Vol. 15—1961 - NorthEastern Weed Science Society

Qolumn Separation: Cellulose. A 24 x 1 7/8 inch column 1
packed with Whatmanstandard grade cellulose powder was used
as a second system. The column was packed wet, the sample
placed on top of the packed powder and 80% Ethanol was passed
through the column. The fractions were collected with a G.M.E •.
fraction collector using a Packard model 235 U.V. monitor to
detect the cuts.
Column ~eparatiQll: Silicic acid. The most recent attempt
at purification has been with Mallinckrodt Silicic acid. The
silicic acid was deactivated as described by Jarboe (2) in
1960. Twelve grams were sulurried in chloroform and added to a
jacketed 15 rom x 450 rom column and the HCC1 3 was drained to the
. top of the column. The residue from the active sections of 8
chromatogram papers was adsorbed to a glass wool plug wetted
with distilled water. A second plug was used to adsorb remaining
residue. A gradient system of chloroform and methyl alcohol
was used to elute the column. 500 ml methanol containing .5 ml
conc NH 40H was dripped into 300 ml HCC1 3 in· B:elosed mixing chamber,
thus the elulion began with 100% HCC1 3 and became logarithmetically
diluted with the ammoniated methyl alcohol. The fractions were
again collected with the G~M.C. fraction collector.
Adsorption Qn Activated Carbon. The extract from one gram
of quackgrass was mixed with 5 grams Acetic acid-washed Norite,
and filtered with a Buchner funnel. The filtrate was eluted
with methanol and with methanol containing ammonia and the three
fractions were tested for activity.
Results
& Discussion
The inhibition from four grams of quackgrass was completely
eluted with 30 ml of water (Table I). A brownish yellow color
was associated with the inhibiting fractions.
Table I. Water extraction of the inhibitor from ground
rhizomes in a column.
MI. water 5 10 15 20 2$ 3Q 8Q
MMgrowth of seedlings 00 00 00 9 24 50 ~ ~ 49
%Inhibition 100 100 100 83 53 3 14 15 5
An increase in growth in the 40 ml fraction indicates the
possibility of stimulation from very small quantities of the
inhibitor. Data from other experiments, particularly on column
work have indicated stimulation. Helgeson (3) reported such
effects~ More data with pure compounds will be needed to
establish this point. .
Ethyl alcohol extractions were less efficient than water
extractions in removing the inhibitor(s).