Evaluation of the protective properties and genotoxic potential of pyrazolo pyridine derivatives against neutron and gamma radiation using the Ames/Salmonella test system.

PURPOSE: Nuclear applications are being increasingly used in various fields, necessitating studies to protect from radiation hazards and their effects. In this study, five different chemical structures of pyrazolo [3,4-b] pyridine derivatives were synthesized. The gamma and neutron radiation protective abilities of these samples were determined and demonstrated their potential use as ingredients in radioprotective drugs. MATERIAL AND METHODS: Gamma radiation absorption parameters were calculated both theoretical and experimental. Important attenuation parameters for fast neutrons (4.5 MeV energy radiation) were figured out using the Monte Carlo simulation Geant4 code. Additionally, experimental dose rates were measured for each sample and compared to those of Paraffin and high-density polyethylene, an organic substance. Besides, Ames/Salmonella test system was aimed to detecting genotoxicity features of pyrazolo pyridine derivatives. RESULTS: All results demonstrated that each sample possesses both gamma and neutron radiation attenuation capabilities. It was determined that sample PPC4 (C20H14BrN5) exhibited the highest gamma radiation attenuation capacity among all samples, while sample PPC2 (C22H20N6) displayed an excellent neutron stopping capacity. The genotoxic properties of pyrazolo[3,4-b] pyridine derivatives were examined using the Ames/Salmonella test, and as a result, it was determined that these substances did not exhibit genotoxic effects at test doses up to 5 mM. CONCLUSION: All obtained results indicate that all PPC (pyrazolo[3,4-b] pyridine derivatives) samples do not possess a toxic effect, and they can be utilized as an active substance for the development of a drug or cream with protective properties against both gamma and neutron radiations.

Isolation and characterization of piceatannol producing bacteria from soil in Erzurum, Turkey.

Piceatannol, resveratrol's derivative, and a valuable polyphenol has managed to become one of the most remarkable candidate molecules for drug development research, with its high bioactive properties and higher stability. On the other hand, the very low amount of piceatannol in plants which are its natural source increases the cost and limits the commercialization possibilities of the product. To overcome this bottleneck, a limited number of studies have recently shown that it is possible to produce piceatannol from the resveratrol precursor much cheaper by regioselective hydroxylation catalyzed by bacteria isolated from the soil, and the search for new bacteria of similar nature in new ecosystems has gained popularity. The aim of our study, which was prepared within this framework, is the bacterial isolate with regioselective hydroxylation potential obtained as a result of selective isolation steps; determination of resveratrol hydroxylation potentials and piceatannol product yields, investigation of possibilities to increase piceatannol yield with optimization trials and identification of isolates with the highest yield. For this purpose, 200 bacterial isolates capable of resveratrol hydroxylation were obtained from soil samples taken from Erzurum (Turkey) and its surroundings by using selective media. In the continuation of the study; resveratrol hydroxylation trials were carried out with these isolates and 55 active isolates capable of producing piceatannol by regioselective hydroxylation were selected. Then, yield improvement studies of active isolates were carried out by using different carbon sources and optimizing the culture conditions. As a result, a culture collection was created by identifying the 6 most active bacterial isolates with commercialization potential using conventional and molecular methods. These are 4 Gram-positive (Rhodococcus sp., Rhodococcus erythropolis, Paeniglutamicibacter sp., Arthrobacter sp.) and 2 Gram-negative (Shinella sp., Ensifer adhaerens) bacterial isolates. As a result of the optimization studies, three of these isolates used phenol as a biocatalyst, while the other three increased the production yield of piceatannol by using 4-hydroxyphenylacetic acid.