Analysis Of Main Chemical Components Of Different Varieties Of Bamboo Leaves And Preparation Of Bamboo Leaf Toothpaste

Objective:In this study,a series of studies were carried out to analyze the components and antioxidation of Phyllostachys nigra,Lophatherum gracile and Pleioblastus amarus bamboo leaves,and the one performed better was subjected to the investigation of extraction process.The extraction technology of propolis and the preparation of bamboo-propolis toothpaste were optimized,and the quality standard was also established preliminarily.Our work promoted the development of a series of healthy bamboo-leaf products.Method:Firstly,a stable and reliable HPLC method was established for the quantitative determination of seven compounds in Phyllostachys nigra,Lophatherum gracile and Pleioblastus amarus bamboo leaves and investigated.Secondly,the suitabale DPPH assay was selected to determinate the antioxidant capacity of active compounds and extracts.In addition,multivariate correlation analysis and regression analysis were used to explore the main antioxidant active compounds based on the datas of contents and antioxidant values.The one with considerable content and excellent activity was selected and optimized the extraction process by methods of single factor,orthogonal test,and comprehensive scoring.Then the quality of propolis was evaluated according to the China pharmacopoeia（2015 edition）,and the preparation technology was explored by a single factor experiment.The formula of toothpaste was optimized on tha basis of sensory properties,and finally,a tube of bamboo-propolis toothpaste was reasonably prepared.Result:1.A new HPLC method was established to determine the content of chlorogenic acid,isoorientin,isoorientin,isovitexin,luteolin,luteolin,apigenin and distinguish Phyllostachys nigra leaves from Lophatherum gracile and Pleioblastus amarus leaves.The method showed good accuracy and repeatability（RSD<3%）.And the results of determination showed high contents of swertiajaponin in Lophatherum gracile leaves,and not in Pleioblastus amarus and Phyllostachys nigra leaves.Lophatherum gracile leaves have a low content of compounds and Phyllostachys nigra leaves have a high content of compounds.Most compounds have higher content in Phyllostachys nigra leaves,and the content of isoorientin was 14 times and the content of isovitexin was 29times that in Lophatherum gracile leaves.2.The prefered bamboo-leaf material was determined through the study of antioxidant active components.In our preliminary tests,ABTS,FRAP and DPPH assay were used to determine the antioxidant capacity of the index components and extracts of leaves.The DPPH assay was selected as the antioxidation evaluation method for it is stable,reproducible,accurate and reliable.Besides,VC and Trolox were used as positive control drugs.Results showed that the antioxidant activities of four index components were stronger than that of VC(IC₅₀=0.926 m M)and Trolox(IC₅₀=0.973 m M),and luteolin(IC₅₀=0.422 m M),cynaroside(IC₅₀=0.427 m M)had the strongest activity.IC₅₀ values of seven batches of Lophatherum gracile leaves were about 5.07±2.67 mg/m L,IC₅₀ values of ten batches of Pleioblastus amarus leaves were around 3.24±1.15 mg/m L,IC₅₀ values of nine batches of Phyllostachys nigra leaves were 1.98±0.42 mg/m L.The results showed that the antioxidant activity of Phyllostachys nigra leaves performed better and variated lightly.Multiple correlation and regression analysis results showed that the content of apigenin and antioxidant activity of Lophatherum gracile leaves was significant positive correlation（P<0.01）,the content of isoorientin was significant related to the activity of Pleioblastus amarus leaves（P<0.01）,and the content of orientin was significant related to the activity of Phyllostachys nigra leaves（P<0.01）.After a comprehensive comparison,we found Zhejiang Quzhou leaves（air-dried）would be the ideal material of bamboo-leaf products.3.The extraction technology of bamboo leaves was optimized.We used the content of components,content of total flavonoids and DPPH free radicals scavenging capacity as reference indexes,and picked the orthogonal experiment,single factor investigation,comprehensive scoring to optimize the extraction process,and the results show that the material liquid ratio should be 40 times,extraction solvent should be 80%ethanol,and soaking for 30 min,reflux extraction for twice,each time is 1 h.And the total flavonoids extract transfer rate is as high as 88.08%,DPPH free radical clearance rate was 73.16%,all results repeated stablely（RSD<3%）and resonably.4.Qualified propolis medicinal materials estimated according to the"Chinese pharmacopoeia"（2015 edition）were chosen and obversed the pretreatment technology.And we finally dissolved it adequately in 80%ethanol,and added the solution into toothpaste.The results of single factor experiment showed that the extract of propolis treated with 80%ethanol had sufficient component transfer and no obvious deficiency of other components.The results were stable and the method was reasonable and feasible.5.We confirmed the formation technology of bamboo-propolis toothpaste.This study used the wet method for the preparation of bamboo-problis toothpaste.The formula contained:non-ionic guar gum 0.75 g,sodium carboxymethyl cellulose 0.25 g,sorbitol40 g,glycerin 20 g,ethylparaben 0.1 g,propylparaben 0.05 g,saccharin sodium 0.35 g,silica 18 g,sodium dodecyl sulfate 2 g,peppermint 1 g,appropriate amount of water,bamboo-leaf extract 2 g,propolis extract 0.5 g.The preparation process is as follows:Firstly,weigh formula amount of non-ionic guar gum,sodium carboxymethyl cellulose and disperse them in sorbitol,glycerin.In addition,weigh ethylparaben,propylparaben,saccharin sodium,extracts and dissolved in water before mixing,stiring and aging.Next,add silica,sodium dodecyl sulfate,peppermint into the aforementioned mixture under stiring and age finally.6.The quality standard（draft）of bamboo-propolis toothpaste was established preliminarily.The expected is 100 g each,it looks like a delicate and bright light yellow paste,and it is fragrant with a cool taste.The test results showed that the single ingredients in toothpaste are unable to be accurately detected,and the flavonoids were the main efficacy components in bamboo leaves and propolis,which can be accurately detected.So the content of total flavonoids was chosen to estimate the quality of bamboo-propolis toothpaste.Each dose contains at least 400 mg of total flavonoids.Conclusion:We established a new HPLC method for the simultaneous determination of three kinds of bamboo leaves,preliminary evaluated their antioxidant capacities,promoted the extraction process of bamboo leaves,examined the pretreatment technology of propolis,optimized the formula of toothpaste,and prepared a bamboo-propolis toothpaste paste reasonably,which is of practical significance for the effective development of bamboo resources and the improvement of quality standards.