植物小娃娃皮的化学成分

为研究川东植物小娃娃皮Daphne gracilis E.Pritz.的化学成分,运用正、反硅胶柱色谱对小娃娃皮乙醇浸膏部分进行分离纯化,通过波谱分析方法鉴定了化合物的结构。结果表明,从小娃娃皮乙醇浸膏中分离得到5个化合物,分别为:neochamaejasmin A(Ⅰ)、chamaejasmenin B(Ⅱ)、sikokianin A(Ⅲ)、sikokianin B(Ⅳ)和长春藤皂苷元(Ⅴ)。化合物Ⅰ~Ⅴ均为首次从该植物中分离得到。

微生物维生素E产业化开发进展

维生素E是一种脂溶性抗氧化剂,仅在光合细菌和高等植物中合成,具有重要的生理学功能。纤细裸藻能有效积聚α-生育酚。本文综述了通过代谢和基因工程、培养系统和反应器等方面的研究来有效生产生育酚的进展情况,旨在促使工业化生产维生素E成为可能。

Hydrodynamics of Euglena Gracilis during locomotion

The hydrodynamics and locomotion mechanism of Euglena Gracilis(E.Gracilis)is investigated using microscopic shadow imaging and micro particle image velocimetry(MicroPIV).Three distinct locomotion modes were observed:translation,spin,and left/right turn.Since the flagellum was not possible to image,the strokes were identified by evaluating the flow field around the protist.The flow field information is obtained using a phase-separated PIV evaluation,which uses a histogram-thresholding based dynamic masking approach.The temporal resolution of the experiment was sufficient to identify the sequence of two modes,translation and spin,and the stroke-pulling frequency.The flow field result during a stroke is compared with existing Stokeslet dipole theories and flow disturbance decay with distance is investigated.The results indicate that the organism has a complex locomotion technique that allows the change of direction,axial orientation and propulsion.