Science and Technology Development Journal - Natural Sciences 2021-06-13T23:28:58+00:00 Phuc Van Pham Open Journal Systems Chemical constituents of Aglaia odorata and Aglaia hoaensis 2021-06-09T18:45:38+00:00 Lien Hoa Dieu Nguyen Hào Chí Lê Thy Ngoc Diem Nguyen Ly Thi Thao Nguyen Le Thu Thi Nguyen Thai Quoc Bui Phuong Thu Tran <p>Aglaia is the largest genus of the Meliaceae family with about 120 species, which grow mainly in the tropical and subtropical regions. In Vietnam, the genus contains about 30 species. Many are used in folk medicine for the treatment of different diseases. Rocaglamides, bisamides, lignans, triterpenoids and steroids are the main classes of compounds found in the genus. Some of them exhibit diverse biological activities. This research work reports the isolation of four compounds from A. odorata and A. hoaensis. Extraction was carried out using Soxhlet extractors with organic solvents followed by concentration of the solvents to yield crude extracts. Isolation was performed using column chromatography on silica gel and gel permeation on Sephadex LH-20. Chemical structures were determined using 1D NMR (<sup>1</sup>H, <sup>13</sup>C NMR, DEPT), 2D NMR (HSQC, HMBC, COSY, NOESY), IR and HRESIMS spectroscopic methods, and comparison of the spectral data with those in literature. Two triterpenoids, aglaiadoratol and 3b -friedelinol, were isolated from the whole tree of A. odorata. Two other compounds, (+)-syringaresinol lignan and threo-9,10-O-isopropylidene- 13-hydroxy-(11E)-octadecenoic acid, a derivative of fatty acid, were obtained from the bark of A. hoaensis. Among the four isolated compounds, this is the first time that aglaiadoratol has been reported in the world. In addition, (+)-syringares inol ligan and threo-9,10-O-isopropylidene-13- hydroxy-(11E)-octadecenoic acid are reported here for the first time in A. hoaensis.</p> 2021-05-09T00:00:00+00:00 ##submission.copyrightStatement## Influence of Cu(NO3)2 content used in thermal shock method on the photocatalytic activity of Cu-Modified ZnO nanoparticles 2021-06-09T18:45:37+00:00 Thế Luân Nguyễn Tiến Khoa Lê Châu Ngọc Hoàng Hữu Khánh Hưng Nguyễn Thị Kiều Xuân Huỳnh <p>The Cu doped ZnO photocatalysts were prepared on ZnO substrate modified with copper nitrate by thermal shock method with different ratio % molar Cu : Zn = 0.3, 0.5, 1.0, 2.0 and 5.0 in order to study the impacts of copper content on the photocatalytic activity of ZnO under both UV and Vis light irradiation. The crystal structure, morphology bulk and surface were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Their photocatalytic activities were studied via time-dependent degradation of methylene blue in aqueous solution. The results exhibit that crystal structure and morphology of Cu doped ZnO photocatalysts is not modified significally than ZnO original but surface charateristicschanged greatly. The photocatalyst was doped with copper content under 2% showed formation of Cu species. These samples perform photocatalytic activity higher than ZnO. The CuNZO-0.05-500 had the highest rate constants for methylene blue degradation (k<sub>UV</sub> = 6,901 h<sup>-1</sup>, k<sub>VIS</sub> = 0,224 h<sup>-1</sup>), which are about 2.2 times and 1.3 times higher than unmodified ZnO under UV light and Vis light, respectively. However, the CuNZO-5.0-500 which had the formation of CuO phase and unchangeable ZnO's surface has photocatalytic activity similar to pure ZnO.</p> 2021-05-09T00:00:00+00:00 ##submission.copyrightStatement## Assessment of aerobic bacteria killing activity of low energry X-rays in potatoes 2021-06-09T18:45:36+00:00 Nguyễn An Sơn Hai Van Cao Trieu Ngoc Le Giang Van Nguyen Ha Thi Nguyet Nguyen Quynh Ngoc Dieu Tran Tien Nguyen Thuy Bui Duc Doan Dinh Le <p>Potato is one of popular agricultural products grown and used in the world with high effective economic and nutritional value. In potatoes, there are always have some harmful bacteria species due to the sources of exposure from the seed, soil as well as the post-harvest environment which make deceasing the quality and quantity of potatoes. Usually, irradiation with gamma isotope sources is used in food irradiation, however, the disadvantage of the gamma source is the safe shielding reason even without the use of irradiation. Nowadays, X-ray irradiation in food is one of the methods interest to storage in long time. The first advantage of X-ray irradiation is that most of aerobic bacteria in food is killed, but does it not change the quality of the potato. Moreever, the advantage of an X-ray generator is that it does not have to cover up radiation when not in use. In this study, we have used low energy X-rays emitted from X-ray generator MBR-1618R-BE (Hitachi -Japan) to study the ability to kill aerobic bacteria in potatoes grown in Da Lat. After preparation, potato samples were irradiated at doses ranging from 50 Gy to 5000 Gy. The irradiated samples were homogenized and inoculated on Nutrient Agar and incubated at 370C in an incubator to check the changes of aerobic bacteria. The research showed that the number of aerobic bacteria decreased dramatically to a dose of 1000 Gy (the aerobic bacteria was only less than 0,6%), despite a sharp increase in the dose of irradiation, this number decreased a little. The results also showed that D10 dose was 471,34 Gy.</p> 2021-05-10T00:00:00+00:00 ##submission.copyrightStatement## Synthesis of pyrano[3,2-c]quinoline derivatives using catalyst prepared from L-proline and p-toluenesulfonic acid 2021-06-09T18:45:35+00:00 Pham Duc Dung Tai Huu Nguyen <p>This research prepared new generation of ionic liquid (Deep eutectic solvent, DES) from L-proline and p-toluenesulfonic acid. The ionic liquid has an asymmetric center in its structure because the original amino acid has an asymmetric center. Subsequently, the ionic liquid was studied catalytic activity in reactions of quinoline[3,2-c]pyrano derivatives synthesis. Conditions affecting the reaction and rate of the two products were also investigated. The results of the reaction conditions showed that aprotic polar solvents gave better yields and the best reaction conditions were: temperature: 50<sup>o</sup>C, time: 2 h, catalytic amount: 35% mol . The ratios of two product isomers showed that the reaction always forms a mixture of two diastereomers and the trans products were synthesized with moderate enantiomeric excess (40% for four derivatives) compared with the cis products. In addition, the results on catalytic reuse also showed that the catalyst had good usability without significant decreasing activity. When benzaldehyde and aniline were changed with their derivates bearing donating electron group (-CH<sub>3</sub>), the reaction yields slightly decrease. However, benzaldehyde bearing withdrawing electron group (-F) gave moderate yield.</p> 2021-05-11T00:00:00+00:00 ##submission.copyrightStatement## Synthesis and electrochemical properties of Na0:67Mn0:75Ni0:25O2 in carbonate-based electrolytes 2021-06-09T18:45:33+00:00 Tuyên Thi Kim Huynh Kha Minh Lê Thịnh Gia Phùng Hoàng Văn Nguyễn Phụng Mỹ Loan Lê <p>In this work, a single phase of P2-Na0:67Mn0:75Ni0:25O2 (NaMNO) material was successfully synthesized via a coprecipitation method with the size varying from 2 to 4 mm. According to the atomic absorption spectroscopy (AAS), all the metallic elements were uniformly distributed in the bulk material with the desired ratio Mn¸Ni = 3¸1. The electrochemical properties of P2-NaNMO were investigated in carbonate-based electrolytes using 1M NaClO4 or 1M NaPF6. Among these electrolytes, this cathode exhibited the best electrochemical performance with initial capacity up to 205.7 mAh/g and capacity retention reaches 63.2% during 60 cycles when using 1M NaClO4/PC + 2% (v/v) VC. Indeed, vinylene carbonate (VC) additive plays an important role in improving the performance of NaMNO cathode through the formation of a stable cathode electrolyte interphase layer (CEI). Electrochemical impedance spectroscopy (EIS) was performed to demonstrate CEI layer formation indicated by the elevation of the electrode surface film and double layer impedance in the initial cycle. During cycling, galvanostatic intermittent titration technique (GITT) helps to calculate the Na+ ion diffusion coefficient, which was increased clearly at the working voltages of Mn3+/Mn4+ and Ni3+/Ni4+ redox couples.</p> 2021-05-13T00:00:00+00:00 ##submission.copyrightStatement## Evaluate the efficiency of resveratrol for treating Parkinson disease on Drosophila melanogaster model 2021-06-09T18:45:32+00:00 Thao Thi Phuong Dang Linh Mỹ Đào Tươi Văn Phan Anh Mẫn Huỳnh <p>Parkinson's is the second most common neurodegenerative disease in the world (after Alzheimer's), characterized by the degeneration of dopaminergic neurons and mobility impairment, which consequently severely reduces patient life quality. Up to now, Parkinson's Disease cannot be completely cured. Base on the relationship between oxidative stress and the formation, the progression of Parkinson's Disease, antioxidant compounds have been studied as potential candidates in rescue or retard disease progression. Resveratrol is a strong antioxidant, anti-inflammatory, anti-apoptosis compound that exists in many fruits, especially grapes, strawberries..., and has activity depends on the used concentration. In this study, we evaluated the potential of resveratrol for treating Parkinson's Disease at concentrations of 0.064 mg/g, 0.32 mg/g, 0.64 mg/g by utilizing the knockdown dUCH (Drosophila ubiquitin carboxyl-terminal hydrolase) Drosophila melanogaster model. This model can mimic the typical symptoms of Parkinson's Disease and has been proved for the efficiency in screening drugs to treat the disease. Our results showed that the use of resveratrol at a concentration of 0.32 mg/g was effective in preventing the degeneration of dopaminergic neurons and improving mobility in dUCH knockdown flies. These results provided scientific evidence for the development of functional products or drugs to support Parkinson's Disease treatment.</p> 2021-05-18T00:00:00+00:00 ##submission.copyrightStatement## Green one-step synthesis of cellulose nanocrystal/ ZnO nanohybrid with high photocatalytic activity 2021-06-09T18:45:31+00:00 An Nang Vu Anh Mai Tran Nghi Tuyet Nguyen Duyen My Ngoc Lam Phong Pham Nam Le Nhan Thuc Chi Ha Hieu Van Le <p>In this work, nanohybrid of zinc oxide/ cellulose nanocrystals (ZnO/CNC) was successfully prepared by using a low cost and green method for photocatalytic degradation of methylene blue (MB). CNC had been derived through the hydrolysis reaction by citric/hydrochloric acid from the pure cellulose isolated from Vietnamese Nypa fruticans trunk. The obtained CNC with carboxyl groups could act as a stabilizing and supporting agent to anchor ZnO nanoparticles. The chemical and crystal structures, morphology, thermal and photocatalytic properties of the ZnO/CNC nanohybrid were characterized by FESEM, FTIR, XRD, FESEM, BET, EDX, TGA, DRS and photocatalytic tests. Analyses of FTIR spectra, XRD, and FESEM indicated that the ZnO nanocrystals with the size of 50 nm formed and loaded on the surface of CNC. The TGA analysis demonstrated that the ZnO loading sample (ZnO/CNC) had the thermal degradation onset temperature higher than that of neat CNC. ZnO/CNC cuold be absorpted ultraviolet light and have high value of specific surface area (S<sub>BET</sub>), based on the DRS spectra and the nitrogen adsorption – desorption isotherms analysis, respectively. ZnO/CNC displayed more photocatalytic activity than pure ZnO upon degradation of methylene blue due to strong interaction between the CNC and ZnO nanoparticles. The maximum degradation of MB was about 95% in 150 minutes for the ZnO/CNC.</p> 2021-06-04T00:00:00+00:00 ##submission.copyrightStatement## Synthesis, characterization and photo-Fenton catalytic activity of magnetic CuFe2O4/Fe2O3 materials 2021-06-09T18:45:30+00:00 Van Hung Phan Thu Uyen Tran Thi Tien Khoa Le <p>In this work, we proposed to immobilize Fe<sub>2</sub>O<sub>3</sub> nanoparticles on the surface of magnetic CuFe<sub>2</sub>O<sub>4</sub> particles by a facile impregnation – annealing method at different annealing temperatures (200, 300, 400 and 500°C) in order to create new heterogeneous photo-Fenton catalysts with enhanced catalytic performance for the oxidation of organic dyes. The influences of annealing temperatures used in the synthesis procedure on the phase composition, the morphology, the particle size and the surface functional groups of our catalysts were investigated by XRD, FE-SEM and FTIR techniques, respectively. The photo-Fenton catalytic performance was evaluated by the degradation of methylene blue under both UVA and visible light illumination in the presence of H<sub>2</sub>C<sub>2</sub>O<sub>4</sub> as radical-producing source. According to the experimental results, Fe<sub>2</sub>O<sub>3</sub> nanoparticles were successfully coated on CuFe<sub>2</sub>O<sub>4</sub> surface, which successfully formed the α-Fe<sub>2</sub>O<sub>3</sub> phase in the phase composition and also increased the Fe<sup>3+</sup> content on the surface. As a consequence, the rate constant of photo-Fenton catalytic degradation of methylene blue over these samples were clearly improved. More especially, owing to the good magnetic property of CuFe<sub>2</sub>O<sub>4</sub> component, our CuFe<sub>2</sub>O<sub>4</sub>/Fe<sub>2</sub>O<sub>3</sub> samples were easy to be separated from the solution by a magnet, making them more feasible in practical applications of environmental treatment. Among our catalytic samples, the CuFe<sub>2</sub>O<sub>4</sub>/Fe<sub>2</sub>O<sub>3</sub> sample annealed at 300°C showed the best performance with the highest rate constants under both UVA light and visible light. Its catalytic activities was found to be 6.8 times higher than CuFe<sub>2</sub>O<sub>4</sub> under UVA light and 2.1 times higher than CuFe<sub>2</sub>O<sub>4</sub> under visible light. However, when the annealing temperature was up to 500°C, the catalytic activity was reduced, which can be explained by the growth of particles and the stabilization of surface Fe-O bonds.</p> 2021-06-04T00:00:00+00:00 ##submission.copyrightStatement## Chemical constituents and their alpha-glucosidase inhibitory activity from the stems of taxotrophis ilicifolius 2021-06-13T23:22:44+00:00 Truong Nhat Van Do Hai Xuan Nguyen Tho Huu Le Mai Thanh Thi Nguyen <p><em>Taxotrophis ilicifolius</em>, called "Gai quít" in Vietnam, belonged to the family of Moraceae. The stems of T. ilicifolius are used in traditional medicine to cure pimples, anti-inflammatory, antibacterial... By column chromatography method together with thin layer chromatography on the ethyl acetate extract of its stems, six compounds were isolated including wogonin (1), 4-hydroxybenzoic acid (2), vanillic acid (3), vanillin (4), syringic acid (5), and syringaldehyde (6). Their chemical structures were elucidated by extensive NMR spectroscopic analysis and comparison with the literature data. The isolated compounds were tested fora-glucosidase inhibitory activity. All compounds showed more potent inhibitory activity with IC50 values 42–142 mM, than that of a positive control acarbose (IC50, 214.5 mM). Among all isolates, compounds 2, 4 and 6 exhibited significant a-glucosidase inhibitory activity with the IC50 values of 49.7, 42.6 and 55.9 mM, respectively. From the present investigation, all these compounds were isolated for the first time as well as their a-glucosidase inhibitoryactivity of <em>T. ilicifolius</em>. These results suggested that the traditional use of<em> T. ilicifolius</em> for the treatment of diabetes disease in Vietnam may be due to thea-glucosidase inhibitory activity of its phenolic constituents.</p> 2021-06-13T23:22:44+00:00 ##submission.copyrightStatement## Chemical constituents and their alpha-glucosidase inhibitory activity of Solanum procumbens 2021-06-13T23:28:58+00:00 Nhan Trung Nguyen Truong Nhat Van Do Tho Huu Le Phu Hoang Dang Hai Xuan Nguyen Thy Anh Nguyen Mai Thanh Thi Nguyen Hoang Minh Nguyen <p><em>Solanum procumbens</em> called ``Cà gai leo'' in Vietnam, belonged to the family of Solanaceae, which is a prickly diffuse, bright green perennial shrub, woody at the base. This plant has been sought for plenty of Vietnamese folk remedies for diseases such as rheumatism, back pain, detoxification, cough, pain relief, hemostasis, hepatitis, and cirrhosis. Chemical reports revealed the presence of lots of secondary metabolites such as steroids, triterpenoids, alkaloids, and phenolic compounds that have good biological activities such as antibacterial, antidiabetic, antioxidant, and antimicrobial... By column chromatography method together with thin layer normal-phase chromatography on the ethyl acetate extract of its entire plant, we isolated four compounds including dioscin (1), b -sitosterol (2), daucosterol (3) and 6'-O-acetyl-b -daucosterol (4). The result of theira-glucosidase inhibitory activity showed that compounds 2 and 4 had strong inhibition with IC50 values of 35.2 and 209.5 mM, comparing to the positive control, acarbose with an IC50 value of 214.5 mM. The results of this study have contributed to the scientific data of chemical compositions of Vietnamese medicinal plants, among them <em>S. procumbens</em> would potentially be developed as a plant-based drug to decrease the blood glucose level.</p> 2021-06-13T23:28:58+00:00 ##submission.copyrightStatement##