Tran Hai Bang

09 water samples, 55 sediment samples and 20 biosamples (bivalve and fish) were collected from 11 locations of Tam Giang Cau Hai lagoon during dry seasons of 2005,2006 and 2007. The samples were treated under EPA methods and analysed by GC-MS for organochlorinated pesticides (OCs). The result showed that concentrations of pesticides of all water samples were at lower level than TCVN-5942-1995 (Vietnamese Standard) for organochlorine compounds (OCs) of surface water. Conversely, these chemicals were determined in sediment samples. Despite of decreasing from 2005 to 2007, the concentrations of them in sediment is still high. The samples from 0 Lau estuary next to Tam Giang lagoon were higher in DDT and HCH concentrations while the ones from Truoi estuary next to Cau Hai lagoon were higher in dieldrin and endrin. Analytical data indicated that the topography strongly affected to the distribution of organochlorinated pesticides.

Ergosterol peroxide was isolated from the ethanol extract of Pleurotus eryngii as an inhibitor of osteoclast differentiation. This compound showed an inhibitory effect in a dose-dependent manner and an inhibition rate of up to 62% with low cytotoxicity, even at a concentration as low as 1.0 μg/mL.

Tubulin polymerization is an important target for anticancer therapies. Even though the potential of Ganoderma triterpenoids against various cancer targets had been well documented, studies on their tubulin polymerization-stimulating activity are scarce. This study was conducted to evaluate the effect of Ganoderma triterpenoids on tubulin polymerization. A total of twenty-four compounds were investigated using an in vitro tubulin polymerization assay. Results showed that most of the studied triterpenoids exhibited microtuble-stabilizing activity to different degrees. Among the investigated compounds, ganoderic acid T-Q, ganoderiol F, ganoderic acid S, ganodermanontriol and ganoderic acid TR were found to have the highest activities. A structure-activity relationship (SAR) analysis was performed. Extensive investigation of the SAR suggests the favorable structural features for the tubulin polymerization-stimulating activity of lanostane triterpenes. These findings would be helpful for further studies on the potential mechanisms of the anticancer activity of Ganoderma triterpenoids and give some indications on the design of tubulin-targeting anticancer agents.

ABSTRACT Many triterpenoids have shown ability to inhibit hydrolyzing activity of angiotensin-converting enzyme; however, there has been no report about the structure–activity relationship and inhibition patterns of these compounds. In this study, 32 lanostane-type triterpenoids derived from Ganoderma lingzhi were assayed to determine the structural features involved in the observed inhibition effects. In silico and in vitro experiments were also used to determine the kinetics of the reaction. Fifteen compounds showed measurable in vitro IC50 values ranging from 0.194 to 0.941 mM. It was shown that carboxyl groups play an important role in inhibiting the enzyme; further, a hydroxyl group or carbonyl group at either C7 or C15 increases the inhibition rate, and a double bond at C24,25 decreases the activity. Based on the docking data we speculated that triterpenoids could not fit into the active site of the enzyme; therefore, the inhibition mode could not be competitive. Dixon plotting showed that the inhibition patterns should be uncompetitive and non-competitive instead.

Twenty-nine mushrooms collected in the mountainous areas of Nepal were analyzed for antioxidant activity by different methods, including Folin-Ciocalteu, ORAC, ABTS, and DPPH assays. Intracellular H2O2-scavenging activity was also performed on HaCaT cells. The results showed that phenolic compounds are the main antioxidant of the mushrooms. Among studied samples,Inonotus andersonii, andPhellinus gilvusexhibited very high antioxidant activity with the phenolic contents up to 310.8 and 258.7 mg GAE/g extracts, respectively. The H2O2-scavenging assay on cells also revealed the potential of these mushrooms in the prevention of oxidative stress. In term of ACE-inhibition, results showed thatPhlebia tremellosawould be a novel and promising candidate for antihypertensive studies. This mushroom exhibited even higherin vitroACE-inhibition activity thanGanoderma lingzhi, with the IC50values of the two mushrooms being 32 μg/mL and 2 μg/mL, respectively. This is the first time biological activi...