Extraction & Isolation Of Bio-activated Constituents In Bamboo Leaves And Its Antifungi Activities

Bamboo, widely distributed in Asia, Latin America and Africa, is one of the tall, treelike evergreen grasses comprising the Bambuaoideae Nees of the family Poaceae plant. 70~80 genera and more than 1,300 species of bamboo have been recorded in botanical literature all over the world, and in which about 39 genera and more than 500 species were located in China. Bamboo leaves consist of abundant bio-active constituents which make it a potential resource for advanced pharmaceutical utilization such as Baicalein, coumarin lactones and activity polysaccharide in Bamboo leaves. It has important physiological and health protective value that makes it significant in food industry and medicine field.In order to study the antimicrobal Bamboo systematically, its leaves were taken as materials with stilled water, alcohol, aether and petroleum ether as solvents, the effect of drying methods and solvents on extraction ratio and antimicrobial activity were reviewed. The effect on extraction ration of ratio between solvents and material, temperature and time were investigated by means of single factor and orthogonal experiments and the optimum extraction condition was determined, furthermore, the antimicrobial activity of different breed and the same organ gathered in different growing periods were compared. With Escherichia coil, Bacillus subtilis, Staphyloccocus arueus and some moulds and yeasts as experimented microbes, the characteristics of antimicrobial activity were studied by means of filter paper method and plate dilution method. Gram-positives Staphylococcus aureus and Gram-negative Escherichia coli were chosen for the antibacterial assays. Firstly, Extract of bamboo leaf (Ebl) were extracted by polar-different organic solvents respectively. The antibacterial activities of all the fractions obtained were studied and the active fractions were established: According to the antibacterial assay, 30% ethanol-soluble fraction of Ebl after leached by petroleum ether-solution and aether-solution is the most significant and attributed to it, it was used for further purification, and 4 compounds of antibacterial activity were obtained through tracing the activity and repetitive column chromatography on silica gel and poly-Hexanolactam. Their structures were identified on the basis of spectral technology (MS, UV) chemical methods and comparison with related reports of literatures. The structure-activityrelationships were established elementarily using compounds 1,2,3,4 and several synthetic products by comparison of their antibacterial activities. Extract was separated with Layer Chromatography and applied in the preservations of stewed meat, damped bean curd and tomato piece. The results indicated:1. Drying methods had significant effect on extraction ration and antimicrobial function and the difference was significant (p<0.01) .The raw material dried by 40 ℃ sirocco had the highest extraction ration with 7.36%, the second higher of 7.08% dry in the shade after shine upon, the third higher of 6.97% appeared in that dried by room temperature and the smallest was in that dried by insolation under sun, which was only 6.50%. The diameter of antimicrobial ring to Escherichia coli of raw material dried by microwave was 12.70mm, which was the most in four treatments , the second of 11.27mm was in that dried in the shade after shine up, the third of 11.13mm was in that dried by room temperature and the last one was in that dried by by insolation under sun ,which was 10.40mm.2. Stilled water and alcohol-water extracts had bacteriostasis to germs, moulds and yeast.The inhibition sequence to experimented microbes of stilled water and 60% alcohol extract was: to germs>to yeast>to moulds. But 60% alcohol extract had the best antimicrobial effect on germs, with the diameter of antimicrobial rings to Escherichia coli beyond 10.02mm and 60% alcohol extract had better inhibition to germs , to yeast and moulds than that of stilled water.3. The effect on extraction ration of ratio between solvents and raw material and temperature were greater than that of time. Alcohol as solvent, the optimum extraction condition was: ratio between solvents and raw material: 12:1, temperature: 80℃, time: 1.5 h. The extraction ration was 7.74% at this condition.4. The antimicrobial activity of different bamboo leaves and that of the same organ growed in different periods were different. The antimicrobial activity of Sinocalamus latiflorus McClure leaves was better than that of others. bamboo leaves gathered in the second part of July and November had better antimicrobial activity than others.5. Bamboo leaves alcohol extract had wide antimicrobial spectrum. Its minimal inhibitory. Concentration to germ was 0.156%, and that to moulds and yeast was 0.625% and 1.25%.