1. Full name: Le Quy Thuong              2. Sex: Male

3. Date of birth: 14/4/1981                   4. Place of birth: Ninh Binh

5. Admission decision number: No 4438/QĐ-ĐHKHTN, dated on  26/11/2015 by Rector of VNU University of Science.

6. Changes in academic process: Extension decision number 4735/QĐ-ĐHKHTN, dated on 28/12/2018 and 569/QĐ-ĐHKHTN, dated on 14/02/2020  by Rector of VNU University of Science.

7. Offcial thesis title: Study on chemical constituents and biological activities of some medicinal plants of the family Araceae in Vietnam.

8. Major: Biochemistry                           9. Code: 9420101.16

10. Supervisors: 1. Assoc. Prof. Dr. Nguyen Quang Huy; 2. Assoc. Prof. Dr. Le Thi Phuong Hoa

11. Summary of the new findings of the thesis

Chemical constituents

Were identified to the aerial parts of 2 species T. flagelliforme, C. esculenta have 8 groups of substances including: glycoside, alcaloid, saponin, flavonoid, sugar, amino acid, fatty acid and sterol.

The chemical structure of 20 compounds (9 compounds from C. esculenta and 11 compounds from T. flagelliforme), including: 2 alcaloids, 6 flavonoids, 5 sterols, 1 diterpene, 1 lignan, 2 fatty acids, 1 acid amin, 1 alcohol and 1 organic acid was isolated and determined. In which, stigmast-4-en-3-one compounds were also for the first time isolated from T. flagelliforme.

Biological activities

LD50 of two species T. flagelliforme and C. esculenta have not been determined.

It has been proved the methanol extracts of T. flagelliforme and C. esculenta at both doses of 1g/kg and 2g/kg have hepatoprotective effects by limiting the increase of liver weight, limiting the increase of activity of enzymes AST, ALT and limiting the damage of liver macroscopically and microscopicall reducing the content of MDA in mouse liver liquid equivalent to silymarin dose of 50mg/kg (p < 0.05).

It has been proved the methanol extracts of T. flagelliforme and C. esculenta at both doses of 50-100 mg/kg have immunomodulating effects on mouse model immunodeficiency caused by cyclophosphamide.

Studies of cytotoxic, antioxidant and antimicrobial activities of compounds isolated from two species were carried out for the first time. In which, compounds (E) -phytol (TF4), luteolin (CE4), vitexin (CE3), isoorientin (CE6), apigenin (CE5) and isovitexin (CE7 and TF10) were higher than the positive control of ascorbic acid respectively 2.6; 2.5; 2.0; 1.9; 1.7 times with EC50 values: 7.11; 7.51; 8.85; 9.50; 10.75; 11.41 μg/mL respectively compared to ascorbic acid 18.47 μg/mL.

Twelve compounds (CE1- CE7, TF4-TF9) exhibited cytotoxic activity against the test cell lines. In which, compound TF4 ((E) -phytol) showed strong cytotoxic activity MCF7 with IC50 value of 10.31 µg/mL, compound luteolin (CE4) showed strongest cytotoxic activity HepG2 with IC50 value of 9.98 µg/mL.

The compounds β-sitosterol (CE1), stigmasterol (CE2), luteolin (CE4) and oleic acid (TF8) showed strong resistance to strains of B. subtilis, S. aureus and E. coli with IC50 values respectively 10.12 ÷ 13.61 μg/mL.

12.  Thesis-related publications

1. Le Quy Thuong, Bach Tuyet Mai, Nguyen Minh Chau, Le Thi Phuong Hoa, Nguyen Quang Huy. (2017), “Study on biological activities of extracted fractions from Typhonium flagelliforme (Lodd.) Blume”, VNU Journal of Science, Natural Sciences and Technology 33(2S), pp. 199-205.

2. Le Quy Thuong, Trieu Quy Hung, Nguyen Quang Huy. (2019), “Immunomodulatory activity of the dried methanolic extracts from Typhonium flagelliforme (Lodd) Blume on experimental immunodeficiency in mice”, Journal of Pharmacy 522, pp. 50 – 55.

3. Le Quy Thuong, Hoang Xuan Huy, Tran Quoc Hung, Tran Quoc Viet, Le Thi Phuong Hoa, Nguyen Quang Huy. (2020), “Study on chemical constituents from ethyl acetate extract of (Colocasia esculenta (L.) Schott) collected in Thanh Son, Phu Tho”, Journal of Pharmacy 526, tr. 43- 47.

4. Nguyen Quang Huy, Le Quy Thuong, Hoang Xuan Huy, Tran Quoc Hung, Phi Thi Mai Huong, Tran Quoc Viet, Le Thi Phuong Hoa. (2020), “Hepatoprotective activities of Colocasia esculenta (L.) Schott in mice model with liver injury induced by paracetamol” VNU Journal of Science, Medical and Pharmaceutical Sciences 3, pp. 66-75.