Synthesis of Allicin and Purification by Solid-Phase Extraction: Volume 290, Number 2 (March 15, 2001), pages 376–378
✍ Scribed by Gregorio Cruz-Villalon
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 13 KB
- Volume
- 304
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
I described a method based on the oxidation of diallyl disulfide with magnesium monoperoxyphthalic salt (MMPP) (1) and tetrabutylammonium hydrogen sulfate (TBHS) as phasetransfer reagent. Because the reaction yield was poor, I studied the phasetransfer process; the results show that, at room temperature, the quaternary ammonium salt behaves as a surfactant or carrier rather than as a catalyst. The overall yield depends on the initial ratio [carrier]/[oxidant]. The synthesis method has therefore been modified and simplified as described below.
MMPP, at 20% molar excess over the disulfide, and TBHS, at 2.5-fold the oxidant concentration, were dissolved in 50 mL of water at pH 4.6. Allyl disulfide, 1 g, was dissolved in 25 mL dichloromethane. The two-phase mixture was stirred at 200 rpm for 35 min in an ice bath. The yield of allicin was nearly 50%. The organic phase was filtered at Ϫ50°C, making unnecessary the previously used extraction with ammonium bicarbonate. Under these conditions, the products can be separated by thin-layer chromatography without the previously used step of concentration with a stream of nitrogen.
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