Sugar-based synthesis of tamiflu and its inhibitory effects on cell secretion

Tamiflu is currently the most effective drug for the treatment of influenza, but the insufficient supply and side-effects of this drug demand urgent solutions. We present a practical synthesis of Tamiflu by using novel synthetic routes, cheap reagents, and the abundantly available starting material D-glucal. The strategy features a Claisen rearrangement of hexose to obtain the cyclohexene backbone and introduction of diamino groups through tandem intramolecular aziridination and ring opening. In addition, this synthetic protocol allows late-stage functionalization for the flexible synthesis of Tamiflu analogues. By using the synthesized Tamiflu and its active metabolite (oseltamivir carboxylate), we inves-tigated their influences on neuroendocrine PC12 cells in various aspects. It was discovered that oseltamivir carboxylate significantly inhibits the vesicular exocytosis (regulated secretion) of PC 12 cells, and suggests a mechanism underlying the Tamiflu side-effects, in particular its possible adverse influences on neurotransmitter release in the central nervous system.