Effective method for extracting protoberberine from Coscinium fenestratum by Microwave-assisted extraction

摘要

Coscinium fenestratum has been used as a traditional medicine in Asean countries, India and Sri Lanka. It was claimed to possess hypoglyceamic, hypotensive, laxative and anti-diabetic activities. It contains protoberberine compounds which are reported to have various biological and pharmacological activities. In this study, microwave-assisted extraction (MAE) was investigated as the efficient method to extract berberine from Coscinium fenestratum. The selection of the plant part (root, stem, leaves, bark) to be used for extration, optimization of extraction conditions and comparison of extraction efficiency with the conventional methods were discussed. We found that palmatine was the main compound in the root , berberine was the major component in the stem. When the stem (dried at room temperature) particle size of 500-1000μm was used, the optimization conditions such as ethanol volume concentration (60%), extraction temperature (60 oC) ,microwave power (400W), sol- id/liquid ratio(0.2g:40ml), MAE achieved the extraction yield of 2.3% (w/w) in 15min of operation period. This extraction yield was equivalent to Soxhlet extraction with methanol (2.5%, 8 hours extraction) and thermal extraction (2.2%, 3 hours extraction), moreover it was higher than extraction by 0.2% sulphuric acid (1.7%, 72 hours extraction). It was found that these optimized conditions were also applicable for the extraction of other derivatives such as palmatine and jatrorrhizine. MAE is more effective than the conventional methods in terms of extraction time and it gave a higher extraction yield for the extraction of protoberberine from Coscinium fenestratum.