守宫木属（Sauropus）植物广泛分布于东南亚地区，其中龙脷叶（Sauropus rostratus）是唯一具有药用价值的植物。其具有清热润肺,、化痰止咳、消炎镇痛的功效，民间用于治疗肺热咳喘痰多、口干、便秘等疾病。据报道龙脷叶不同种类提取液具有抗炎、抗氧化、镇痛、抗菌等生物活性，但目前尚缺乏对其单体化合物系统的药学研究。2014年报道了5个具有新颖结构的3,6-脱水己糖苷类化合物从龙脷叶的分离。鉴于3,6-脱水己糖苷结构是许多天然产物及活性小分子重要的药效结构，我们认为对其合成、潜在的生物活性及构效关系研究对于龙脷叶系统的药学研究至关重要。本项目中，我们将在课题组前期所建立的高效的构建3,6-脱水己糖苷片段的方法学基础上。设计合理的路线完成该五种天然产物的全合成、结构修饰；对所得化合物研究其多种潜在的生物活性；总结初步的构效关系，为该类天然产物及龙脷叶进一步的药学研究打下坚实的基础。

The plant Sauropus rostratus Miq. (‘Longliye’ in Chinese) belongs to the genus Sauropus in the Euphorbiaceae family, and mainly distributed in Guangdong, Guangxi and Fujian Provinces in China. It is also the only pharmaceutically valuable plant in genus Sauropus. It has been used to treat cough and bronchitis in traditional Chinese medicines. Recent pharmacological investigations of this plant showed that S. rostratus possessed anti-inflammatory, anti-anaphylaxis and analgesic effects. Generally, the pharmaceutial studies on Sauropus rostratus is focused on the pharmaceutical evaluation of its diffrent extarctions while no specific study on its chemical constituents was reported. In 2014, five new natural products bearing 2-deoxy-3,6-anhydro hexoside structures was isolated from Sauropus rostratus. Since 3,6-anhydro hexoside moiety is the basic structural component of many bioactive natural and nonnatural molecules, we believe it would be important to carry out systematic studies including total synthesis, biological evaluation and structural modification. In the present project, we will accomplish the first total synthesis of these 5 natural products by applying our formerly developed synthetic methodology to construct 3,6-anhydro hexoside structures. In addition, we will synthesize several groups of their analogs. The potential biological activities of the synthesized compounds will be evaluated. Preliminary SAR will be concluded. The above studies would be the solid foundation for further pharmaceutical investigation of Sauropus rostratus.