Effective Components And Extraction Technology From Leaves Of Feijoa Sellowiana Berg.

Feijoa sellowiana Berg., a monotypic species of the family Myrtaceae. It is also commonly known as the pineapple guava, Brazilian guava, or guava. The Feijoa is an evergreen shrub or small tree, which originates from Brazil and Urμ guay of South America. The main component of the leaves of Feijoa sellowiana is flavonoids and polyphenols and other water-soluble ingredients. The pharmacological experiments indicate that the leaves of Feijoa sellowiana has a wide curative effects as antibacterial, antioxidant, anti-tumor, anti-inflammatory and enhance the immune etc. The flavonoids and polyphenols and other water-soluble components are the main effective components. To obtain the virtual components of leaves of Feijoa sellowiana, extracted and separated flavonoids and polyphenols of the leaves of Feijoa sellowiana. Then the antioxidant activity was researched, effective components analysis method was established and extraction technology of effective components was researched. Finally the quality and acute toxicity of effective components in the extracts from leaves of Feijoa sellowiana was researched. The main research contents and results are as follows:The compounds were isolated by column chromatography and crystallization. The structure of the compounds was identified by MS, 1H-NMR, 13C-NMR and other spectral analysis method. Result: Five compounds were isolated and identified, as flavone, β-sitosterol, oleanolic acid, quercetin and avicularin. Oleanolic acid, quercetin and avicularin were isolated from this plant for the first time.The antioxidant activity was detected by free radical scave nging assay with 1, 1-diphenyl bitter phenylhydrazine(DPPH·). The antioxidant experiment showed that the ethanol extracts and the aqueous extracts from leaves of Feijoa sellowiana, quercetin and avicularin have strong antioxidant activity and eliminating free radical activity.To determine the optimal extraction technology of quercetin from leaves of Feijoa sellowiana. Taking extraction rate, and the purity and yield of quercetin as the indices, effects of extraction solvent, extraction temperature, extraction time, solid to liquid ratio and extraction times on the extraction rate of quercetin were studied. And the optimal extraction technology was sel ected. The optimal extraction technology was as follow: leaves of Feijoa sellowiana powder was added into 90% alcohol with the ratio of l: 10( g/ml)under 50 oC, the leaves was by reflux extraction for 4 times with each time for 2 h. The extraction rate, extraction rate of quercetin, and purity of quercetin were 3.49%, 0.033%and 0.95%, respectively.Taking extraction rate, and the purity and yield of total flavonoids as the indices, effects of extraction solvent, extraction temperature, extraction time, and extraction times on the extraction rate of total flavonoids were studied.And the optimal extraction technology was selected. Result: The optima l extraction technology was as follow: Under 90 oC, leaves of Feijoa sellowiana powder was by reflux extraction in water for 3 times with each time for 2 h. The ratio of solid to liquid was 1:10 at the 1st time and 1:5 at the 2ed & 3rd time. The extraction rate, extraction rate of total flavonoids, and purity of total flavonoids were 16.23%, 6.90% and 42.51%, respectively.In order to establish the quality standard of the extracts from leaves of Feijoa sellowiana, total flavonoids, flavonoid, quercetin, vitamin C, minerals and heavy metals in the extracts from leaves of Feijoa sellowiana were determined in this paper. The extracts from leaves of Feijoa sellowiana were analyzed by the method of thin layer chromatography qualitatively. Using the method of ultraviolet spectrophotometric, the content of total flavonoid in the extracts from leaves of Feijoa sellowiana was determined to be 52.6%. Using the method of high performance liquid chromatography, the content of quercetin in the extracts from leaves of Feijoa sellowiana was determined to be 0.21%. The content of flavonoids was determined to be 2.77%. Using the method of iodine titration, the content of vitamin C in the extracts from leaves of Feijoa sellowiana was determined to be 0.93%. Using the method of Inducti vely coupled plasma to detecte the extracts from leaves of Feijoa sellowiana, the result showed that it contained a variety of minerals, such as K, Fe, Zn, Mg, Ca and the content of heavy metal was in line with national standards.In order to study the acute toxicity of the extracts from leaves of Feijoa sellowiana, the mice received orally by gavage the maximum tolerated oral dose of extracts of more than 10000 mg/kg.BW. In the acute toxicity test, no abnormal behavior in mice and no evident poisoning symptoms and animal death were detected after 14 d continuous observation. The mice were sacrificed for gross anatomy after administration and no visible anomalies in liver, lung, intestine, stomach, kidneys and other major organs produce, observation, which preliminarily indicated that the extracts from leaves of Feijoa sellowiana were of nontoxicity.