Synthesis of new simplified hemiasterlin derivatives with α,β-unsaturated carbonyl moiety.

International audienceIn this Letter, we report a convenient and efficient method for the synthesis of new simplified derivatives of hemiasterlin in which the α,α-dimethylbenzylic moiety A is replaced by α,β-unsaturated aryl groups as Michael acceptor. Most of these derivatives have a strong cytotoxic activity on three human tumor cell lines (KB, Hep-G2 and MCF7). Analogs 17b and 17f showed a high cytotoxicity against KB and Hep-G2 cancer cell lines comparable to paclitaxel and ellipticine

Synthesis of new bioisosteric hemiasterlin analogues with extremely high cytotoxicity

International audienceIn this article, we report a convenient and efficient method for the synthesis of new simplified derivativesof hemiasterlin in which the α,α-dimethylbenzylic moiety A is replaced by α,β-unsaturated aryl groupsas Michael acceptor. Most of these derivatives have a strong cytotoxic activity on three human tumorcell lines (KB, Hep-G2 and MCF7). Analogs 17b and 17f showed a high cytotoxicity against KB andHep-G2 cancer cell lines comparable to paclitaxel and ellipticine

GLYCOSIDES ISOLATED FROM THE AERIAL PARTS OF Premna integrifolia L. GROWING IN THAI BINH

From the aerial parts of Premna integrifolia L., three glycosides acteoside (1), premnaodoroside A (2), and premnaodoroside B (3) were isolated. Their chemical structures were elucidated by means of ESI-MS, 1H-NMR, 13C-NMR, HSQC, HMBC spectra and in comparison with the previous literature. To our best knowledge, this is the first report of 1 and 3 from P. integrifolia

Study on synthesis of carboxymethyl cellulose from pineapple leaf waste and its potential applications as a thickener

In this study, cellulose and hemicellulose were successfully extracted from pineapple leaf waste at yields of 58.8 and 16.1% by dried weight, respectively. Carboxymethyl cellulose (CMC) was synthesised from pineapple leaf cellulose by an esterification process using sodium hydroxide (NaOH) and monochloroacetic acid (MCA) with isopropanol as the supporting medium. Preparation of CMC was investigated by varying three free factors, namely, NaOH concentration, MCA dose, and cellulose size. The carboxymethylation process was optimised to produce CMC with differing degrees of substitution (DS). The highest DS of CMC (0.86) was obtained with 15% (w/v) NaOH solution, 0.6 g of MCA/g cellulose, and 50 μm cellulose. The obtained CMC were characterised by FTIR spectroscopy, SEM images and XRD diffractions. Moreover, the thickening performance of obtained CMC was also determined. The influence of the CMC’s molecular weight and degree of substitution on the viscosity of 1% (w/v) aqueous solution was tested. The experimental results suggest that the viscosity of the solution increases with increasing molecular weight and degree of substitution of CMC

Logging intensity drives variability in carbon stocks in lowland forests in Vietnam

Forest degradation in the tropics is generating large carbon (C) emissions. In tropical Asia, logging is the main driver of forest degradation. For effective implementation of REDD+ projects in logged forests in Southeast Asia, the impacts of logging on forest C stocks need to be assessed. Here, we assess C stocks in logged lowland forests in central Vietnam and explore correlations between logging intensity, soil, topography and living aboveground carbon (AGC) stocks. We present an approach to estimate historical logging intensities for the prevalent situation when complete records on logging history are unavailable. Landsat analysis and participatory mapping were used to quantify the density of historical disturbances, used as a proxy of logging intensities in the area. Carbon in AGC, dead wood, belowground carbon (BGC) and soil (SOC) was measured in twenty-four 0.25 ha plots that vary in logging intensity, and data on recent logging, soil properties, elevation and slope were also collected. Heavily logged forests stored only half the amount of AGC of stems ≥10 cm dbh as lightly logged forests, mainly due to a reduction in the number of large (≥60 cm dbh) trees. Carbon in AGC of small trees (5–10 cm dbh), dead wood and BGC comprised only small fractions of total C stocks, while SOC in the topsoil of 0–30 cm depth stored ~50% of total C stocks. Combining logging intensities with soil and topographic data showed that logging intensity was the main factor explaining the variability in AGC. Our research shows large reductions in AGC in medium and heavily logged forests. It highlights the critical importance of conserving big trees to maintain high forest C stocks and accounting for SOC in total C stock estimates

Capital attraction solution for social housing development in Vietnam in the period of 2023 – 2030

Social housing development for low-income people, industrial park workers and poor households is one of the key tasks in socio-economic development of the Vietnamese Government. In recent years, the government has had many incentive policies to mobilize capital for investment in social housing development (incentives on land use levy, land rental, incentives on value-added tax, corporate income tax, incentives on bank loans). However, the supply of social housing has been still lacking, reaching 65% of the set target. The capital supported by the government for Vietnam Bank for Social Policies is 3,163.9/9,000 billion VND, reaching 35% of the demand in the period of 2016 – 2020 [1], while the private sector has not been really interested in this field. The article analyzes the current situation of capital attraction for social housing development in Vietnam, identifies the achievements and shortcomings, at the same time establishes and evaluates the influencing factors, thereby proposing some solutions for capital attraction for this task

Study on the Pathogenesis of the White Spot Syndrome Virus (WSSV) on Juvenile Penaeus monodon in Vietnam

The white spot syndrome virus (WSSV) causes disease and mortality in cul- tured and wild Penaeus monodon. In this study, specific pathogen-free P. monodon were injected with WSSV to determine in which primary organs the virus replicates and to analyze viral spread. Shrimps were injected with a low SID50 endpoint (shrimp infectious dose resulting in 50% infected shrimp) of 101.5 or a high SID50 of 104 of the virus. Six shrimps per treat- ment were collected at 0, 3, 6, 9, 12, 15, 18, 21, 24, 30, 36, 42, 48, 54, and 60 h post injection (hpi) for detection of the virus in tissues from 10 organs by immunohistochemistry. In shrimps injected with the low dose, WSSV- infected cells were first detected in the heart and antennal gland 12 hpi, then in the foregut, stomach, and gills at 18 hpi. The integument was infect- ed 24 hpi and the hematopoietic tissue, lymphoid organ, midgut, and con- nective tissues 36 hpi. In shrimps that received the high dose, the heart, antennal gland, stomach, gill, and connective and hematopoietic tissues were WSSV-positive 12-15 hpi while the foregut and cuticular epithelium were positive 18 hpi and the lymphoid organ and midgut were positive 21 hpi. The present study confirmed the replication of WSSV in P. monodon heart, antennal gland, foregut, stomach, gills, cuticular epithelium, hematopoietic tissue, connective tissue, and lymphoid organ

COPD Patients with Asthma Features in Vietnam: Prevalence and Suitability for Personalized Medicine

COPD patients with asthma features usually benefit from inhaled corticosteroids (ICS)-containing regimens, but their burden and diagnostic criteria remain to be established. The aims of this study were to estimate the proportion of patients with asthma features among patients with physician-diagnosed COPD and to investigate differences in clinical characteristics and current medications between COPD patients with asthma features and patients with COPD alone. A cross-sectional study was conducted at two respiratory out-patient clinics at the University Medical Center in Ho Chi Minh City and Bach Mai Hospital in Ha Noi, Vietnam. COPD patients with asthma features were identified by attending physicians following the approach recommended by the GINA/GOLD joint committee. Of the 332 patients screened, 300 were enrolled in the study. The proportion of COPD patients with asthma features was 27.3% (95% confidence interval (95% CI) 22.6–32.6%). COPD patients with asthma features were younger, with higher FEV1 values, a greater proportion of positive bronchodilator reversibility tests, higher blood eosinophil count, and were more often treated with ICS/LABA (ICS/long-acting bronchodilator beta-2 agonist) than patients with COPD alone. The prevalence of COPD patients with asthma features is particularly high in Vietnam thus requiring appropriate action plans in clinical practice