Objective To determine the content of taurine in Mactra veneriformis by pre-column derivation HPLC.Methods Ultrasound method was used for the extraction of taurine from Mactra veneriformis.In alkaline condition,amino acids reacted with phenyl isothiocyanate and resulted in the derivatives of benzene isothiocyanate-amino acid complex.Kromasil C18 column(4.6 mm ?250 mm,5 ?m) was used and the absorbance at 254 nm was measured.The mobile phase consisted of sodium acetate solution,water and methanol.Results Corresponding chromatographic peaks of taurine were obtained in extract sample and the control.The linear range of taurine was from 10.04 ?g?mL-1 to 50.20 ?g?mL-1,and the recovery was 97.95 %(RSD=1.41%,n=9).Conclusion This method is simple,accurate and reproducible.The seasonal variation range of taurine level is from 10.56 mg/g to 20.91 mg/g,and the taurine level arrived to the peak in June.

Objective A HPLC method was established to measure the contents of major nucleosides in Hyriopsis cumingii.Method Separation was performed on a Lichrosper-C_(18) column, pure water was used as mobile phase,the flow rate was 1.0mL min~(-1),the column temperature at 30℃and the detective walvelength at 254 nm.Results The contents of uracil,hypoxanthine, xanthine,uridine and thymine were 153.2～173.3?g?g~(-1),106.6～360.8?g?g~(-1),117.6～172.8?g?g~(-1),70.3～153.1?g?g~(-1) and 343.9～511.4?g?g~(-1),respectively. Conclusion This method showed good repeatability and flexibility.It could be used as a conventional method for determination of major nucleosides in H.cumingii.

OBJECTIVE To study the structural characteristics of purified polysaccharide isolated from Polygonatum cyrtonema Hua and explore its anti-fatigue and intestinal bacteria improvement effects,so as to provide theoretical basis for the development of products using this polysaccharide as functional ingredients.METHODS PMP pre-column derivatization-high performance liquid chromatography,trimethylsilyl ether derivatization-gas chromatography and other methods were used to chemically characterize the pu-rified polysaccharide;the mouse weight-loading swimming test and biochemical indicators were used to evaluate its anti-fatigue effect;16S rRNA intestinal flora sequencing was adopted to study the effect of the purified product in improving intestinal bacteria.RESULTS The obtained polysaccharide was a fructan product and contained small amounts of glucose(Glc),galactose(Gal),arabinose(Ara),mannose(Man),rhamnose(Rha)and galacturonic acid(GalA),which had a relative molecular mass in the range of 0.4-285 kDa,and the molecular weight of the main component was around 3 kDa.Compared with the model group,the high-dose polysaccha-ride group could significantly prolong the exhaustive swimming time of mice(P＜0.01),reduce the levels of BUN and UA in serum and the LA(P＜0.01)and MDA levels(P＜0.05)in muscle tissue,and enhance SOD(P＜0.01),GSH-Px(P＜0.001)and CAT(P＜0.05)levels in liver tissue.Compared with the blank control group,the low-dose polysaccharide group could increase the relative a-bundance of probiotics Eggerthelaceae(g_unclassified_f_Eggerthelaceae)and Weissella(g_Weissella)in the fecal microorganisms of mice(P＜0.05).CONCLUSION The chemical composition of purified polysaccharide isolated from Polygonatum cyrtonema Hua is determined,and it is proven that the polysaccharide has a good anti-fatigue effect and can promote the growth of probiotics in the intes-tine,which provides a basis for product development using this polysaccharide as a functional ingredient.