[Optimization of Stabilizing Agent of Camptothecin Extraction from Nothapodytes pittosporoides Roots].

Objective: To optimize the stabilizing agent of camptothecin extraction from Nothapodytes pittosporoides roots. Methods: The single factor experiment had been conducted to study the impact on the yield of camptothecin with different kinds of stabilizer, stabilizer concentration and temperature. Results: The results showed that with 0. 5% ferrous sulfate at 80 ℃,the best concentration of camptothecin extraction from Nothapodytes pittosporoides roots was got, and the yield of camptothecin after concentration reached to 94. 58%. Conclusion: This process method is efficient and simple, which can be used to solve camptothecin reduction when the extract is concentrated, and the method is benefit for the industrialization of camptothecin extraction.

Synthesis and anti-hepatitis B virus activity of novel benzimidazole derivatives.

A series of novel benzimidazole derivatives was synthesized and evaluated for their anti-hepatitis B virus (HBV) activity and cytotoxicity in vitro. Strong activity against HBV replication and low cytotoxicity were generally observed in these benzimidazoles. The most promising compounds were 12a and 12b, with similar high antiviral potency (IC50 = 0.9 and 0.7 microM, respectively) and remarkable selectivity indices (>1111 and 714, respectively). They were selected for further evaluation as novel HBV inhibitors.