METHYLENE BLUE SENSITIZED PHOTOINACTIVATION OF <i>E. COLI</i> RIBOSOMES: EFFECT ON THE RNA AND PROTEIN COMPONENTS†

Singh, Harwant; Ewing, Donald D.

doi:10.1111/j.1751-1097.1978.tb06967.x

Cited by 18 publications

(9 citation statements)

References 15 publications

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“…The desired boc-protected derivatives 17 and 18 were prepared starting from (14) in good yields using an excess of the appropriate boc-protected amine (15 or 16) in presence of triethylamine in dichloromethane. After deprotection with TFA using standard conditions, the counterion was exchanged versus chloride using amberlite IRA958.…”

Section: Synthesismentioning

confidence: 99%

A novel set of symmetric methylene blue derivatives exhibits effective bacteria photokilling — a structure — response study

Gollmer

Felgenträger

Bäumler

et al. 2015

Photochem Photobiol Sci

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This study focuses on the structure-response relationship of symmetrically substituted phenothiazinium dyes. Four hydrophilic derivatives with the ability of additional hydrogen bonding (, ) or additional electrostatic interaction (, ) were synthesized, photophysically characterized and compared to the parent compound methylene blue (MB, ) and a lipophilic derivative () without additional coordination sites. Derivative was most effective against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli reaching a maximum photodynamic efficacy of >5log10 steps (≥99.999%) of bacteria killing in 10 minutes (5 μM, 30 J cm(-2)) without inherent dark toxicity after one single treatment with the incoherent light source PDT1200 (λmax = 660 nm, 50 mW cm(-2)). Interestingly, one derivative with two additional primary positive charges () showed selective killing of Escherichia coli (5 μM, 30 J cm(-2), 4log10 steps inactivation (≥99.99%)) and no antimicrobial effect on Staphylococcus aureus. This might allow the development of a new generation of photosensitizers with higher antimicrobial efficacy and selectivity for future applications.

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Section: Synthesismentioning

confidence: 99%

A novel set of symmetric methylene blue derivatives exhibits effective bacteria photokilling — a structure — response study

Gollmer

Felgenträger

Bäumler

et al. 2015

Photochem Photobiol Sci

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“…Methylene blue and its derivatives were proven to be versatile photosensitizers for the inactivation of pathogens in suspension [9–11], for example, Candida species [12, 13], E. coli [14, 15], S. aureus [16] and MRSA [17], tropical diseases [18], or several viruses [19, 20], and therefore finds its application in antimicrobial fields, like blood disinfection [21–24]. In vivo the phenothiazinium chromophore system is used with benefit against oral infections [25] performing photodynamic root channel disinfection [26–29] or treatment of periodontitis, inactivating bacteria like E. faecalis [30], P. gingivalis [31], or A. actinomycetemcomitans [32].…”

Section: Introductionmentioning

confidence: 99%

Hydrogen Bond Acceptors and Additional Cationic Charges in Methylene Blue Derivatives: Photophysics and Antimicrobial Efficiency

Felgenträger

Maisch

Dobler

et al. 2013

BioMed Research International

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Photodynamic inactivation of bacteria (PIB) by efficient singlet oxygen photosensitizers might be a beneficial alternative to antibiotics in the struggle against multiresistant bacteria. Phenothiazinium dyes belong to the most prominent classes of such sensitizers due to their intense absorption in the red-light region (λ abs, max ca. 600–680 nm, ε > 50000 L mol−1 cm−1), their low toxicity, and their attachment/penetration abilities. Except simple substituents like alkyl or hydroxyalkyl residues, nearly no modifications of the phenothiaziniums have been pursued at the auxochromic sites. By this, the properties of methylene blue derivatives and their fields of application are limited; it remains unclear if their potential antimicrobial efficacy may be enhanced, also to compete with porphyrins. We prepared a set of six mainly novel methylene blue derivatives with the ability of additional hydrogen bonding and/or additional cationic charges to study the substituents' effect on their activity/toxicity profiles and photophysical properties. Direct detection of singlet oxygen was performed at 1270 nm and the singlet oxygen quantum yields were determined. In suspensions with both, Gram-positive and Gram-negative bacteria, some derivatives were highly active upon illumination to inactivate S. aureus and E. coli up to 7 log10 steps (99.99999%) without inherent toxicities in the nonirradiated state.

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“…MB exhibits affinity for binding to isolated DNA [OhUigin et al, 1987;Fujimoto et al, 1994;Tuite and Norden, 1994] and RNA [Antony et al, 1993], but does not covalently link to nucleic acids [Tuite and Kelly, 1993]. Illumination results in strand breaks, base modification, loss of bases [Schneider et al, 1990[Schneider et al, ,1993Epe et al, 1993;Kvam et al, 1994) and crosslinks of RNA to proteins [Singh and Ewing, 1978]. Guanine residues appear particularly sensitive and are involved in most cases of damage.…”

Section: Discussionmentioning

confidence: 99%

Hepatitis C and human immunodeficiency virus RNA degradation by methylene blue/light treatment of human plasma

Müller-Breitkreutz

Mohr

1998

J. Med. Virol.

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Treatment of human plasma with methylene blue in combination with visible light (MB/light) inactivates several bloodborne viruses such as retro viruses and herpes viruses. The viral nucleic acid is thought to be a critical target for the inactivation procedure. We investigated the effects of photodynamic treatment on the RNA of hepatitis C virus (HCV) and human immunodeficiency virus type 1 (HIV-1) using Amplicor reverse transcriptase polymerase chain reaction (RT-PCR), which detects and quantifies a small fragment of the viral RNA. The detectable HCV RNA load (5-nontranslated region) in infected human plasma declined by 94-97 % within 10 min of illumination in small-scale experiments (1-2 ml vol.). Since the same effect was observed in both anti-HCV positive and negative ("window") samples, it can be concluded that HCV antibodies do not influence virus inactivation by photodynamic treatment. The effect of treatment on RT-PCR signals of HIV-1, which is known to be inactivated rapidly by MB/light treatment, was examined. Plasma was infected with HIV-1 and subjected to RT-PCR, which detected a part of the gag gene. The extent and kinetics of PCR signal reduction induced by MB/light treatment were similar to those observed for HCV. Experiments at production scale where single plasma units (300 ml) were infected with HCV showed reduction rates of PCR signals consistent with those measured in the small-scale experiments. The data support the view that MB/light treatment affects the viral nucleic acids and suggest that HCV is susceptible to the procedure.

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METHYLENE BLUE SENSITIZED PHOTOINACTIVATION OF E. COLI RIBOSOMES: EFFECT ON THE RNA AND PROTEIN COMPONENTS†

Cited by 18 publications

References 15 publications

A novel set of symmetric methylene blue derivatives exhibits effective bacteria photokilling — a structure — response study

A novel set of symmetric methylene blue derivatives exhibits effective bacteria photokilling — a structure — response study

Hydrogen Bond Acceptors and Additional Cationic Charges in Methylene Blue Derivatives: Photophysics and Antimicrobial Efficiency

Hepatitis C and human immunodeficiency virus RNA degradation by methylene blue/light treatment of human plasma

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