カワカワの成分(第一報)カワ酸に就て

概要

論文の詳細を見る
In a preliminary note on the subject one of the authors and K.Mayeda (this Journ. No.477,Nov.1921) described an acidic compound C_<15>H_<16>O_5 or (C_6H_5・C_7H_7O_2) (OCH_3)・COOH. which was obtained by treating kawa resin with aqueous caustic potash at ordinary temperature. Borsche and Roth (Ber. 54,2229) obtained a compound named kawaic acid (C_<13>H_<12>O_3) from kawa resin by heating it with aqueous caustic soda, wich on distillation in vacuo lost CO_2 and yielded cinnamalaceton. hThey considered the constitution of their kawaic acid to be C_6H_5CH : CH・CH : C (CH_3) CO・COOH or C_6H_3・CH : CH・CH : CH・CO・CH_3・COOH, but an attempt to synthesize it gave no deffinite result. When kawaic acid of M. and S. (C_<15>H_<16>O_3) was treated with aqueous caustic potash at 100° a compound C_<14>H_<16>O_3 or rather C_<14>H_<14>O_3 (m.p. 175-177°) was obtained, which yielded cinnamalaceton on warming with dilute sulphuric acid. The latter was also obtained directly from kawaic acid by treating with dilute sulphuric acid or on distillation under diminished pressure. Probably the kawaic acid of Borsche (m p. 164-165°) may be identical with the alkali decomposition product of the kawaic acid of M. and S., as the latter at first melts at about 165°, which by repeated recrystallisation attains the constant m.p. 177-179°. The authors demonstrated the chemical constitution and transformation of the kawaic acid as follows : [numerical formula] The further confirmation of this formula is at present in pragress. Kawaic Acid. To prepare this acid 100g of the kawa resin was shaken with 300 c.c. of 6% aqueous caustic potash for 5-7 hours. The separated crystalline substances were fiitrated off and the filtrate was acidified with 5% acetic acid fractionately. At first a yellowish crystalline substance (m.p. 177-179°) and then the crude kawaic acid are presipitated. The latter, dissolved in chloroform, was shaken several times with sodium carbonate solution, which was acidified with acetic acid. The kawaic acid, after recrystallisation from absolute ether melted at 87°. The yield was 0.5% of the root. [table] The optical rotation was [α]^<20>_D-40^0_0 in 10% alcoholic solution. Alkali Decomposition of Kawaic acid. 10g of kawaic acid was mixed with 100cc. of 10% sodium hydroxide solution and warmed on the water bath for 7 hours. The reaction mixture was acidified with dilute acetic acid, when resinous decomposition products were separated. On repeated recrystallization from acetone, a yellowish bright krystalline substance m.p. 175-177° (formerly 164°) was obtained. It is in soluble in cold sodium carbonate solution, soluble in hot carbonate solution and on cooling a krystalline sodium compounds separated out, from which the original substance may be isolated by the acid. Hnalysis : -[table] Methoxyl number (Zeisl's method) [talbe] The alkali decomposition product m.p. 175-177° was warmed with dilute sulphuric acid. The reaction mixture was distilled with steam, when yellow krystals passed over which were collected and dried on porous plate. It melted at 67-68° after recrystallization from absolute ether. [table] Action of dilute Sulphuric acid on Kawaic acid. 10g of kawaic acid was mixed with 400cc. of 5% sulphuric acid and warmed on the water bath for 2-3 hours. The reaction mixture was distilled with steam, the oily distillate was converted into semicarbazone in the usual manner. The semicarbazone melted at 193° and proved to be identical with the semicarbazone of cinnamalacetone, as no depression in melting point was observed on admixture. Distillation of Kavaic acid. When 2g of kava acid was distilled under reduced pressure, a small quantity of yellow oil was obtained. It was converted into semicarbazone m.p. 193° which was proved to be identical with cinnamalacetone semicarbazone.
公益社団法人日本薬学会の論文
1925-02-26

カワカワの成分(第一報)カワ酸に就て

スポンサーリンク

概要

著者

関連論文

スポンサーリンク