Removing Tannins from Medicinal Plant Extracts Using an Alkaline Ethanol Precipitation Process: A Case Study of Danshen Injection

The alkaline ethanol precipitation process is investigated as an example of a technique for the removal of tannins extracted from Salviae miltiorrhizae Radix et Rhizoma for the manufacture of Danshen injection. More than 90% of the tannins can be removed. However, the recoveries of danshensu, rosmar...

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Main Authors: Xingchu Gong, Yao Li, Haibin Qu
Format: Article
Language:English
Published: MDPI AG 2014-11-01
Series:Molecules
Subjects:
Online Access:http://www.mdpi.com/1420-3049/19/11/18705
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spelling doaj-903b796e66f54c919bbf344a1b95412b2020-11-24T22:34:33ZengMDPI AGMolecules1420-30492014-11-011911187051872010.3390/molecules191118705molecules191118705Removing Tannins from Medicinal Plant Extracts Using an Alkaline Ethanol Precipitation Process: A Case Study of Danshen InjectionXingchu Gong0Yao Li1Haibin Qu2Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, ChinaPharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, ChinaPharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, ChinaThe alkaline ethanol precipitation process is investigated as an example of a technique for the removal of tannins extracted from Salviae miltiorrhizae Radix et Rhizoma for the manufacture of Danshen injection. More than 90% of the tannins can be removed. However, the recoveries of danshensu, rosmarinic acid, and salvianolic acid B were less than 60%. Total tannin removal increased as the refrigeration temperature decreased or the amount of NaOH solution added increased. Phenolic compound recoveries increased as refrigeration temperature increased or the amount of NaOH solution added decreased. When operated at a low refrigeration temperature, a relative high separation selectivity can be realized. Phenolic compound losses and tannin removal were mainly caused by precipitation. The formation of phenol salts, whose solubility is small in the mixture of ethanol and water used, is probably the reason for the precipitation. A model considering dissociation equilibrium and dissolution equilibrium was established. Satisfactory correlation results were obtained for phenolic compound recoveries and total tannin removal. Two important parameters in the model, which are the water content and pH value of alkaline supernatant, are suggested to be monitored and controlled to obtain high batch-to-batch consistency.http://www.mdpi.com/1420-3049/19/11/18705alkaline ethanol precipitationtannin removalphenolic compoundmechanismmodel
collection DOAJ
language English
format Article
sources DOAJ
author Xingchu Gong
Yao Li
Haibin Qu
spellingShingle Xingchu Gong
Yao Li
Haibin Qu
Removing Tannins from Medicinal Plant Extracts Using an Alkaline Ethanol Precipitation Process: A Case Study of Danshen Injection
Molecules
alkaline ethanol precipitation
tannin removal
phenolic compound
mechanism
model
author_facet Xingchu Gong
Yao Li
Haibin Qu
author_sort Xingchu Gong
title Removing Tannins from Medicinal Plant Extracts Using an Alkaline Ethanol Precipitation Process: A Case Study of Danshen Injection
title_short Removing Tannins from Medicinal Plant Extracts Using an Alkaline Ethanol Precipitation Process: A Case Study of Danshen Injection
title_full Removing Tannins from Medicinal Plant Extracts Using an Alkaline Ethanol Precipitation Process: A Case Study of Danshen Injection
title_fullStr Removing Tannins from Medicinal Plant Extracts Using an Alkaline Ethanol Precipitation Process: A Case Study of Danshen Injection
title_full_unstemmed Removing Tannins from Medicinal Plant Extracts Using an Alkaline Ethanol Precipitation Process: A Case Study of Danshen Injection
title_sort removing tannins from medicinal plant extracts using an alkaline ethanol precipitation process: a case study of danshen injection
publisher MDPI AG
series Molecules
issn 1420-3049
publishDate 2014-11-01
description The alkaline ethanol precipitation process is investigated as an example of a technique for the removal of tannins extracted from Salviae miltiorrhizae Radix et Rhizoma for the manufacture of Danshen injection. More than 90% of the tannins can be removed. However, the recoveries of danshensu, rosmarinic acid, and salvianolic acid B were less than 60%. Total tannin removal increased as the refrigeration temperature decreased or the amount of NaOH solution added increased. Phenolic compound recoveries increased as refrigeration temperature increased or the amount of NaOH solution added decreased. When operated at a low refrigeration temperature, a relative high separation selectivity can be realized. Phenolic compound losses and tannin removal were mainly caused by precipitation. The formation of phenol salts, whose solubility is small in the mixture of ethanol and water used, is probably the reason for the precipitation. A model considering dissociation equilibrium and dissolution equilibrium was established. Satisfactory correlation results were obtained for phenolic compound recoveries and total tannin removal. Two important parameters in the model, which are the water content and pH value of alkaline supernatant, are suggested to be monitored and controlled to obtain high batch-to-batch consistency.
topic alkaline ethanol precipitation
tannin removal
phenolic compound
mechanism
model
url http://www.mdpi.com/1420-3049/19/11/18705
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AT yaoli removingtanninsfrommedicinalplantextractsusinganalkalineethanolprecipitationprocessacasestudyofdansheninjection
AT haibinqu removingtanninsfrommedicinalplantextractsusinganalkalineethanolprecipitationprocessacasestudyofdansheninjection
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