Determination of polysaccharides and total alkaloids in four Caulis dendrobii materials from Xingyi,Guizhou

Objective To analyze the content of polysaccharides and total alkaloids in Dendrobium chrysanthum,Dendrobium nobile,Dendrobium fimbriatum and Dendrobium loddigesii from Xingyi,Guizhou.Methods 3,5-Dinitrosalicylic acid( DNS)colorimetry was used to determine the content of polysaccharides,and the content of total alkaloids were measured by acid dye colorimetry1.Results In the four Caulis Dendrobii materials,the drying rates of were 13.72%,18.13%,20.77% and 32.63%;the content of polysaccharides were 22.70%,12.88%,6.29% and 5.20%; in addition,the content of total alkaloids were 0.41%,0.58%,0.68% and 0.46%,respectively.The content of polysaccharides showed negative correlations with the content of total alkaloids( r =-0.522,P = 0.448) and drying rates( r =-0.810,P = 0.190),while the correlation between the content of total alkaloids and drying rates was-0.041( P = 0.959).Conclusion Dendrobium chrysanthum had higher content of polysaccharides and lower content total alkaloids and drying rates than the others.And the content of total alkaloids in Dendrobium fimbriatum was higher.Besides,no significant difference among the three indicators in t test may result from a small sample.