| [Objective]This paper is "Authenticity identification and quality control of high value-added agricultural products":Taking Dendrobium officinale Kimura et Migo collected in the Chinese Pharmacopoeia of the 2015 edition as the key research object and nine other Dendrobium species(Dendrobium fimbriatum,Dendrobium nobile,Dendrobiumchrysotoxum,Dendrobium devonianum,Dendrobiumthyrsiflorum,Dendrobiu wardianum,Dendrobium aphyllum,Dendrobium chrysanthum,Dendrobium denneanum Kerr),using TLC,HPLC-PDA,ultraviolet-visible spectrophotometry,amino acid automatic analyzer,ICP-MS and other modern analytical techniques,in order to accurately and efficiently identify different varieties of Dendrobium and evaluate their quality.[Methods]1.TLC identification:TLC identification method referring to Chinese Pharmacopoeia,systematic reseach on different polarity parts(petroleum ether,ethyl acetate and n-butyl alcohol)of ten kinds of Dendrobium.2.EstabIishment of the HPLC fingerprint by using the technology of HPLC-PDA,identification of eight Dendrobium species by comparison and similarity calculation of fingerprints,and combining cluster analysis and principal component analysis.3.Eight components(scopoletin,scoparone,coumarin,naringenin,apigenin,gigan-tol,erianin,dendrobine)analysis method was established by HPLC-PDA technology and the content was determined;Ten Dendrobium polysaccharides were determined by phenol-sulphuric acid method with ultraviolet-visible spectrophotometer.Determination of 17 hydrolyzed amino acids in ten Dendrobium species by amino acid analyser.The quality of Dendrobium was evaluated by the content difference of ten chemical constituents combined with variance analysis and t-test.4.ICP-MS technology was used to determine the content of rare earth elements and trace elements in ten species of Dendrobium.[Results]1.According to TLC spots characteristics,ten varieties of Dendrobium have the identical spots,and each has its own special spots,the results showed that there are differences in chemical constituents among different varieties of Dendrobium.2.HPLC fingerprints of 13 batches of Dendrobium officinale Kimura et Migo with a similarity of 0.791-0.929;8 different varieties of Dendrobium similarity between 0.169-0.875,marked 23 common peaks and identified six peaks(vanillic acid,syringic acid,p-hydroxybenzoic acid,scopoletin,ferulic acid,naringenin)by reference materials,and the chromatographic peaks of 16 chemical constituents of Dendrobium thyrsiflorum were marked.Combining cluster analysis and principal component analysis,63 batches of Dendrobium samples can be quickly divided into two categories,and then 60 batches of Dendrobium samples are further divided into four categories.The comprehensive application of the three analytical methods verified the feasibility of chemical pattern recognition for Dendrobium species identification and classification.3.The content determination,variance analysis and t-test showed that,the contents of ten chemical constituents in ten species of Dendrobium were different(P<0.05).Gigantol,erianin and dendrobine can be respectively as content determination indicators to control quality of Dendrobium fimbriatum,Dendrobium chrysotoxum and Dendrobium nobile.Coumarin can be used as a reference indicator for quality control of Dendrobium denneanum Kerr.Naringin and apigenin can be used as reference indicators for quality control of Dendrobium thyrsiflorum.Quantitative analysis methods of Dendrobium can provide reference for quality control.The content of polysaccharide and the total content of 17 kinds of amino acids can be used as the evaluation index for quality control of Dendrobium officinale Kimura et Migo and Dendrobium devonianum,and can be used as reference for quality control of Dendrobium aphyllum..The total content of 17 kinds of amino acids can also be used as reference for quality control of Dendrobium chrysanthum.4.The total contents of rare earth elements in 11 batches of Dendrobium officinale Kimura et Migo from Wenshan,Dehong,Maile and Tengchong are different.There is no significant difference in the total content of rare earth elements among eight varieties of Dendrobium in Dehong,but there are differences in the content of 16 rare earth elements among different species of Dendrobium from the same producing area.The contents of chromium(Cr),nickel(Ni)and zinc(Zn)in 11 batches of Dendrobium officinale Kimura et Migo from Wenshan,Dehong,Maile and Tengchong are different.The contents of chromium(Cr),nickel(Ni),zinc(Zn)and selenium(Se)in eight varieties of Dendrobium from Dehong are abundant,while tin(Sn)is only detected in Dendrobium nobile and Dendrobium wardianum.The contents of chromium(Cr),nickel(Ni),zinc(Zn)are different among the eight Dendrobium species.18 batches of Dendrobium heavy copper(Cu),cadmium(Cd),mercury(Hg),lead(Pb)elements are within the limits,Dendrobium thyrsiflorum,Dendrobium officinale Kimura et Migo and Dendrobium wardianum produced in Dehong have obvious excess of arsenic(As)elements.[Conclusion]The chemical composition of the ten varieties of Dendrobium is different in species and content.TLC and HPLC fingerprints can identify ten species of Dendrobium.Multi-component analysis can reflect the quality of Dendrobium to a certain extent,and can provide reference for the identification and quality control of Dendrobium.The determination of 16 rare earth elements,5 essential trace elements and 5 harmful heavy metal elements in Dendrobium can provide the necessary scientific basis for the evaluation of the nutritional and health value and some pharmacodynamic effects,as well as for the evaluation of its medicinal quality and safety from different place of origin.. |
