Studies On Semisynthesis Of Two Natrual Compounds And Structure Modification, Bioactivity Of Schisantherin A

We can prove the structure of natural product by the method of semisynthesis using cheap easy natural products or non-natural analogues as raw materials. Taking natural products as lead compounds, modifying its structural, and then on the derivatives for structure-activity relationship studies, provide a basis for the development of new drugs.In this paper, we conducted semisynthesis studies on the new natural product didodecyl 3,3’-disulfanediyldipropanoate isolated from the endophytes of Melia azedarach L and the diosgenin microbial transformation product (25R)-spirost-5- ene-3β.Taking 3,3’-dithiodipropionic acid and lauryl alcohol as substrates, we get didodecyl 3,3’-disulfanediyldipropanoate by two methods: DCC/DMAP and concentrated sulfuric acid catalytic esterification, further validated the structure of natural product. Diosgenin as raw material, (25R)-spirost-5-ene-3β, 7β-diol was obtained by four continuous steps: acetylated protection of C-3 hydroxyl group, oxidation of C-7 carbon-hydrogen bond, stereoselective reduction of C-7 ketone group and deprotection of C-3 acetyl group, futher validated the C-7 hydroxyl spatial configuration of this microbial product. In this process, we probed deeply into the reaction of steroid allylic oxidation, TBHP as oxidation, searching high efficiency catalytic agents will be the burning issue of allylic oxidation.Natural product Schisantherin A as raw material, its hydrolyzate, condensation with a range of long chain acyl chloride, 10 new derivatives were obtained, oxidation using active manganese dioxide, 1 known derivative was obtained. We tested inhibition rate of derivatives on human glioma cell line U87 Id1 expression, initially speculated that the position C6 of Schisantherin A is a active site which is necessary to conduct more in-depth research. Their structures were confirmed by methods of IR, MS, NMR, et al.