Antimicrobial and Cytotoxic Secondary Metabolites from a Marine-Derived Fungus Penicillium Citrinum VM6.

Investigation of an antimicrobial and cytotoxic ethyl acetate extract prepared from solid fermentation of the marine-derived fungus Penicillium citrinum VM6 led to the isolation of eight metabolites (1-8), including one citrinin dimer dicitrinone F (1). Of these, compound 7 was isolated for the first time from the Penicillium genus and compound 1 with carbon-bridged C-7/C-7' linkage is rarely reported. All compounds (1-8) exhibited selective antimicrobial activity against the tested Gram-positive bacteria and Candida albicans with MICs of 32-256 µg/mL. Compounds 1 and 8 exhibited cytotoxicity against all tested cell lines A549, MCF7, MDA-MB-231, Hela, and AGS with IC50 values of 6.7 ± 0.2 to 29.6 ± 2.2 µg/mL, whereas compound 5 had selective cytotoxicity against the MCF7 cell lines with IC50 of 98.1 ± 7.8 µg/mL.

A Pair of Undescribed Alkaloid Enantiomers from Marine Sponge-Derived Fungus Hamigera avellanea and Their Antimicrobial and Cytotoxic Activities.

From marine sponge-associated fungus Hamigera avellanea, thirteen secondary metabolites including a pair of undescribed alkaloid enantiomers (+)-hamiavemin A (4S) (+)-1 and (-)-hamiavemin A (4R) (-)-1. Compound 1 was enantiomers resolved by the Chiralpak AS-3 column, using a hexane/isopropanol mobile phase. Their structures were determined based on extensive analyses of HR-ESI-MS, 1D and 2D NMR spectra. The absolute configuration of (+)-1 and (-)-1 were assigned tentatively by ECD calculations. Among the isolates, compound 6 showed strongest antibacterial activity against Enterococcus faecalis, Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella enterica, and Candida albicans with the MIC values of 2, 2, 16, 32, 64, and 16 µg/mL, respectively, which were stronger than that of the positive control compound, kanamycin (MIC values ranging from 4 to 128 µg/mL). In addition, compounds 1, 2, and 9 showed moderate cytotoxic activity against three cancer cell lines, HepG2, A549, and MCF-7 with the IC50 values ranging from 55.35±1.70 to 83.02±2.85 µg/mL.

Short communication: phylogenetic characterization of HIV type 1 CRF01_AE V3 envelope sequences in pregnant women in Northern Vietnam.

Characterization of HIV-1 strains is important for surveillance of the HIV-1 epidemic. In Vietnam HIV-1-infected pregnant women often fail to receive the care they are entitled to. Here, we analyzed phylogenetically HIV-1 env sequences from 37 HIV-1-infected pregnant women from Ha Noi (n=22) and Hai Phong (n=15), where they delivered in 2005-2007. All carried CRF01_AE in the gp120 V3 region. In 21 women CRF01_AE was also found in the reverse transcriptase gene. We compared their env gp120 V3 sequences phylogenetically in a maximum likelihood tree to those of 198 other CRF01_AE sequences in Vietnam and 229 from neighboring countries, predominantly Thailand, from the HIV-1 database. Altogether 464 sequences were analyzed. All but one of the maternal sequences colocalized with sequences from northern Vietnam. The maternal sequences had evolved the least when compared to sequences collected in Ha Noi in 2002, as shown by analysis of synonymous and nonsynonymous changes, than to other Vietnamese sequences collected earlier and/or elsewhere. Since the HIV-1 epidemic in women in Vietnam may still be underestimated, characterization of HIV-1 in pregnant women is important to observe how HIV-1 has evolved and follow its molecular epidemiology.