Singlet molecular oxygen, 02(’Ag) , has been intensively investigated over the last few decades, primarily in relation to photosensitization reactions. In combination with the increasing awareness and interest in singlet oxygen has been the development of various methodologies for the detection and quantification of singlet oxygen production. A large body of literature now exists concerning the singlet oxygengenerating abilities of a large variety of endogenous and exogenous compounds that can be photoactivated in the UV and visible regions of the electromagnetic spectrum. The purpose of this review was to compile data from many different sources to provide a convenient resource for biological scientists with interest in this area. This compilation is essentially an updated subset of the excellent comprehensive review on singlet oxygen yields by Wilkinson et af. (l), which, unlike this compilation, was not limited to biological molecules. The data are current up to the early months of 1999. The following tables include various related parameters in addition to the central parameter of the quantum yield of singlet oxygen generation (QA) for a given photosensitizer. The methodology or technique used to measure the QA value for each entry is given and ranges from direct detection of the luminescence produced on relaxation of singlet oxygen (time-resolved [TRILIT or steady-state [SSIL]), calorimetric

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1751-1097.1999.tb08240.x

A Compilation of Singlet Oxygen Yields from Biologically Relevant Molecules

Metal Complexes as Photo- and Radiosensitizers

Photoprocesses of Copper Complexes That Bind to DNA

This paper reviews the best known techniques using circular dichroism spectroscopy such as conventional circular dichroism (i.e. electronic circular dichroism), magnetic circular dichroisms (magnetic vibrational circular dichroism, x-ray magnetic circular dichroism), fluorescence detected circular dichroism, near-infrared circular dichroism, vibrational circular dichroism, Fourier transform infrared circular dichroism, high pressure liquid chromatography circular dichroism, stopped-flow circular dichroism, and synchrotron radiation circular dichroism. Also, we have described here the most important applications of circular dichroism spectroscopy in structural biochemistry and nanoscience.

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Circular Dichroism Techniques: Biomolecular and Nanostructural Analyses- A Review

Publisher Summary This chapter discusses DNA and RNA cleavage by metal complexes. DNA and RNA cleavage, a very active field of research, has been developed in two main and complementary directions within the past decade: oxidative cleavage and hydrolysis. In general, the difference between the two different approaches are (1) the preparation of new chemical tools to study genomic DNA. The recognition sites of most of the restriction enzymes are often limited to palindromic sequences, and it is useful to have artificial nucleases able to cleave DNA at any desired sequence, and (2), the synthesis of compounds that cleave nucleic acids should help in the design of potential therapeutic agents for the treatment of cancer and viral diseases. The challenging development of new, efficient DNA and RNA cleavage agents can require a strong cooperation between chemists, biochemists, and molecular biologists.

DNA And RNA Cleavage by Metal Complexes

In the presence of oxygen and visible light, various synthetic water-soluble porphyrins cleave pBR 322 plasmid supercoiled DNA (form I) producing relaxed (form II) and linear (form III) DNA corresponding to single-strand and double-strand breaks respectively. Large variations are observed in the efficiency of the porphyrins containing a diamagnetic metal or no metal at all. Singlet oxygen (1O2) seems to be involved in the mechanism of cleavage consistent with the inhibitory effect of the azide anion, N–3. The higher efficiency of cationic porphyrins (as compared to anionic ones) is due to their greater affinity for DNA as shown by experiments carried out at either high ionic strength or in the presence of the surfactant, sodium dodecyl sulfate.

Jean-Baptiste Verlhac

Papers

Photocleavage of DNA in the presence of synthetic water-soluble porphyrins.