Trần Anh Tuấn

Chemical investigation of the Vietnamese soft coral Sarcophyton mililatensis resulted in the isolation of four new cembranoid diterpenes, namely (-)-7beta-hydroxy-8alpha-methoxydeepoxysarcophytoxide (1), (+)-7beta,8beta-dihydroxydeepoxysarcophytoxide (2), (-)-17-hydroxysarcophytonin A (3) and sarcophytol V (4), along with two known compounds, (+)-sarcophine (5) and sarcophytoxide (6). The NMR spectral data of the new compounds were completely assigned by using a combination of 2D NMR experiments including (1)H-(1)H COSY, HSQC, HMBC, and ROESY. To investigate the bioactivities of compounds, which act on bone metabolism, we studied the effects of compounds on the function of osteoblastic MC3T3-E1 cells. Compound 1 caused a significant elevation of alkaline phosphatase activity, collagen content, and nodules mineralization compared to those of the control (p<0.05). These results suggest that newly isolated compound 1 has a direct stimulatory effect on bone formation in vitro and may contribute to the prevention for osteoporosis.

Cua Dai is one of the major estuarine areas in Central Vietnam that plays a significant role in local maritime transport, fisheries, and tourism activities. This paper presents a study that monitored the shoreline dynamics of the Cua Dai estuary over a period of 50 years (1964–2014) by using field survey data, geographic information systems techniques, and multi-temporal satellite remote sensing images (ALOS-AVNIR2 and Landsat imageries). The assessment of shoreline changes was divided into three phases: 1964–1980, 1981–2000, and 2001–2014. The results revealed that over the last 50 years, shoreline changes dramatically occurred between 1964 and 1980. The general trends of erosion and accretion at the Cua Dai estuary show that the river mouth moved towards the south due to the erosion of shorelines in the north and the river bank in the south of the Cua Dai estuary. The study outcomes can provide essential information for planning, zoning, and sustainable development activities of the coastal zones in the context of climate change.