天然产物是药物研究的启迪或泉源，氟代药物由于其药效强、代谢稳定性和生物利用度高而成为药物的主要形式,构成25%的上市药物，故氟代天然产物对氟代药物的研发具有重要参考价值。但由于自然界中可被利用的水溶性氟的含量极低、且不易被卤代酶氧化为氟正离子，氟代天然产物稀少，目前只有19个。申请者推测：生活在高氟环境中的微生物，能利用氟生产氟代天然产物（简称“产氟”）；并在前期研究中发现，氟含量极高的南极磷虾中存在丰富的共附生微生物，这些微生物表现出较好的NaF耐受性、产生19F NMR呈阳性的天然产物，即所谓“产氟菌株”。本项目拟在此基础上，进一步研究南极磷虾微生物的多样性及其对宿主的化学生态作用；通过宿主诱导、共培养等手段，提高南极磷虾微生物“产氟菌株”的“产氟”能力，获得氟代等新颖的活性天然产物。为氟代药物的研究提供先导结构，开拓南极磷虾新用途，亦为深入研究南极磷虾微生物的生态作用提供科学依据。

Natural products (NPs) are the inspiration or source of drug discovery. Fluorochemicals are the main form of drugs because of their strong efficacy, high metabolic stability and high bioavailability, which constitute 25% of the marketed drugs. Therefore, fluorinated natural products (FNPs) are of great reference value for the development of fluorine-containing drugs. However, due to the extremely low content of water-soluble fluorine that can be utilized in nature, and the difficulty to be oxidized by a halogenase to fluorine cations, FNPs are extremely rare and only nineteen FNPs were identified. We hypothesized that microorganisms living in high-fluorine habitats should be able to use fluorine to synthesize FNPs, and carried out related study. The previous study revealed that there were diverse symbiotic or epiphytic microorganisms in Euphausia superba with a high fluorine content. These microbes showed good tolerance to NaF and produce 19F NMR-positive NPs, which we called "FNPs-producing strains". Based on these findings, the diversity of microorganisms associated with E. superba and their chemo-ecological effects on the host will be further studied in this project. And the FNPs and other new bioactive NPs will be obtained by improvement of the ability of "FNPs-producing strains" to produce FNPs through host-induced and co-culture strategies. The results are expected to provide the lead structures for the discovery of fluorine-containing drugs, expand the new uses of E. superba, and provide a scientific basis for further study on the ecological function of microorganisms associated with Antarctic krill, E. superba.