Ishii H, Tan S, Wang J P, Chen I S, Ishikawa T
Faculty of Pharmaceutical Sciences, Chiba University, Japan.
Yakugaku Zasshi. 1991 Jul;111(7):376-85. doi: 10.1248/yakushi1947.111.7_376.
It is well known that toddalolactone (1) is a main component of Toddalia asiatica (L.) Lam. (T. aculeata Pers.) (Rutaceae). However, supercritical fluid (SCF) extraction of the plant by using CO2 showed that a main component of the extract was not 1, but aculeatin (2), a coumarin having an epoxy ring on the side chain. The same result was obtained from Soxhlet extraction by using aprotic solvents. On the other hand, Soxhlet extraction by using methanol yielded 13, corresponding to a methanol adduct of 2, as an additional component, which was able to be also produced in 50.2% yield only by heating pure 2 in methanol, indicating that the epoxy ring in 2 can be easily attacked by a weak nucleophile like methanol. These facts strongly suggested that 1, corresponding to the hydrate of 2, was an artefact derived from 2 during extraction. SCF extraction under various conditions was examined in detail by quantitative analyses of 1 and 2 by high performance liquid chromatography and the optimum condition extracting the both components was found to be at 40 degrees C and at 300 kg/cm2. The condition was applied to the plant treated with aqueous sodium hydrogen carbonate in order to remove any acidic substances and 1 was still detected in the extract. Thus, it is conclude that 1 should be a genuine natural coumarin but that previous isolation of 1 as a main component resulted in an isolation of an artefact derived from 2. SCF extraction was suggested to be a useful extraction method.
众所周知，飞龙掌血内酯（1）是飞龙掌血（Toddalia asiatica (L.) Lam. (T. aculeata Pers.)，芸香科）的主要成分。然而，用二氧化碳对该植物进行超临界流体（SCF）萃取表明，提取物的主要成分不是1，而是刺桐亭（2），一种侧链上带有环氧环的香豆素。用非质子溶剂进行索氏提取也得到了相同的结果。另一方面，用甲醇进行索氏提取得到了13，它相当于2的甲醇加合物，作为一种额外的成分，仅通过在甲醇中加热纯2也能以50.2%的产率得到，这表明2中的环氧环很容易被像甲醇这样的弱亲核试剂攻击。这些事实有力地表明，1相当于2的水合物，是萃取过程中由2衍生而来的人工产物。通过高效液相色谱对1和2进行定量分析，详细研究了各种条件下的SCF萃取，发现同时萃取这两种成分的最佳条件是在40℃和300 kg/cm²。将该条件应用于用碳酸氢钠水溶液处理过的植物以去除任何酸性物质，提取物中仍能检测到1。因此，可以得出结论，1应该是一种真正的天然香豆素，但之前将1作为主要成分分离出来的结果是分离出了一种由2衍生而来的人工产物。SCF萃取被认为是一种有用的萃取方法。
