| Rehmannia is the root of Scrophulariaceae Rehmannia glutinosa Libosch, and stachyose which is the nature sugar and widely distributed in leguminous plants is one of the main active ingredients in fresh Rehmannia. It is belonging to the raffinose galactosidaseclass of non-reducing functional oligosaccharides. In the present, there are many studies about the extraction of Rehmannia, such as warter extraction, ultrafiltration membrane extraction and ethanol extraction. Because of the importance of stachyose were increasing in medical, functional food and health care, so we optimize stachyose extraction from fresh Rehmannia glutinosa Libosch want to find a new basis for industrial study.Colored rice is different from ordinary color rice color. The reason of its color is that the number of anthocyanidin in mesocarp is depositing in seed development process. The colored rice is precious specific rice germplasm, mainly in the southwestern mountains, especially in Yunnan, and widely distributed in Guizhou. In this study, using high performance liquid chromatography to establish fingerprint method of the different varieties of colored rice, and chemical pattern recognition.It provides the basis for further study.The research content as follows:(一)The fingerprint research of Color riceThe aim was to establish the method of fingerprint analysis by HPLC for the quality control of the different variety Colored Rice from Yunnan. The fingerprint was performed by HPLC-UV. The conditions of chromatography:Venusil ASB-C18(5μm,250mm×4.6mm) was used with a mobile phase of methanol-water, flow rate:1.0mL/min, detection wave length at262nm, column temperature30℃.A high performance liquid chromatographic method was developed to establish the fingerprint of the different variety Colored Rice from Yunnan and24samples from various batches were analyzed, in the result eleven common peaks were determined. Cluster analysis and principal component analysis (PCA) were applied to study on HPLC fingerprint, the result of PCA and hierarchical cluster analysis showed that the samples were divided into two types. The fingerprint with hierarchical cluster analysis and principal component analysis was one of feasible methods for identifying the different variety Colored Rice which could be used to provide useful information for quality evaluation.We established the fingerprints for investigating water-soluble components of the colored rice by gas chromatography-mass spectrometry. We also investigated the effect of different volumes of extracts and derived reagents (MSTFA) for peak signal intensity and numbers. We determined the best conditions with each100mg material extracted by use of300μL extract and100μL MSTFA. we also studied the pattern recognition of the colored rice components by principal component analysis. We could provide valid data and reference values for further research into the colored rice.(二)Orthogonal test to optimize stachyose extraction process from fresh Rehmannia glutinosa LiboschBy orthogonal test the single factor experiments were conducted, in which, the effects of the pH, extraction time and the concentration of ethanol were studied separately. Determine the best extraction conditions:pH=12, extraction time1.5h,5%ethanol-water solvent. The extraction process is reasonably practicable which provide a basis for industrial production. A high-performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was applied for simultaneous determination of stachyose, sucrose and raffinose in Rehmanniag lutinosa Libosch. Carbohydrates were separated on a XBridgeTM Amide column using a mixture solvent of acetonitrile-warter (70:30, v/v) as mobile phase. Optimal extraction process was determined by optimizing stachyose extraction methods from Rehmannia glutinosa Libosch. In the results, it was interestingly founded that the content of stachyose was loss (approximately30-40%) when precipitate by the addition of ethanol. |
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