Baicalin baicalin Extraction Process
Author: Ning-Fei Lei Peng Shu-Ming Zhou Jiayu Liu Ran
Chen Fang Hu treasury
【Abstract】 Objective To investigate the baicalin
Scutellaria the best extraction process. Methods temperature
dip method, boiling method, temperature and alkali leaching of better ways to study particle size, frequency, extraction time and number of separation methods and other factors on the yield of baicalin. Results decoction method is better than the
other two methods, boiling extraction of baicalin the optimum conditions were: particle size 40 mesh, boiling two times, 1:10 and 1:5 ratio of materials, time 60 min, and 30 min, and
then double-cloth filter centrifuge, 70 ? heat 60 min, acid-
quiet home 3 h leaching, 50% ethanol, washed two times, dried products may baicalin. Baicalin yield of 13.67 percent, its content was 85.7%, baicalin low-temperature water bath at pH
3.98 in the nature of the more stable. Conclusion The results produced for large-scale extraction of baicalin provide a
Key words baicalin baicalin extraction process stability
Abstract: ObjectiveTo investigate the best extracting
technology of baicalin from Scutellaria baicalensis Georgi.MethodsThe best extraction method was selected from controlled temperature water immersing, decoction and
controlled temperature alkali added water immersing method, and the affecting factors on yield and content of baicalin
were investigated. ResultsThe decoction method was better than others, the good technology conditions were as follows: decocted the Scutellaria baicalensis 2 times with decuple water in 60 min and 5 folds water 30 min, respectively, then
removed the residue with double filtration cloth and centrifuged, kept the temperature at 70 ? for 60 min, laid
aside 3 hours, separated with centrifuge, dried the residue and obtained the baicalin product.The yield and content of baicalin was 13.67% and 85.7% respectively, the baicalin was stable at pH 3.98.ConclusionThe results provide a theoretical basis for large-scale prodution of baicalin.
Key words: Scutellaria baicalensis Georigi; Baicalin; Extracting technology; Stability
Skullcap Scutellaria baicalensis Georgi with heat dampness, Xiehuo detoxification, hemostasis efficacy of tocolysis and so on. The main component of baicalin (Baicalin) from Scutellaria baicalensis root extract isolated a flavonoid compound, has antibacterial, diuretic, anti-inflammatory,
anti-metamorphosis and spasm, and has a strong physiological reaction to the effectiveness of anti-cancer . Baicalin can
absorb ultraviolet light, scavenging oxygen free radicals, the same time, can inhibit melanin production, is a good
functional cosmetics raw materials, has high prospects for the development and utilization.
Chemical Constituents of Scutellaria gradually attracted much attention in pharmaceutical and chemical workers, at present, the domestic extraction of baicalin studies have more reports, and its extraction methods are mainly temperature-dip
method, boiling method, microwave method, ultrafiltration France [1 ~ 6], but how to improve the yield and purity of baicalin has been a problem in the actual production, the lack of a comprehensive study of the entire process conditions, it is therefore necessary to impact baicalin extraction technology and its impact factors to make a comprehensive study. In this study, to be on the temperature dip method,
boiling method, temperature and alkali leaching method to
explore, study baicalin extraction process, and its stability study is designed to extract the production of large-scale
production practice to provide baicalin theoretical basis.
1.1 baicalin extraction method should be the right way to refer to Hu , Huang Qin ? crush ? Weigh skullcap meal 20
g ? ? Serve hot water boiling ? 40 ? isolated from the
filtrate and added two hydrochloric acid adjusted pH 1 ~ 2 ?
80 ?, heat ? put it aside for isolation of precipitation ?
washing ? drying ? crude baicalin and its content by UV
spectrophotometry. Alkali leaching temperature and processing temperature and leaching were used distilled water and pH value of 10 NaOH solution, 60 ? water bath extraction.
Determined by the formula baicalin yield: the yield of baicalin (%) = M/M0 × 100% where: M - derived from the weight
of crude baicalin M0 - When extracting with the weight of
1.2 Determination of baicalin
1.2.1 Standard Curve drawing precision Weigh baicalin standard 50 mg, with 50% ethanol, and dissolved in 100 ml flask constant volume, the preparation of 0.5 mg / ml standard solution of baicalin, respectively, marked absorb liquid 0.5,1.0 , 1.5,2.0,2.5,3.0,3.5,4.0 ml in 100 ml flask in
constant volume with 50% ethanol, UV-Vis absorbance measured
at 278 nm values obtained absorbance - concentration
regression curve y = 0.064x - 0.010 2, r2 = 0.998 2.
1.2.2 Determination of exact sample said that the experiment of the proceeds of crude baicalin 50 mg with 50% ethanol dissolved in 100 ml flask constant volume. With dry filter paper filter, discard filtrate to the beginning, drawing continued filtrate 2.5 ml in 100 ml flask in constant volume with 50% ethanol. Another 50% ethanol as a blank check, on the absorbance measured at 278 nm wavelength by the regression equation to calculate the corresponding
concentration, determined by the formula baicalin.
Baicalin (%)=[ corresponds to the concentration (μg /
ml) × 100 × 40] / sample weight (mg)
2 Results and analysis
2.1 The effect of different extraction methods of extracting relatively warm dip method, boiling method, temperature and alkali leaching three kinds of extraction methods (Figure 1), plus alkali leaching temperature was the highest rate, but the crude product contains a lot of black material, its Scutellaria glycoside content is relatively low, mainly due to NaOH accession has also led to other impurities
leaching, temperature leaching yield and baicalin contents were the lowest, the highest content of boiling method, mainly boiling water when boiling, reduce the enzymatic destruction of Scutellaria Scutellaria glycosides probability, the yield
is also high, considering the yield and the content of baicalin, Radix effect has to be better than the other two methods.
2.2 The boiling method of extraction
2.2.1 baicalin baicalin size on the yield and content of baicalin after crushing, sieving with different mesh to change the granularity of Scutellaria, in the other conditions remain unchanged under extracted by boiling. The results in Table 1. Table 1 skullcap of particle size on yield and content of baicalin effects (abbreviated)
From Table 1 we can see the finer granularity baicalin, baicalin, the higher the yield, but according to our experimental results point of view, particle size is too small, the material easy to bond together, and lead to difficulties in filtration and extraction of liquid turbidity unclear and so on, and skullcap when the particle size of 60 mesh to raise the yield little more than 40 mesh, for ease of
operation, select the skullcap 40 mesh particle size is appropriate.
2.2.2 Extraction of water on the yield and content of baicalin in order to explore the impact of the amount of extracting solvent on the yield of baicalin and content of the impact of other conditions remain unchanged, the change in water extraction, extracted with boiling, from Table 2 we can
see when the M (water) / M (skullcap) for 105 times, baicalin crude product yield reaches its maximum, continue to increase the material ratio, the crude product yield of baicalin increase was not significant, while the baicalin was also due
to the dissolution of impurities decreased slightly, so a better material than that for the 105. Table 2 Extraction of water on the yield and content of baicalin effects (abbreviated)
2.2.3 baicalin extraction time on yield and content in
order to explore the optimum extraction time, other things being equal, the change in extraction time, using boiling extracted by boiling in Table 3 we can see the longer, yellow baicalin the higher the yield, but the net decline of baicalin, quality good. On their reason may be, with the boiling time increased, the impurities are dissolved in large numbers, resulting in an increase in impurity baicalin. Bring difficulties to the follow-up operation and reduce the content
of baicalin. Time was 60 min 30 min, the yield of baicalin
higher levels are also high, integrated the best results. Table 3 baicalin extraction time on the yield and content of (omitted)
2.2.4 Extraction of times on the yield and content of baicalin the impact of changes in extraction times, other
things being equal, using decoction extracted from Table 4 we can see, with the increase in the number extract, baicalin crude product revenue rates rising, the content is not much difference, considering the yield and content, and economical
aspects in order to select suitable extraction twice. Table 4 Extraction of times on the yield and purity of baicalin effects (omitted) reposted elsewhere in the paper for free download http://
2.2.5 Separation of residue method and content of
baicalin the impact of changes in the yield of extract and residue of the separation method, other things being equal, using the boiling method extraction can be seen from Table 5 with the centrifugal separation of the treatment process, so out of baicalin in the highest, 87.03%, double the lower levels of fine cloth filter, and only 68.4%. Therefore, in acid-insoluble in water before removal of impurities as much as possible is essential. Table 5 Separation of extract residue methods on yield and content of baicalin effects
2.2.6 Acid-acid when the temperature increases the yield and content of baicalin the impact of changes in acid-acid
temperature increases, other things being equal, using the boiling method extracted the results shown in Table 6,40 ?
and 60 ? plus The results more or less acid, 60 ? results
slightly, while in 80 ?, in particular, when adding acid at 90 ? make some black granular or oily impurities precipitated in the acid-liquid dispersion, the impact of Scutellaria
glycosides purity. 60 ? plus acid was chosen. Table 6 Acid-
acid when the temperature increases the yield and content of baicalin effects (abbreviated)
2.2.7 Acid-holding time on the yield and content of baicalin the impact of changes in acid-soaking time, from
Table 7 we can see with the holding time increased, the higher the yield of baicalin, which is due to the molecular baicalin The C2 structure is easy on the formation of carboxyl salt, add acid molecules after baicalin was to restore it, but such
a response must have a higher temperature and longer time to complete the reaction, relatively speaking, the longer the holding time, Huang Qin the higher the yield of glycosides, but the insulation 90 min, the yield was no significant increase in concentration declines and heat 60 min is sufficient to complete reaction, so we believe that a good thermal insulation effect of 60 min. Table 7 Acid-holding time
on the yield and content of baicalin effects (abbreviated)
2.2.8 Acid quiet time on the set of baicalin yield and
content of change in acid-quiet home time, other things being
equal, using the boiling method extraction. The results in Table 8. Table 8 Acid quiet home time yield and content of baicalin effects (abbreviated)
From Table 8 we can see that standing time increased, the yield increase is not much, 3 h of standing time to promote acid-response has been basically full, standing time to continue to increase although the yield will increase a little, but the purity of crude products are declined.
Analysis of the reasons may be due to the time frame is of the majority of the impurities dissolved in water mixed with baicalin, so that the purity of baicalin against decline.
2.2.9 Sediment washing methods on the yield and content
of baicalin the impact of changes in sediment washing method, other things being equal, using the boiling method extraction. The results in table 9. Table 9 sediment washing conditions on the yield and content of baicalin effects (abbreviated)
From Table 9 we can see that twice the amount of distilled water and washing the best, although the content is slightly lower than that precipitated with ethanol, but that higher rate than other methods, and production costs lower than other methods. The yield of 1% hydrochloric acid
precipitation and baicalin are not high. This may be due to hydrochloric acid to join in the wash polysaccharides, resins and other impurities, while taking some of baicalin. Ethanol can be purified to remove some impurities of baicalin, the
yield of precipitation is slightly lower than that of distilled water. Comprehensive considering the selection of 50% ethanol washing.
2.3 baicalin aqueous solution of stability
2.3.1 Temperature on the Stability of baicalin aqueous
solution, said crude baicalin take 50 mg in the beaker by adding a certain amount of distilled water, coupled with NaOH
adjusted pH 6 ~ 7 to make it completely dissolved, add water to 100 ml, filter, take filtrate measured concentration of,
respectively, 50 ~ 90 ? water bath pot heating, cooling out
at regular intervals, measured absorbance, calculate concentration to the percentage of drug residues mapping the natural logarithm of time. From Figure 3 we can see the temperature, heating time on the stability of baicalin aqueous solution affect the higher the temperature, the longer the break the more. The various experimental temperatures of baicalin content of the relative percentage of the value of time is graphed, it has a linear relationship, indicating the
degradation of baicalin belongs to a chemical equation k = [Ln (C0 / C)] / t. Taking all factors, not only guarantee the extraction efficiency, but also to avoid the loss of baicalin
at least, this experiment that the 70 ? heat better.
2.3.2 pH on the stability of baicalin aqueous solution of lessons in this product test content, with sodium hydroxide and hydrochloric acid were made of pH value of 2,3,4,5,6,7,8-
conditioning solution, to 100 ? heating 1 h, remove the
cooling, test content, and the following calculated reaction rate constants of baicalin K = [Ln (C0 / C)] / t. Experiments show that the product solution influenced by the pH, to-Lnk
right pH mapping, the most stable around pH 3.98.
2.4 Based on the above optimal conditions for
experiments, design extraction process according to the above-
mentioned experiments the best conditions to particle size 40 mesh, 15-fold in water, boiling twice (60 min and 30 min),
double-fine cloth filter and then centrifugal separation,
60 ? plus acid adjusted pH 1 ~ 2, 70 ? insulation 60min,
acid-quiet home 3h, 50% ethanol washing, the yield was 13.67%, content 85.7%, its yield and content of fairly stable.
Extracted by boiling a better effect of baicalin and its optimum extraction conditions: boiling twice, the material ratio of 10 and 5 times the time for 60 min and 30 min, separated way for the first double-fine cloth with the
filtration and then centrifugation, 60 ? adjusted with
hydrochloric acid pH 1 ~ 2, and then 70 ? heat 60 min, put it
aside for 3 h, distilled water and separation of the two washing, drying may baicalin crude yield of 13.67%, the content was 85.7%.
Baicalin at high temperature and strong alkaline solution
is very unstable and at low temperatures and relatively stable under acidic conditions, extraction pH, should not exceed 4, acid-heat temperature is not too high.
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