Isolation of endophytic fungi from Taxus chinensis var. mairei Cheng et L. K and its antimicrobial activity / 中国药学杂志

OBJECTIVE: To isolate the endophytic fungi from medicinal plant Taxus chinensis var. mairei Cheng et L. K in Guangxi Zhuang autonomous region, and investigate its antimicrobial activity. METHODS: Endophytic fungi were isolated by the tissue separation method. Staphylococcus aureus, Escherichia coli, and Candida albicans were used as the indicators for human pathogenic microbes. Antimicrobial tests of the isolated endophytic fungi were carried out by agar block and disc diffusion. RESULTS: Among 34 strains of endophytic fungi isolated from roots, stems, and leaves of T. chinensis var. mairei, eight strains (23.53% of the total isolated strains) showed antimicrobial activity against one or more of three human pathogenic microbes. CONCLUSION: Diverse antimicrobial natural products exist in endophytic fungi from T. chinensis var. mairei, which can be the resources for new antimicrobial products.

Content Comparison of Taxol in Different Parts of Taxus Madia and Taxus Chinensis var. Mairei / 中国药师

Objective:To compare the taxol content in different parts of Taxus madia and Taxus chinensis var. mairei to provide reference for the future researches. Methods:The active ingredients were extracted by a mixed solvent (50% acetone and 50% ethyl acetate) , the target compound taxol was separated by a neutral Al2 O3 solid phase column, and then the taxol content was analyzed and compared among the different parts of Taxus madia and Taxus chinensis var. mairei by HPLC. Results:Taxol in velamen of Taxus ma-dia had the highest content among all the samples, which was 0. 0439% and 88 times as high as that in the bark of Taxus chinensis var. mairei. Conclusion:Among all the samples of Taxus madia and Taxus chinensis var. mairei, velamen of Taxus madia has the highest taxol content.

Tissue culture and analysis on taxane diterpenoids in callus of Taxus chinensis var. mairei / 中草药

Objective: To investigate some factors which could influence the tissue culture of callus from Taxus chinensis var. mairei such as the culturing callus time, callus induction rate, callus development rate, growth rate, and browning degree. Then, the five taxane diterpenoids including paclitaxel in callus were studied and compared. Methods: The factors which influence the T. chinensis var. mairei callus induction and growth rate were studied by single factor analysis and orthogonal test design. The five taxane diterpenoids including paclitaxel in callus from different sources were determined by HPLC analysis. The weighted score for each of the above factors mentioned would be taken account to optimise the tissue culture conditions. Results: Among the explants, the stems intacted leaves would exhibit the best ability of dedifferentiation to form callus. The enrichment dark culture was conducive to paclitaxel and other five kinds of terpene constituents. The most optimum culture medium of the callus induction was B5 + 2, 4-D 3.0 mg/L + 6-BA 1.0 mg/L + NAA 1.0 mg/L + KT 0.5 mg/L. Conclusion: The callus culture conditions for T. chinensis var. mairei have indicated greater association with different types of the explantation, nutrient medium, and light illumination. The five kinds of enrichment taxane paclitaxel diterpenoids would be significantly affected by the type and concentration of the plant growth regulators. This study has shown some references value for T. chinensis var. mairei tissue culture and for the screening of high-yielding cell lines.

Studies on chemical constituents of planted Taxus mairei (III) / 药学学报

From the chloroform-soluble fraction of the ethanol extracts of the whole plant of Taxus chinensis var. mairei (Lemee et Levl), four compounds were isolated by using repeated column chromatography on silica gel and Sephadex LH-20. Based on spectroscopic data (UV, IR, ESI-MS, 1H NMR and 13C NMR), the compounds were identified as taxamairin K (1), 2α, 4α-dideacetoxy-7β-benzoyloxy-5β,20-epoxy-9α,10β,13α,15-tetrahydroxy-11(15→1)abeotaxa-11-ene (2), 7β-xylosyl-taxol (3), 10-deacetoxy-7-xylosyl-taxol (4). Among them, taxamairin K is a new compound.

Effect of explant source from different maternal tree and medium composition on callus growth and paclitaxel yield of Taxus chinensis var. mairei / 中草药

Objective To establish and optimize the technology and method of producing large quantity and high-paclitaxe yield callus of 〖WTBX〗Taxus chinensis var. mairei. Methods Wild maternal tree grown in Lingchuan County of Shanxi Province and cultivated tree grown in Xi′an were used as explant source. And the optimum maternal tree for explant cutting, optimum explant type, basic medium, composition and concentration of growth regulators in medium and so on, which were factors of affecting on callus induction, growth and paclitaxe yield, were examined in a series order. Results The juvenile stem segments were the optimum explants because of their earlier and higher rate callus induction than that of other explants. Medium Y5: MS+2,4-D 4.0 mg/L+KIN 1.0 mg/L or medium B5 Ⅲ: B5+2,4-D 3.0 mg/L+KIN 0.1 mg/L+Phe 0.1 mol/L was confirmed optimum callus induction medium in which callus induction rate had reached to 100%. In callus subculture medium, lower concentration of 2,4-D (0.5—3 mg/L) always increased callus growth, but higher concentration of 2,4-D (8 mg/L) reduced callus growth. When 2,4-D concentration was suitable, callus grown on B5 medium displayed lighter browning and faster tissue growth than that on MS medium. Further more, HPLC analysis confirmed that the paclitaxel yield in callus grown on medium MSⅢ was highest and had reached 0.004% of callus dry weight. In a general condition, the level of paclitaxel in calli derived from juvenile stems of wild maternal tree was higher than that in calli initiated from cultivated maternal tree's juvenile stems. Conclusion The optimization sequence of obtaining a large quantity and high-paclitaxe yield callus of T. chinensis var. mairei are dividing juvenile stem segments from wild maternal tree in May and culturing on medium Y5 or B5 Ⅲ for callus induction. After the calli having been subcultured on the same medium for 8—10 generations, one or two generations are recultured on medium MSⅢ. Finally, the calli with more paclitaxel are obtained by extracting paclitaxel out of it.

Effects of fed-batch carbohydrate, nitrogen, phosphorus on growth of Taxus chinensis var. mairei cell during suspension culture / 中草药

Object To solve the problem that Taxus chinensis var. mairei (Lemee et L?vl.) Cheng et L. K.Fu grows slowly. Methods The consumption of phosphorus during the cell suspension culture and the effect of fed-batch carbohydrate, nitrogen and phosphorus on cell growth and living-cell activity were assayed. Results The carbohydrate was exhausted in the middle phase of suspension culture, dificiency of carbohydrate led to inhibition of cell growth in the late culture. Conclusion Compared with the control group, the cell growth rate and the cell density in the fed-batch carbohydrate group were increased significantly, and the cell growth rate was up to 83%.