Effects Of Different Fertilizing Amount, Harvesting Time And Processing Methods On The Chemical Constituents Of Rhodiola Crenulata

The 2015 edition of the Chinese Pharmacopoeia provides that Rhodiola crenulatae radix et rhizoma comes from the dried roots and rhizomes of R.crenulata Hook.f.et Thoms.Ohba.It has the effect of"replenishing Qi and activating Blood Circulation,Tongmai relieving Asthma",it is mainly used in"Qi deficiency and Blood stasis,chest obstruction and Heart pain,apoplexy hemiplegia,Burnout Asthma"and so on.With the increasing consumption of the Tibetan medicine R.crenulata and the gradual depletion of wild resources,the mixed use of medicinal materials of different harvest periods and drying methods has become more serious,which has brought great hidden dangers to the clinical efficacy of the Tibetan medicine R.crenulata.The establishment of scientific and systematic quality evaluation method is the premise to ensure the safety and effectiveness of Tibetan medicine.Objectives:1.To improve the quality control method of TLC qualitative identification and HPLC content determination of R.crenulata;2.To determine the reasonable amount of nitrogen,phosphorus and potassium fertilizer applied in the artificial domesticated cultivation of R.crenulata;3.The suitable harvest time and drying method of R.crenulata were determined based on the comprehensive scoring method of multi-index evaluation.Methods:1.The TLC method was used to identify three effective components of gallic acid,salidroside and tyrosol,Quantitative analysis of four effective components of gallic acid,salidroside,tyrosol and ethyl gallate was carried out by HPLC.2.Using"3414"field test,the effects of different nitrogen,phosphorus and potassium fertilization on the four effective components were analyzed.3.The content of four active components was determined by HPLC,total polysaccharides,total phenols and total flavonoids was determined by UV-Vis.The systematic study was carried out on the R.crenulata with different harvest time and different drying methods by comprehensive scoring method.Results:1.A TLC method for simultaneous identification of Gallic acid,salidroside and tyrosol was established,and a HPLC method for simultaneous determination of Gallic acid,salidroside,tyrosol and ethyl gallate was established.2.The results showed that nitrogen fertilizer was the most important factor in domestication and cultivation of R.crenulata by applying different nitrogen, phosphorus and potassium fertilizers,and the results showed that nitrogen fertilizer was the most important factor.It is suggested that the best formula of NPK fertilization is N₁P₂K₂,that is,30kg hm^-22 for nitrogen fertilizer,100kg hm^-22 for phosphorus fertilizer,and 160kg hm^-22 for potassium fertilizer.3.The results of different harvest periods showed that the content of salidroside and the total amount of four active components were the highest in early October,the contents of total phenol,total flavonoids and total polysaccharides were the highest in early October,and the contents of total phenols,flavonoids and polysaccharides were the highest in the mid-October.The content of alcohol-soluble extracts was the highest,and the suitable harvest time of R.crenulata was suggested to be early October.4.The results of different processing methods showed that the freeze-dried R.crenulata had the best appearance characters,and the contents of salidroside and total phenol were the highest,and the total amount of four effective ingredients of the dried Medicinal slices of R.crenulata was 30?,while the content of salidroside and total phenol was the highest.The contents of total flavonoids and alcohol-soluble extracts were the highest;the content of total polysaccharides in dried R.crenulata was the highest;considering the high cost of freeze-drying,it was suggested that the best drying method of R.crenulatae was low temperature drying.Conclusions:1.The quality control method of the thin layer identification and the HPLC content determination of the R.crenulata of the Tibetan medicine is improved;2.It provides a reference for the rational amount of nitrogen,phosphorus and potassium fertilizer,harvest period,and drying method of the rare and endangered Tibetan medicine R.crenulata.