Extraction and purification of polyphenolic compounds and determination of EGCG from eagle tea (Litsea coreana Lévl. var. lanuginosa)
The polyphenolic compounds were prepared using reflux extraction and polyamide chromatography from the powder of eagle tea (Litsea coreana Lévl. var. lanuginosa). Polyphenolic compounds were extracted with the 80% ethanol for three times at 100 ℃, of which, the extraction time was 30, 20, 10 min and...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Zhejiang University Press
2010-05-01
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| Series: | 浙江大学学报. 农业与生命科学版 |
| Subjects: | |
| Online Access: | https://www.academax.com/doi/10.3785/j.issn.1008-9209.2010.03.015 |
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| Summary: | The polyphenolic compounds were prepared using reflux extraction and polyamide chromatography from the powder of eagle tea (Litsea coreana Lévl. var. lanuginosa). Polyphenolic compounds were extracted with the 80% ethanol for three times at 100 ℃, of which, the extraction time was 30, 20, 10 min and the ratio of material to liquid was 1∶20, 1∶10, 1∶10 respectively, and the crude extraction rate reached 31.46%. Then, the supernatant was collected after adjusting the pH of crude extract to 2.0 and centrifugating at 12 000 r·min<sup>-1</sup> for 10 min, the yield rate of polyphenolic compounds from which was 93.59%. Finally, the supernatant was diluted to 2 mg·mL<sup>-1</sup> and its pH was adjusted to 2.0 as the sample solution, the optimum conditions for purification of polyphenolic compounds using polyamide resin were as follows: the ratio of column height to diameter was 22 with sample volume at 1.5 BV and 1 h of adsorption equilibrium time, and the eluent was little deionized water and 80% ethanol successively with 6 mL·min<sup>-1</sup> of eluent flow rate. Under the optimal conditions, the desorption rate of polyphenolic compounds reached 97.20%. The purity and extraction rate of polyphenolic compounds which were attained by freeze vacuum drying from concentrated eluent reached 92.80% and 18.06%, respectively. The epigallocatechin gallate (EGCG) content of polyphenolic compounds measured by HPLC was 49.82%. |
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| ISSN: | 1008-9209 2097-5155 |