Spiropyrans are organic compounds with photochromic (change color when exposed to light) properties. Due to this feature, such molecules can be used in medical and other technologies as probes and markers with photo-controlled fluorescence.

Researchers at the Southern Federal University have synthesized 12 new spiropyrans with photo-controlled fluorescence, whose structure includes various substituents and anions.

"Spiropyrans are one of the most interesting classes of organic photochromic compounds. Under the influence of ultraviolet or visible light, they can dramatically change their fluorescent properties. This makes them promising candidates for use as probes with controlled fluorescence," said Artem Pugachev, senior researcher at the SFedU Laboratory of Special Organic Synthesis.

As part of the study, the influence of the structure of the obtained compounds on their properties was established. Thus, according to scientists, the toxicity of compounds depends on the anion in the molecule, and the spectral characteristics are determined primarily by the structure of the molecular cation.

"This means that by choosing the structure of the molecular cation, it is possible to obtain a substance with the desired fluorescent characteristics. And then, by selecting a suitable anion, you can adjust the toxicity of substances," explained Artem Pugachev.

The scientist also noted that the least toxic fluorescent dyes can be used as markers for safe staining of living tissues. The most toxic ones can be used as theranostic agents – special molecules that help detect and destroy cancer cells or clusters of pathogenic microorganisms.

Using the least toxic compounds and a fluorescence microscope, scientists have successfully visualized planktonic bacteria and bacterial biofilms of various microorganisms.

"The bacteria in biofilms are characterized by increased resistance to antibiotics, and they often cause chronic diseases and implant rejection. Therefore, it is important to detect and destroy such bacterial formations in time," the researcher said.

In the near future, it is planned to investigate the anticancer activity of the obtained compounds. Scientists also expect to obtain and study spiropyrans with other functional substituents and cationic heterocyclic fragments that can dissolve well in water and have antibacterial and anticancer properties.

It is important to note that it is still very early to talk about ready-made drugs and solutions available in medical institutions and pharmacies. So far, only an approach to the potential treatment of a number of diseases, including cancer, has been developed, but years of preclinical studies are needed before its practical implementation, and then, if the method pays off, then clinical ones. research.

The study, the results of which are published in the scientific journal ChemBioChem, was supported by the federal program "Priority 2030" (national project "Science and Universities") and was carried out in accordance with the program of the strategic project "Fast and Furious Materials", as well as the Russian Science Foundation project "Photo-controlled fluorescent markers and probes based on new spiropyrans operating in the near-infrared range"(Project No. 22-73-00330).