When sulfur (S)-, selenium (Se)-, or tellurium (Te)-containing chalcogen compounds are administrated to living organisms, they are Absorbed, Distributed to the whole body, Metabolized in cells, and then Excreted to the environment. Through this ADME cycle, the chalcogen compounds are assimilated into various functional biomolecules and dissimilated to small organic or inorganic chalcogen compounds.^1–3  The production of various chalcogen-containing biomolecules in vivo can be either an active process, which is strictly controlled by genomic information, or a passive random process without genetic control. In any case, these chalcogen-containing biomolecules, in particular Se- or Te-containing ones, attract much attention of researchers in the fields of chemical biology, metallomics, and medicinal science as they exhibit interesting biological activities, such as antioxidant activity, anticancer activity, cell toxicity, etc.^4,5