Nucleotide Oxidation Mediated by Naphthalimide Excited States with Covalently Attached Viologen Cosensitizers¶

Rogers, Joy E.; Le, Thao P.; Kelly, Lisa A.

doi:10.1562/0031-8655(2001)0730223nombne2.0.co2

Cited by 20 publications

(6 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…d Number of nucleotides occluded by a bound ligand. e Rate of static quenching by DNA calculated as reported earlier ( , ). f Compound 2 , under similar conditions exhibited DNA association constants ( K ) 8.5 × 10 5 M -1 and 4.12 × 10 5 M -1 and electron-transfer rate constants ( k DNA ) 3.8 × 10 10 s -1 , and 0.24 × 10 10 s -1 with poly(dG).poly(dC) and poly(dA).poly(dT), respectively.…”

Section: Resultsmentioning

confidence: 99%

Tuning of Intercalation and Electron-Transfer Processes between DNA and Acridinium Derivatives through Steric Effects

et al. 2004

View full text Add to dashboard Cite

A series of acridinium derivatives 1-6, wherein steric factors have been varied systematically through substitution at the 9 position of the acridine ring, have been synthesized and their DNA interactions have been investigated by various biophysical techniques. The unsubstituted and methylacridinium derivatives 1 and 2 and the o-tolylacridinium derivative 6 exhibited high fluorescence quantum yields (Phi(f)() congruent with 1) and lifetimes (tau = 35, 34, and 25 ns, respectively), when compared with the arylacridinium derivatives 3-5. The acridinium derivatives 1 and 2 showed high DNA binding affinity (K = 7.3-7.7 x 10(5) M(-)(1)), when compared to the arylacridinium derivatives 3-5 (K = 6.9-10 x 10(4) M(-)(1)). DNA melting and viscosity studies establish that in the case of the aryl-substituted systems, the efficiency of DNA binding is in the order, phenyl > p-tolyl > m-tolyl >>>> o-tolyl derivative. The increase in steric crowding around the acridine ring hinders the DNA binding interactions and thereby leads to negligible binding as observed in the case of 6 (o-tolyl derivative). These results indicate that a subtle variation in the substitution pattern has a profound influence on the photophysical and DNA interactions. Further, they demonstrate that pi-stacking interactions of the ligands with DNA are essential for efficient electron transfer between the DNA bases and the ligands. These water soluble and highly fluorescent molecules which differ in their DNA binding mode can act as models to study various DNA-ligand interactions.

show abstract

Section: Resultsmentioning

confidence: 99%

Tuning of Intercalation and Electron-Transfer Processes between DNA and Acridinium Derivatives through Steric Effects

et al. 2004

View full text Add to dashboard Cite

show abstract

“…The titration with ct-DNA induced weak emission quenching of 1a (Figure 3, top) but an increase in the emission of 1e (Figure 3, bottom). The quenching of fluorescence by ct-DNA may be rationalized by PET between the naphthalimide and guanine, which is the nucleobase with the lowest oxidation potential [59,60,89], and in principle, it can be static (due to the formation of a nonfluorescent complex) or dynamic (due to diffusion). To check if the quenching is static, we performed TC-SPC measurement for 1a and a mixture of 1a and ct-DNA, in the same concentrations as in the fluorescence titration experiments (see Figures S20-S21 and Table S7 in the ESI).…”

Section: Uv-vis and Fluorescence Titrationsmentioning

confidence: 99%

“…On the contrary, the addition of polynucleotide to the solution of 1e resulted in an increase in the fluorescence (Figure 3, bottom), further supporting the possibility that the changes in fluorescence are not due to dynamic quenching. A tentative explanation for the fluorescence enhancement is the aggregation of the larger molecule 1e in the aqueous medium, yielding a lower intensity in respect to 1a The quenching of fluorescence by ct-DNA may be rationalized by PET between the naphthalimide and guanine, which is the nucleobase with the lowest oxidation potential [59,60,89], and in principle, it can be static (due to the formation of a nonfluorescent complex) or dynamic (due to diffusion). To check if the quenching is static, we performed TC-SPC measurement for 1a and a mixture of 1a and ct-DNA, in the same concentrations as in the fluorescence titration experiments (see Figures S20-S21 and Table S7 in the ESI).…”

Section: Uv-vis and Fluorescence Titrationsmentioning

confidence: 99%

“…Of particular interest is the ability of 1,8-naphthalimide derivatives to intercalate into DNA [ 50 , 51 ], which was exploited in the development of anticancer agents [ 52 , 53 ], initiating further clinical studies [ 54 , 55 , 56 , 57 , 58 ]. Furthermore, 1,8-naphthalimides undergo photoinduced electron transfer with guanine-rich polynucleotides [ 59 , 60 ] and induce cleavage of the chains [ 61 , 62 ]. Consequently, newly designed molecules contain two warheads for their anticancer activity.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Photochemical Reactivity of Naphthol-Naphthalimide Conjugates and Their Biological Activity

et al. 2021

View full text Add to dashboard Cite

Quinone methide precursors 1a–e, with different alkyl linkers between the naphthol and the naphthalimide chromophore, were synthesized. Their photophysical properties and photochemical reactivity were investigated and connected with biological activity. Upon excitation of the naphthol, Förster resonance energy transfer (FRET) to the naphthalimide takes place and the quantum yields of fluorescence are low (ΦF ≈ 10−2). Due to FRET, photodehydration of naphthols to QMs takes place inefficiently (ΦR ≈ 10−5). However, the formation of QMs can also be initiated upon excitation of naphthalimide, the lower energy chromophore, in a process that involves photoinduced electron transfer (PET) from the naphthol to the naphthalimide. Fluorescence titrations revealed that 1a and 1e form complexes with ct-DNA with moderate association constants Ka ≈ 105–106 M−1, as well as with bovine serum albumin (BSA) Ka ≈ 105 M−1 (1:1 complex). The irradiation of the complex 1e@BSA resulted in the alkylation of the protein, probably via QM. The antiproliferative activity of 1a–e against two human cancer cell lines (H460 and MCF 7) was investigated with the cells kept in the dark or irradiated at 350 nm, whereupon cytotoxicity increased, particularly for 1e (>100 times). Although the enhancement of this activity upon UV irradiation has no imminent therapeutic application, the results presented have importance in the rational design of new generations of anticancer phototherapeutics that absorb visible light.

show abstract

“…The site-selectivity is governed by the substitution pattern of the naphthalimide ring (13,14). Several reports, including work from our own laboratory, have demonstrated the photonuclease activity of variety of 1,8-naphthalimide derivatives (15)(16)(17)(18).…”

Section: Introductionmentioning

confidence: 99%

Sequence‐dependent Interactions of Cationic Naphthalimides and Polynucleotides

McMasters

Kelly²

2007

Photochem & Photobiology

Self Cite

View full text Add to dashboard Cite

The binding interactions of three naphthalimide derivatives with heteropoly nucleic acids have been evaluated using fluorescence, absorption and circular dichroism spectroscopies. Mono- and bifunctionalized naphthalimides exhibit sequence-dependent variations in their affinity toward DNA. The heteropoly nucleic acids, [Poly(dA-dT)]2 and [Poly(dG-dC)]2, as well as calf thymus (CT) DNA, were used to understand the factors that govern binding strength and selectivity. Sequence selectivity was addressed by determining the binding constants as a function of polynucleotide composition according to the noncooperative McGhee-von Hippel binding model. Binding affinities toward [poly(dA-dT)](2) were the largest for spermine-substituted naphthalimides (Kb = 2-6 x 10(6) M(-1)). The association constants for complex formation between the cationic naphthalimides and [poly(dG-dC)]2 or CT DNA (58% A-T content) were 2-500 times smaller, depending on the naphthalimide-polynucleotide pair. The binding modes were also assessed using a combination of induced circular dichroism and salt effects to determine whether the naphthalimides associate with DNA through intercalative, electrostatic or groove-binding. The results show that the monofunctionalized spermine and pyridinium-substituted naphthalimides associate with DNA through electrostatic interactions. In contrast, intercalative interactions are predominant in the complex formed between the bifunctionalized spermine compound and all of the polynucleotides.

show abstract

Nucleotide Oxidation Mediated by Naphthalimide Excited States with Covalently Attached Viologen Cosensitizers¶

Cited by 20 publications

References 20 publications

Tuning of Intercalation and Electron-Transfer Processes between DNA and Acridinium Derivatives through Steric Effects

Tuning of Intercalation and Electron-Transfer Processes between DNA and Acridinium Derivatives through Steric Effects

Photochemical Reactivity of Naphthol-Naphthalimide Conjugates and Their Biological Activity

Sequence‐dependent Interactions of Cationic Naphthalimides and Polynucleotides

Contact Info

Product

Resources

About