In continuation of our investigation, a new diterpene, rabdonervosin C (Ⅰ), was isolat-ed from the leaves and stems of Rabdosia nervosa (Hemsl.) C. Y. Wu et H. W. Li. Its structure wasidentified as lα, 15β, -dihydroxy-6β-ethoxy-6, 7-B-seco-ent-kaur-16-en-6, 20-epoxy-7, 20-δ-olide on thebasis of spectroscopic (MS, IR, 1HNMR, 13CNMR, DEPT and 2D-NMR) data and in comparison with theknown rabdonervosin A(Ⅲ) and B (Ⅱ).

Objective To establish a HPLC method for the determination of ferulic acid in Xuefu Zhuyu Decoction. Methods A Kromasil C18(250 mm ×4. 6 mm, 5 μm) column was adopted. The mobile phase consisted of acetonitrile-0. 085 % phos-phoric acid(17 : 83)with the flow rate of 1.0 mL/min. The column temperature was at 35 ℃ and detection wavelength was set at 316 nm. Results A good linearity of ferulic acid was in the range of 0. 0252μg to 0. 504μg and r=0. 999 9. The average recovery was 100. 15 % and RSD=1.69 %. Conclusion The method is simple and rapid, and it is suitable for the determi-nation of ferulic acid in Xuefu Zhuyu Decoction.

Objective To evaluate the effectson experimental posterior vitreous detachment(PVD) induced by intravitrous injection of hyaluronidase and perfIuoroethane(C3F8),and whether it is safe or not.Methods Twelve rabbits(24 eyes) were divided into 3 experimental groups,the contralateral eyes in same animals served as the controls.The eyes in group A(4 eyes) and B(4 eyes) were injected with 10IU of hyaluronldase(0.2ml) and 0.2ml perfluoropropane(C3F8) respectively.The eyes in group C(4 eyes) were received vitreous injections of 10IU(0.1ml) of hyaluronldase and 0.1ml perfluoropropane(C3F8) together.All control eyes were injected with balanced salt solution(0.2ml).The ocular and fundus signs were examined for 2 following weeks and then killed for histological examination.Results Four eyes in group C showed complete separation of the vitreous cortex from the retina(PVD) by B-scan and scanning electron microscopy,and no PVD was detected in group A、B and all control eyes.No evidence of retinal toxicity was revealed by light or transmisson electron microscopy in all eyes.Conclusion Vitreous injection of hyaluronidase combined with perfluoropropane(C3F8),as a safety method,can induce posterior vitreous detachment after 2 weeks.