Tamio Kondo

The Termiticidal Substances from the Wood ofChamaecyparis pisiferaD. Don

The termiticidal activity of different fractions of the essential oil of Sawara wood (Chamaecyparis pisifera D. Don) were persued. The neutral fraction possessing the whole activity of original wood chromatographed on alumina column followed by preparative T. L. C. and G. L. C. finally yielded strongly active B2_3, B3_35 B2_4 and B3_4 fractions. Chamaecynone, a major component of B2_3 and B3_3 fractions, and isochamaecynone, one of the main components of B2_4 and B3_4 fractions possess marvelous termiticidal activity, however, the presence of other derivatives of Chamaecynone and their high activities are also expected. Thus the activity of Sawara wood (Ch. pisifera) is due to these minor components which are new types of termiticides having high volatility and acting as contact insecticides.

Studies on Lignin:Part V. A Reexamination of Hydrogen Sulfide Cooking of Vanillyl Alcohol, and Conversion of Vanillyl Disulfide into Vanillyl Monosulfide

buffer solutions is shown in Table I. On the determined, solutions slightly acidic gave vanillyl disulfide even after the expulsion of oxygen by bubbling through hydrogen sulfide. The reaction products, after one recrystalliza tion from toluene, showed the same melting points as vanillyl disulfide or vanillyl mono sulfide, and were identified by mixed melting point determinations with authentic speci mens. However, in case of cooking with phosphate buffer solutions in which hydrogen sulfide was bubbled through, the effect of pH was not so distinct as in the case of acetate buffer; the main product was vanillyl mono sulfide even in acidic solutions. Gierer re ported that p-hydroxybenzyl alcohols yielded monosulfides when cooked with a sodium hydrosulfide solution of pH 9, but unfortu nately no description was given on the con ditions by which disulfide was formed. (3) Some unknown factors on the reaction me chanism of disulfide-and monosulfide-forma tion may still exist. According to Schoberl, disulfide groups were converted into mercaptans and sulfenic acids, of which the latter were further decomposed to carbonyl groups upon heating with alkaline so lution. (4) Enkvist and Moilanen supported this finding after they had obtained vanillin by alkali treatment of vanillyl disulfide. (1) Also, on the other hand accord basis of these data, it seemed reasonable to assume that the determining factor is the pH of the cooking solution. Although the oxygen contents of the cooking solutions were not ing to Schoberl, cystine (disulfide) in wool upon soda treatment is reported to yield lanthionine (monosulfide). (5) It therefore,