Ginseng sample extraction and preparation for NMR
investigations
Twenty to 23 ginseng roots (P. quinquefolius) were collected
from 1 m×1 m plots at five farms in Norfolk County,
Ontario, with the following GPS coordinates: landrace The landraces were
ordered according to their GPS locations with respect to
each other. Eight samples of Asian ginseng roots (P. ginseng)
were obtained from a supplier in Markham, Ontario,
Canada; these had been imported from China and Korea. All
Ontario ginseng samples were obtained from the same farms
or were derived from the same collections as ones used in
the study by McIntyre et al. [5] and were extracted as
described. The Asian ginseng was extracted similarly and
in conjunction with the Ontario ginseng. Briefly, ground
ginseng was extracted by sonication three times for 25 min
each time at room temperature (25 °C) in 70 % methanol,
using 10 mL twice and 4 mL for the third extraction. The
phases were centrifuged using a 5810 R centrifuge (Eppendorf,
Hamburg, Germany) at 2,220g and the supernatants
were pooled and brought to 25 mL in a volumetric flask.
Extracts were dried using a centrifugal evaporator and lyophilized
using a Super Modulyo freeze dryer (Edwards
Crawley, UK). Then, 25 mg of crude ginseng extract was
dissolved in 1 mL of deuterated dimethyl sulfoxide (DMSOd6)
by vortexing for 25 s. Each sample was then centrifuged