The radical pair mechanism accounts for the magnetic field sensitivity of a large class of chemical reactions and is hypothesised to underpin numerous magnetosensitive traits in biology, including the avian compass. Traditionally, magnetic field sensitivity in this mechanism is attributed to radical pairs with weakly interacting, well-separated electrons; closely bound pairs were considered unresponsive to weak fields due to arrested spin dynamics. In this study, we challenge this view by examining the FAD-superoxide radical pair within cryptochrome, a protein hypothesised to function as a biological magnetosensor. Contrary to expectations, we find that this tightly bound radical pair can respond to Earth-strength magnetic fields, provided that the recombination reaction is strongly asymmetric-a scenario invoking the quantum Zeno effect. These findings present a plausible mechanism for weak magnetic field effects in biology, suggesting that even closely associated radical pairs, like those involving superoxide, may play a role in magnetic sensing.
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Nat Commun
January 2025
Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, College of Chemistry, Fuzhou University, Fuzhou, China.
Photodynamic immunotherapy (PIT) has emerged as a promising approach for efficient eradication of primary tumors and inhibition of tumor metastasis. However, most of photosensitizers (PSs) for PIT exhibit notable oxygen dependence. Herein, a concept emphasizing on transition from molecular PSs into semiconductor-like photocatalysts is proposed, which converts the PSs from type II photoreaction to efficient type I photoreaction.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Blvd, Boston, MA, 02125, USA.
Oxidative stress, associated with excessive production of reactive oxygen and nitrogen species (ROS, RNS), contributes to the development and progression of many ailments, such as aging, cardiovascular diseases, Alzheimer's disease, Parkinson's disease, diabetes, cancer, preeclampsia or multiple sclerosis. While phenols and polyphenols are the most studied antioxidants structurally similar compounds such as anilines or thiophenols are sporadically analyzed despite their radical scavenging potential. This work assesses the impact of structural features of phenols and thiophenols on their antioxidant activity.
View Article and Find Full Text PDFNanoscale
January 2025
School of Chemical Engineering, Yeungnam University, Gyeongsan, 38541, South Korea.
Eliminating hazardous antibiotics from aquatic environments has become a major concern in recent years. Tetracycline (TC) compounds pose a challenge for the selective degradation of harmful chemical groups. In this study, we successfully designed carbon vacancies in a gCN@WC (GW) heterostructure for the effective removal of TC pollutants under visible light.
View Article and Find Full Text PDFACS Omega
December 2024
State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Co-Construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, Shaanxi University of Chinese Medicine, Xianyang 712083, China.
Due to the lower oxidation potential than natural nucleic acid bases, one-electron oxidation of DNA is usually funneled into the direction of intermediates for oxidized DNA damage like 8-oxo-7,8-dihydroadenine (8-oxoA) leading to a radical cation, which may undergo facile deprotonation. However, compared to the sophisticated studies devoted to natural bases, much less is known about the radical cation degradation behavior of an oxidized DNA base. Inspired by this, a comprehensive theoretical investigation is performed to illuminate the deprotonation of 8-oxoA radical cation (8-oxoA) in both free and encumbered context by calculating the p value and mapping the energy profiles.
View Article and Find Full Text PDFNat Commun
December 2024
Living Systems Institute, University of Exeter, Stocker Road, Exeter, Devon, EX4 4QD, UK.
The radical pair mechanism accounts for the magnetic field sensitivity of a large class of chemical reactions and is hypothesised to underpin numerous magnetosensitive traits in biology, including the avian compass. Traditionally, magnetic field sensitivity in this mechanism is attributed to radical pairs with weakly interacting, well-separated electrons; closely bound pairs were considered unresponsive to weak fields due to arrested spin dynamics. In this study, we challenge this view by examining the FAD-superoxide radical pair within cryptochrome, a protein hypothesised to function as a biological magnetosensor.
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