A renal-targeted triptolide aminoglycoside (TPAG) conjugate for lowering systemic toxicities of triptolide.

Triptolide (TP), a naturally derived compound, is proven effective in the treatment of nephritis and chronic allograft nephropathy. However, the severe multiorgan toxicity greatly limited it from further clinic use. 2-Glucosamine was demonstrated as a potential targeting ligand that could specifically interact with megalin receptors highly expressed in renal proximal tubules. In this study, 2-glucosamine was employed as a glycosyl donor while triptolide the acceptor to afford a nonhydrolyzable triptolide derivative-triptolide aminoglycoside (TPAG). The kidney-targeting efficiency, pharmacodynamic properties and safety of TPAG were thus evaluated. TPAG displayed 6.94-fold of AUC(0-t, kidney) and 13.96-fold of MRT(0-t, kidney) compared to TP. Additionally, TPAG presented improved protective effect against renal ischemia/reperfusion injury. Compared to TP's multiorgan toxicity, TPAG showed minimum toxicity toward the kidney and genital systems, and greatly lowered toxicity in the liver and immune systems. In sum, our study presented an alternative structure modification of triptolide with improved safety and efficacy profiles.