Centaury. N. F. IV. Centaurium.
Related entry: Canchalagua
Centaury. N. F. IV. Centaurium. Common European Centaury. Herba Centaurii, P. G. Erythraea Centaurium (L.) Pers. Centaurium Centaurium (L.) Wight. (Fam. Gentianaceae.)—This is a small, annual herbaceous plant which grows wild in most parts of Europe. The dried flowering plant is found in commerce. It is described in the N. F. as "the dried flowering plant of Erythraea Centaurium (Linne) Persoon (Fam. Gentianaceae). Glabrous, from 1.5 to 5 dm. in height, much branched from the base, but little branched, if at all, from above; stems slender, sharply angled or narrowly winged, sparsely leafy; leaves opposite, entire, mostly three-nerved, sessile, those at the base obovate and obtuse, from 2 to 5 cm. in length, their base narrowed and petiole-like, those of above gradually changing to oval, then ovate or even lance-linear, acute; flowers in a terminal and at length compound cyme, rose-colored; calyx from 5 to 7 mm. in length, deeply five-parted, the tube short, sharply angled, lobes linear-attenuate with a sharp midrib; corolla tube nearly twice the length of the calyx, slender, the limb from 10 to 15 mm. in breadth, its lobes broadly oblong or oval; stamens five, exserted, bright-yellow, their anthers twisted when old; pistil two carpelled. Odor faint but characteristic; taste persistently bitter. Centaury yields not more than 5 per cent. of ash." N. F. The fresh, bitter, odorless herb yields an odorous, pungent distillate in which Mehu (J. P. C., 1862, xliii, 38) has found valeric acid, also a peculiar, colorless, crystalline, non-nitrogenous substance, erythrocentaurin, C27H24O8. Erythrocentaurin occurs in needle-shaped crystals, fusing at 136° C. (276.8° F.), and crystallizing easily on cooling again. They are strongly reddened by exposure to solar light, and reacquire their colorless character upon being again dissolved and crystallized, or by mere heating to 130° C. (266° F.). They are almost insoluble in cold water, more readily soluble in boiling water, alcohol, ether, and chloroform. Carbon disulphide, benzene, volatile and fatty oils dissolve them easily. J. F. Huneker believes that erythrocentaurin exists also in American centaury. (See Sabbatia.) Leuderich assigns to erythrocentaurin the formula C9H14O5 and states that in its decomposition a dextrorotatory carbohydrate is produced, while R. Reis states that the formula of the crystals is C10H10O3. (Ap. Ztg., 1911, 148.) Herissey and Bourdier isolated a glucoside from centaury, erytaurin (J. P. C., 1908, No. 6), but later R. Reis could not detect a glucoside in it. (Ap. Ztg., 1911, 148.) The common centaury of Europe has tonic properties very closely resembling those of gentian. The dose of centaury is from twenty to forty grains (1.2-2.3 Gm.).
A species of Erythraea, E. chilensis Pers., is employed to a considerable extent in Chili as a mild tonic. (For details, see J. P. C., 3e ser., xxv, 434.) E. acaulis, which grows in great abundance in the territory of French Algiers bordering on the Sahara, yields a root which, under the name of rejagnou, is much employed by the natives for dyeing yellow. (J. P. C., 1867, v, 87.)