 3D QSAR. The action mechanism studies revealed that the in vivo anti-tumor action of Trp-Trp-AA-OBzls was the result of DNA intercalation.

A class of novel carboline intercalators: Their synthesis, in vitro anti-proliferation, in vivo anti-tumor action, and 3D QSAR analysis

Based on DOCK scores 18 N-(3-benzyloxycarbonylcarboline-1-yl)ethylamino acid benzylesters (6a-r) were synthesized as anti-tumor agents. Their IC(50) values against five human carcinoma cell lines ranged from 11.1muM to more than 100muM. The in vivo assay identified five derivatives of them had no anti-tumor action, the anti-tumor activity of nine derivatives of them equaled that of cytarabine, and the anti-tumor activity of three derivatives of them was higher than that of cytarabine. The UV and fluorescence spectra, as well as the relative viscosity and melting temperature measurements of calf thymus DNA (CT DNA) with and without the representative compound suggested that DNA intercalation could be their action mechanism. The 3D QSAR analysis of N-(3-benzyloxycarbonylcarboline-1-yl)ethylamino acid benzylesters (6a-r) revealed that their in vivo anti-tumor activity significantly depends on the molecular electrostatic and steric fields of the side chain of the amino acid residue.