多甲氧基黄酮（PMFs）是柑橘果实中具有特色的一类黄酮类化合物，已有研究表明，PMFs的活性普遍高于其他黄酮类组分。我们前期研究发现，瓯柑果实PMFs含量普遍高于其他柑橘品种，且种类丰富；细胞模型研究发现其PMFs提取物抑制HepG2、HL-60等活性亦高于其他柑橘品种。因此，本项目拟以瓯柑果实为材料，应用植物化学、色谱化学、分子生物学、医学生物学等技术，研究其PMFs抑制SCG-7901活性，明确具有抑制活性的主效PMFs组分，并从不同层面探讨其作用机理；分析果实不同组织部位及不同发育阶段PMFs组分含量及其关键酶基因CHS、CHI、FOMT的表达差异，探讨CHS、CHI、FOMT基因表达模式与PMFs含量关系，初步阐明瓯柑果实PMFs积累代谢规律与调控机制。该项目研究对深入了解柑橘PMFs基于CHS、CHI、FOMT基因协同表达模式的积累与代谢和调控机制及其对人体健康的影响有重要意义。

Abstract: Polymethoxylated flavonoids (PMFs) is a class of distinctive flavonoids in citrus fruits which possessing outstanding bioactivities. The previous studies in our group indicated that, Ougan (Citrus reticulata cv. Suavissima) fruit was rich in PMFs in the species and content. The PMFs-rich extract from Ougan fruit showed higher cytotoxicity on tumor cells compared to other citrus cultivars. On this basis, we are planning to carry out a mechanistic investigation on SCG-7901carcinoma inhibition activity as well as the accumulation rules of Ougan PMFs through the combination of phytochemical, molecular biological and medical biological technologies. SCG-7901cells and its mice xenotransplant model are applied to screen the major bioactive Ougan PMFs components. The mechanisms of PMFs’ effects will be further investigated from different aspects of tumor development. To explore the accumulation rules of PMFs in Ougan fruit, the PMFs composition of different tissues in a series of developmental stages will be investigated, and the genes of the key enzymes (e.g., CHS, CHI, FOMT, et al.) involved in the PMFs accumulation in Ougan fruit will be studied. The research will provide insights into the accumulation rules of PMFs in citrus fruits and their benefits to human health.