Total synthesis of quinolactacin-H from marine-derived Penicillium sp. ENP701 and biological activities.

The quinolactacins are a family of pyrroloquinoline-type natural products from Penicillium sp. From the organic extract of Penicillium sp. ENP701 fermentation broth, a microorganism from the east China sea, one new quinolactacin was isolated and named quinolactacin-H. The structure of quinolactacin-H was determined by spectroscopic analysis and the absolute configurations by X-ray crystallographic analysis. Enantioselective total synthesis of ( R )-(+)-quinolactacin-H and ( S )-(-)-quinolactacin-H was achieved. When assayed through crystal violet (CV) microtiter plate biofilm, both ( R ) and ( S )-quinolactacin-H showed a strong inhibition and dispersion of Pseudomonas aeruginosa PAO1 biofilms. Thus, quinolactacins could be proposed and developed as natural anti-bioflm agents in order to solve the problem of microbial resistance in future.