Novel DNA fluorescence probes based on N-[5-(11-functionalised-undecylamino)-9H-benzo[a]phenoxazin-9-ylidene]propan-1-aminium chlorides: synthesis and photophysical studies

Abstract

Fluorescent benzo[a]phenoxazinium chlorides possessing undecylamino chains with functionalised ending-groups (hydroxyl, carboxylic acid and the ester group) as substituents at the 5-position of the heterocycles were successfully synthesised and characterised. These compounds were used in photophysical studies with DNA, and compared to the corresponding analogue with a non-functionalised terminal (methyl group). It was found that the functionalised terminal exerts a dramatic influence on the type of interaction with the hydroxyl group promoting intercalation, while the ester group promotes groove binding.

Application of benzo[a]phenoxazinium chlorides in antimicrobial photodynamic therapy of Candida albicans biofilms

“…2. The compound with a longer alkyl chain (FSd) is slightly red-shifted showing a higher fraction of a band near 500 nm, that corresponds to the neutral basic form [28,29]. Also, as expected, compound FSd has much less solubility in PBS aqueous buffer.…”

“…The benzo[a]phenoxazinium chlorides termed N-(5-(3hydroxypropylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium chloride -FSc and N-(5-(11-hydroxyundecylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium chloride -FSd (Fig. 1) were previously synthetized in the Department of Chemistry of University of Minho [28,29] and the respective powders were solubilized in Dimethyl Sulfoxide (DMSO) to a final concentration of 10 mM. Then, the solutions were transferred to sterile amber microtubes (VWR International, LLC.…”

N‐(Di)icosyl‐Substituted Benzo[a]phenoxazinium Chlorides: Synthesis and Evaluation as Near‐Infrared Membrane Probes

“…100 nm to the blue). [23][24][25][26][27][28][29][30] Recently, we have also provided evidence that the main site of acid-base equilibria is the amine at the 5-position. [29] An acid-base equilibrium was not observed in aqueous solutions, probably because the basic neutral form was hydrogen-bonded and showed a similar photophysical behaviour to that of the positive acid form.…”

“…Considering these facts, and as part of our current research interests in the synthesis and characterisation of fluorescence probes, [23][24][25][26][27][28][29][30] this work describes the synthesis of five benzo[a]phenoxazinium chlorides with different combinations of substituents at the 5-, 9-and 10-positions of the polycyclic aromatic ring, as well as their photophysical behaviour in homogeneous media and in zwitterionic/ cationic vesicles. presence of hydrochloric acid, gave the benzo[a]phenoxazinium chlorides 1a-c.…”

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

“…Moreover, NB was used as a marker for the detection of DNA in gel electrophoresis experiments [21,22]. Continuing our research towards the synthesis and photophysical studies of fluorescent molecules [23][24][25][26][27][28][29][30][31], the present work is focused to study the DNA interaction with a set of benzo[a]phenoxazinium dyes bearing chlorinated terminals at the 2-and 5-positions of the heterocycle. Additionally, we evaluated the influence of methyl, hydroxyl or the amino group terminals at 5-position of the polycyclic systems [31] and photophysical studies of the interaction with DNA and in agarose gel electrophoresis assays were studied.…”