The invention belongs to the field of biomedical research involving the 1,3,4-selenyldiazo derivatives that have cell protective activity. Because there are not so many heterocyclic selenium compounds, we synthesized a new type of selenium analog of BPTES. As the isoacceptor of BPTES, the compounds have antitumor activity, anti-oxidation and cell protection function. Currently many drugs contain the thiodiazo motif, so synthesis of selenyldiazo functional group could further optimize these drugs and are important in new drug development and application.

The invention belongs to the field of biomedical research involving the 1,3,4-selenyldiazo derivatives that have cell protective activity. Because there are not so many heterocyclic selenium compounds, we synthesized a new type of selenium analog of BPTES. As the isoacceptor of BPTES, the compounds have antitumor activity, anti-oxidation and cell protection function. Currently many drugs contain the thiodiazo motif, so synthesis of selenyldiazo functional group could further optimize these drugs and are important in new drug development and application.

The invention relates to small, conjugatable, orthogonal and tunable fluorophores for imaging of small bioactive molecules. The invention further relates to processes for the preparation of the compounds, and uses of the compounds in therapeutic, diagnostic, surgery and analytical applications. The invention provides a compound of formula (I), a derivative or a salt thereof. Wherein X is selected from the group consisting of NH, O, S, SeR5R6, CR7R8; R1 is selected from the group consisting of amines, alcohols, thiols, thiophenols, selenols, selenophenols and aryl groups; R2 and R3 are independently H or a halogen; R4 tis either H, nitro or cyano; R5 is either absent or methyl or oxygen; R6 is either absent or methyl or oxygen; and R7 and R8 are independently selected from the group consisting of linear or cyclic alkyl groups containing halogen, amino, cyano or carboxylic ester substituents, and alkyl aryl groups. ##STR00001##