Kosan: Reviving the motherlode
Among the most fertile areas of drug discovery from natural products has been polyketides, a diverse group of about 10,000 known natural products found in soil bacteria, mainly Actinomycetes, as well as in fungi, marine microorganisms and plants. Polyketides have yielded a wide array of drugs, including antibiotics (tetracyclines, erythromycins, rifamycins), anti-fungals (amphotericin B, nystatin), cancer drugs (daunorubicin, adriamycin), immunosuppressants (FK506, rapamycin), and cholesterol lowering agents (Mevacor).
About one of every 100 polyketide molecules has yielded a drug candidate. But the natural product vein appears to be pretty well mined, and few novel natural polyketides are being discovered. The goal of Kosan Biosciences Inc. is to generate libraries of novel polyketides to provide more diversity...