Secondary metabolites from Dipterocarpus obtusifolius Teijsm. Ex Miq

Six known compounds daphneresinol (1), (+)-neo-olivil (2), methyl gallate (3), bergenin (4), asiatic acid (5) and blumenol A (6) were obtained from the organic extract of the leaves of Dipterocarpus obtusifolius Teijsm. Ex Miq. by various chromatographic techniques. Structural elucidation of the metabolites was carried out by analysis of their spectroscopic data and by comparison with those reported in the literature. Compounds 1-4 and 6 were isolated from this plant for the first time

GLUCOSIDES AND UREA DERIVATIVES FROM THE SEEDS OF SCAPHIUM MACROPODUM (MIQ.) BEUMÉE

Five known compounds {carbonylbis[imino(6-methyl-3,1-phenylenel)]}bis[carbamic acid] dimethyl ester (1), (1'R,3'S,5'R,8'S,2E,4E-dihydrophaseic acid) 3'-O-beta-D-glucopyranoside (2), 3-methylbutan-1-ol beta-D-glucopyranoside (3), astragalin (4) and daucosterol (5) were isolated from the methanol extract of the seeds of Scaphium macropodum (Miq.) Beumée. The structures of the isolated compounds were elucidated by the spectroscopic methods including NMR and MS, and also by comparison with the literature data. Compounds 1-3 were isolated from this plant for the first time

The Endo-α(1,4) Specific Fucoidanase Fhf2 From Formosa haliotis Releases Highly Sulfated Fucoidan Oligosaccharides

Fucoidanases are endo-fucoidanases (also known as endo-fucanases) that catalyze hydrolysis of α-glycosidic linkages in fucoidans, a family of sulfated fucose-rich polysaccharides primarily found in the cell walls of brown seaweeds. Fucoidanases are promising tools for producing bioactive fucoidan oligosaccharides for a range of biomedical applications. High sulfation degree has been linked to high bioactivity of fucoidans. In this study, a novel fucoidanase, Fhf2, was identified in the genome of the aerobic, Gram-negative marine bacterium Formosa haliotis. Fhf2 was found to share sequence similarity to known endo-α(1,4)-fucoidanases (EC 3.2.1.212) from glycoside hydrolase family 107. A C-terminal deletion mutant Fhf2∆484, devoid of 484 amino acids at the C-terminus, with a molecular weight of approximately 46 kDa, was constructed and found to be more stable than the full-length Fhf2 protein. Fhf2∆484 showed endo-fucoidanase activity on fucoidans from different seaweed species including Fucus evanescens, Fucus vesiculosus, Sargassum mcclurei, and Sargassum polycystum. The highest activity was observed on fucoidan from F. evanescens. The Fhf2∆484 enzyme was active at 20–45°C and at pH 6–9 and had optimal activity at 37°C and pH 8. Additionally, Fhf2∆484 was found to be calcium-dependent. NMR analysis showed that Fhf2∆484 catalyzed hydrolysis of α(1,4) linkages between L-fucosyl moieties sulfated on C2 (similar to Fhf1 from Formosa haliotis), but Fhf2∆484 in addition released oligosaccharides containing a substantial amount of 2,4-disulfated fucose residues. The data thus suggest that the Fhf2∆484 enzyme could be a valuable candidate for producing highly sulfated oligosaccharides applicable for fucoidan bioactivity investigations

Bio-activities of the methanol extracts from some species belonging to the genus Polygonum in Lam Dong province

The methanol extracts from the aerial parts of eight species (Polygonum odoratum Lour., P. pesicaria L., P. chinensis L., P. perfoliatum L., P. alatum Buch.-Ham. ex D. Don, P. strigosum R. Br., P. orientale L., P. hydropiper L.) collected in Lam Dong province were submitted to bio-tests in order to evaluate the antibacterial, antioxidant and cytotoxic effects. All of these extracts had antimicrobial activities, especially P. strigosum R. Br. could resist to E. coli, S. aureus, F. oxysporum, A. niger and S. cerevisiae; P. orientale L. could resist to S. aureus, B. subtillis, F. oxysporum and A. niger; P. hydropiper could resist E. coli, S. aureus, B. subtillis, F. oxysporum, A. niger and S. cerevisiae. As far as DPPH test, the MeOH extracts from P. chinensis L., P. perfoliatum L. and P. alatum Buch.-Ham. ex D. Don were found to be the most active extracts. The MeOH extracts from these eight species had antioxydant and antimicrobial activities, therefore they had been used to cure the skin desease in the traditional medicine

Short-Term Adverse Effects Immediately after the Start of COVID-19 Booster Vaccination in Vietnam

Background: Risk communication is necessary to improve the booster vaccination rate, but Vietnam does not have a system to collect and disclose such information. Therefore, the purpose of this study was to clarify adverse reactions and their frequency in the early period after booster vaccination, and to obtain primary data for improving the booster vaccination rate. Methods: A cross-sectional survey was conducted among adults aged ≥18 years. Clinical data were collected 14 days after booster vaccination by using a standard questionnaire. Results: A total of 1322 participants were included with median age = 23 and sex ratio (Male/Female) = 0.53. AstraZeneca was the most commonly used vaccine for the first and second doses, while Pfizer was the most commonly used vaccine for booster shots. Injection site pain, fatigue, and myalgia were the most common side effect reported (71.9%, 28.1%, and 21.8%, respectively). Compared to previous COVID-19 vaccine injections, 81.9% of participants reported that their symptoms were similar or milder after receiving the booster dose. They were more likely to present injection site pain (OR = 1.43, p p p p = 0.002) were less often reported after booster shots compared to the first and second injections. The severity of symptoms occurring after booster dose versus first and second doses increased significantly with each additional year of age and among participants receiving the Pfizer and Moderna vaccines. Conclusion: Adverse reactions to booster vaccination are minor and their incidence is the same as for the first or the second vaccination. Multicenter studies with larger sample sizes on the side effects and safety of COVID-19 vaccine booster shots need to be conducted to make the population less worried, in order to increase the vaccination rate, to protect individuals’ and communities’ health

Enzyme-Assisted Fucoidan Extraction from Brown Macroalgae Fucus distichus subsp. evanescens and Saccharina latissima

Fucoidans from brown macroalgae (brown seaweeds) have different structures and many interesting bioactivities. Fucoidans are classically extracted from brown seaweeds by hot acidic extraction. Here, we report a new targeted enzyme-assisted methodology for fucoidan extraction from brown seaweeds. This enzyme-assisted extraction protocol involves a one-step combined use of a commercial cellulase preparation (Cellic®CTec2) and an alginate lyase from Sphingomonas sp. (SALy), reaction at pH 6.0, 40 °C, removal of non-fucoidan polysaccharides by Ca2+ precipitation, and ethanol-precipitation of crude fucoidan. The workability of this method is demonstrated for fucoidan extraction from Fucus distichus subsp. evanescens (basionym Fucus evanescens) and Saccharina latissima as compared with mild acidic extraction. The crude fucoidans resulting directly from the enzyme-assisted method contained considerable amounts of low molecular weight alginate, but this residual alginate was effectively removed by an additional ion-exchange chromatographic step to yield pure fucoidans (as confirmed by 1H NMR). The fucoidan yields that were obtained by the enzymatic method were comparable to the chemically extracted yields for both F. evanescens and S. latissima, but the molecular sizes of the fucoidans were significantly larger with enzyme-assisted extraction. The molecular weight distribution of the fucoidan fractions was 400 to 800 kDa for F. evanescens and 300 to 800 kDa for S. latissima, whereas the molecular weights of the corresponding chemically extracted fucoidans from these seaweeds were 10–100 kDa and 50–100 kDa, respectively. Enzyme-assisted extraction represents a new gentle strategy for fucoidan extraction and it provides new opportunities for obtaining high yields of native fucoidan structures from brown macroalgae

Chemical composition, antibacterial and antioxidant activities of acetone extract from the branches and leaves of Jasminum annamense subsp. annamense (Oleaceae)

Jasminum annamense subsp. annamense is a rare subspecies of Jasminum annamense belonging to the Oleaceae family. The aims of this study were to address the chemical profiles, antibacterial and antioxidant activities of acetone extract isolated from branches and leaves Jasminum annamense subsp. annamense for the first time. The chemical constituents of acetone extracts of studied samples were investigated by gas chromatography-mass spectrometry. There were a total of 24 components identified from the leaf extract, including lup-20(29)-en-3-one (27.93%), levodopa (19.68%), trans-cinnamic acid (7.58%), linolenic acid (6.35%) as the major compounds. Meanwhile, 26 components were reported from the branch extracts which are sorbitol (25.74%), lupeol (13.3%), cis-vaccenic acid (6.97%), glycerin (6.35%) and n-hexadecanoic acid (5.86%) were the main components. The two acetone extracts of J. annamense subsp. annamense exhibited antibacterial effect against Bacillus cereus, Escherichia coli, Salmonella enteritidis and Staphylococcus aureus based on disk diffusion assay. In addition, leaf and branch extracts of the studied species also display notable antioxidant activity in the ABTS assay with IC50 values of 311.75±3.39 and 664.46±3.732 µg/ml, respectively. This is the first report on the chemical and biological properties of J. annamense subsp. annamense and provides a promising perspective for developing good sources of antioxidant and antimicrobial compounds against both Gram positive and negative bacteria