Abstract

Having reported that rare earth elements displayed potential toxicity i n vivo , often be found in soil, plants and etc. , which might be easily chelated with the natural functional molecule rutin to form rutin metal complexes, ultimately entering the human body by means of food chain . However, few reports paid the attention on the toxicology of the complexes consisting of rutin with rare earth ions. Here, we focused on the potential toxicity by probing the site-selective binding of the rutin-rare earth ions complexes to human serum albumin (HSA). As a proof-of-concept, we selected Pr 3+ as the representative to conjugate with rutin to form rutin-Pr(III) complex, which was further applied to interact with HSA in aqueous solution. The results exhibited that the rutin-Pr(III) complex primary bound to the hydrophobic cavity at site II (subdomain IIIA) of HSA through hydrogen bonding and van der Waals force . Through the thermomechanical analysis, we found this binding process was spontaneous because of the negative Δ G. We believe that this work may offer a new insight into understanding the physiological effects ( e.g. toxicology) of rutin and rare earth ions, which could be helpful to guide their rational use in the agriculture and environment-related industries.