From the root of Thalictrum Thunbergii DC. (Japanese name “Akikaramatsu”) growing in Tokushima, a new tertiary phenolic base, thalicrine, was isolated as colorless needles, m.p. 221-222°, [α]D+341.2° (CHCl3), and a new non-phenolic base, homothalicrine, as colorless cubic crystals, m.p. 235-236° (decomp.), [α]D+425.3° (CHCl3). O-Methylthalicrine, obtained by brief methylation of thalicrine with diazomethane, was found to be identical with homothalicrine, from its elemental analytical values, melting point, and infrared spectrum (in chloroform).Composition and empirical formula of thalicrine agree with C36H38O6N2=C32H25O3-(OH)(OCH3)2(NCH3)2 and those of homothalicrine with C37H40O6N2=C32H25O3(OCH3)3-(NCH3)2.The Hofmann degradation of thalicrine dimethochloride and oxidation of its methylmethine with potassium permanganate afforded 4-methoxy-3, 4′-oxydibenzoic acid (I). The same Hofmann degradation of O-ethylthalicrine and permanganate oxidation of its methylmethine afforded an acid of m.p. 274-275°. In order to elucidate the structure of this acid, O-ethylberbamine (II) was submitted to the same degradation and oxidation, and authentic sample of 4-ethoxy-3, 4′-oxydibenzoic acid (V) thereby obtained was found to be identical with the foregoing acid of m.p. 274-275° in melting point and infrared spectrum (in Nujol). From these experimental evidences and ultraviolet spectra (Fig. 1, A-D), the two bases here obtained were considered to be new bases of the biscoclaurine type. It was also proved that the phenolic hydroxyl in thalicrine is in the position ortho to the ether bond connecting the two phenyl rings and para to the benzyl group.