Search

Triumfetta pseudocana is a medicinal plant with cool properties. It is used in folk medicine to treat a number of diseases. Currently, there are not many published studies on the biological activity and especially the chemical composition of this plant. In this study, we chose to study the chemical composition from leaves and stems of Triumfetta pseudocana collected in Dalat, Lamdong province, Vietnam in July 2017. By chromatography, four compounds were isolated, include: tiliroside (1), friedelan-3-one (2), 3β-hydroxyfriedelane (3) and triumboidin (4). Their structures were determined by spectroscopic methods (1D and 2D-NMR) and in comparison with the reported data. This is the first time the chemical composition of the species Triumfetta pseudocana has been investigated.

Nanosilica is a versatile nanomaterial suitable as, e.g., drug carriers in medicine, fillers in polymers, and fertilizer/pesticide carriers and potentially a bioavailable source of silicon in agriculture. The enhanced biological activity of nanosilica over quartz sand has been noted before; it is directly related to the altered physicochemical properties of the nanoparticles compared to those of the bulk material. Therefore, it is feasible to use nanosilica as a form of plant stimulant. Nanosilica synthesis is a relatively cheap routine process on the laboratory scale; however, it is not easily scalable. Largely for this reason, studies of nanosilica fertilizers are scarce. This study will focus on industrial-scale silica nanoparticle production and the application of nanosilica as a plant stimulant in maize. A variant of the sol-gel method is used to successfully synthesize nanosilica particles starting from silica sand. The resulting particles are in the size range of 16-37 nm with great purity. The potential of nanosilica as a plant stimulant is demonstrated with the increased quantity and quality of maize crops.

A new species of the genus Camellia L. (Theaceae) from Southern Vietnam is described and illustrated under the name Camellia proensis. Morphological differences between C. proensis and closely related species in the genus Camellia L. (sect. Piquetia) were identified. C. proensis is easily distinguishable from C. honbaensis, C. piquetiana and C. longii by the yellow flowers; from C. dalatensis by the glabrous twigs and leaves; from C. dongnaiensis by light yellow flowers; from C. sonthaiensis by mature fruit flat-globose, 4.0–5.5 cm tall and 8.5–10.0 cm wide. Ecological environment and distribution were also provided for this new species. The images and type specimens of this species were processed and stored in Vietnam (holotype, isotypes, DLU).

EU—Vietnam Free Trade Agreement (EVFTA) was signed on June 30, 2019 and approved by the European Parliament (EP) on February 02, 2020 and the National Assembly of Vietnam has officially ratified the EVFTA on June 08, 2020, marking a significant milestone for the trade relations between Vietnam and the European Union. EVFTA is a comprehensive new generation agreement and the first EU's FTA with a developing country like Vietnam. This paper provides a review of new opportunities, challenges for and tasks of Vietnam once this agreement comes into enforcement.

From an ethyl acetate extract of twigs and barks of Dacrydium elatum a new diterpenoid named dacrydianone (1), together with lambertic acid (2), three ecdysteroids: 20-hydroxyecdysone (3), ajugasterone C (4), ponasterone A (5), and daucosterol (6), has been isolated. Their structures were elucidated by an extensive analysis of the UV/Vis, FT-IR, MS and NMR spectra as well as comparison with those in published literature. The EtOAc extract and the isolated compounds 1–5 were evaluated for their cytotoxicity on four cancer cell lines: breast cancer (MCF-7), lung cancer (Lu-1), liver cancer (HepG2) and human oral cancer (KB). The EtOAc extract and compound 2 showed a medium activity on four tested cancer cell lines, while compounds 3 and 5 exhibited week activity on these cell lines. Compounds 1 and 4 did not show activity on the tested cell lines.

In this paper, the synthesis of nickel ferrite and its use for voltammetric determination of uric acid (UA) are presented. Nickel ferrite was synthesized via a hydrothermal process using spherical carbons as hard template followed by calcination at 500 °C. It was found that iron and nickel compositions in nickel ferrite can be controlled by the initial Fe/Ni molar ratio. The stoichiometric nickel ferrite (NiFe2O4) with hollow spherical morphology was obtained from a reaction mixture with Fe/Ni molar ratio of around 1.2–1.5. Glassy carbon electrode modified with nickel ferrite was employed to quantitatively determine UA by different pulse voltammetric method. Under the optimum conditions, the anodic peak current was linearly proportional to UA concentration in the range of 0.398 to 6.761 μM. The detection limit (3σ) was found to be 0.15 μM. The proposed method has been employed to determine UA in human urine samples with acceptable recoveries of 95.15–104.8%. On the other hand, the results obtained from this method were also compared with that from standard HPLC method, showing no statistical difference.