A new safe and effective compound of formula I or II, a stereoisomer, a tautomer or a mixture thereof of the compound, a pharmaceutically acceptable salt, eutectic, polymorphic substance or solvate of the compound, or a stable isotope derivative, metabolite or prodrug of the compound: (D) nL-G(L-D) m formula I or (G) nL-D(L-G) m formula II.本發明提供了一類新的安全有效的通式為I或II的化合物,該化合物的立體異構體、互變異構體或其混合物,該化合物藥學上可接受的鹽、共晶、多晶型物或溶劑合物,或者該化合物的穩定同位素衍生物、代謝物或前藥:或。