Usually, molecules from the spiropyran class change dramatically in structure, shape, and even toxicity under ultraviolet radiation. Scientists from the SFedU Research Institute of Physical and Organic Chemistry studied spiropyran, which had an additional fragment (the so-called azomethine) added to it, and tested how it would react to light. And then an interesting thing happened.

As a result of the irradiation of the molecule, the experts concluded that the classic scenario did not work. The expected transformation into a color form did not happen. Instead, the light caused not the main part of the molecule to "bend", but the very additional fragment. Moreover, the original spiropyran itself was quite photoactive, but after adding this fragment, it seemed to transfer to it all its ability to react to light.

"I was surprised that the original spiropyran was quite photochromic, and after the introduction of the azomethine fragment, it "transferred" all its photoactivity to it. This, by the way, has the greatest fundamental value among all the research results," says Artem Pugachev, Senior researcher at the Laboratory of Special Organic Synthesis at the SFedU Institute of Chemical Physics and Technology, Candidate of Chemical Sciences.

For researchers at the SFedU Research Institute of Physical and Organic Chemistry, this is an important discovery: the molecule has changed the "rules of the game." The Rostov School of Synthetic Chemists specializing in photochromic spiropyranes and related compounds began to form more than half a century ago, at the Scientific Research Institute of the Russian State University of Physics and Technology in the 1970s. Outstanding scientists Gennady Dorofeenko and Vladimir Minkin stood at the origins of the direction, and Anatoly Metelitsa, Anatoly Chernyshev, Boris Lukyanov, Leonid Nivorozhkin, Nikolai Voloshin, Nikolai Shelepin and other researchers made a significant contribution to its development.

Over the decades, the Rostov school has become one of the most famous in the field of chemistry of photochromic compounds. Its representatives conducted pioneering research on the synthesis and study of spiropyrans based on various heterocyclic systems, published their results in leading international scientific journals and regularly presented their developments at major specialized conferences, including the International Symposium on Organic Photochromism (ISOP).

For many years, Boris Sergeevich Lukyanov, Candidate of Chemical Sciences, has been one of the leaders of this field, who headed the Laboratory of Special Organic Synthesis at the SFedU Institute of Chemical Engineering until 2023. Under his leadership, new generations of researchers were trained, including Ilya Ozhogin and Artyom Pugachev. Today, the laboratory is headed by Ilya Ozhogin, a student of Boris Sergeevich, Candidate of Chemical Sciences, who continues to develop research in the field of photo—controlled molecular systems, photopharmacology, biovisualization and organic photovoltaics.

"The main areas of work of the Laboratory of Special Organic Synthesis at the SFedU Institute of Physics and Technology are related to such areas as photopharmacology, biovisualization and organic photovoltaics. The laboratory receives grants from the Russian Science Foundation on an ongoing basis, and students and postgraduates of the laboratory have been winners of the UMNIK and Student Startup programs of the Innovation Promotion Foundation over the years, as well as recipients of Scholarships from the President of the Russian Federation," said Evgenia Korshunova, Acting Dean of the Faculty of Chemistry.

And for medicine, there are also options for various applications. The problem of chronic infections is largely related to the so-called biofilms. These are communities of bacteria that cover themselves with a protective film — and conventional antibiotics often do not take them. The issue of treating Alzheimer's disease is no less acute: the drug must be delivered exactly to the target so that there are no side effects.

And that's where this unusual molecule can come in handy. According to the scientist, it has the potential to become the basis for drugs activated by light. Imagine: you gave the drug, it is safe, and then you directed a beam of light to the desired area — and the medicine turned on.

"The introduction of an azomethine fragment into the structure of spiropyran makes it a potentially promising candidate for the development of drugs aimed at treating Alzheimer's disease, or an effective antibiotic capable of destroying biofilms by controlling light," explains Artem Pugachev.

The results of the study are published in the journal "Structural Chemistry". So far, this is a fundamental science, but it is these "wrong" results that most often lead to the real technologies of the future.