Study on obtaining new secondary metabolites with antimicrobial, anti-cancer and neuroprotective activities from Vietnamese marine fungi
Immediate objective: Study on obtaining secondary metabolites with antimicrobial, anti-cancer and neuroprotective activities from marine fungi isolated in Nha Trang Bay.  

From 62 marine fungal strains isolated from 20 sponge samples, 01 soft coral sample and 01 sediment sample collected in Nha Trang Bay, we found that 45 fungal isolates have antimicrobial activity against at least one tested microorganism, 38 (61.2%) fungal isolates capable of catching DPPH free radicals and 59 (95.1%) strains capable of catching ABTS free radicals with SC% > 50%. Ten natural compounds have been isolated from 02 selected fungal strains, as follow:
+ Strain A. flocculosus 01NT-1.12.3: Six compounds have been obtained including 03 new compounds, 12-epi-aspertetranone D (3), 6β,9α,14-trihydroxycinnamolide (5), 6β,7β,14-trihydroxyconfertifolin (6) and 03 known compounds are aspilactonol F (1), dihydroaspyrone (2), và aspertetranone D (4).
+ Strain A. niveoglaucus 01NT-1.10.4: Four compunds have been obtained, including neoechinulin B (7), neoechinulin C (8), neoechinulin E (9) and neoechinulin (10).  
In particular, compounds 1-6 showed antimicrobial activity against 6 strains of tested microorganisms with MIC values of 16-64 µg/ml. Compounds 6β, 9α, 14-trihydroxycinnamolide (5) and neoechinulin (10) exhibited cytotoxicity towards 22Rv1 with IC50 values of 31.5 and 49.9 µM, respectively. Compound 10 inhibited the growth of two prostate cancer cell lines PC-3 and LNCaP with IC50 values of 63.8 and 38.9 µM, respectively. Compounds 7-10 have capable of capturing DPPH free radicals with IC50 values of 34.0, 31.1, 46.0 and 62.6 µM, respectively. The compounds neoechinulin B (7) and neoechinulin E (9) increased the viability of the Neuro-2a cell line by 68.4% and 55.6%, respectively, when treated with rotenone.
These are the initial results in the research orientation for discovering new sources of pharmaceutical materials for biomedical field from marine organisms in Vietnam. The obtained results have contributed to strengthening the cooperation between Vietnamese and Russian scientists, along with improving the scientific level of researchers at Nha Trang Institute of Technology Research and Application.

The study isolated 10 compounds from 2 selected marine fungi, in which three compounds are new and exhibit interesting biological activities including antibiotics and toxic to prostate cancer cells.

- Publications:
1. Smetanina O.F., Yurchenko A.N., Trinh P.T.H., Antonov A.S., Dyshlovoy S.A., von Amsberg G., Kim N.Y., Chingizova E.A., Pislyagin E.A., Menchinskaya E.S., Yurchenko E.A., Van T.T.T, Afiyatullov S.S. 2020. Biologically active echinulin-related indolediketopiperazines from the marine sediment-derived fungus Aspergillus niveoglaucus. Molecules, 25(1):61.
2. Yurchenko A.N., Trinh P.T.H., Smetanina O.F., Rasin A.B., Popov R.S., Dyshlovoy S.A., von Amsberg G., Menchinskaya E.S., Van T.T.T., Afiyatullov S.S. 2019. Biologically active metabolites from the marine sediment-derived fungus Aspergillus flocculosus. Marine drugs, 17(10):579.
3. Phan Thi Hoai Trinh, Tran Thi Thanh Van, Ngo Thi Duy Ngoc, Cao Thi Thuy Hang, Le Thi Hoa, Dinh Thanh Trung, Huynh Hoang Nhu Khanh, Le Dinh Hung. 2019. Evaluation of antioxidant and antimicrobial activities of
marine fungi isolated from Nha Trang Bay. Vietnam Journal of Biology,  41 (2se1 & 2se2): 409-417.
- The certificate of instructing student to complete the graduation thesis and the copy of Bachelor's degree.

*Conclusion:
Scientists from Pacific Institute of Bioorganic Chemistry (PIBOC-FEB-RAS) are the world's leading scientists in the field of bioactive compounds from marine organisms for functional foods and new medicines for treating diseases. Therefore, the cooperation of research with Russian scientists is extremely advantageous to deploy this new research direction in our country. The research results of the Mission, in addition to producing new scientific and technological data, also contribute to improving the professional qualifications of scientists in researching new issues of marine science and technology.
*Suggestion:
It is necessary to continue expanding the direction of researching bioactive substances from microorganisms in Vietnam's waters to rationally exploit, use and conserve marine natural resources, along with affirm the biodiversity potential of our sea area.