AbstractsBiology & Animal Science

A pharmacognostic study was made of the root of Heracleum mantegazzianum, an umbelliferous species which is of value as a source of natural coumarins. Three groups of seeds were tested to determine the presence of a germination requirement for moist cold and the possible value of gibberellic acid in obviating this requirement. The first group of seeds was cold-treated for 74 days at a range of from 2 to 5°C. The second group of seeds was soaked for 20 hours in a solution containing 100 parts per million of gibberellic acid. The third group of seeds, used as controls, was soaked in water. When planted and maintained under greenhouse conditions only the cold-treated seeds germinated. The germination rate was 10.3%. Both seeds treated with gibberellic acid and the controls failed to germinate, showing that a cold requirement does exist and that treatment with gibber-ellic acid will not substitute for the cold requirement. A fourth group of seeds, cold- treated for 294 days, germinated at a rate of approximately 55%, showing that germination is proportional to total days of cold treatment. Sequential selective solvent extraction with a series of increasing polarity gave the following fractions as average percentages of dry weight: petroleum ether, 2.4; ether, anhydrous, 2.5; ether U.S.P., 2.0 alcohol 95%, 8.5; water, 19.4. Copious foaming of the aqueous fraction showed the possible presence of saponins. The description and histology of the whole root as well as the character of the powdered root was recorded. Among diagnostic characters of the powdered root are its blue coloration when moistened with iodine water, a slight yellow fluorescence under ultraviolet light turning to luminescence for several seconds following extinction of the light, and the presence of numerous clustered starch grains which gelatinize rapidly in chloral hydrate solution. Thin-layer chromatography of the ether extract of the air-dried root on Silica Gel G showed seven principal spots fluorescing under ultraviolet light. R[subscript f] values and colors corresponded to those of six standard coumarins. The following coumarins are presumed to be present: isobergapten, pimpinellin, bergapten, isopimpinellin, sphondin and umbelliferone. The seventh spot was not identified. The R[subscript f] values in two solvent systems and the fluorescent colors under ultraviolet light are reported for the extract spots as well as for six coumarins. Studies were also made to determine the relative stability of coumarins to heat. Six standard coumarins as well as the extract of the air-dried root were spotted individually on Silica Gel G plates and developed two-dimensionally. Following development in the first direction and prior to development in the second direction the plates were exposed to a temperature of 65°C. for 30 minutes in an oven. With the exception of sphondin the chromatograms of the individual coumarins showed from one to two additional spots. This indicates that coumarins as a group are subject to…