Dendrobium Nobile Quality Control Methods

Some Dendrobium species are used in traditional Chinese medicine as Yin tonic and to benefit stomach,reduce fever and promote secretion of siliva.Now,the research is focused on tissue culture and rapid propagation.The research on quality control is not so much.How to identify Dendrobium only denpend upon its externality and microsopic structer,and there is no scientific quality standard in Chinese Pharmacopoeia(2005 published),so it is very difficult to apply and develop them rensonably.In this paper,Dendrobium nobile which was plant in the standard plant base of Guizhou was used as the material.The quality standard of Denduobium nobile was established.The factors that influnence the quality were analysed.Part one:Literatures and summarizationsDocuments summarize the present research situation in chemistry, pharmacology and the analyzing ways for the quality control of Dendrobium.86 references are cited.Part two:Reference substance.Dendrobine was isolated from the alcohol extract by solvent extraxtion,silica. By employing physical and chemical properties,modern spectrometric analysis techniques such as UV,IR,EI/MS,¹H-NMR and ¹³C-NMR,the structure of the dendrobine was elucidated.Dendrobine was chosen as the reference substance for qualitative and quantitative analysis of the crude drug for its speciality and content.Part three:The quality sandard of Dendrobium nobile.Determination of total alkaloides from Dendrobium nobile.The denrobine was chosen as the reference substance for quantiative determation of total alkaloids.The content of total alkaloids was measureed by spectrophotometry with bromocresol green as color-developing agent and determined at the wavelength of 410.0 nm.The liner range is 0.00129～0.00645mg/mL and the regression epuation is A=0.11032C+0.012 giving a correlation(r) of 0.9982.The average recovery was 97.77%.The spectrophotometry is suitable for the determination of total alkaloides.Determination of polysaccharides from Dendrobium nobile.The glucose was chosen as the reference substance for quantiative determation of polysaccharides. The content of polysaccharides was measureed by spectrophotometry with phenol-srlfric acid as color-developing agent and detected at 487.0nm wavelength.The liner range was 0.005145～0.05145mg/mL and the regression epuation was A=13.752C-0.0062 giving a correlation(r) of 0.9991.The average recovery was 95.35%.The spectrophotometry is suitable for the determination of polysaccharides.At the same time,studying the morphology,the microscopic identification and the routine examination including the percentage of containing water,ash and heavy metal control.We analyzed samples from different style of cultivation.We found that illumination have large influence on Denduobium's growth.The content of polysaccharides which was cultivated in shady slope(11.50%) are higher than that in sunny slope(4.82%) obviously,but the content of alkaloides are similar.Part four:Samples of different mutants and differerent collecting time.Samples of different harvest time were analysed and the reuslts indicated the contens of polysaccharides and alkaloides were different through the year.There were two highest value of alkaloides and only one highest value of polysaccharides in one year growing periods.Having high content of polysaccharides in October and November.Having high content of alkaloides in Marh,September to December.The most approtiate harvest time is from October to November,refering to traditional collecting time and the contenes of polysaccharides and alkaloides.Samples of different mutants were analysed and the results indicated that Zhu-ye-lan have the highest content of polysaccharides(13.53%),and the content of polysaccharides in Xie-zhua-lan is 11.82%,Qi-cun-lan haved the lowest content of polysaccharides(6.32%).The conten of alkallides in Xie-zhua-lan,Yu-du-lan and Qi-cun-lan were 0.28%,0.27%,0.28%.FTIR was used to analysed the different mutants.