Studies On The Total Synthesis Of Natural Prenylated Flavonoids And Labdane Diterpene Lactones

The synthesis of four double isoprenylated flavonoids and two terpene "Labdane" lactones natural product Curcucomosins C was introduced, the specific contents were summarized as the following four parts:Part1:Review of research on FlavonoidsSome basic properties of flavonoids were summarized,including molecular structure, distribution, properties, physiological activity,and the domestic researches on the synthetic methods of flavones.Part2:Study on the total synthesis of four flavonoidsAbyssinone-V,4’-hydroxy-6,3’,5’-triprenylisoflavonone, abyssinone-VI and abyssinone-IV are natural dual prenylated flavonoids were isolated from the erythrina plants, according to the inverse synthetic analysis, we choose the proper strategy to2,4,6-trihydroxyacetophenone,2,4-dihydroxyacetophenone and4-hydroxybenzaldehyde as starting material, through prenylation, hydroxyl protection, aldol condensation, cyclization, remove protection radical steps to complete the synthesis of four natural products. In the process of synthesis of new compounds were confirmed by NMR and HRMSPart3:Study on the biological activity of flavonoids compoundsStudied the antibacterial activity of compounds1-8with gram negative model bacteria (Escherich ia coli) and gram positive model bacteria (Staphylococcus aureus) by using the broth microdilution method.The results showed that compounds1-8had good inhibition activity on these two kinds of bacteria, the inhibitory effect of compounds2and3were obvious, the minimum inhibitory concentratio n was8ug/ml, which had a certain pharmacological application prospect.In addition, tested the antioxidant activity of8compounds by using radical scavenging capacity to measure the antioxidant activity. Compared the antioxidant ability of8compounds, choosing compoun ds of3and5which had prominent scavenging effect to compare with Vc, studied scavenging effect of following compounds on DPPH-, in order to provide reference datas for the antioxidative effect and oth er biological activity research of8flavonoids.Part4:Total synthesis of Curcucomosins CThe synthesis of two terpene "Labdane" lactones natural product Curcucomosins C was introduced, An important intermediate compound of Curcucomosins C was achieved, which taken geraniol as starting material, through hydroxyl protection, AD-mix-β-catalyzed asymmetric dihydroxylation, epoxidation, bromination, alkylation, enol phosphonic acid, allyl silicon and cyclization catalyzed by Lewis acid and functional transformation steps.All structures of new compounds were confirmed by NMR and HRMS.