1952 Volume 34 Issue 12 Pages 386-390
Even if the pine heartwood has been thoroughly extracted by alcohol, aceton etc., its sulphite digestion is more or less difficult, and especially, in the case of special heartwood the delignification is very difficult. For the reason of this, we considered that a part of phenolic substances of the pine heartwood has been perhaps combined with lignin of the wood, in the natural state.
The following are the results of the experiments which have been carried out to confirm such a consideration. From these results, the consideration is made sure.
(1) The difference between the delignification rate of the extracted heartwood (see table 1.) and that of the extracted sapwood in the digestion by the Na2SO3 liq. (pH≅9.8) is smaller than the difference in the digestion by the kullgrenliq. (pH≅6.0).
(2) The etracted heartwood which was sulphonated by Na2SO3 liq. is easily delignif icated by the cooking with acetic acid liquor with pH of 2.2, but the delignification of the extracted heartwood sulphonated by kullgren-liq. is difficult.
(3) The amount of phloroglucinol which combines with the extracted heartwood is smaller than that which combines with the extracted sapwood.
(4) The pinosylvin phenols can be separated by paper partition chromatography from the ether extract of the alkali soluble fraction of the extracted heartwood.