Three metabolites from the mangrove endophytic fungus Sporothrix sp. (#4335) from the South China Sea.

Three metabolites, sporothrins A, B, and C (1-3), were isolated from the mangrove endophytic fungus Sporothrix sp. (#4335). Their structures were identified by the spectral data and X-ray diffractive techniques, with compound 1 showing strong inhibition of acetylcholine esterase. 1,3,6,8-Tetrahydroxynaphthalene (T4HN) was deduced as one of the precursors in the biosynthesis of 1 and 2. In a primary biosynthesis gene study, the partial gene fragment obtained with the LC1-Im/2c-Im primer pair was shown to be closely related to genes encoding T4HN synthase. The deduced protein sequences were highly homologous to the ketosynthase domains of other fungal PKS genes involved in T4HN biosynthesis.

3-Hydr-oxy-7,8-dimethoxy-quinolin-2(1H)-one.

In the crystal structure of the title compound, C(11)H(11)NO(4), intra-molecular O-H⋯O hydrogen bonding results in the formation of a planar five-membered ring, which is nearly coplanar with the quinoline group. Inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers.

Titanium-catalyzed enantioselective alkynylation of aldehydes.

A simple and practical method to make chiral propargylic alcohols has been developed: in the presence of a titanium alkoxide catalyst prepared in situ from titanium tetraisopropoxide and (R)-H8-binaphthol, a variety of aromatic aldehydes were converted to the corresponding chiral propargylic alcohols with very good enantioselectivities (up to 96.2% e.e.) and yields.

Paeciloxanthone, a new cytotoxic xanthone from the marine mangrove fungus Paecilomyces sp. (Tree1-7).

The metatrophic fungus Paecilomyces sp. (Tree1-7) was isolated from an estuarine mangrove from the Taiwan Strait. The methanol extract of the fungal mycelium exhibited cytotoxicity against hepG2. Paeciloxanthone (1), a new xanthone, and the known compounds emodin (2) and chrysophanol (3), were isolated from the extract. Their structures were elucidated by spectroscopic experiments. Paeciloxanthone (1) exhibited in vitro cytotoxicity against hepG2 (IC(50)=1.08 microg/mL), acetylcholineesterase (AChE) inhibitory (IC(50)=2.25 microg/mL) and antimicrobial activities.

Self-assembled gold nanoshells on biodegradable chitosan fibers.

A novel chitosan fiber core/gold shell structural organic-inorganic composite was presented via a facile and eco-friendly approach. The chitosan fiber and gold/chitosan composites were characterized with the assistance of scanning electron microscopy and transmission electron microscopy observations. The chitosan fibers used in this study were 50 nm to 5 microm in diameter and up to hundreds of micrometers in length. The gold shells were typically 20-50 nm in depth, and their lattice fringes obliquely intersecting at an angle of 60 degrees were displayed. The formation mechanism of the as-fabricated chitosan fiber core with gold as the shell structural composites was also schematically discussed.