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Glycosmis stenocarpa is a species of shrub found in the Northern provinces of Vietnam. Its roots contain different carbazolic derivatives, mainly Murrayafoline A (Mu-A), which exhibits valuable biological activities. In this study, we performed an extraction of Mu-A from the roots of G. stenocarpa and optimized this process using response surface methodology (RSM) according to a central composite design, with three independent parameters including extraction time (min), extraction temperature (°C), and solvent/material ratio (mL/g). Two dependent variables were the Mu-A content (mg/g raw materials) and extraction efficiency (%). The optimal conditions to extract Mu-A were found to be as follows: extraction temperature, 67°C; extraction time, 165 min; and solvent/material ratio, 5:1. Under these conditions, the Mu-A content and extraction efficiency were 38.94 ± 1.31 mg/g raw materials and 34.98 ± 1.18%, respectively. Mu-A exhibited antiproliferation and antitumor-promoting activity against the HepG-2 cell line. The present optimization work of Mu-A extraction from G. stenocarpa roots contributed to the attempt of designing a large-scale extraction process for the compound and further exploitation of its potential in vivo applications.

This study explores the possibility of applying high-gravity rotating packed bed (HGRPB) in removing H2S and CO2 from biogas. Ca(OH)2 aqueous solution was used as the absorbent in this study. Different experimental conditions including solution pH, rotating speed (R S) of HGRPB, gas flow rate (Q G), and liquid flow rate (Q L) were investigated with respect to the removal efficiency (E) of H2S and CO2. The experimental and simulated results show that the optimal removal efficiency of H2S and CO2 using HGRPB achieved nearly the same as 99.38 and 99.56% for removal efficiency of H2S and 77.28 and 77.86% for removal efficiency of CO2, respectively. Such efficiencies corresponded with the following optimal conditions: a solution pH of 12.26, HGRPB reactor with the rotating speed of 1,200 rpm, the gas flow rate of 2.46 (L/min), and the liquid flow rate of 0.134 (L/min).

Sea urchins (Tripneustes gratilla) are among the most highly prized seafood products in Vietnam because of their nutritional value and medicinal properties. In this research, lipid classes and the phospholipid (PL) molecular species compositions from the body and eggs of T. gratilla collected in Hon Tam, Nha Trang, Khanh Hoa, Vietnam, were investigated. Hydrocarbon and wax (HW), triacylglycerol (TG), mono- and diacylglycerol (MDAG), free fatty acid (FFA), sterol (ST), polar lipid (PoL), and monoalkyl-diacylglycerol are the major lipid classes. In PL, five main glycerophospholipid classes have been identified, in which 137 PL molecular species were detected in the body and eggs of T. gratilla, including 20 inositol glycerophospholipids (PI), 11 serine glycerophospholipids (PS), 22 ethanolamine glycerophospholipids (PE), 11 phosphatidic acids (PA), and 73 choline glycerophospholipids (PC). PI 18:0/20:4, PS 20:1/20:1, PE 18:1e/20:4, PA 20:1/20:1, and PC 18:0e/20:4 are the most abundant species with the highest content values of 38.65–48.19%, 42.48–44.41%, 41.21–40.03%, 52.42–52.60%, and 7.77–7.18% in each class of the body–eggs, respectively. Interestingly, PL molecules predominant in the body sample were also found in the egg sample. The molecular species with the highest content account for more than 40% of the total species in each molecular class. However, in the PC class containing 73 molecular species, the highest content species amounted to only 7.77%. For both the body and egg TL samples of the sea urchin T. gratilla, a substantial portion of C20:4n polyunsaturated fatty acid was found in PI, PE, and PC, but C16, C18, C20, and C22 saturated fatty acids were reported at low levels. The most dominant polyunsaturated fatty acid in PI, PE, and PC was tetracosapolyenoic C20, while unsaturated fatty acid C20:1 was the most dominant in PS and PA. To our knowledge, this is the first time that the chemical properties of TL and phospholipid molecular species of the PoL of Vietnamese sea urchin (T. gratilla) have been studied.

Essential oils are promising as environmentally friendly and safe sources of pesticides for human use. Furthermore, they are also of interest as aromatherapeutic agents in the treatment of Alzheimer’s disease, and inhibition of the enzyme acetylcholinesterase (AChE) has been evaluated as an important mechanism. The essential oils of some species in the genera Callicarpa, Premna, Vitex and Karomia of the family Lamiaceae were evaluated for inhibition of electric eel AChE using the Ellman method. The essential oils of Callicarpa candicans showed promising activity, with IC50 values between 45.67 and 58.38 μg/mL. The essential oils of Callicarpa sinuata, Callicarpa petelotii, Callicarpa nudiflora, Callicarpa erioclona and Vitex ajugifolia showed good activity with IC50 values between 28.71 and 54.69 μg/mL. The essential oils Vitex trifolia subsp. trifolia and Callicarpa rubella showed modest activity, with IC50 values of 81.34 and 89.38, respectively. trans-Carveol showed an IC50 value of 102.88 µg/mL. Molecular docking and molecular dynamics simulation were performed on the major components of the studied essential oils to investigate the possible mechanisms of action of potential inhibitors. The results obtained suggest that these essential oils may be used to control mosquito vectors that transmit pathogenic viruses or to support the treatment of Alzheimer’s disease.

Essential oils (EOs) from the stem barks, leaf petioles, fruit petioles, fresh leaves, and fresh and dried fruits of Zanthoxylum rhetsa were extracted by hydrodistillation. The volatile compounds of the products were analyzed by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC/MSD). Monoterpene hydrocarbons formed the predominant fraction of all six EO samples, of which sabinene is one of the major components (from 12.37% to 41.13%). For the leaf petiole EO, limonene (25.01%), sabinene (14.56%), and linalool (12.63%) are the major constituents, while the main constituents of fruit petiole EO were terpinolene (19.66%), terpinen-4-ol (19.07%), and sabinene (17.83%). The major components of stem bark EO are terpinen-4-ol (18.23%), sabinene (12.37%), α-phellandrene (7.34%), β-phellandrene (6.32%), and γ-terpinene (6.12%), while sabinene (38.35%), terpinen-4-ol (13.71%), γ-terpinene (6.47%), and limonene (6.02%) are the major constituents of fresh leaf EO. For the EOs of dried fruits and fresh fruits, sabinene, terpinolene, limonene, and terpinen-4-ol are the major constituents. The essential oils were also tested for their cytotoxic and antimicrobial activities. The results revealed that six EOs at concentrations of 50 μg/mL exhibited inhibitory activity against at least one tested cancer cell line but were nontoxic on Vero normal cells. Most EOs showed moderate antimicrobial activity against F. oxysporum; however, there were no obvious activity against B. subtilis and S. aureus.

Introduction: Premature ejaculation (PE) is a prevalent sexual dysfunction in men that greatly affects their quality of life. In PE, the duration of sexual performance is considered an important aspect. However, a self‐estimated value of intravaginal ejaculation latency time (perceived IELT, PIELT) as a criterion for diagnosis has not been specified. Aim: This study aimed to determine the validity and a threshold value for PIELT in PE diagnosis. Method: In our cross‐sectional study, we recruited 550 men from March 2019 to January 2020 and interviewed them regarding their general demographic characteristics, sexual habits, PIELT and completed a premature ejaculation diagnostic tool (PEDT) questionnaire. Eventually, a combination of a clinical diagnosis and PEDT score was used, in which those with PEDT ≥ 11 and diagnosed with possible PE were assigned to the final PE(+) group; those with PEDT score ≤ 8 and diagnosed with no PE were included in the final PE(−) group. Results: Men PE(−) had more frequent sexual intercourse (9.74 ± 5.38 vs. 6.69 ± 5.38 episodes per month, p < 0.001) and had higher marriage rate (72.7% vs. 60.4%, p = 0.002) than PE(+) patients. No significant difference was noted regarding age, smoking habit, age of first sexual experience, and number of sexual partners between the two groups. The mean PIELT of control subjects and PE(+) patients were 11.69 ± 6.83 min and 2.01 ± 1.21 min, respectively. On receiver operating characteristic curve analysis, the cut‐off value of PIELT of 3.75 min can be used to distinguish PE men (area under the curve = 0.982, sensitivity/specificity = 0.961/0.909), which means that men with a PIELT ≤ 3.5 min is suggestive of PE. Conclusion: The impact of PE is dramatic both from a social and a personal perspective. PE(+) patients married significantly less and have significantly lower sexual activity compared to a PE(‐) population. Furthermore, a PIELT of ≤ 3.5 min predicts PE demonstrating the need to revise its taxonomy and definition. [ABSTRACT FROM AUTHOR]

The effects of Cu2O nanoparticles (Cu2O NPs) modified with 3-(trimethoxysilyl)propyl methacrylate (TMSPM) (m-Cu2O NPs) on the properties of a polysiloxane (PS) coating were investigated. The organic surface modifications improved the antimicrobial activity of the Cu2O NPs and their dispersion in a PS matrix. Due to the broad dispersion of the m-Cu2O NPs, the PS/m-Cu2O coating exhibited better mechanical properties and better thermal stability than unmodified Cu2O (u-Cu2O) coatings. The onset temperature of PS/m-Cu2O was 24 °C higher than that of the neat PS coating and 11 °C higher than that of the PS/u-Cu2O coating. The PS/m-Cu2O coating exhibited high antibacterial activity for sulfate-reducing bacterial strains, but the PS/m-Cu2O coating showed slight bacterial inhibition of Pseudomonas stutzeri B27 bacteria (which were isolated under seawater at Phu Quoc Island, Kien Giang Province, Vietnam). Biofilm inhibition by the PS coatings with and without the m-Cu2O NPs was also tested with a natural seawater immersion test. After a 60-day test, the biofilm formed on the PS coating surface was ten times thicker than that on the PS/m-Cu2O coating. Fourier transform infrared spectroscopy (FTIR) data and the surface properties of the coating indicated that immersion in natural seawater insignificantly affected the functional groups of the coating but had a substantial influence on the smoothness of the coating, which made the surface of the coating more hydrophilic. These results suggested that the PS/m-Cu2O could be used as an antifouling coating for the marine industry. [ABSTRACT FROM AUTHOR]