ISOLATION OF BRADYOXETIN
Preparation of CDF
1. Bacteria cultures were grown up in Minimal medium to
late log phase (OD600 = 2.0).
2. Equal volume of ethyl acetate (Optima Grade, Fisher
Scientific) was then added and incubated, with shaking at 200 rpm, for 1
h.
3. The flasks were then allowed to sit for 1 h, or as
long as it takes to separate the aqueous phase from the ethyl acetate
phase. Should the layers fail to separate, additional ethyl acetate is
added and step 3 is repeated.
4. Remove the top layer containing the ethyl acetate
using a glass pipette, and store in glass container. The ethyl acetate
is removed by blow-drying, using the house air-line.
5. The concentrated extract, containing CDF, is then
stored at -20 C.
HPLC analyses of CDF
1. For analyses of CDF, the extracts are first
reconstituted in water, and then applied to a Sep-pak column (C18-M,
phenomenex). The sep-pak columns are prepared using the following
steps:
a. wash in Methanol
b. wash in Water
2. The sample is then applied and pass through the
column with the pressure provided by a disposable syringe.
3. Reapply flow through of sample 4 times.
4. Wash column with water, and elute with 100%
methanol.
5. Eluted sample is then concentrated via blow-drying
(as above), and then resuspended in water before being applied to the
HPLC (C18 jupiter, phenomenex; 250 x 4.6 mm; 5 micron).
6. The following gradient is used for CDF isolation:
1 min 95% water/5% MeOH (inject sample)
1 min to 10 min (gradient to 40% MeOH)
hold 10 min
gradient to 100% MeOH in 30 min
return solutions to 95% water/5% MeOH
7. CDF should elute at about 20 min after start of
gradient (ie. During the 10 min hold at 40% MeOH.