Central Grass Dendrobium Medicinal Quality Analysis And Evaluation Methods

Herba Dendrobium(Shi-hu) is the fresh or dried stem of Dendrobium nobile,D. candidum(D.offcinale) or D.fimbriatum var. oculatum(D.fimbriatum) and their allied species according to the Chinese Pharmacopoeia(2005) for nourishing"Yin"and clearing heat. Because of lower reproduction rate and slow growth,the wild resources decreased seriously. Now it propagate by artificial cultivation because of the decrease of resource and the medical material by artificial cultivation is become the main source. The quality of Shi-hu was very instability and there haven't had a standard and method to evaluate it acroding to the Chinese Pharmacopoeia due to diversify and confusion of species.In this paper we take D.loddigesii Rolfe which is one of the plants of D.loddigesii Rolfe according to the Chinese Pharmacopoeia(2000) as the material,based on a number of literatures and information, analyzed D.loddigesii Rolfe of different places of production,different growth years,different style of cultivation,diffferent harvest time by content determination and fingerprint,so we can establish a method to evaluate the quality of D.loddigesii Rolfe initially,and offer a reference evidence to establish the quality criteria.The chief findings are as follows:(1)Established a method for content determination of polysaccharides,UV fingerprint, and estabished the HPLC fingerprint by comparing and analyzing 10 batches of samples,and 9 common peaks were confirmed.The similarity of each fingerprint was between 0.823 and 0.997.We use HPLC-MS as supplement to identify some constituents and 2 chemical constituents contained were confirmed by analyzing their extracted mass spectrum basing on references,these are No.5 Shihunine,No.9 moscatilin.(2) Established a method for qualitative analysis of total alkaloids and obtained crude total alkaloids then had qualitative analysis.We find that the crude was coincide with peak No.5 in HPLC fingerprint, so peak No.5 is identified as alkaloid further.(3)We analyzed samples from different places of production and different style of cultivation. Compared with samples from Guizhou,Guangxi,Yunnan,Yuenan,we find that samples in Guizhou have higher content of polysaccharides,more HPLC peaks and larger area ratio;the content of polysaccharides in Zhenfeng Guizhou is 17.06%,which is the highest. Illumination and temperature have larger influence on Dendrobium's growth. The content of polysaccharides and area of peak of HPLC fingerprint which is cultived in shady slope is higher than that in sunny slope obviously.Samples cultivated in sunny slope which to shade by broad leaved forest is beneficial for accumulate of effective constituent.(4)The content of polysaccharides of different parts is root>stem>leaf,UV spectrum showed that there are larger difference in root,stem and leaf except the petroleum system,especially in leaf.There are less compositions in stem but these are similar to the compositions in stem.In HPLC fingerprint the numbers of peaks are root