Influences of Anthraquinone Extraction Techniques from Morinda sp. on Extraction Efficiency

Abstract

The comparison of anthraquinone levels in root, stem, bark and leaf of Morinda sp. were investigated by HPLC with Alltima^TM C8 column using 32%(v/v) acetonitrile and 0.5% (v/v) acetic acid as mobile phase at 40°C for 20 min. The roots contained the highest specific concentration of
anthraquinone at 103.2 ± 4.8 mg/g dried mass, followed by stem (45.3 ± 6.3 mg/g), bark (6.90 ± 0.3 mg/g) and leaf (1.20 ± 0.6 mg/g). Four extraction techniques were employed to extract anthraquinone from the roots of Morinda sp and the anthraquinone content was analyzed using spectrophotometer. Soxhlet apparatus was utilized in the first technique with 50% (v/v) methanol as an extraction solvent. It was found that 14.6 ± 1.0 mg/g dried root powder was extracted with the expenses of 3.97 ± 0.17 Baht/mg anthraquinone. This was compared to the second extraction method at room temperature with 80%(v/v) acetone and 50%(v/v) ethanol that led to the highest concentration of extracted anthraquinone at 38.9 ±
1.6 and 27.0 ± 6.9 mg/g with the accompanied cost of 2.94 ± 0.12 and 1.42 ± 0.36 Baht/mg, respectively. The third extraction procedure was carried out in the pressurised steamer at 1 bar and 100°C for 5 min with 80% (v/v) ethanol. The highest level of extracted anthraquinone was 95.3 ± 0.6 mg/g at the cost of 4.28 ± 0.03 Baht/mg. The last method of extraction was performed in the closed-circuit solid-liquid extraction unit at room temperature. Although the extraction cost was relatively small (1.50 ± 0.08 Baht/mg), the specific concentration obtained was not high (only 2.27 ± 0.11 mg/g).