Extraction of Centella asiatica leaves using a mixture of subcritical dimethyl ether and ethanol: Optimization of conditions by response surface methodology

Abstract

This study aimed to develop an effective extraction method to recover triterpenoid saponins from Centella asiatica (L.) Urban leaves using a mixture of subcritical dimethyl ether (DME) and ethanol (EtOH) as extractant. The optimal extraction conditions, as suggested by response surface methodology, were a mixture of 2.9 ml EtOH and 5.3 g subcritical DME per g of sample at 48.7ºC. It can provide 18.8% of total triterpenoid saponins (weight/ dry weight of C. asiatica) which is 2- to 4-fold that obtained from the extractions with only EtOH (9.3%) or only subcritical DME (4.8%) under the same conditions.

Keywords

• centella asiatica
• response surface optimization
• triterpenoid saponins
• dimethyl ether
• extraction