Antiproliferative extracts from algae and cyanobacteria found in acidic mine drainage sites

As part of an ongoing investigation of the bioactivity of natural products found within the highly-biodiverse southern Appalachian region of the United States, samples of algae and cyanobacteria were collected from an acid mine drainage site. Organisms were grown in pH adjusted BG-11 medium, and extracted with DCM/MeOH, and fractionated using Diaion HP-20 with an IPA gradient. Extracts of the samples were evaluated for antiproliferative activity against a mammalian cancer cell line. Thirty percent of all fractions examined to date have moderate antiproliferative activity (IC₅₀ <200µg/mL) against JEG-3 cells. Of those, ten percent exhibit IC₅₀ values ranging from 50–100µg/mL and approximately five percent have significant activity (IC₅₀ <25µg/mL). Additional fractionation of active fractions using HPLC is ongoing as are activity assays against prokaryotic microorganisms.