Monacolin K is a secondary metabolite synthesized by polyketide synthases (PKS) from Monascus, and it has the same structure as lovastatin, which is mainly produced by Aspergillus terreus. In the present study, a bacterial artificial chromosome (BAC) clone, mps01, was screened from the BAC library constructed from Monascus pilosus BCRC38072 genomic DNA. The putative monacolin K biosynthetic gene cluster was found within a 42 kb region in the mps01 clone. The deduced amino acid sequences encoded by the nine genes designated as mokA- mokI, which share over 54% similarity with the lovastatin biosynthetic gene cluster in A. terreus, were assumed to be involved in monacolin K biosynthesis. A gene disruption construct designed to replace the central part of mokA, a polyketide synthase gene, in wild-type M. pilosus BCRC38072 with a hygromycin B resistance gene through homologous recombination, resulted in a mokA-disrupted strain. The disruptant did not produce monacolin K, indicating that mokA encoded the PKS responsible for monacolin K biosynthesis in M. pilosus BCRC38072.

Bioassay-directed fractionation of an ethanolic extract of stems of Vernonia cinerea has resulted in the isolation of two novel sesquiterpene lactones, vernolide-A and -B. Their structures were elucidated on the basis of spectroscopic analysis. Biological evaluation showed that vernolide-A demonstrated potent cytotoxicity against human KB, DLD-1, NCI-661, and Hela tumor cell lines (ED(50)=0.02, 0.05, 0.53, 0.04 microg/ml for KB, DLD-1, NCI-661, and Hela, respectively); vernolide-B had marginal cytoxicity (ED(50)=3.78, 5.88, 6.42 microg/ml for KB, NCI-661, and Hela, respectively).

On cultivation of the fungus Antrodia cinnamomea (BCRC 36799) on a medium, the mycelium was extracted and evaluated for nitric oxide (NO) inhibitory activity. Bioactivity-directed fractionation led to the isolation of two new maleimide derivatives, antrocinnamomins A (1) and B (2), and two new maleic anhydride derivatives, antrocinnamomins C (3) and D (4), along with three known compounds, 3-isobutyl-4-[4-(3-methyl-2-butenyloxy)phenyl]furan-2,5-dione (5), 3-isobutyl-4-[4-(3-methyl-2-butenyloxy)phenyl]-1H-pyrrole-2,5-dione (6), and 3-isobutyl-4-[4-(3-methyl-2-butenyloxy)phenyl]-1H-pyrrol-1-ol-2,5-dione (7). Structural elucidation of compounds 1-4 was carried out by spectroscopic data. Compound 1 displayed significant inhibitory effect on nitric oxide (NO) production.