LC/MS analysis and antibiotic assays of the crude EtOAc extract (986 mg) showed potent bioactivity and displayed characteristic UV spectral data (123 nm and 234 nm). Subsequently, this extract was suspended in 1.5 mL of 20% aqueous MeOH and was fractionated using a reversed-phase C18 Sep-pak (10 g) column with a stepped gradient of MeOH/H2O elution. Seven fractions were collected starting at 20% MeOH with increments of 20% MeOH followed by a dichloromethane (CH2Cl2) and 0.1% TFA washes. LC-MS and antibiotic activity of the fractions indicated that the antimicrobial compounds were distributed in the 40% - 100% MeOH fractions with the highest concentration in 80% MeOH (306 mg). Subsequent fractionation was performed using a reversed-phase C18 Baker Bond (6 g) column and a stepwise elution gradient of MeOH/H2O starting with 60% MeOH. Fractions were collected according to the color of bands as they eluted from the column. A total of 14 fractions were collected and three fractions X-Z (70 mgs each) following 80% MeOH elution showed the most potent activity. These fractions were further purified by HPLC using a semiprep C18 column (Sun Fire; 10 x 250 mm, 5 μm) with a gradient mobile phase (20%-70% MeOH over 28 minutes). Active fractions obtained from this step were further fractionated using an analytical C18 column (Sun Fire; 4.6 x 150 mm, 3.5 μm) and a gradient mobile phase 30%-45% acetonitrile (ACN). This final fractionation process yielded 1-4 mg of each of 8 active compounds that were eventually identified as frigocyclinone derivatives.