Hydroxycinnamyl Derived BODIPY as a Lipophilic Fluorescence Probe for Peroxyl Radicals

Herein, we describe the synthesis of a fluorescent probe NB-2 and its use for the detection of peroxyl radicals. This probe is composed of two receptor segments (4-hydroxycinnamyl moieties) sensitive towards peroxyl radicals that are conjugated with a fluorescent reporter, dipyrrometheneboron difluoride (BODIPY), whose emission changes depend on the oxidation state of the receptors. The measurement of the rate of peroxidation of methyl linoleate in a micellar system in the presence of 1.0 µM NB-2 confirmed its ability to trap lipid peroxyl radicals with the rate constant kinh = 1000 M−1·s−1, which is ten-fold smaller than for pentamethylchromanol (an analog of α-tocopherol). The reaction of NB-2 with peroxyl radicals was further studied via fluorescence measurements in methanol, with α,α′-azobisisobutyronitrile (AIBN) used as a source of radicals generated by photolysis or thermolysis, and in the micellar system at pH 7.4, with 2,2′-azobis(2-amidinopropane) (ABAP) used as a thermal source of the radicals. The reaction of NB-2 receptors with peroxyl radicals manifests itself by the strong increase of a fluorescence with a maximum at 612–616 nm, with a 14-fold enhancement of emission in methanol and a 4-fold enhancement in the micelles, as compared to the unoxidized probe. Our preliminary results indicate that NB-2 behaves as a “switch on” fluorescent probe that is suitable for sensing peroxyl radicals in an organic lipid environment and in bi-phasic dispersed lipid systems

Efficient melt stabilization of polyethylene with quercetin, a flavonoid type natural antioxidant

The potential use of quercetin, a flavonoid type natural antioxidant, as a stabilizer in polyethylene was explored in this work. Its efficiency was compared to that of Irganox 1010, a hindered phenolic antioxidant used routinely in industrial practice, both in the presence and the absence of a phosphorous secondary stabilizer. The study was carried out with a Phillips type polyethylene and the efficiency of the additive packages was checked by various methods on samples produced by multiple extrusions. Quercetin content changed from 0 to 1000 ppm in 10 steps. The results showed that quercetin is a very effi-cient antioxidant. It prevents the formation of long chain branches already at a concentra-tion as small as 50 ppm and its dosage at 250 ppm renders the polymer sufficient long term residual stability. The efficiency of quercetin is considerably better than that of Irganox 1010, the hindered phenolic antioxidant used as reference stabilizer. The difference in efficiency might be explained with the dissimilar number of active –OH groups on the two molecules, but the stabilization mechanism of quercetin may be also different from that of I1010. Quercetin interacts with the phosphonite secondary stabilizer used, which improves dispersion and increases efficiency. Besides its advantages, quercetin has also some drawbacks (very high melting temperature, poor solubility in polyethylene and strong yellow color), which must be overcome before the substance can be used in practice

Nanotechnology meets radiobiology: Fullerenols and Metallofullerenols as nano-shields in radiotherapy

Despite significant advances in the development of radioprotective measures, the clinical application of radioprotectors and radiomitigators remains limited due to insufficient efficacy and high toxicity of most agents. Additionally, in oncological radiotherapy, these compounds may interfere with the therapeutic effectiveness. Recent progress in nanotechnology highlights fullerenols (FulOHs) and metallofullerenols (Me@FulOHs) as promising candidates for next-generation radioprotectors. These nanostructures possess unique antioxidant properties, demonstrating greater efficacy in rediucing oxidative stress compared to conventional agents. Moreover, their potential to minimize pro-oxidative risks depends on the precise identification of cellular environments and irradiation conditions that optimize their radioprotective effects. In parallel, Me@FulOHs serve as powerful theranostic tools in oncology. Their strong imaging signals enable high-resolution PET and MRI, facilitating early detection and accurate localization of pathogenic alterations. This dual functionality positions Me@FulOHs as key components in advanced radiotherapy. By integrating these nanomaterials with modern theranostic approaches, it is possible to enhance the precision of treatment while minimizing side effects, addressing a critical need in contemporary oncology. This review emphasizes the importance of systematic evaluation of context-dependent effects of Me@FulOHs, particularly in pre- and post-irradiation scenarios, to optimize their clinical relevance. The dual role of Me@FulOHs as both radioprotectors and diagnostic agents distinguishes them from traditional compounds, paving the way for innovative practical applications. Their use in radiotherapy represents a significant step toward the development of safer and more effective strategies in radiation protection and cancer treatment. We also review ionizing radiation effects, classifications, cancer radiotherapy applications, and countermeasures

Quantum-chemical investigation of the structure and the antioxidant properties of α-lipoic acid and its metabolites

Quantum-chemical computations were used to investigate the structure–antioxidant parameter relationships of α-lipoic acid and its natural metabolites bisnorlipoic acid and tetranorlipoic acid in their oxidized and reduced forms. The enantiomers of lipoic and dihydrolipoic acid were optimized using the B3LYP/6-311+G(3df,2p), B3LYP/aug-cc-pVDZ and MP2(full)/6-31+G(d,p) levels of theory as isolated molecules and in the presence of water. The geometries of the metabolites and the values of their antioxidant parameters (proton affinity, bond dissociation enthalpy, adiabatic ionization potential, spin density, and the highest occupied molecular orbital energy) were calculated at the B3LYP/6-311+G(3df,2p) level of theory. The results obtained reveal similarities between these structures: a pentatomic, nonaromatic ring is present in the oxidized forms, while an unbranched aliphatic chain (as found in saturated fatty acids) is present in both the oxidized and the reduced forms. Analysis of the spin density and the highest occupied molecular orbital energy revealed that the SH groups exhibited the greatest electron-donating activities. The values obtained for the proton affinity, bond dissociation enthalpy and adiabatic ionization potential indicate that the preferred antioxidant mechanisms for α-lipoic acid and its metabolites are sequential proton loss electron transfer in polar media and hydrogen atom transfer in vacuum

Osiemnastowieczny fife z wraku General Carleton of Whitby

In the course of the fatal voyage, General Carleton was transporting a cargo of tar and iron. This cargo facilitated the preservation of artefacts: the spilled tar formed a shell, which protected the artefacts from seawater. Therefore, the wood was not damaged nor deformed. These conditions allowed the divers to find another musical instrument, which happened to be a wooden fife. It was lying in the south-eastern part of the wreck, behind the mainmast step, where most personal belongings of the crew members were discovered. The state of preservation of the flute is good. The X-ray photo confirmed the cylindrical cross section of the instrument. It’s dimensions indicate the C# or C tuning (transposed to B or Bb). Notwithstanding its atypical two-part construction, it should be classified, according to the Anglo-Saxon nomenclature as a fife, that is „a small cylindrical transverse Flute, but with a narrower bore and hence a louder, shriller sound than the flute proper”. The maker’s marks are visible on the surface, under the embouchure hole and between the 3rd and the 4th finger hole. The name indicates that the fife was made by John Just Schuchart or Charles Schuchart. The dating suggests Charles (1720–65) as the maker. He had a shop on Chandois-street, Covent-garden, London, called “Two Flutes and Hautboy”. Based on the signature type it can be said that the fife was produced in years 1759–65. The collections around the world include 8 recorders, 26 transverse flutes, 3 oboes, a clarinet and a bassoon from the workshops of father and son. It might be possible that there are no preserved analogies for the described instrument, which enriches the known collection of Schucharts’ instruments by one fife.W 1995 r. nurkowie z Narodowego Muzeum Morskiego w Gdańsku odkryli wrak brytyjskiego statku handlowego z II poł. XVIII w., który zatonął w pobliżu wsi Dąbki u ujścia rzeki Piaśnicy. Wrak, oznaczony jako W-32, zidentyfikowano dzięki znalezionemu dzwonowi, na którym widnieje nazwa statku oraz data odlania: GENERAL CARLETON OF WHITBY 1777. Podczas swojego ostatniego rejsu General Carleton przewoził ładunek żelaza i dziegciu. Ten drugi surowiec przyczynił się do doskonałego zakonserwowania zabytków drewnianych, tworząc skorupę chroniącą je przed wodą morską. Wśród licznych przedmiotów należących do załogi znaleziono drewniany flet poprzeczny, według nomenklatury angielskiej zwany fife. Zalegał on w południowo-wschodniej części wraku, za gniazdem grotmasztu, gdzie znajdowało się najwięcej przedmiotów prywatnych marynarzy. Przypuszczalnie była to własność jednego z oficerów. Fife zachował się w bardzo dobrym stanie. Pomimo nietypowej dwuczęściowej budowy, identyfikację instrumentu potwierdziło zdjęcie rentgenowskie, ukazujące jego charakterystyczny cylindryczny przekrój. Flety tego rodzaju odznaczają się wąską średnicą, a w grze ostrzejszym i wyższym dźwiękiem w porównaniu do pozostałych fletów poprzecznych. Na powierzchni instrumentu, poniżej otworu zadęciowego oraz pomiędzy trzecim i czwartym otworem palcowym, widoczna jest sygnatura wytwórcy. Wskazuje ona na warsztat Charlesa Schucharta (1720–65), który posiadał sklep pod nazwą „Two Flutes and Hautboy” przy Chandois Street, Covent Garden w Londynie. Ponad nazwiskiem umieszczono literę C informującą o stroju instrumentu. Typ sygnatury wskazuje, że fife powstał pomiędzy 1759 a 1765 rokiem. Wśród zachowanych w światowych kolekcjach instrumentów sygnowanych przez Johna Just Schucharta i Charlesa Schucharta, znajduje się osiem fletów prostych, dwadzieścia sześć poprzecznych, trzy oboje, klarnet i fagot. Flet z wraku statku General Carleton wzbogaca ten zbiór o prawdopodobnie jedyny jak dotąd fife