RESUMO
Polysaccharides exhibit multiple pharmacological activities which are closely related to their structural features.Therefore,quantitatively quality control of polysaccharides based on their chemical charac-teristics is important for their application in biomedical and functional food sciences.However,poly-saccharides are mixed macromolecular compounds that are difficult to isolate and lack standards,making them challenging to quantify directly.In this study,we proposed an improved saccharide mapping method based on the release of specific oligosaccharides for the assessment of Hericium eri-naceus polysaccharides from laboratory cultured and different regions of China.Briefly,a polysaccharide from H.erinaceus was digested by β-(1-3)-glucanase,and the released specific oligosaccharides were labeled with 8-aminopyrene-1,3,6-trisulfonic-acid(APTS)and separated by using micellar electrokinetic chromatography(MEKC)coupled with laser induced fluorescence(LIF),and quantitatively estimated.MEKC presented higher resolution compared to polysaccharide analysis using carbohydrate gel elec-trophoresis(PACE),and provided great peak capacity between oligosaccharides with polymerization degree of 2(DP2)and polymerization degree of 6(DP6)in a dextran ladder separation.The results of high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector(HPSEC-MALLS-RI)showed that 12 h was sufficient for complete digestion of polysaccharides from H.erinaceus.Laminaritriose(DP3)was used as an internal standard for quantifi-cation of all the oligosaccharides.The calibration curve for DP3 showed a good linear regression(R2＞0.9988).The limit of detection(LOD)and limit of quantification(LOQ)values were 0.05 μg/mL and 0.2 μg/mL,respectively.The recovery for DP3 was 87.32(±0.03)％in the three independent injections.To sum up,this proposed method is helpful for improving the quality control of polysaccharides from H.erinaceus as well as other materials.
RESUMO
Due to the extensive use of xylooligosaccharides (XOS) as functional food ingredients,many inferior goods and even adulterants are generally found in the market,which may pose a health hazard to certain populations.Chromatography method such as high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) is traditionally applied for the quality analysis of XOS.However,it is time consuming due to the prolonged separation and pre-or post-derivatization procedure.In this study,a fast saccharide mapping method based on matrix-assisted laser desorption/time-of-flight mass spectrometry (MALDI-TOF-MS) was developed for the quality consistency analysis of 22 batches of XOS collected from different manufacturers in China.The time needed for saccharides analysis using MALDI-MS was less than 30 min for one plate,at least 6 times faster than that by the traditional HPTLC chromatography method.In addition,MALDI-MS possessed higher resolution for XOS with DP4-DP7 based on the difference of m/z,which is hardly separated using HPTLC.The results showed that XOS were present only in samples XY01-XY11,samples XY12-XY14 only consisted of hex oligo-saccharides,and samples XY15-XY22 were free of oligosaccharides.These indicate that the quality consistency of XOS products in the China market was poor,which should be carefully investigated.